Animals

16 pages, 5442 KB

Open AccessArticle

Polymorphisms and Expression Characteristics of the ZSWIM7 Gene Are Associated with the Fertility of Male Allotetraploid of Red Crucian Carp × Common Carp

by Tao Dai, Minglin Dong, Siyang He, Weiling Qin, Conghui Yang and Yi Zhou

Animals 2026, 16(2), 352; https://doi.org/10.3390/ani16020352 - 22 Jan 2026

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Abstract

Allotetraploid fish produced by distant hybridization are valuable germplasm for the mass production of sterile triploids. The allotetraploid crucian–carp hybrid (4nAT, 4n = 200) is derived from the intergeneric cross between a female red crucian carp (Carassius auratus red var., 2n = [...] Read more.

Allotetraploid fish produced by distant hybridization are valuable germplasm for the mass production of sterile triploids. The allotetraploid crucian–carp hybrid (4nAT, 4n = 200) is derived from the intergeneric cross between a female red crucian carp (Carassius auratus red var., 2n = 100) and a male common carp (Cyprinus carpio L., 2n = 100). However, after 33 successive generations, this lineage faces a critical bottleneck in maintaining male fertility. The present study aimed to develop new biomarkers for testicular development and characterize the associated functional gene expression profile in 4nAT. Following whole-genome resequencing and selection signature analysis of 15 male 4nAT individuals from each of the high-development group (HDG) and low-development group (LDG), ZSWIM7 (Zinc Finger SWIM-Type Containing 7), a gene implicated in reproductive development, was selected as a candidate for further fertility association studies. Seven SNPs were screened in the coding region of ZSWIM7 of 70 4nAT males; among these, SNP3 (c.23T/C) exhibited a significant correlation between genotypes and testicular development: individuals with the CT genotype showed a higher gonadosomatic index (1.17 ± 0.68 vs. 0.65 ± 0.50) and greater counts of mature spermatozoa (2537.67 ± 283.95 vs. 341.56 ± 121.66) compared to those with the TT genotype. Further quantitative PCR and immunofluorescence assays demonstrated that ZSWIM7 was highly expressed in the testis and specifically localized to the nuclei of early meiotic primary spermatocytes. Collectively, these results establish ZSWIM7 as a promising biomarker for 4nAT testicular development, offering a potential molecular tool for maintaining male fertility in allotetraploid fish breeding. Full article

(This article belongs to the Special Issue Molecular Genetics in Aquaculture: Practical Applications for Sustainable Production)

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20 pages, 3134 KB

Open AccessArticle

Spatial Associations and Co-Occurrence Networks of Sympatric Species in an Asian Elephant Community

by Jingshan Wang, Xu Li, Yuan Tian, Wenguan Duan, Yuhui Si, Dusu Wen, Weibin Wang and Dehuai Meng

Animals 2026, 16(2), 351; https://doi.org/10.3390/ani16020351 - 22 Jan 2026

Viewed by 139

Abstract

Understanding how species share resources (niche dynamics) and associate with each other is crucial for maintaining stable ecological communities. Using infrared camera traps, we constructed spatial association networks for an isolated Asian elephant population. The Asian elephant (Elephas maximus), a keystone [...] Read more.

Understanding how species share resources (niche dynamics) and associate with each other is crucial for maintaining stable ecological communities. Using infrared camera traps, we constructed spatial association networks for an isolated Asian elephant population. The Asian elephant (Elephas maximus), a keystone species in tropical forests, faces significant threats from habitat fragmentation and human disturbances, particularly in the isolated population of Nangunhe National Nature Reserve, Yunnan, China. Using infrared camera trapping, niche analysis, and interspecific association models, we examined the ecological role of Asian elephants and their sympatric species networks in fragmented habitats. We identified 44 species, including 11 species with higher relative abundance showing significant ecological correlations with elephants. Asian elephants exhibited the broadest spatial distribution, consistent with their role as ecological engineers due to high environmental tolerance and diverse resource utilization. Sympatric herbivores exhibited moderate spatial co-occurrence. Wild boars (Sus scrofa), red-bellied squirrels (Callosciurus erythraeus), northern pig-tailed macaques (Macaca leonina), and red junglefowl (Gallus gallus) demonstrated significant spatial associations with elephants. Lambda coefficient analysis revealed asymmetric associations reflecting spatial reliance of red-bellied squirrels and wild boars on elephant activity zones. Temporally, Asian elephants exhibited a stable bimodal activity pattern at dawn and dusk. Despite varying degrees of diel overlap with sympatric species, no significant temporal avoidance was detected, suggesting fine-scale coexistence mechanisms beyond the temporal dimension. We argue that conservation strategies are in urgent need of a transformation from single-species protection to the preservation of ecological interaction networks. This study clarifies the dominant position of Asian elephants in the community by mapping the spatial association networks between Asian elephants and sympatric species, and its findings hold substantial guiding significance for the recovery and protection of isolated Asian elephant populations. Full article

(This article belongs to the Section Ecology and Conservation)

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18 pages, 6398 KB

Open AccessArticle

Exploration of Novel Markers in Tan Sheep Spermatogenesis

by Yuan Ma, Haoyan Jin, Nana Wang, Yaru Xie, Lingkai Zhang and Bei Cai

Animals 2026, 16(2), 350; https://doi.org/10.3390/ani16020350 - 22 Jan 2026

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Abstract

In livestock farming, the reproductive function and breeding performance of Tan sheep are crucial for enhancing farming efficiency. Despite advances in research on sheep germ cells, studies on the identification of markers for spermatogonia, spermatocytes, and spermatozoa in Tan sheep remain limited and [...] Read more.

In livestock farming, the reproductive function and breeding performance of Tan sheep are crucial for enhancing farming efficiency. Despite advances in research on sheep germ cells, studies on the identification of markers for spermatogonia, spermatocytes, and spermatozoa in Tan sheep remain limited and inadequate. In this study, Tan sheep were used as research subjects to investigate the morphological characteristics of testicular tissues, the developmental status of germ cells, and potential novel markers for spermatogonia, spermatocytes, and spermatozoa across different ages (0 days, 60 days, 180 days, and 365 days). Homology of the SMC3, G3BP1, and AKAP4 genes was analyzed via NCBI alignment. The localization and expression characteristics of these genes in the testis tissues of Tan sheep were investigated using HE staining, qPCR, and immunofluorescence double staining. The results showed that from 0 to 365 days of age, with increasing age, spermatogonia, spermatocytes, and spermatids exhibited an orderly distribution, and mature spermatozoa appeared in the tubular lumen, marking the initial establishment of the spermatogenic process. The homology of SMC3, G3BP1, and AKAP4 was 90%, 85%, and 81%. The mRNA levels of SMC3 and G3BP1 in the testes of 60-day-old Tan sheep were significantly increased, while AKAP4 expression showed a gradual increase with advancing age. SMC3 was co-localized with PLZF in undifferentiated spermatogonia, G3BP1 was co-expressed with SYCP2 in spermatocytes, and AKAP4 was co-expressed with PNA in spermatozoa. The findings of this study provide further supportive evidence for novel markers of spermatogonia, spermatocytes, and spermatozoa in Tan sheep. Full article

(This article belongs to the Special Issue Enhancing Male Animal Reproduction: Focus on Testicular Health, Semen Quality, and Fertility)

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14 pages, 3312 KB

Open AccessArticle

Sonographic Assessment of Fetometric Parameters in Pigs of Different Prolific Genotypes for Gestational Age Estimation

by Frauke Janelt, Johannes Kauffold, Haukur Lindberg Sigmarsson, Ahmad Hamedy, Katharina Riehn, Martin Koethe, Jörg Altemeier and Philipp Maximilian Rolzhäuser

Animals 2026, 16(2), 349; https://doi.org/10.3390/ani16020349 - 22 Jan 2026

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Abstract

The slaughter of pregnant sows remains a relevant concern in modern swine production, with prevalence rates reported from 1.5–13% in Europe. Considering fetal sensitivity during late gestation and legal restrictions on transport and slaughter, reliable assessment of fetal age is of considerable practical, [...] Read more.

The slaughter of pregnant sows remains a relevant concern in modern swine production, with prevalence rates reported from 1.5–13% in Europe. Considering fetal sensitivity during late gestation and legal restrictions on transport and slaughter, reliable assessment of fetal age is of considerable practical, ethical, and legal relevance. In this study, 70 pregnancies from low-prolificacy (purebred German Saddleback) and medium-to-high prolificacy genotypes (purebred German Landrace and Duroc × German Landrace hybrids) were repeatedly examined using transabdominal ultrasonography, with a total of 15 examinations per pregnancy. Seven fetometric parameters—rosto-occipital distance, bi-parietal distance, orbital distance, sternum length, thorax diameter, body diameter, and crown–rump length—were measured in vivo, assessing two fetuses per pregnancy and calculating mean values to account for intra-individual variation. Parameter feasibility varied across gestation: during early gestation (gestation days 38 and 40), orbital distance, sternum length, and crown–rump length could be reliably measured; in mid-gestation, all seven parameters were measurable, whereas in late gestation (from gestational day 87 onward), crown–rump length was no longer measurable, and the remaining six parameters remained assessable for gestational age estimation. Crown–rump length (CRL) increased from a median of 3.2 cm (range 1.9–4.2 cm) at day 38 to 16.3 cm (range 14.0–18.2 cm) at day 77, representing the most practical parameter for determining the stage of gestation. Litter size had no significant effect on fetometric growth, except for a weak correlation with thorax diameter at day 77, and parity showed no measurable influence on any parameter. The results show that fetometric values in modern sow genotypes are smaller than those reported in earlier literature, highlighting the need for updated gestational age assessment. These findings provide practical guidance for gestational age estimation, supporting the enforcement of animal welfare legislation and potentially contributing to a reduction in the slaughter of highly pregnant sows. Full article

(This article belongs to the Section Animal Genetics and Genomics)

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43 pages, 1026 KB

Open AccessReview

Insights into Non-Antibiotic Alternative and Emerging Control Strategies for Chicken Coccidiosis

by Rochelle A. Flores, Paula Leona C. Fletcher, Kyu-Yeol Son and Wongi Min

Animals 2026, 16(2), 348; https://doi.org/10.3390/ani16020348 - 22 Jan 2026

Viewed by 328

Abstract

Coccidiosis, caused by an obligate intracellular parasite of the genus Eimeria, is the most economically parasitic disease in poultry. Long-term reliance on synthetic anticoccidials and ionophores has accelerated the emergence of drug resistance and intensified the need for effective, residue-free alternatives. This [...] Read more.

Coccidiosis, caused by an obligate intracellular parasite of the genus Eimeria, is the most economically parasitic disease in poultry. Long-term reliance on synthetic anticoccidials and ionophores has accelerated the emergence of drug resistance and intensified the need for effective, residue-free alternatives. This narrative review synthesizes findings from peer-reviewed studies published between 1998 and 2025, summarizing advances in non-antibiotic control strategies encompassing five domains: (i) phytochemicals and botanicals, (ii) functional nutrition and mineral modulators, (iii) microbial and gut modulators, (iv) host-directed immunological and biotechnological approaches, and (v) precision and omics-guided biotherapeutic platforms. These approaches consistently reduce lesion severity, oocyst shedding, oxidative stress, and mortality while improving growth parameters in a variety of Eimeria models. However, translation to field settings remains constrained by variable bioactive composition, limited standardization, inadequate pharmacokinetic data, and the scarcity of large-scale, multi-farm validation studies. This review provides a concise summary of current evidence and delineates critical knowledge gaps to guide the development, optimization, and deployment of next-generation anticoccidial strategies. Together, natural products and emerging biotechnologies provide a promising foundation for sustainable, high-welfare, antibiotic-independent coccidiosis control. Full article

(This article belongs to the Section Poultry)

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28 pages, 1714 KB

Open AccessFeature PaperArticle

Effects of Including Partially Destoned Olive Cake in Sheep Diet on Meat Quality and Salami Production

by Giuseppe Maniaci, Riccardo Gannuscio, Cristina Giosuè, Mahmood Ul Hassan, Gabriele Busetta, Elena Franciosi, Raimondo Gaglio, Massimo Todaro and Marco Alabiso

Animals 2026, 16(2), 347; https://doi.org/10.3390/ani16020347 - 22 Jan 2026

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Abstract

The valorization of cull sheep and the incorporation of agro-industrial by-products into animal feeding represent effective approaches to enhancing the sustainability of small ruminant production systems. This study investigated the effects of dietary inclusion of 17% partially destoned olive cake (OC) in the [...] Read more.

The valorization of cull sheep and the incorporation of agro-industrial by-products into animal feeding represent effective approaches to enhancing the sustainability of small ruminant production systems. This study investigated the effects of dietary inclusion of 17% partially destoned olive cake (OC) in the concentrate fed to Valle del Belice ewes on carcass characteristics, as well as on meat and salami quality. A 14-week feeding trial was conducted on 124 animals allocated to a control (CTR) and an experimental (EXP) group, balanced for parity, days in milk, and daily milk yield. At the end of the trial, five animals per group were slaughtered and their meat was processed into three types of salami: 100% sheep meat (SM), 90% sheep meat with 10% beef heifer brisket (HB), and 90% sheep meat with 10% pork backfat (PB). Meat and salami were evaluated for chemical composition, fatty acid profile, polyphenol content, antioxidant capacity, lipid oxidation, microbiological status, textural properties, and sensory characteristics. Dietary OC supplementation resulted in increased carcass weight, separable fat, intramuscular fat content, and monounsaturated fatty acids—particularly oleic acid—along with higher polyphenol levels and antioxidant activity. Salami produced from OC-fed ewes exhibited reduced weight loss during ripening, lower lipid oxidation, an improved MUFA/SFA ratio, and satisfactory sensory attributes. Microbiological analyses indicated a dominance of lactic acid bacteria and coagulase-negative staphylococci, with no pathogenic microorganisms detected. Overall, the inclusion of olive cake in the diet enhanced meat and processed product quality, supporting the valorization of olive oil by-products within circular economy frameworks. Full article

(This article belongs to the Section Animal Products)

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43 pages, 5339 KB

Open AccessReview

Encephalitozoonosis in Pet Rabbits: Epidemiology, Pathogenesis, Immunology and Consensus on Clinical Management

by Emma Keeble, Frank Kϋnzel, Fabiano Montiani-Ferreira, Jennifer Graham, Edita Jeklová, Sari Kanfer, Angela Lennox, Guillaume Desoubeaux, Ethan Biswell, Carolyn Cray and Anja Joachim

Animals 2026, 16(2), 346; https://doi.org/10.3390/ani16020346 - 22 Jan 2026

Viewed by 515

Abstract

Members of the microsporidial genus Encephalitozoon have the capacity to infect both mammals and birds, and E. cuniculi is most commonly found in rabbits. With a seroprevalence ranging up to 85%, E. cuniculi can be a problem in pet rabbits as well as [...] Read more.

Members of the microsporidial genus Encephalitozoon have the capacity to infect both mammals and birds, and E. cuniculi is most commonly found in rabbits. With a seroprevalence ranging up to 85%, E. cuniculi can be a problem in pet rabbits as well as in food production and laboratory animal science. While most infections are likely subclinical, there are three main clinical presentations: neurological, renal, and ocular. Typical clinical signs including vestibular disease and phacoclastic uveitis may develop with initial or relapsing infection, while renal infection is usually progressive and associated with non-specific clinical signs. High-sensitivity/specificity ante mortem diagnostic options are lacking, and serological testing most often provides adjunct rather than definitive information such that physical examination and other diagnostics are used more so for ruling out other differentials and comorbidities, rather than confirming infection. In the veterinary community, treatment regimens are variable given the lack of thorough studies and a consensus. The aim of this document is to present the available literature to give a concise review of this organism and its infection of rabbits as well as to propose guidelines and protocols for diagnostics and treatment regimens. In addition, the current challenges and recommendations for further studies are discussed. Full article

(This article belongs to the Special Issue Advances in Exotic Pet Medicine)

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14 pages, 1467 KB

Open AccessArticle

BioControl 3.0: Biological Control Complex for Pest Control—Enhanced Control of Locusta migratoria manilensis via Combined Application of Metarhizium anisopliae var. acridum and Carabus smaragdinus

by Linqiang Gao, Yan Wang, Ruxin Wang, Jinshu Yang, Meiyi Yang, Yusheng Liu, Guangjun Wang, Mark R. McNeill, Zehua Zhang, Xinghu Qin and Haiyan Wang

Animals 2026, 16(2), 345; https://doi.org/10.3390/ani16020345 - 22 Jan 2026

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Abstract

Locusta migratoria manilensis (Meyen) is a highly destructive insect pest worldwide. However, excessive reliance on insecticides has resulted in significant environmental pollution. Biocontrol complexes combine two or more BCAs to address the limitations of individual agents. However, biocontrol complex for locust control has [...] Read more.

Locusta migratoria manilensis (Meyen) is a highly destructive insect pest worldwide. However, excessive reliance on insecticides has resulted in significant environmental pollution. Biocontrol complexes combine two or more BCAs to address the limitations of individual agents. However, biocontrol complex for locust control has been rarely reported. Here, we propose BioControl 3.0, which integrates Metarhizium anisopliae var. acridum (Driver and Milner) and Carabus smaragdinus (Fischer von Waldheim) for locust control. We evaluated this system through a series of laboratory bioassays and semi-field cage experiments, comparing single-agent applications, sequential combinations (BioControl 2.0), and predator-mediated delivery (BioControl 3.0), and quantified locust mortality and interaction effects between predation and infection We found that M. anisopliae caused >85% mortality of locust nymphs at 1 × 10⁸ conidia/mL (LT₅₀ ≈ 6 days) while exhibiting negligible virulence toward C. smaragdinus. BioControl 2.0 (sequential application) increased mortality compared to single agents. However, this approach revealed a significant negative interaction between predation and infection, which limited the total control efficacy. BioControl 3.0 (predator-vectored fungus) achieved the highest corrected mortality, with predation and infection acting independently and additively (no detectable antagonistic interaction). By leveraging a predatory vector, BioControl 3.0 decouples negative interaction and harnesses dual biotic pressures, offering a cost-effective, environmentally benign alternative to conventional locust control. Our findings provide a blueprint for designing integrated predator-pathogen complexes and optimizing deployment strategies for sustainable management of locust outbreaks. Full article

(This article belongs to the Section Ecology and Conservation)

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21 pages, 15965 KB

Open AccessArticle

Research on Seasonal Disease Warning Methods for Northern Winter Sheep Based on Ear-Base Temperature

by Jianzhao Zhou, Runjie Jiang, Dongsheng Xie and Tesuya Shimamura

Animals 2026, 16(2), 344; https://doi.org/10.3390/ani16020344 - 22 Jan 2026

Viewed by 137

Abstract

The temperature at the base of the ear is highly correlated with the core body temperature of sheep and responds sensitively to febrile conditions, making it a valuable indicator of sheep health. In northern China, the closed housing environment during winter increases the [...] Read more.

The temperature at the base of the ear is highly correlated with the core body temperature of sheep and responds sensitively to febrile conditions, making it a valuable indicator of sheep health. In northern China, the closed housing environment during winter increases the incidence of seasonal diseases such as upper respiratory infections and pneumonia, which severely affect the economic efficiency of sheep farming. To address this issue, this study proposes an early-warning method for winter diseases in sheep based on ear-base temperature. Ear temperature, body weight, and environmental data were collected, and Random Forest was employed for feature selection. Bayesian optimization was used to fine-tune the hyperparameters of a one-dimensional convolutional neural network to construct a predictive model of ear-base temperature using data from healthy sheep. Based on the predicted normal range, an early-warning strategy was established to detect abnormal temperature patterns associated with disease onset. Experimental results demonstrated that the proposed method achieved a high detection rate for common winter diseases while maintaining a low false positive rate, and validation experiments confirmed its effectiveness under practical farming conditions. Combined with low-cost temperature-sensing ear tags, the proposed approach enables real-time health monitoring and provides timely early warnings for winter diseases in large-scale sheep farming, thereby improving management efficiency and economic performance. Full article

(This article belongs to the Section Animal System and Management)

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22 pages, 2485 KB

Open AccessArticle

Metabolomic Markers Reveal How hCG–Ketoprofen Intervention Increase Pregnancy Percentage Following Timed Artificial Insemination in Dairy Cows

by Hubdar Ali Kolachi, Muhammad Shahzad, Jesse Oluwaseun Ayantoye, Baigao Yang, Xiaomeng Zhang, Pengcheng Wan and Xueming Zhao

Animals 2026, 16(2), 343; https://doi.org/10.3390/ani16020343 - 22 Jan 2026

Viewed by 301

Abstract

The objective of this study was to determine if the use of human chorionic gonadotrophin (hCG) and ketoprofen would affect the pregnancy percentages of dairy cows following timed artificial insemination (TAI). This experiment was conducted on a commercial dairy farm in China involving [...] Read more.

The objective of this study was to determine if the use of human chorionic gonadotrophin (hCG) and ketoprofen would affect the pregnancy percentages of dairy cows following timed artificial insemination (TAI). This experiment was conducted on a commercial dairy farm in China involving 799 healthy Holstein cows (2–4 parities) between October and December 2024. Cows were randomly assigned to three groups: hCG-3 = treated with (0 d: GnRH, 100 μg; 7–8 d: PGF_2α, 0.4 mg; 52 h: GnRH, 100 μg; 14–16 h: TAI) + hCG 3 vials (300 µg)/cow on day 7 of TAI; hCG-2 group = TAI + 2 vials (200 µg) hCG/cow on day 7; and hCG+ketoprofen = TAI + 300 µg hCG/cow + ketoprofen 10 mL/cow on days 15 and 16 of TAI. Metabolomic profiling (untargeted and targeted) of 22 pregnant cows was conducted on serum collected on days 17 and 21 post-TAI. Results indicated greater pregnancy percentages in the cows of the hCG+ketoprofen-treated group compared to those in the other two groups (60.1% compared with 49.6% and 41.9%). The cows treated with hCG+ketoprofen had less oxidative stress markers, downregulation of arachidonic acid metabolism and upregulation of glycerophospholipid metabolism on day 17 after TAI, indicating that there was upregulation of tryptophan and serotonergic pathways, increased amino acid metabolism and continued anti-inflammatory effects on day 21 after TAI. These findings were confirmed by evaluation data collected by conducting the targeted metabolomic procedures, as indicated by the greater progesterone and melatonin and lesser 17-estradiol and 21-deoxycortisol concentrations. These findings indicate that combined hCG+ketoprofen administrations following the TAI treatment regimen improve pregnancy percentages in dairy cattle as a result of metabolic and endocrine milieu modulations. Full article

(This article belongs to the Special Issue Advances in Dairy Cattle Reproduction: Second Edition)

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19 pages, 2873 KB

Open AccessArticle

Computed Tomographic Study in 73 Pet Rabbits (Oryctolagus cuniculus): Evaluation of the Correlation Between Dental and Thoracic Pathology

by Glenda Murciano, Iván Alonso-Fernández, Rosa Novellas, Osvaldo Fonseca-Rodríguez and Jaume Martorell

Animals 2026, 16(2), 342; https://doi.org/10.3390/ani16020342 - 22 Jan 2026

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Abstract

Background: Dental and respiratory diseases are common in companion rabbits. While upper respiratory tract disorders have been described in association with dental pathology, the possible correlation between dental disease and pulmonary lesions has not yet been investigated. Methods: A cross-sectional study was conducted [...] Read more.

Background: Dental and respiratory diseases are common in companion rabbits. While upper respiratory tract disorders have been described in association with dental pathology, the possible correlation between dental disease and pulmonary lesions has not yet been investigated. Methods: A cross-sectional study was conducted on client-owned rabbits presented for suspected dental disease that underwent head and thoracic computed tomography (2012–2025) at a veterinary teaching hospital. Seventy-three rabbits met the inclusion criteria (mean age 4.96 years). Results: Dental involvement was present in 81% (59/73) of the rabbits and pulmonary lesions in 29% (21/73). Among rabbits with dental disease, frequent osseous findings included osteomyelitis (49%), inflammatory resorption (42%), and maxillary deformities (33%). Pulmonary abnormalities occurred in 32% of rabbits with dental disease compared to 14% of those without. In Poisson models with log link adjusted for age and sex, dental disease was not significantly associated with pulmonary lesions (prevalence ratio [PR] 2.14; 95% CI 0.55–8.38; p = 0.275). Sensitivity analyses using 1:1 matching with cluster-robust variance (PR 3.24; 95% CI 0.65–16.1; p = 0.152) and overlap-weighted doubly robust estimation (PR 2.08; 95% CI 0.42–10.4; p = 0.371) yielded directionally positive but imprecise results. Conclusions: Computed tomography proved valuable for the evaluation of thoracic comorbidities in rabbits with dental disease. Although dental and pulmonary abnormalities were often observed together, a statistically significant association was not established. Larger, prospective studies are warranted to further clarify this relationship. Full article

(This article belongs to the Special Issue Advances in Exotic Pet Medicine)

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16 pages, 4573 KB

Open AccessArticle

Odontoblasts in Equine Hypsodont Teeth—How They Cope with Permanent Occlusal Wear

by Laura Beate Heilen, Jessica Roßgardt, Jutta Dern-Wieloch, Jörg Vogelsberg and Carsten Staszyk

Animals 2026, 16(2), 341; https://doi.org/10.3390/ani16020341 - 22 Jan 2026

Viewed by 376

Abstract

Horses’ hypsodont (high-crowned) teeth face permanent dental wear. This is compensated for by a continuous eruption, which requires a high adaptability of odontoblasts; otherwise, the dental pulp would be exposed. Here, we report on how equine odontoblasts respond to the challenge of maintaining [...] Read more.

Horses’ hypsodont (high-crowned) teeth face permanent dental wear. This is compensated for by a continuous eruption, which requires a high adaptability of odontoblasts; otherwise, the dental pulp would be exposed. Here, we report on how equine odontoblasts respond to the challenge of maintaining a high production rate of dentin. We analyzed CD90, a marker of odontoblastic differentiation, and nestin, a marker of mature odontoblasts, in equine pulpal tissue via immunofluorescence. For comparison, we examined the hypselodont (ever-growing) incisors and brachydont (short-crowned) molars of rats. Immunofluorescence and Western blot analysis of pulpal tissue revealed a higher content of CD90-positive cells in hypsodont equine teeth than in brachydont and hypselodont rat teeth. The odontoblastic layer of hypsodont teeth was positive for CD90 (marker for differentiating odontoblasts), which was not the case for brachydont and hypselodont rat teeth. Most samples of hypsodont teeth were negative for nestin, whereas in hypselodont and brachydont teeth, odontoblasts were positive for nestin (marker for mature odontoblasts). Our findings suggest that there is a constant replacement of odontoblasts in the equine dentition, enabling a continuous high production rate of dentin. These results contradict the idea of lifelong vital, postmitotic and productive odontoblasts. Full article

(This article belongs to the Section Equids)

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18 pages, 785 KB

Open AccessArticle

Effect of Water Extract of Artemisia annua L. on Growth Performance, Blood Biochemical Parameters and Intestinal-Related Indices in Mutton Sheep

by Gen Gang, Ruiheng Gao, Manman Tong, Shangxiong Zhang, Shiwei Guo, Xiao Jin, Yuanyuan Xing, Sumei Yan, Yuanqing Xu and Binlin Shi

Animals 2026, 16(2), 340; https://doi.org/10.3390/ani16020340 - 22 Jan 2026

Viewed by 174

Abstract

Objective: This experiment aimed to explore the effects of water extract of Artemisia annua L. (WEAA) on growth performance, blood parameters, and intestinal-related indices in mutton sheep, so as to evaluate its potential as a natural growth promoter. Methods: The experiment was conducted [...] Read more.

Objective: This experiment aimed to explore the effects of water extract of Artemisia annua L. (WEAA) on growth performance, blood parameters, and intestinal-related indices in mutton sheep, so as to evaluate its potential as a natural growth promoter. Methods: The experiment was conducted using a completely randomized design. Thirty-two 3-month-old Dorper × Han mutton sheep were randomly assigned to 4 groups (n = 8). The control group was fed only the basal diet, while the other groups were fed the basal diet supplemented with, respectively, 500, 1000, and 1500 mg/kg WEAA. The adaptation period lasted 15 days, followed by a 60-day experimental period. Results: Results showed that dietary supplementation of WEAA significantly reduced average daily feed intake (ADFI) and feed-to-gain ratio (F:G) of mutton sheep, significantly improved the apparent digestibility of crude protein (CP) and phosphorus (P), and optimized blood biochemical indices, such as significantly increasing the concentrations of total protein (TP), albumin (ALB), high-density lipoprotein cholesterol (HDL-C), and glucose (GLU), while significantly decreasing blood urea nitrogen (BUN) level (p < 0.05). Additionally, WEAA significantly improved intestinal morphology by reducing the crypt depth (CD) of the duodenum, jejunum, and ileum, increasing jejunal villus height (VH), and elevating the villus-to-crypt ratio (VH/CD) across intestinal segments (p < 0.05). It also significantly enhanced the activity of intestinal digestive enzymes, including α-amylase and trypsin in the duodenum, lipase and chymotrypsin in the jejunum, and α-amylase and chymotrypsin in the ileum, with the 500 mg/kg and 1000 mg/kg WEAA groups reaching better activity (p < 0.05). Furthermore, WEAA supplementation significantly increased the counts of beneficial bacteria (Bifidobacteria and Lactobacilli) and decreased the count of harmful bacteria (Escherichia coli) in rectal fecal samples (p < 0.05). Notably, most of these beneficial effects were dosage-dependent, with overall optimal performance observed in the 1000 mg/kg WEAA group. Conclusion: In conclusion, supplementing the diet with 1000 mg/kg WEAA exerted significant positive effects on the feed efficiency, nutrient digestibility, and intestinal health status of mutton sheep. Full article

(This article belongs to the Section Small Ruminants)

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14 pages, 639 KB

Open AccessFeature PaperArticle

The Influence of Cat Coat Colour, Eye Shape, and Pupil Size on Ratings of Adoptability Based on a Standardised Online Image, in an Australian Sample

by Sarah C. Whelan, Deanna L. Tepper, Jessica K. Dawson, Diana Rayment, Lily Chilcott, Pauleen C. Bennett and Tiffani J. Howell

Animals 2026, 16(2), 339; https://doi.org/10.3390/ani16020339 - 22 Jan 2026

Viewed by 627

Abstract

Online pet adoption profiles, which present images of available pets, can create powerful first impressions. Research about factors influencing pet adoptability online is limited and has mainly focused on dogs, yet cats are also in need of homes. People may judge a cat’s [...] Read more.

Online pet adoption profiles, which present images of available pets, can create powerful first impressions. Research about factors influencing pet adoptability online is limited and has mainly focused on dogs, yet cats are also in need of homes. People may judge a cat’s behaviour based on physical factors, like coat colour, eye shape, and pupil size. This study aimed to determine whether those physical traits relate to cat adoptability and, if so, whether they might do this through influencing perceptions of cuteness and specific behaviours. Australian adults (N = 624) were surveyed online using a single cat image that was modified to have all possible combinations of four different coat colours, three eye shapes, and three pupil sizes. Adoptability scores varied significantly with the cat’s coat colour and eye shape, but not pupil size. Black cats with walnut-shaped eyes had the highest adoptability ratings. A stepwise multiple regression determined seven variables influencing adoptability scores, including the degree to which the image was rated as cute, friendly, shy, active, difficult, playful, and devoted. Cuteness had the strongest influence, explaining 34% of the model variance. Multiple two-way ANOVAs compared these seven variables across combinations of coat colour and eye shape, with black cats being perceived as significantly more friendly and playful. This information may help animal adoption agencies understand how cats’ physical features can be utilised in online profiles to enhance adoption outcomes. Full article

(This article belongs to the Special Issue Featured Papers in the 'Human–Animal Interactions, Animal Behaviour and Emotion' Section)

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22 pages, 4500 KB

Open AccessArticle

Climatic and Host-Related Drivers of Gastrointestinal Parasite Dynamics in Domestic Ruminants of North Bengal, India

by Subrata Saha, Manjil Gupta, Rachita Saha, Muhammad Saqib, Elena I. Korotkova and Pradip Kumar Kar

Animals 2026, 16(2), 338; https://doi.org/10.3390/ani16020338 - 22 Jan 2026

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Abstract

Gastrointestinal (GI) parasitic infections pose a formidable global challenge to livestock production and continue to affect livestock health and productivity, particularly in tropical and subtropical regions. This study investigated the prevalence, diversity, and epidemiological determinants of GI parasites in 1406 cattle, goats, and [...] Read more.

Gastrointestinal (GI) parasitic infections pose a formidable global challenge to livestock production and continue to affect livestock health and productivity, particularly in tropical and subtropical regions. This study investigated the prevalence, diversity, and epidemiological determinants of GI parasites in 1406 cattle, goats, and sheep from three districts of North Bengal, India (Cooch Behar, Alipurduar, and Jalpaiguri). Parasitological data were analysed using descriptive statistics and inferential methods. Overall prevalence was 69.4%, with cattle showing the highest infection rate (71.62%), followed by sheep (69.30%) and goats (67.19%). Spatial variation was evident among districts, with Cooch Behar recording the highest prevalence (71.20%). Seasonal effects were assessed using Generalized Linear Mixed Models (GLMs), which indicated significantly higher infection probabilities during the monsoon (75.70%) and summer (72.95%) compared with winter (57.78%). The predominant parasite genera identified were Eimeria spp., Strongyloides spp., and Fasciola spp. Host-parasite associations were further explored using Multiple Correspondence Analysis (MCA), revealing distinct clustering patterns, with cattle associated mainly with Eimeria spp. and Strongyloides spp., goats with Trichuris spp. and Nematodirus spp., and sheep with Fasciola spp. and Paramphistomum spp. A species-specific heatmap was used to visualize parasite distribution across host species and seasons, highlighting higher infection intensities during the summer and monsoon periods. Overall, the results demonstrate that GI parasitic infections in North Bengal are influenced by host species and seasonal climatic factors, supporting the implementation of targeted, species- and season-adapted parasite management strategies. Full article

(This article belongs to the Topic Advances in Infectious and Parasitic Diseases of Animals)

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36 pages, 2189 KB

Open AccessArticle

SNPs with High Linkage Disequilibrium Increase the Explained Genetic Variance and the Reliability of Genomic Predictions

by José Guadalupe Cortes-Hernández, Felipe de Jesús Ruiz-López, Francisco Peñagaricano, Hugo H. Montaldo and Adriana García-Ruiz

Animals 2026, 16(2), 337; https://doi.org/10.3390/ani16020337 - 22 Jan 2026

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Abstract

The objective of this study was to compare the proportion of explained genetic variance (EXGV) and the reliability of genomic breeding values (GBVs) predictions for milk yield (MY), fat yield (FY), protein yield (PY) fat percentage (FP), protein percentage (PP), and somatic cell [...] Read more.

The objective of this study was to compare the proportion of explained genetic variance (EXGV) and the reliability of genomic breeding values (GBVs) predictions for milk yield (MY), fat yield (FY), protein yield (PY) fat percentage (FP), protein percentage (PP), and somatic cell score (SCS) in Holstein cattle. Three types of genomic information were evaluated. (a) SNP-ALL: this analysis included 88,911 single nucleotide polymorphisms (SNP) from 8290 animals. (b) HAP-PSEUDOSNP: haplotypes, defined based on high linkage disequilibrium (LD, r² ≥ 0.80) between SNPs, which were encoded as pseudo-SNPs, with a total of 35,552 pseudo-SNPs and 8331 animals included. (c) SNP-HAP: analysis using only individual SNPs included in the haplotypes (without recoding); for this analysis, 33,010 SNPs and 8192 individuals were retained. All analyses were conducted using the single-step genome-wide association study method implemented in the BLUPF90 software package. The results showed that the inclusion of SNPs with high LD (SNP-HAP) increases the reliability of GBVs’ predictions compared to the SNP-ALL analysis; average reliability increased between 0.05 and 0.11. Moreover, the SNP-HAP analysis resulted in a twofold increase in the EXGV for all traits, likely due to increased estimates of individual marker effects compared to the SNP-ALL analysis. Full article

(This article belongs to the Special Issue Quantitative Genetics of Livestock Populations)

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15 pages, 2322 KB

Open AccessArticle

Construction and Immunogenicity Evaluation of a Recombinant Infectious Bronchitis Virus H120-Based Vaccine in Broiler Chickens

by Ali Nayef, Sara Jibreen and Mustafa Ababneh

Animals 2026, 16(2), 336; https://doi.org/10.3390/ani16020336 - 22 Jan 2026

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Abstract

Infectious Bronchitis Virus is one of several major viral infections in poultry, affecting the respiratory, reproductive, and renal systems and causing significant economic losses worldwide. Current vaccines, including the H120 strain, provide limited cross-protection against emerging variants, underscoring the need for improved vaccine [...] Read more.

Infectious Bronchitis Virus is one of several major viral infections in poultry, affecting the respiratory, reproductive, and renal systems and causing significant economic losses worldwide. Current vaccines, including the H120 strain, provide limited cross-protection against emerging variants, underscoring the need for improved vaccine strategies. In this study, the complete genome of IBV H120 was divided into 12 fragments, synthesized, and assembled using the Golden Gate Assembly (GGA) method. The recombinant virus (rH120) was successfully rescued in chicken fibroblast cells and propagated in embryonated specific-pathogen-free (SPF) chicken eggs. Growth kinetics in embryonated SPF chicken eggs revealed similar replication patterns between rH120 and the original H120 strain. In broiler chickens, rH120 replicated efficiently, as confirmed by viral RNA detection in throat and cloacal swabs, and induced a stronger antibody response by 14 days post-infection. The rH120 virus proved to be genetically stable, infectious, and immunogenic, indicating that GGA-based reverse genetics is an effective system for IBV vaccine development. Full article

(This article belongs to the Section Poultry)

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11 pages, 746 KB

Open AccessArticle

Investigation of Respiratory Metastrongyloids and Other Endoparasites in Domestic Cats Living in the States of Rio de Janeiro and Rio Grande do Sul, Brazil

by Luciano Antunes Barros, Simone Morelli, Angela Di Cesare, Ananda Senhoretto do Nascimento, Sandra Márcia Tietz Marques, Lebana Fernandes Knopp, Caio dos Santos Gomes, Eduarda Nóbrega Fialho Tavares, Júlia Pereira da Silva, Aline Silva de Mattos Queiroz, Claudio Alessandro Massamitsu Sakamoto, Shihane Mohamad Costa Mendes, Tatiana Moniz Portella Lovatto, Frederic Beugnet, Karin Botteon, Donatella Damiani, Ilaria Lallone and Donato Traversa

Animals 2026, 16(2), 335; https://doi.org/10.3390/ani16020335 - 22 Jan 2026

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Abstract

The metastrongyloids Aelurostrongylus abstrusus and Troglostrongylus brevior, and the capillariid Capillaria aerophila, are major respiratory nematodes infecting cats. In recent decades these nematodes have been recorded in several areas of the world and have called for epizootiological studies to update knowledge [...] Read more.

The metastrongyloids Aelurostrongylus abstrusus and Troglostrongylus brevior, and the capillariid Capillaria aerophila, are major respiratory nematodes infecting cats. In recent decades these nematodes have been recorded in several areas of the world and have called for epizootiological studies to update knowledge on their distribution. While A. abstrusus is known to occur in some areas of Brazil, the presence of T. brevior remains uncertain, and feline infections with C. aerophila have never been reported. This study has investigated the occurrence of lungworms with or without other endoparasitoses in domestic cat populations of selected areas of Brazil. Individual faecal samples were collected from 537 cats, i.e., 521 in metropolitan area of Rio de Janeiro and 16 in Porto Alegre (Rio Grande do Sul). All samples were examined with Sheather’s flotation, and 521 of them also with the Baermann test. DNA was extracted from 425 Baermann sediments and molecularly examined for A. abstrusus and T. brevior. The most frequent parasites found at the copromicroscopy were Ancylostomatidae (n. 30, 5.8%), Toxocara cati (14, 2.7%), and Cystoisospora felis (n. 8; 1.5%). Larvae of A. abstrusus were identified by Baermann in 3 samples from Rio de Janeiro, while at PCRs, A. abstrusus DNA was amplified in 10 samples from Rio de Janeiro (n. 3), Seropédica (n. 3), Niterói (n. 3), and Porto Alegre (n. 1). The results indicate that A. abstrusus is enzootic in the investigated areas of Brazil and underline the usefulness of PCR when larvae are not detected by copromicroscopy or when only a single stool sample is analysed. Epizootiological implications, along with the absence of T. brevior in the examined cats and the presence of zoonotic endoparasites, are discussed. Full article

(This article belongs to the Section Veterinary Clinical Studies)

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18 pages, 7789 KB

Open AccessArticle

Dose-Dependent Responses of Weaned Piglets to Multi-Species Solid-State Fermented Apple Pomace: Enhanced Growth Performance, Intestinal Health, and Gut Microbiota Modulation

by Jiongjie He and Shengyi Wang

Animals 2026, 16(2), 334; https://doi.org/10.3390/ani16020334 - 21 Jan 2026

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Abstract

Background/Objectives: Apple pomace, a major by-product of juice production, represents both an environmental burden and an underutilized resource. This study aimed to enhance the nutritional value of apple pomace via solid-state fermentation (SSF) to develop a functional feed ingredient and systematically evaluate its [...] Read more.

Background/Objectives: Apple pomace, a major by-product of juice production, represents both an environmental burden and an underutilized resource. This study aimed to enhance the nutritional value of apple pomace via solid-state fermentation (SSF) to develop a functional feed ingredient and systematically evaluate its effects on growth, metabolism, and intestinal health in weaned piglets. Methods: Apple pomace was fermented using a multi-species consortium (Geotrichum candidum, Saccharomyces cerevisiae, Rhizopus oryzae, Bacillus subtilis, and Trichoderma viride). A total of 180 weaned piglets were fed iso-nitrogenous diets containing 0, 2, 4, 6, 8, or 10% fermented apple pomace for 35 days. Growth performance, serum biochemical and immuno-antioxidant indices, diarrhea incidence, jejunal morphology, and fecal microbiota were analyzed. Results: Dietary fermented apple pomace supplementation showed dose-dependent effects. The 8% fermented apple pomace group exhibited optimal growth performance, with increased average daily gain and feed intake and reduced feed-to-gain ratio (p < 0.05). Serum analysis indicated enhanced protein synthesis, antioxidant capacity (T-AOC, SOD, GSH-Px), and immunoglobulin levels (IgA, IgG, IgM), along with reduced urea nitrogen and oxidative stress marker MDA. This group also had the lowest diarrhea rate, associated with improved jejunal villus morphology. Microbiota analysis revealed that 8% fermented apple pomace effectively increased α-diversity, promoted beneficial bacteria (e.g., lactic acid bacteria and butyrate-producing Clostridium sensu stricto_1), and suppressed pathogens (Escherichia coli, Salmonella, Streptococcus). Conclusions: Multi-species SSF successively enhanced the nutritional profile of apple pomace. Inclusion at 8% showed the most favorable response in terms of growth performance, metabolic profile, and immune–antioxidant status in weaned piglets, mediated through improved intestinal morphology and targeted modulation of the gut microbiota toward a more diverse and beneficial ecosystem. These findings support the high-value, functional utilization of apple pomace as a feed additive in swine nutrition. Full article

(This article belongs to the Special Issue The Role of Nutrition in Enhancing Health and Production Performance in Swine)

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14 pages, 977 KB

Open AccessArticle

Persistence and Dissemination of Enrofloxacin and Ciprofloxacin Residues: The Hidden Role of Litter and Droppings in the Emergence of Antimicrobial Resistance

by María Belén Vargas, Camila Nettle, Ignacia Soto, Ekaterina Pokrant, Aldo Maddaleno, Lisette Lapierre and Javiera Cornejo

Animals 2026, 16(2), 333; https://doi.org/10.3390/ani16020333 - 21 Jan 2026

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Abstract

The objective of this study was to evaluate the persistence and environmental dissemination of enrofloxacin (EFX) and its metabolite ciprofloxacin (CFX) residues in poultry systems, as well as their effect on antimicrobial resistance in Escherichia coli. The experimental design included three groups: [...] Read more.

The objective of this study was to evaluate the persistence and environmental dissemination of enrofloxacin (EFX) and its metabolite ciprofloxacin (CFX) residues in poultry systems, as well as their effect on antimicrobial resistance in Escherichia coli. The experimental design included three groups: one treated group (A) and two untreated groups (B.1 and B.2), located in pens adjacent to or within 30 cm of group A to assess residue transfer. Birds in group A received EFX orally (10 mg·kg⁻¹ every 24 h for 5 days) via orogastric tube. EFX and CFX residues persisted in litter and excreta for up to 18 days post-treatment, reaching initial concentrations of 20,968 µg·kg⁻¹ in litter and 884.8 µg·kg⁻¹ in droppings in group A. Significant differences were detected between groups (Kruskal–Wallis, p < 0.05), confirming greater accumulation in the treated group and environmental dissemination. E. coli isolates obtained from litter and droppings from group A showed 73% resistance after treatment and correlated positively with residue concentration (ρ = 0.53). While the untreated groups B.1 and B.2 showed resistance rates of 24% and 13%, respectively, the control group exhibited a resistance rate of 3.3%. This study shows the detection of low levels of EXF and CFX residues in the litter of untreated groups, indicating limited dispersion. These findings highlight the importance of proper byproduct management and targeted environmental monitoring within the One Health framework, as continuous environmental exposure over time, combined with the persistence of this compound, may contribute to the selection of resistant bacteria. Full article

(This article belongs to the Section Poultry)

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10 pages, 1724 KB

Open AccessArticle

Sexual Dimorphism in Three Populations of the Chiala Mountain Salamander, Batrachuperus karlschmidti (Caudata: Hynobiidae)

by Xiuying Liu, Chunhao Shen, Yuanhua Xu, Jian Song, Min Lou and Jianli Xiong

Animals 2026, 16(2), 332; https://doi.org/10.3390/ani16020332 - 21 Jan 2026

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Abstract

Sexual dimorphism (SD) is a widespread phenomenon among animals and has attracted considerable interest in evolutionary biology. Most studies on SD have been limited to a single population, and few have focused on multiple populations. In this study, size and shape SD were [...] Read more.

Sexual dimorphism (SD) is a widespread phenomenon among animals and has attracted considerable interest in evolutionary biology. Most studies on SD have been limited to a single population, and few have focused on multiple populations. In this study, size and shape SD were evaluated in three populations of Batrachuperus karlschmidti, a hynobiid species endemic to China. SD was not found in body size, but was observed in body shape. Males had larger relative dimensions in head length, head width, forelimb length, forelimb width, hindlimb length, hindlimb width, and tail length. Conversely, females were larger in the relative dimension of interlimb distance. Sexual selection can account for SD in head and limbs, thereby enhancing male reproductive success. Conversely, fecundity selection drives SD in limbs, tail length, and interlimb distance, ultimately improving the reproductive ability of both sexes. Differences in sexual shape dimorphism (SShD) traits were also found among populations, which may be caused by dissimilar levels of selection forces in the environment. This study provides insight into identifying the causes that promote sexual dimorphism, as well as the degree of difference in SShD traits among populations. Full article

(This article belongs to the Section Herpetology)

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15 pages, 2070 KB

Open AccessArticle

Microscopic and Molecular Identification of Sarcocystis Species in Wild Brown Rats (Rattus norvegicus) in Lithuania and Latvia

by Giedrius Šidlauskas, Evelina Juozaitytė-Ngugu, Dalius Butkauskas and Petras Prakas

Animals 2026, 16(2), 331; https://doi.org/10.3390/ani16020331 - 21 Jan 2026

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Abstract

Sarcocystis is a genus of heteroxenous, globally distributed apicomplexan parasites found in reptiles, birds, and mammals. Typically, sarcocysts develop in muscles of intermediate hosts, and oocysts sporulate in intestines of definitive hosts. The parasite’s life cycle is based on prey–predator relationships and usually [...] Read more.

Sarcocystis is a genus of heteroxenous, globally distributed apicomplexan parasites found in reptiles, birds, and mammals. Typically, sarcocysts develop in muscles of intermediate hosts, and oocysts sporulate in intestines of definitive hosts. The parasite’s life cycle is based on prey–predator relationships and usually involves two distinct host species. However, some Sarcocystis spp. can complete their full development within a single host species. Brown rats (Rattus norvegicus) are invasive, synanthropic, highly adaptable rodents that are true omnivores and opportunistic feeders. Therefore, it is possible that they can act as definitive hosts of Sarcocystis parasites. This study provides the first comprehensive assessment of Sarcocystis protists in brown rat intestinal samples under natural conditions, combining microscopy and molecular analyses. Of 27 brown rats investigated, 25.9% (7/27) of animals harbored oocysts/sporocysts of Sarcocystis spp. Based on nested PCR and sequencing of four genetic loci (18S rRNA, 28S rRNA, ITS1, and cox1), 59.3% of samples were positive for Sarcocystis spp. Parasites identified were genetically similar to Sarcocystis spp. using bird–bird, bird–Carnivora, rodent–Carnivora, or ungulate–Carnivora as their intermediate–definitive hosts. The present study suggests that synanthropic rodents may facilitate cross-ecosystem transmission of these parasites, increasing infection pressure on livestock, companion animals, and wildlife in human-dominated environments. Future molecular and dietary ecological studies are needed to assess the role of synanthropic and opportunistic hosts, such as the brown rat, in the transmission of Sarcocystis spp. Full article

(This article belongs to the Section Veterinary Clinical Studies)

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20 pages, 771 KB

Open AccessArticle

Evaluation of Different Terrestrial Oils as an Alternative to Dietary Fish Oil on Feed Physical Properties, Growth, Feed Utilization, and Fatty Acid Profile of Gangetic Catfish (Mystus cavasius)

by Sadia Taslim Helen, Tanwi Dey, Anwesha Bharoteshwari, Kazi Rakib Uddin, Muhammad Anamul Kabir, Md. Rakibul Hasan and Md. Sakhawat Hossain

Animals 2026, 16(2), 330; https://doi.org/10.3390/ani16020330 - 21 Jan 2026

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Abstract

The global demand for fish oil (FO) is increasing while its supply is decreasing, which has limited its use in aquafeeds. Research on alternative terrestrial oils (TOs) for commonly cultured fish species in Bangladesh is limited. This research involved a 70-day feeding experiment [...] Read more.

The global demand for fish oil (FO) is increasing while its supply is decreasing, which has limited its use in aquafeeds. Research on alternative terrestrial oils (TOs) for commonly cultured fish species in Bangladesh is limited. This research involved a 70-day feeding experiment to assess the effectiveness of replacing FO with TOs in the diet of Gangetic catfish (Mystus cavasius). Five diets were formulated: a control diet (D1) with fish meal and FO, and four diets replacing FO with soybean oil (D2), black soldier fly larvae oil (D3), palm oil (D4), or a mixed oil combination (D5) of 50% black soldier fly larvae oil, 25% soybean oil, and 25% palm oil. A total of 675 fish (0.5 g each) were distributed in 15 100 L aquariums (45 fish/aquarium) and fed to satiation twice daily. Fish fed with Diet D5 showed significantly higher growth, followed by those fed with D3, D4, and D1, while D2 resulted in significantly lower growth. Fish on the D5 diet consumed the most feed, followed by those on the D3 and D2 diets, with similar feed intake levels for those on the D1 and D4 diets. FCR, FCE, and PER were not significantly affected by dietary oil sources. Whole-body lipid content (p < 0.05) was significantly lower in the D3 group and higher in the D2 group, while other groups showed intermediate values. The fatty acid composition in the fish reflected their diets: significantly higher n-3 LC-PUFA (EPA + DHA) content was observed in the D1 group, followed by the D4 and D3 groups, and fish fed with D2 and D5 showed significantly lower values. Alpha-linolenic acid C18:3n-3) was significantly higher in the D2 group, followed by the D3, D1, and D4 groups, with the D5 group having a significantly lower value. Total MUFA was significantly higher in D4, followed by D1, D5, and D3; the D2-fed group showed a significantly lower value. Lauric acid (C12:0) was significantly higher in D3, followed by D5; other groups showed significantly lower values. Feed physical properties were significantly influenced by oil type, with water stability, pellet durability, and palatability being significantly highest in the D2 and D5 diets, followed by D3 and D4, with D1 being the lowest. Fish on the D1 and D5 diets had a significantly higher condition factor (CF) compared to fish on the D2 diet. Considering the growth and overall performance in the current study, we concluded that under the current dietary composition, TOs can effectively replace FO in the diets of Gangetic catfish, with mixed oils, black soldier fly larvae oil, and palm oil being the most promising alternatives. Full article

(This article belongs to the Section Animal Nutrition)

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11 pages, 236 KB

Open AccessArticle

Effects of Dendrobium officinale Leaf Powder on Bone Health and Bone Metabolism in Laying Hens

by Yutao Wu, Bingji Xu, Haoxin Zhang, Wen Ge, Ayong Zhao, Han Wang and Feifei Yan

Animals 2026, 16(2), 329; https://doi.org/10.3390/ani16020329 - 21 Jan 2026

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Abstract

Dendrobium officinale Kimura et Migo (D. officinale) is a traditional Chinese medicinal herb with recognized anti-inflammatory, antioxidant, and immunomodulatory properties. This study evaluated whether dietary supplementation with D. officinale leaf powder could influence bone mass, mechanical strength, and molecular markers of [...] Read more.

Dendrobium officinale Kimura et Migo (D. officinale) is a traditional Chinese medicinal herb with recognized anti-inflammatory, antioxidant, and immunomodulatory properties. This study evaluated whether dietary supplementation with D. officinale leaf powder could influence bone mass, mechanical strength, and molecular markers of bone metabolism in caged laying hens. A total of 192 healthy 19-week-old Jinghong No. 1 hens were randomly assigned to three dietary groups: a control group fed a basal diet and two treatment groups supplemented with 1200 or 3600 mg/kg of D. officinale leaf powder for 16 weeks. Tibial and femoral bone strength and mineral density did not differ significantly among treatments (p > 0.05). However, tibial breaking strength displayed upward trends in both supplemented groups (p = 0.08), and similar tendencies were observed for femoral bone mineral content and bone density (p = 0.08). At the molecular level, dietary supplementation produced selective changes in gene expression. The low-dose diet significantly increased VEGFA expression (p < 0.05), whereas the high-dose diet resulted in significantly higher TGF-β1 expression (p < 0.05). Several other genes related to bone formation, bone resorption, or cytokine signaling exhibited numerical increases but did not reach statistical significance. These findings indicate that D. officinale leaf powder may modulate bone metabolic processes at the transcriptional level, although these molecular alterations were not accompanied by significant improvements in bone mass. Full article

(This article belongs to the Special Issue Welfare and Behavior of Laying Hens)

20 pages, 3667 KB

Open AccessArticle

Effects of Water-Delivered Probiotics on Performance, Carcass Traits, Immunity, Blood Biochemistry, and Ileal Morphology of Broilers Reared at High Stocking Density Under Warm Ambient Temperature

by Ibrahim Al-Homidan, Abdulla Alsuqayhi, Osama Abou-Emera, Zarroug Ibrahim and Moataz Fathi

Animals 2026, 16(2), 328; https://doi.org/10.3390/ani16020328 - 21 Jan 2026

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Abstract

This study investigated the effects of dietary probiotic supplementation and stocking density on the growth performance, carcass traits, immunity, blood biochemical parameters, and ileal histomorphology of broiler chickens. A total of five hundred ten 1-day-old unsexed broiler chicks (Cobb 39) were allocated to [...] Read more.

This study investigated the effects of dietary probiotic supplementation and stocking density on the growth performance, carcass traits, immunity, blood biochemical parameters, and ileal histomorphology of broiler chickens. A total of five hundred ten 1-day-old unsexed broiler chicks (Cobb 39) were allocated to three probiotic levels (0%, 0.1%, 0.2%) and two stocking densities (low vs. high). Results indicated that stocking density significantly influenced body weight from the third week onward, with birds reared under low density showing higher weight and better feed-to-gain ratio. Probiotic supplementation did not significantly affect weekly body weight, feed intake, or mortality, although mortality tended to be lower in probiotic-fed groups. Carcass traits and lymphoid organ indices were largely unaffected by treatments, except for a higher heart percentage in low-density birds. Cell-mediated immunity was enhanced under low stocking density, and probiotic supplementation at 0.2% increased the immune response at 48 h post-challenge. Blood biochemical analysis revealed significant effects of stocking density on total protein, globulin, and triglycerides, while probiotics reduced total lipid and LDL levels. Ileal histomorphology was significantly improved by probiotics, with increased villus height, crypt depth, and villus-to-crypt ratio. Similarly, low stocking density further enhanced these parameters. Overall, probiotic supplementation, particularly at 0.1%, combined with low stocking density, positively influenced gut morphology and immune responses, contributing to improved broiler health and performance. Full article

(This article belongs to the Collection Application of Antibiotic Alternatives in the Poultry Industry)

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14 pages, 2297 KB

Open AccessArticle

Transcriptomics Analysis of Testis Development in Thamnaconus septentrionalis Responding to a Rise in Temperature

by Yan Liu, Xueli Zhang, Wengang Xu, Jiulong Wang, Li Bian, Yanqing Wu, Meng Li and Liming Liu

Animals 2026, 16(2), 327; https://doi.org/10.3390/ani16020327 - 21 Jan 2026

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Abstract

Thamnaconus septentrionalis is an emerging commercially important aquaculture species in China, distributed extensively in the Indo-West Pacific Ocean. Recently, because of the seriously declining population and considerable economic potential of this aquaculture fish, increasing attention has been paid to the conservation and development [...] Read more.

Thamnaconus septentrionalis is an emerging commercially important aquaculture species in China, distributed extensively in the Indo-West Pacific Ocean. Recently, because of the seriously declining population and considerable economic potential of this aquaculture fish, increasing attention has been paid to the conservation and development of T. septentrionalis. Artificial fish breeding is essential and has become progressively implemented on local farms in China, which benefits the protection of T. septentrionalis resources and facilitates the development of its fishery industry. Previous studies have demonstrated that temperature could significantly influence ovary development in T. septentrionalis. However, the potential molecular mechanisms underlying the influence of temperature on testis development in T. septentrionalis have been scarcely studied. Thus, this study comprehensively explores the effects of temperature on testis development in T. septentrionalis using histological observation and transcriptomic techniques. Histological and transmission electron microscopy analyses indicated that T. septentrionalis testes, undergoing a rise in temperature, developed from phase III to IV. Transcriptomic analysis identified 315 differentially expressed genes, including 200 upregulated and 115 downregulated genes. Moreover, rising temperatures may enhance testis development by regulating steroid hormone biosynthesis, cellular senescence, and nucleotide metabolism. The upregulation of four genes (hsd11b2, cyp11b, cyp11a, and hsd17b3) involved in the steroid hormone biosynthesis process may significantly contribute to the increased level of testosterone and 11-keto-testosterone. This study is the first to elucidate the potential molecular mechanism involved in T. septentrionalis testis development induced by temperature, offering valuable and novel insights for its artificial breeding and fishery resources conservation. Full article

(This article belongs to the Section Aquatic Animals)

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15 pages, 975 KB

Open AccessArticle

Complications Following Orchiectomy in Stallions in Field Conditions: Descriptive Results and Predictors in a Study of 612 Cases

by Panagiota Tyrnenopoulou, Eugenia Flouraki, Leonidas Folias, Epameinondas Loukopoulos, Alexandros Starras, Panagiotis Chalvatzis, Vassiliki Tsioli, Vasia S. Mavrogianni and George C. Fthenakis

Animals 2026, 16(2), 326; https://doi.org/10.3390/ani16020326 - 21 Jan 2026

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Abstract

The objectives of this work were (i) to evaluate the incidence of complications in male horses after orchiectomy performed in the field, i.e., away from a veterinary hospital, (ii) to describe the post-operative complications that occurred in these animals and (iii) to study [...] Read more.

The objectives of this work were (i) to evaluate the incidence of complications in male horses after orchiectomy performed in the field, i.e., away from a veterinary hospital, (ii) to describe the post-operative complications that occurred in these animals and (iii) to study the potential predictors for the development of such complications. This study involved 612 animals, on which orchiectomy was performed. The operative part of the study was carried out by one of three experienced veterinary surgeons. Standard pre-operative procedures were followed. Orchiectomy was performed using one of three principal surgical techniques, open, semi-closed or closed, and hemostasis was achieved by means of one of the various procedures, specifically the use of the Henderson instrument, the use of the Reimer emasculator, the ligation of the testicular artery or combinations thereof. In cases of reported complications, these were verified and identified appropriately. At least one (any) post-operative complication was recorded in 145 horses (23.7%). The most frequently observed complication was scrotal swelling/seroma formation, which was observed in 130 animals (21.2% of all animals; 89.7% of animals with at least one (any) complication). Another six different complications were observed, specifically colic, continued stallion-like behavior, evisceration, funiculitis, hemorrhage and scrotal infection. The median age of horses with complications was significantly older than that of animals with no complications: 11 versus 9 years. Animals in which the open technique was applied developed post-operative complications more frequently (30.1% of animals thus operated); further, complications were observed more frequently in animals on which operations were performed by using the Henderson instrument (84.6% of animals) versus animals on which any of the various other procedures were applied (22.4%). In multivariable analysis, the following predictors emerged for the development of complications: the surgical technique employed, the procedure applied for hemostasis, older animal age, and heavier animal bodyweight. The findings confirm that orchiectomy in stallions, even when performed in field conditions, is, in general, a safe procedure. The identification of predictors suggests that veterinarians should take additional care when planning to operate on animals at higher risk or when using surgical approaches that increase the potential for the development of complications. Full article

(This article belongs to the Special Issue Equine Surgery and Postoperative Management)

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20 pages, 4131 KB

Open AccessArticle

Calcium Nitrate Supplementation Improves Meat Quality in Hu Sheep via Microbial and Transcriptomic Regulation

by Yuanshu Zheng, Chen Zheng, Kang Sun, Huihui Liu, Huiyu Fan, Yi Wang, Xuan Nan, Lijing An, Faming Pan, Xinji Wang, Guoyan Xu and Ting Liu

Animals 2026, 16(2), 325; https://doi.org/10.3390/ani16020325 - 21 Jan 2026

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Abstract

Research has demonstrated that incorporating nitrate into animal feed can effectively decrease methane production in ruminants, though its impact on carcass characteristics and meat attributes in Hu sheep requires further investigation. This experiment examined how a dietary inclusion of 3% calcium nitrate (CN) [...] Read more.

Research has demonstrated that incorporating nitrate into animal feed can effectively decrease methane production in ruminants, though its impact on carcass characteristics and meat attributes in Hu sheep requires further investigation. This experiment examined how a dietary inclusion of 3% calcium nitrate (CN) influenced slaughter parameters, meat properties, gut microbial populations, and host gene regulation in Hu sheep. The study involved sixty healthy male Hu sheep aged 120 days with comparable body weights (31.11 ± 3.39 kg), randomly allocated into two groups: a control group receiving standard feed (CON) and a CN-supplemented group. The trial lasted 60 days, including a 15-day adaptation period and a 45-day formal trial period. They were housed individually and fed twice daily (at 8:00 and 18:00). The findings revealed that CN supplementation notably reduced the water loss rate in the longissimus dorsi muscle (LD), elevated meat color brightness, and enhanced the proportion of polyunsaturated fatty acids (PUFA), particularly n-6 PUFA, along with the n-3/n-6 PUFA ratio. Conversely, it reduced the levels of saturated fatty acids such as myristic acid (C14:0) and oleic acid (C18:1n9t). Additionally, the treatment boosted ruminal Ammoniacal nitrogen content and total short-chain fatty acid production, thereby contributing to energy metabolism in the animals. Microbiological examination demonstrated that CN supplementation led to a decrease in Fibrobacterota and Methanobrevibacter populations within the ruminal environment, while promoting the growth of Proteobacteria in the duodenal region. The gene expression profiling of digestive tract tissues showed an increased activity in nitrogen processing genes (including CA4) and oxidative phosphorylation pathways (such as ATP6), indicating an improved metabolic efficiency and acid–base homeostasis in the host animals. These findings demonstrate that CN-enriched diets enhance the carcass characteristics of Hu sheep by modifying intramuscular lipid profiles through gastrointestinal microbial community restructuring and metabolic pathway adjustments. Such modifications affect energy utilization and acid–base equilibrium, ultimately impacting muscle characteristics and adipose tissue distribution, presenting viable approaches for eco-friendly livestock farming practices. Full article

(This article belongs to the Special Issue Advanced Welfare-Oriented, Efficient, and High-Quality Ruminant Production: Mechanisms and Practices)

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21 pages, 3126 KB

Open AccessArticle

Effect of Coated Inorganic Micro-Minerals on Growth, Mineral Retention, and Intestinal Health in Juvenile American Eels Under a Commercial RAS

by Xiaozhao Han, Deying Ma, Yichuang Xu and Shaowei Zhai

Animals 2026, 16(2), 324; https://doi.org/10.3390/ani16020324 - 21 Jan 2026

Viewed by 179

Abstract

Micro-minerals are essential for fish, but traditional inorganic micro-minerals (IMM) have low bioavailability. This study evaluated coated inorganic micro-minerals (CIMM) in juvenile American eels under commercial recirculating aquaculture system (RAS) conditions. Three experimental groups (n = 3 tanks per group, stocking density: [...] Read more.

Micro-minerals are essential for fish, but traditional inorganic micro-minerals (IMM) have low bioavailability. This study evaluated coated inorganic micro-minerals (CIMM) in juvenile American eels under commercial recirculating aquaculture system (RAS) conditions. Three experimental groups (n = 3 tanks per group, stocking density: 138 fish/m³) were fed basal diets supplemented for 56 days with: 1000 mg/kg IMM (IMM group, providing Cu 7, Fe 200, Mn 30, Zn 70, I 1.6, Se 0.4, and Co 1.2 mg/kg diet), 1000 mg/kg CIMM (CIMM group I), or 500 mg/kg CIMM (CIMM group II). Compared to the IMM group, the CIMM group I demonstrated significantly enhanced growth performance, with the specific growth rate increasing by approximately 31.14%, higher whole-body content and retention of minerals (Ca, P, Cu, Fe, Mn, Zn), and superior intestinal health, as reflected by significantly increased activities of digestive enzymes (amylase and lipase), enhanced antioxidant capacity (elevated SOD and CAT, reduced MDA), and improved morphology (villi length and muscular thickness), an altered intestinal microbiota (increased relative abundance of Firmicutes and reduced relative abundance of Proteobacteria), and significant metabolomic alterations in purine metabolism and linoleic acid metabolism. The CIMM group II maintained growth performance, with no significant difference in WGR and SGR compared to the IMM group, while still showing significant improvements in feed intake and mineral retention (P, Cu, Fe, Zn), and antioxidant capacity. Collectively, this study not only confirms the efficacy of CIMM in commercial RAS but also reveals that the supplementation level previously shown to be effective in the laboratory (50% CIMM) is insufficient under commercial farming conditions, implying that the dietary micro-mineral requirements for juvenile American eels in commercial RAS may be higher than those established in laboratory settings. Full article

(This article belongs to the Special Issue Nutrition and Health of Aquatic Animals)

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16 pages, 395 KB

Open AccessReview

Haptic Signals as a Communication Tool Between Handlers and Dogs: Review of a New Field

by Hillary Jean-Joseph and Dalila Bovet

Animals 2026, 16(2), 323; https://doi.org/10.3390/ani16020323 - 21 Jan 2026

Viewed by 501

Abstract

Developing new haptic communication tools to enhance communication between dogs and their handlers during field operations has garnered interest in recent years. It is a promising field that could ameliorate dog–handler interactions in the field while addressing practical challenges, such as the need [...] Read more.

Developing new haptic communication tools to enhance communication between dogs and their handlers during field operations has garnered interest in recent years. It is a promising field that could ameliorate dog–handler interactions in the field while addressing practical challenges, such as the need for discrete communication during operations. When extended to the public, such technology could improve communication with impaired dogs. With this review, we aim to (1) give an overview of dogs’ understanding and discrimination of haptic signals, (2) highlight the need to investigate the possible impact of such tools on dogs’ welfare, as well as (3) point out current caveats and future research directions. Full article

(This article belongs to the Special Issue Beyond the Home: Exploring Human–Animal Relationships in Veterinary, Agricultural, and Workplace Contexts)

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Animals, Volume 16, Issue 2 (January-2 2026) – 199 articles

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