Search Results (134)

Reproductive inefficiencies, such as delayed age at first calving (AFC) and a prolonged calving interval (CI), hinder the productivity of Thai swamp buffaloes. This study aimed to improve the genetic evaluation of these traits by integrating genomic selection (GS) and genome-wide association studies (GWASs). Reproductive records (n = 1034) and genotypes (n = 474) from swamp buffaloes across Thailand were analyzed. Variance components were estimated using pedigree data, and genomic predictions were performed via weighted single-step genomic best linear unbiased prediction. AFC heritability was moderate (0.36 and 0.45), whereas CI heritability was low (0.051 and 0.043). The positive genetic correlation ($r_g$ = 0.495 and 0.517) between AFC and CI suggested potential for the simultaneous genetic improvement of both traits through selection. The WssGBLUP method showed greater effectiveness, with the prediction accuracy increasing by up to 41% for CI and 28% for AFC when compared to the ABLUP method. The GWAS revealed 20 associated single-nucleotide polymorphisms (SNPs) on chromosomes 3, 4, 14, 15, and 25. Candidate genes COLEC10, TNFRSF11B, PDZRN4, and MACROD2 were linked to immune function, hormonal regulation, and reproductive tissue development. Pleiotropic SNPs affecting both traits were identified, indicating shared genetic control mechanisms. These findings support the application of tailored GS programs to improve reproduction in swamp buffaloes under tropical smallholder systems. Full article

The determination of the live body weight of camels (required for their successful breeding) is a rather difficult task due to the problems with handling and restraining these animals. Therefore, the main aim of this study was to predict the ABW of eight indigenous camel (Camelus dromedarius) breeds of Pakistan (Bravhi, Kachi, Kharani, Kohi, Lassi, Makrani, Pishin, and Rodbari). Selected productive (hair production, milk yield per lactation, and lactation length) and reproductive (age of puberty, age at first breeding, gestation period, dry period, and calving interval) traits served as the predictors. Six data mining methods [classification and regression trees (CARTs), chi-square automatic interaction detector (CHAID), exhaustive CHAID (EXCHAID), multivariate adaptive regression splines (MARSs), MLP, and RBF] were applied for ABW prediction. Additionally, hierarchical cluster analysis with Euclidean distance was performed for the phenotypic characterization of the camel breeds. The highest Pearson correlation coefficient between the observed and predicted values (0.84, p < 0.05) was obtained for MLP, which was also characterized by the lowest root-mean-square error (RMSE) (20.86 kg), standard deviation ratio (SD_ratio) (0.54), mean absolute percentage error (MAPE) (2.44%), and mean absolute deviation (MAD) (16.45 kg). The most influential predictor for all the models was the camel breed. The applied methods allowed for the moderately accurate prediction of ABW (average R² equal to 65.0%) and the identification of the most important productive and reproductive traits affecting its value. However, one important limitation of the present study is its relatively small dataset, especially for training the ANN (MLP and RBF). Hence, the obtained preliminary results should be validated on larger datasets in the future. Full article

This study aimed to determine the thermoneutral zone (TNZ) in Sahiwal zebu calves under controlled environmental conditions. The experiment was conducted in the psychrometric chamber in two phases on six calves aged 8 to 11 months and weighing 120 to 150 Kg at the beginning of the experiment. In the first phase, to determine the upper critical temperature (UCT), calves were kept for six hours per day over 10 consecutive days at six different increasing temperature ranges from 24 to 39 °C with corresponding temperature humidity indexes (THIs) between 67 and 93. In the second phase, the same calves were exposed to decreasing temperatures (24 °C to 9 °C) to determine the lower critical temperature (LCT). On the 10th day of each temperature exposure, physiological parameters were recorded, and blood sampling was done. Using segmented regression analysis (SegReg standard version software), the breakpoints in linear regressions for different parameters with respect to exposure temperatures and THI in both phases were separately determined and considered to be the critical temperatures and threshold THIs, respectively. The LCT and UCT were arranged on a temperature scale. The temperature range between the highest LCT and the lowest UCT with respect to different studied parameters was considered as the thermoneutral zone (TNZ). The highest LCT was observed for granulocyte % at 18.15 °C, whereas the lowest UCT was observed at 30.10 °C (THI: 82.35). It was found that the LCT and UCT varied with respect to different physiological parameters. A subset of parameters displayed identifiable LCT and UCT values, while some did not exhibit clear breakpoints. The respiration rate (RR), rectal temperature (RT), total leukocyte count (TLC), granulocyte%, aspartate amino-transferase (AST), Alanine amino-transferase (ALT), cortisol, IL6, and HSP90 were the sensitive parameters for both cold stress and heat stress, whereas pulse rate (PR), triglyceride, and urea were only sensitive to cold stress, and erythrocytic parameters and lymphocyte % were sensitive only to heat stress. Based on heat stress responses, the UCT for zebu calves was identified at approximately 30.10 °C (THI: 82.35), whereas based on cold stress responses, the LCT for zebu calves was identified at approximately 18.15 °C. Thus, the TNZ for zebu calves can be proposed to be between 18.15 and 30.10 °C. These findings can inform climate-adaptive housing and management strategies for improving calf welfare and productivity in subtropical environments. Full article

The study objective was to compare the ability of Brix values and the D2Dx immunity test to predict the mortality risk of calves under 30 days of age. Heifer calves at 2–3 days of age were enrolled from two farms: Farm A, which has a low calf mortality rate (n = 849, 2.9% mortality), and Farm B, which has a high calf mortality rate (n = 698, 11.7% mortality). Serum samples were collected from the calves when they were 2–3 days of age. The D2Dx scores and Brix values of serum samples were compared between calves that died or survived between 3–30 days of age. For both farms, calves that survived their first 30 days of life had greater serum Brix values (9.05 vs. 8.48, p = 0.002 for Farm A; 9.26 vs. 8.99, p = 0.05 for Farm B) and D2Dx scores (0.0281 vs. 0.0036, p < 0.001 for Farm A; 0.0342 vs. 0.0286, p = 0.05 for Farm B) at 2–3 days of age compared with calves that died. On Farm A, the D2Dx score shows significantly better sensitivity (96% vs. 48%) and Area Under the Curve (0.87 vs. 0.69) than the Brix value in predicting calf mortality. However, similar results were not observed for the high-mortality farm (Farm B) due to other factors in addition to calf immune status that influenced calf survival. This study concludes that the D2Dx immunity test can be used to identify newborn dairy calves with low immunity and increased mortality risk; however, the prediction is most effective if no other risk factors are involved. Full article

Introduction: Paediatric hip disorders present unique challenges for artificial intelligence (AI)-aided assessments of medical imaging due to disease-related and age-dependent changes in hip morphology. This scoping review aimed to describe current and emerging applications of AI in medical imaging for paediatric hip disorders. Methods: A descriptive synthesis of articles identified through PubMed, Embase, Cochrane Library, Web of Science, Emcare, and Academic Search Premier databases was performed including articles published up until June 2024. Original research articles’ titles and abstracts were screened, followed by full-text screening. Two reviewers independently conducted article screening and data extraction (i.e., data on the article and the model and its performance). Results: Out of 871 unique articles, 40 were included. The first article was dated from 2017, with annual publication rates increasing thereafter. Research contributions were primarily from China (17 [43%]) and Canada (10 [25%]). Articles mainly focused on developing novel AI models (19 [47.5%]), applied to ultrasound images or radiographs of developmental dysplasia of the hip (DDH; 37 [93%]). The three remaining articles addressed Legg–Calvé–Perthes disease, neuromuscular hip dysplasia in cerebral palsy, or hip arthritis/osteomyelitis. External validation was performed in eight articles (20%). Models were mainly applied to the diagnosis/grading of the disorder (22 [55%]), or on screening/detection (17 [42.5%]). AI models were 17 to 124 times faster (median 30) in performing a specific task than experienced human assessors, with an accuracy of 86–100%. Conclusions: Research interest in AI applied to medical imaging of paediatric hip disorders has expanded significantly since 2017, though the scope remains restricted to developing novel models for DDH imaging. Future studies should focus on (1) the external validation of existing models, (2) implementation into clinical practice, addressing the current lack of implementation efforts, and (3) paediatric hip disorders other than DDH. Full article

Fetal programming suggests that maternal nutrition during gestation influences offspring growth, development, and productivity. This study evaluated the effects of prenatal protein-energy supplementation on the lifetime performance of Nellore cattle. Twenty-eight nulliparous heifers were inseminated and assigned to one of two groups: Non-Programmed; receiving only mineral supplementation; or Fetal Programmed (FP); receiving additional protein-energy supplementation throughout gestation. Cows in the FP group maintained significantly better body condition score during gestation (p < 0.01), and their calves exhibited greater body weight (BW) during the first 56 days (p < 0.05) and a tendency to grow to a greater BW up to 250 days (p < 0.10) in addition to improved morphological traits, such as increased rump width and length at 45 days of age (p ≤ 0.02). However, these advantages were not sustained in later growth stages, as no significant differences were observed in final body weight, ultrasound carcass traits, or overall feedlot performance. These findings suggest that while prenatal nutrition can influence early developmental traits, its long-term impact on offspring performance may be limited under consistent postnatal management. Nonetheless, the limited sample size, combined with the absence of molecular data and individual feed intake and efficiency measurements, constrains a more comprehensive interpretation of the programming effects on offspring performance. Further research is needed to explore the molecular mechanisms of fetal programming, particularly its epigenetic effects and interactions with postnatal nutrition, to optimize strategies for improving the efficiency and sustainability of beef cattle. Full article

Implementing genomic selection in smallholder dairy systems is challenging due to limited genetic connectedness and diverse management practices. This study aimed to optimize genomic evaluation models for crossbred cattle in South India. Data included 305-day first lactation milk yield (FLMY) records from 17,650 cows (1984–2021), with partial pedigree and genotypes for 1004 bulls and 1568 cows. Non-genetic factors such as geography, season and period of calving, and age at first calving were significant sources of variation. The average milk yield was 2875 ± 123.54 kg. Genetic evaluation models used a female-only reference. Heritability estimates using different approaches were 0.32 ± 0.03 (REML), 0.40 ± 0.03 (ssGREML), and 0.25 ± 0.08 (GREML). Bayesian estimates (Bayes A, B, C, Cπ, and ssBR) ranged from 0.20 ± 0.02 to 0.43 ± 0.04. Genomic-only models showed reduced variance due to the Bulmer effect, as genomic data belonged to recent generations. Breeding value prediction accuracies were 0.60 (PBLUP), 0.45 (GBLUP), and 0.65 (ssGBLUP). Using the LR method, the estimates of bias, dispersion, and ratio of accuracies for ssGBLUP were −39.83, 1.09, and 0.69; for ssBR, they were 71.83, 0.83, and 0.76. ssGBLUP resulted in more accurate and less biased GEBVs than ssBR. We recommend ssGBLUP for genomic evaluation of crossbred cattle for milk production under smallholder systems. Full article

Objectives: This article presents a study evaluating the antibody levels against infectious bovine rhinotracheitis (IBR) and bovine viral diarrhea (BVD) in Kazakh Whiteheaded calves born to dams immunized with an experimental inactivated combined vaccine against these infections. The vaccine formulation includes the strains “R-93” (IBR) and “Oregon C₂₄V” (BVD), which are preserved in the microorganism collection of the Research Institute for Biological Safety Problems. Methods: To assess the immune response in newborn calves, blood serum samples were collected before the first intake of colostrum, followed by weekly sampling for 28 weeks post-birth. The antibody response was determined using a virus neutralization assay on MDBK cell cultures and lamb testicle cell cultures. Results: The results demonstrated that the protective antibody level against the IBR virus (≥2 log₂) persisted for up to 25 weeks, while the protective level against the BVD virus (≥3 log₂) remained for 23 weeks. Based on these findings, the vaccine was deemed safe, as it did not induce abortions or clinical manifestations of the diseases. The overall duration of the colostral immunity in calves against the IBR and BVD viruses reached 23 weeks. Conclusions: Therefore, it is recommended that Kazakh Whiteheaded calves be vaccinated with the associated inactivated vaccine against infectious bovine rhinotracheitis and bovine viral diarrhea no earlier than 23 weeks of age. Full article

Within the agricultural sector, dairy cattle farming systems are of the main ammonia emitters contributing to nitrogen (N) pollution. As a main strategy to mitigate N pollution, increased N use efficiency (NUE) of dairy cattle farms has been proposed. Dairy replacement heifers are an important aspect of dairy herds, and improving their NUE is a step toward addressing the issue holistically. The aim of the current review was to describe and assess heifer nutritional practices that affect NUE and examine protein supplementation to minimize N excretion in the environment. Heifer management practices related to growth and nutrition appear to have an important role on improving overall farm NUE. In particular, age at first calving, dietary crude protein level and rumen degradable protein level appear to be among the factors that affect N losses during the growth period. From a management point of view, frequent body weight monitoring at growth benchmarks and the use of mechanistic nutritional models are highly desirable to increase NUE under on-farm conditions. Full article

Background: The reproductive performance of water buffalo significantly impacts the economic aspects of production. Traditional breeding methods are constrained by low heritability and numerous influencing factors, making it difficult to effectively improve reproductive efficiency. Genome-wide association studies (GWAS) offer new possibilities for exploring reproductive traits in water buffalo, opening up new avenues for efficient breeding. Methods: Using whole-genome resequencing, we identified quantitative trait loci (QTLs) associated with four suggestive reproductive traits: calving interval (CI), calf birth weight (CBW), dam birth weight (BW), and age at first calving (FCA). The study focused on identifying genetic variants that influence these reproductive traits. Results: Our research identified 52 suggestive regulatory loci associated with reproductive traits in water buffalo. Based on a 50 kb interval, we annotated these loci to 58 candidate genes. These loci involve genes such as AGBL4, GRM1, NCKAP5, and NRXN1, which are primarily enriched in pathways including the FOXO signaling pathway, calcium ion pathways, estrogen signaling pathway, and phospholipase D signaling pathway. These pathways directly or indirectly regulate the reproductive efficiency of water buffalo. Conclusions: This study has revealed suggestive regulatory genes (AGBL4, GRM1, NCKAP5, NRXN1) associated with reproductive traits in water buffalo. This not only enhances our understanding of the molecular mechanisms underlying complex traits but also points towards strategies for improving the reproductive capacity of water buffalo. These findings provide a solid foundation for future breeding programs aimed at enhancing water buffalo productivity. Full article

The cost-effective rearing of heifers depends on the provision of adequate nutrients at an appropriate age to meet nutrient requirements for growth and production. The objective of the present study was to investigate how the time of switching to a rumen-undegradable protein (RUP) source affects the ruminal fermentation and growth performance of Holstein dairy calves. A total of 36 Holstein female calves were randomly allocated to one of three dietary treatments on day 28 or 42 of life. In the first 28 days of life, they were on the same soybean meal (SBM)-based starter diet containing 22.2% crude protein with 37% RUP. The RUP content of the experimental diet was increased to 48% by a total replacement of the original SBM with xylose-treated soybean meal (XSBM). The following treatments were used: (1) starter diet containing SBM from d 28 (SBM28); (2) starter diet containing XSBM from d 28 (XSBM28); and (3) starter diet containing XSBM from d 42 (XSBM42). All the calves were fed a constant amount of milk (4 L/d), weaned on day 60, and then remained in the experiment until day 70 of life. The results showed that neither feed intake nor BW were influenced by the treatments in the pre-weaning period (days 28 to 60). The calves fed the XSBM28 and XSBM42 diets had greater daily gain and gain-to-feed ratio compared to those on the SBM28 diet post-weaning from day 61 to 70 (p < 0.05). The inclusion of XSBM in the starter diets from days 28 and 42 increased the calves’ height pre- and post-weaning (p < 0.05). The ruminal pH and concentrations of butyrate and iso-butyrate were higher at weaning when the calves were fed the XSBM diets. The calves fed the XSBM diets had less ammonia-N and total short-chain fatty acids at day 70 of life (p < 0.05) and a lower neutral detergent fiber digestibility in the post-weaning period (p < 0.05). The fecal scores and blood metabolites were not different among the treatments. The results showed that increasing the RUP content from 37% to 48% in the starter diets by a total replacement of SBM with XSBM during the pre-weaning period may improve the growth performance around weaning. A later replacement at 42 days of life appears equally effective compared to a replacement at 28 days of life. Full article

Cautery disbudding is a painful procedure and major welfare concern in organic dairy production, which lacks effective and easily implemented methods of pain control. Willow bark (WB) has been used to treat chronic pain in humans, but there is no scientific evidence that WB has an analgesic effect in dairy cattle. The objective of this study was to evaluate the effect of an oral WB bolus on heart rate, salivary cortisol concentration, ocular temperature, and lying behavior (time, bouts, and bout duration) of 42 Holstein and crossbred calves. Heifer calves were born at the University of Minnesota West Central Research and Outreach Center, Morris, MN organic dairy. Calves were disbudded from 4 to 7 weeks of age (42 ± 3 d) and randomly assigned to one of three treatments (n = 14 calves/treatment): hot iron disbudding with lidocaine (LID; 5 mL per horn bud), hot iron disbudding with oral WB (200 mg/kg), or sham disbudding (SD). Saliva samples and thermal images were collected 1 h before disbudding, at disbudding, and 5 min, 10 min, and every 30 min until 240 min after disbudding. Cardiac monitors recorded heart rates continuously throughout the 5 h study period. HOBO loggers recorded lying behavior during the 72 h following disbudding. The variables included in the statistical model for analyses were fixed effects of treatment, time, and the interaction between treatment and time, and calf was a random effect. The mean heart rate of LID calves (123.3 ± 2.8 beats/minute) and WB calves (124.5 ± 3.2 beats/minute) were higher than SD calves (110.8 ± 2.3 beats/minute). Salivary cortisol concentrations were higher for the LID calves (103.8 pg/mL) and for the WB calves (103.4 pg/mL) than for the SD calves (85.5 pg/mL). The ocular temperature was not affected by treatment group. There were fewer lying bouts 24 to 48 h after disbudding compared to the first 24 h after disbudding in both the LID and WB treatment groups. Treatment group did not affect lying time or lying bout duration. Neither LID nor WB alleviated the pain of calves throughout the post-disbudding period. The results highlighted the need to discover suitable options for pain mitigation of calves in organic livestock production. Full article

This study aimed to evaluate the effects of an ultra-diluted complex on the health status, growth performance, and blood parameters of dairy calves during the preweaning phase in a double-blind, placebo-controlled trial. During a 75-period trial, thirty-four Holstein newborn calves at the second day of life were completely randomized individually into two treatments: (1) control (CON), oral saline supplementation (5 mL/d); and (2) oral supplementation with 5 mL/d of a ultra-diluted complex (UD): Sulfur: ${10}^{60}$ + Viola tricolor: ${10}^{14}$ + Caladium seguinum: ${10}^{30}$ + Zincum oxydatum: ${10}^{30}$ + Phosphorus: ${10}^{60}$ + Cardus marianus: ${10}^{60}$ + Colibacillinum: ${10}^{30}$ + Podophyllum: ${10}^{30}$ + Vehicle: alcohol. Free access to water and a starter was ensured during the trial period. Feed intake and fecal and health scores were monitored daily. Calves were weighed and measured weekly. Blood samples were collected at enrollment on the first day and every 21 days until the 75th day, 2 h after morning milk feeding, and tested for hematology, blood urea nitrogen, aspartate aminotransferase, gamma-glutamyl transferase, total protein albumin, globulin, and creatinine. At 70 days of age, calves were disbudded following the standard management practices of the farm. The inflammatory profile, including Immunoglobulin A, Immunoglobulin G, ceruloplasmin, transferrin, albumin, and haptoglobin, was quantified in serum samples. The ultra-diluted complex was ineffective in reducing the incidence of diseases, starter feed intake, daily weight gain, and body measurements and inflammatory profile. Blood parameters were also not affected. Thus, the ultra-diluted complex was inefficient in reducing the incidence of diseases and did not affect the performance and metabolites of pre-weaned Holstein calves. Full article

Background: Water buffaloes represent a crucial genetic resource for the global dairy industry, yet enhancements in their production performance remain relatively constrained. The advent of advanced sequencing technologies, coupled with genome-wide association studies (GWASs), has significantly boosted the potential for breeding superior-quality water buffalo. Methods: An integrated genomic analysis was performed on sequencing data from 100 water buffaloes, utilizing the high-quality UOA_WB_1 genome assembly as a reference. This study particularly emphasized reproduction-related traits, with a focus on age at first calving (AFC). Results: Our analysis revealed two significant single-nucleotide polymorphisms (SNPs). Based on these genetic markers, the GRM1 gene was identified as a candidate gene. This gene shows substantial involvement in various reproduction-associated pathways, including the FOXO signaling pathway, calcium signaling pathway, and estrogen signaling pathway. Conclusions: The identification of GRM1 as a candidate gene provides a robust theoretical basis for molecular breeding strategies aimed at enhancing fertility in water buffaloes. These findings offer critical scientific support for optimizing breeding programs, thereby improving overall production efficiency. Full article

The microbiome of dairy calves undergoes extensive change due to various forces during the first weeks of life. Importantly, diseases such as bovine respiratory disease (BRD) and calf diarrhea can have profound impacts on the early-life microbiome. Therefore, a longitudinal, repeated-measures pilot study was designed to characterize the establishment of nasal and fecal microbiomes of dairy calves, assess the governing forces of microbial assembly, and evaluate how disease states impact these microbial ecologies. Dairy calves (n = 19) were clinically evaluated for gastrointestinal and respiratory disease across three weeks beginning at age ≤ seven days old. Fecal (n = 57) and nasal (n = 57) microbial samples were taken for paired-end 16S rRNA gene amplicon sequencing. Taxonomy and diversity analyses were used to characterize early-life nasal and fecal microbiomes. Stochasticity and determinism were measured using normalized stochasticity testing (NST) and Dirichlet multinomial model (DMM). All analyses were tested for statistical significance. Clinical diarrhea was observed in 11 of the 19 calves. Clinical BRD was not independently observed among the cohort; however, two calves presented clinical signs of both BRD and diarrhea. Taxonomic analysis revealed that fecal samples were highlighted by Bacteroidaceae (40%; relative abundance), Ruminococcaceae (13%), and Lachnospiraceae (10%), with changes in diversity (Kruskal–Wallis; p < 0.05) and composition (PERMANOVA; p < 0.05). Clinical diarrhea reduced diversity in the fecal microbiome but did not impact composition. Nasal samples featured Moraxellaceae (49%), Mycoplasmataceae (16%), and Pasteurellaceae (3%). While no diversity changes were seen in nasal samples, compositional changes were observed (p < 0.05). NST metrics (Kruskal–Wallis; p > 0.01) and DMM (PERMANOVA; p < 0.01) revealed that stochastic, neutral theory-based assembly dynamics govern early-life microbial composition and that distinct microbial populations drive community composition in healthy and diarrheic calves. Full article