Search Results (64)

This study evaluated the effects of early-life creep feeding with a high-protein, high-energy diet on growth performance, ruminal fermentation, and gut microbiota in Hanwoo calves (n = 10). Calves were assigned to control or treatment groups from birth to 6 months of age. No significant differences were observed in body weight, average daily gain (ADG), or feed conversion ratio (FCR), but ADG and dry matter intake (DMI) tended to be higher in the treatment group. Ruminal pH, NH₃-N, and volatile fatty acid (VFA) concentrations showed no significant differences. Fecal VFA profiles exhibited numerical trends suggesting higher propionate at 3 months and lower acetate, butyrate, and total VFA at 6 months in the treatment group, potentially reflecting altered substrate availability or absorption capacity, though these mechanisms were not directly measured. Microbiota analysis indicated stable ruminal alpha diversity, with numerical increases in fecal Bacteroidetes and genera such as Fournierella and Flavonifractor in the treatment group. These results suggest that early creep feeding with high-nutrition diets can support intake and promote potential shifts in hindgut microbiota composition without compromising overall microbial stability. Further research with larger sample sizes is needed to confirm these trends and assess long-term impacts on calf health and productivity. Full article

Records from 2012 to 2019 for two herds were analyzed to determine how tall fescue (Schedonorus arundinaceus (Schreb.) Dumont) endophyte (Epichloë coenophialum) status affected the productivity of spring-calving cows and calves. Pastures either contained tall fescue with wildtype endophyte (high levels of ergot alkaloids) or novel- or endophyte-free tall fescue (largely ergot alkaloid free). The experimental design was a randomized complete block with year as the replication unit. Forage samples from the farm with toxic endophyte-infected tall fescue contained 1136 ± 413 ppb total ergot alkaloids, while forage from the non-toxic pastures on the second farm contained 118 ± 83 ppb total ergot alkaloids. Artificial insemination pregnancy rates and calving rates were greater (p < 0.05) for cows that grazed non-toxic tall fescue (51.2 ± 2.8% and 93.5 ± 1.4%, respectively) than for cows on toxic endophyte-infected tall fescue (43.3 ± 2.8% and 88.8 ± 1.4%, respectively). Birth weights and weaning weights were greater (p < 0.05) for calves from the non-toxic tall fescue system (37 ± 1 kg and 278 ± 8 kg, respectively) than for calves from the toxic endophyte-infected tall fescue system (33 ± 1 kg and 254 ± 8 kg, respectively). Raising cattle on tall fescue without the toxic endophyte improved cow and calf productivity. Full article

Neonatal calves possess an immature and naïve immune system and are reliant on the intake of maternal colostrum for the passive transfer of immunoglobulins. Maternal antibodies delivered to the calf via colostrum, are crucial to prevent calfhood diseases and death. Failure of transfer of passive immunity (FTPI) is a condition in which calves do not acquire enough maternal antibodies, mostly in the form of IgG, due to inadequate colostrum quality or delayed colostrum feeding. The diagnosis and risk factors for FTPI have been widely studied in dairy cattle; however, in beef calves, the research interest in the topic is relatively recent, and the most adequate diagnostic and preventative methods are still in development, making it difficult to define recommendations for the assessment and prevention of FTPI in cow–calf operations. The objective of this scoping review is to identify the published literature on best practices for colostrum management and transfer of passive immunity (TPI) in neonatal beef calves. The literature was searched using three electronic databases (CAB Direct, Scopus, and PubMed) for publications from 2003 to 2025. The search process was performed during the period from May to July 2023, and was repeated in January 2025. All screening processes were performed using Covidence systematic review software (Veritas Health Innovation, Melbourne, Australia). A total of 800 studies were initially identified through database searches. After removing duplicates, 346 studies were screened based on their titles and abstracts, leading to the exclusion of 260 studies. The remaining 86 studies underwent full-text screening, and 58 studies were considered eligible for data extraction. Hand-searching the references from published review papers on the subject yielded an additional five studies, bringing the total to 63 included articles. The prevalence of FTPI has been estimated to be between 5.8% and 34.5% in beef calves. Factors studied related to colostrum management include quality and quantity of colostrum intake, the timing and method of colostrum feeding, and the microbial content of the colostrum. Studies on risk factors related to the calf include the topics calf sex, twin status, calf vigor, weight, month of birth, cortisol and epinephrine concentrations, and the administration of nonsteroidal anti-inflammatory drugs to calves after difficult calving. The dam-related risk factors studied include dam body condition score and udder conformation, breed, parity, genetics, prepartum vaccinations and nutrition, calving area and difficulty, and the administration of nonsteroidal anti-inflammatory drugs at C-section. Most importantly for beef systems, calves with low vigor and a weak suckling reflex are at high risk for FTPI; therefore, these calves should be given extra attention to ensure an adequate consumption of colostrum. While serum IgG levels of < 8 g/L or < 10 g/L have been suggested as cutoffs for the diagnosis of FTPI, 16 g/L and 24 g/L have emerged as cutoffs for adequate and optimal serum IgG levels in beef calves. Several field-ready diagnostics have been compared in various studies to the reference standards for measuring indicators of TPI in beef calves, where results often differ between models or manufacturers. Therefore, care must be taken when interpreting these results. Full article

In cattle, the transfer of passive immunity from mother to calf across the placenta is limited. Therefore, providing quality colostrum or supplementing with additives that enhance this attribute is crucial to optimise the transfer of passive immunity (TPI). The objective of the present study was to investigate the effect of capsaicin on the absorption of immunoglobulins, metabolites, and enzymes to optimise TPI in neonatal calves, and to assess its impact on selected physiological parameters. Two experimental groups were established: a control group (CON; n = 8), which received colostrum in three feedings (at 1, 12, and 20 h after calving), and a capsaicin group (CAP; n = 8) which received 40 mg of capsaicin per kilogram of body weight added to the colostrum. Birth weight (CON = 36.7 ± 1.10 kg; CAP = 36.2 ± 2.64 kg) and weight at 48 h of age (CON = 38.5 ± 1.11 kg; CAP = 38.0 ± 2.82 kg) were similar between the two experimental groups. At 48 h post-colostrum feeding, the CAP group exhibited significantly higher serum concentrations of IgG, total protein, and albumin—up to 23.4 times greater than those observed in the CON group (p < 0.001). Moreover, levels of glucose, cholesterol, and triglycerides were significantly elevated in the CAP group compared to the CON group (p < 0.05). Similarly, higher concentrations of alkaline phosphatase, aspartate aminotransferase, and alanine aminotransferase were observed in the CAP group. These findings suggest that the inclusion of 40 mg of capsaicin per kilogram of body weight in colostrum is safe and contributes positively to improving TPI in crossbred Holstein calves raised at altitudes higher than 2500 m above sea level. Full article

This study introduces a non-contact, single-target method for real-time monitoring of dairy cow calving posture and behavior using the YOLOv8 model. In total, 600 videos were collected, from which 10,544 image samples were extracted through frame-by-frame processing. Complete video recordings of 86 cows (30 primiparous and 56 multiparous) were utilized to investigate changes in calving behavior. The YOLOv8 model achieved excellent performance with precision (P), recall (R), and mean average precision (mAP) of 96.72%, 96.53%, and 97.41%, respectively, and recognition P of 89.19% for lying postures and 82.61% for standing postures. Behavioral analysis revealed that lying postures were more frequent than standing, and primiparous cows had more frequent posture transitions (9.07 changes) than multiparous cows (5.29 changes), particularly during early parturition. Primiparous cows also showed significantly higher average times for parturition and lying as well ashigher frequency of behavioral changes compared to multiparous cows. Additionally, calf birth weight was positively correlated with maternal behaviors, especially in primiparous cows. Our proposed model effectively and accurately recognizes calving postures in dairy cows, enabling the early detection of abnormal calving events. This provides a scientific basis and technical support for intelligent farm management. 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 physiological functions of newborn calves are undeveloped, especially the immune system, making them susceptible to infections. In recent years, the theory of trained immunity has attracted attention and provided new strategies to prevent unknown infections in animals. This study investigated the effects of feeding yeast β-glucan on the intestinal and respiratory health of calves during the suckling period. Newborn Holstein calves (average birth weight: 36.18 ± 0.61 kg, mean ± SE) were randomly assigned to two groups: the PO (Per Os) group (n = 22) and the CON (Control) group (n = 22). Calves in the PO group were fed a yeast β-glucan solution (0.1 g/mL, 65 mg/kg body weight) at 3 and 6 days of age, respectively, while calves in the CON group received equal volumes of sterile saline orally at the same time. Blood and fecal samples were collected at 7 and 30 days of age, respectively. The results showed that (1) Compared to the CON group, being fed yeast β-glucan resulted in an inflammatory response after 24 h of the second administration, including increased gene expression of interleukin-6 (IL-6, p < 0.01), interleukin-1 beta (IL-1β, p < 0.01), and malonaldehyde (MDA, p < 0.001) content. Also, stimulation with β-glucan increased the concentrations of secreted immunoglobulin A (sIgA, p < 0.01) and defensins (p < 0.05) in the rectal feces. (2) Pre-stimulation with yeast β-glucan effectively reduced the incidence of diarrhea (p < 0.05) and bovine respiratory disease (BRD, p < 0.05) from day 31 to day 60. (3) At 30 days of age, the pre-stimulated calves had significantly lower serum DAO (p < 0.001) and MDA levels (p < 0.05), while they had higher levels of serum IL-6 (p < 0.01) and fecal slgA (p < 0.05) than calves in the CON group. (4) Pre-stimulation with yeast β-glucan altered the intestinal bacterial community; the Beta diversity results showed that the CON group and the PO group were clustered separately in the principal coordinate analysis (PCoA) graph. Obviously, the PO group sample points were more clustered. In conclusion, this study highlights the potential of yeast β-glucan-induced trained immunity to improve calf health during the suckling period. The findings offer new insights into the prevention of intestinal and respiratory infections in calves. Full article

This study was performed to determine the effects of dietary supplementation of Bacillus amyloliquefaciens FD777 (BA) and Macleaya cordata extract (MCE) on the performance, morbidity and mortality rates, body measurements, immunity, rumen parameters, antioxidant parameters, microbiome level, and profitability of calves during the pre-weaning period. In the study, 51 calves were divided into three groups as one control and two treatment groups considering their age (1 day old), gender (nine females and eight males in each group), and birth weight (37.7 ± 0.4 kg). The calves in the control group (CON) were fed milk without supplements whereas the first treatment group (BA) was fed milk containing 10 mL/day/head of Bacillus amyloliquefaciens FD777 and the second treatment group (MCE) was fed milk containing 2 g/day/head of MCE. As a result, supplementing BA and MCE to calf milk had no significant effect on body weight (BW), dry matter intake (DMI), feed efficiency (FE), morbidity and mortality rates, rumen pH, IgG, IgA, and IgM values, and gastrointestinal microbiota (p > 0.05). On the other hand, it was determined that body weight gain (BWG), body length, body depth, rump width, withers height change, rump height change, rump width change, and serum GSH level increased significantly in the BA group compared to the control group (p < 0.05). According to the partial budget analysis, despite the additional cost of supplementing BA to the calf milk, no calf deaths and lower disease were observed in this group, unlike the other groups, resulting in a lowest calf rearing cost and highest profit. In calves receiving MCE, withers height, rump height, body length, rump width, body depth, chest circumference change, withers height change, rump height change, and rump width change values increased significantly compared with the control group (p < 0.05). In conclusion, the results obtained not only reveal the positive effects of BA and MCE on calves during the pre-weaning period, but also encourage the necessity of investigating their effects on the long-term performance of animals and farm economies. Full article

The objective of this narrative review is to provide a systematic framework for veterinarians to investigate dairy calf health, focusing on critical control points and key performance indicators (KPIs) to address morbidity and mortality challenges in preweaned calves. Recommendations target prenatal maternal nutrition, heat stress abatement, and optimal calving management to minimize risks associated with perinatal mortality and preweaning morbidity. Further, comprehensive colostrum management is discussed to ensure excellent transfer of passive immunity, which includes prompt collection and feeding within two hours of birth at a volume of 8.5–10% of calf body weight. Nutritional guidance emphasizes the importance of transition milk and feeding higher planes of nutrition to support immunity, with recommendations that milk total solids exceed 10% to meet energy needs. Environmental management recommendations include a minimum of 3.3 m² of space per calf, the use of low-dust bedding, and air quality controls to reduce respiratory disease. Lastly, regular health data collection and KPI monitoring, such as average daily gain and morbidity rates, are essential for data-driven improvements. By implementing these evidence-based recommendations, veterinarians can support dairy farmers in reducing calf morbidity and mortality, ultimately enhancing calf welfare and lifetime productivity. Full article

This study hypothesized that combining oregano essential oil (OEO) and yeast cultures (YCs) would modulate rumen microbiota to promote gastrointestinal homeostasis and function. Twenty-four newborn, healthy, disease-free, crossbred Simmental male calves (birth weight ≥ 35 kg) were assigned to one of four treatments based on birth data. Treatments were as follows: (1) Control (CON), calves fed calf starter without additives; (2) OEO, calves fed calf starter containing 60 mg/kg body weight (BW) of OEO per day; (3) YCs, calves fed calf starter containing 45 mg/kg BW of YC per day; and (4) MIX, calves fed calf starter with OEO (60 mg/kg, BW) and YC (45 mg/kg, BW) combination. The experimental period lasted 70 days. Rumen fluid was collected on the final day, and 16S rRNA sequencing was performed to assess alterations in rumen microbiota. Calves fed MIX exhibited significantly greater microbial richness, species diversity, and lineage diversity (p < 0.05) compared with calves in the other groups. MIX-fed calves also showed changes (p < 0.05) in the relative abundance of certain rumen species, identified as through LEfSe analysis (LDA > 4, p < 0.05). These biomarkers included f_Rikenellaceae, g_Rikenellaceae_RC9_gut_group, g_Erysipelotrichaceae_UCG-002, c_Saccharimonadia, o_Saccharimonadales, f_Saccharimonadaceae, and g_Candidatus_Saccharimonas. Pathways enriched (p < 0.05) in MIX-fed calves involved nucleotide metabolism, lipid metabolism, glycan biosynthesis and metabolism, amino acid metabolism, terpenoids and polyketides metabolism, antimicrobial drug resistance, xenobiotic biodegradation and metabolism, antineoplastic drug resistance, and excretory system pathways. In conclusion, this study demonstrates that the OEO and YC combination enhances rumen microbial community modulation in calves more effectively than OEO or YCs fed individually or with the control diet. Full article

This study investigates morbidity, mortality, and weight gain in pre-weaned female dairy calves, which pose economic and animal welfare challenges for farms, particularly in family-run operations in southern Brazil. We aimed to identify the rates and factors associated with these outcomes in Alto Uruguai, Rio Grande do Sul, Brazil, tracking 547 calves from 70 farms across 27 municipalities from July 2015 to September 2016. We assessed calf-rearing practices, nutrition, health, and the environment using farmer questionnaires, direct observations, and systematic weight and health monitoring of female calves from birth to weaning. The association between predictors and perinatal mortality (stillbirths and deaths within 24 h), postnatal mortality (deaths from 25 h after birth to weaning), calf morbidity, and weight gain was analysed through regression models. The participating farms had 25 (9–70) (median and range) lactating cows and produced 411 (96–1631) L/d of milk (median and range). Total mortality rate was 6.8% (median 0, range 0–50%/range), of which 2.4% (median 0, range 0–50%/range) was perinatal and 4.5% (median 0, range 0–40%/range) postnatal. Average morbidity was one case for every five calves born alive (106/538), 83% of which were reported as diarrhoea cases. Weight gain was 570 ± 212 g/d (mean and standard deviation). The postnatal mortality rate was highest in the first few weeks of life and among calves with at least one case of diarrhoea. Younger and winter/spring-born calves became sick more frequently. The calves of purebred bulls, fed with cow’s milk, which received at least 4 L of milk and 0.5 kg of feed daily, had greater weight gain. The calf mortality rate was at the lower end of the range reported in international research. The main disease affecting calves was diarrhoea, and weight gain was insufficient for calves to double their weight by the time they were weaned. The results of the present study suggest that the quality of the management adopted in calf rearing in many of the family-run dairy farms of southern Brazil may be compromising the welfare, health, performance, and survival of the calves and possibly the productivity of dairy herds. Full article

This study investigated the factors influencing gestation length in a herd of Wagyu cattle in Rio Grande do Sul, Brazil. Fifty-five multiparous purebred Wagyu cows underwent a Fixed-Time Artificial Insemination (FTAI) protocol using semen from a bull randomly selected from five bulls representing three distinct genetic lines. Following birth, we recorded the calves’ gender, weight, and gestation length. The ANOVA test was employed to assess genetic effects on calf weight and gestation length, with significance set at p < 0.05. The 55 inseminations resulted in 52 births, comprising 34 females and 18 males. The average calf weight was 25.9 kg, with 25.2 kg for females and 27.2 kg for males (p = 0.38). No significant effect was observed for birth weight concerning the sire’s genetic line (p = 0.42), although there was a trend towards an effect from the maternal grandfather (p = 0.09). The mean duration of pregnancy was 283.8 ± 5.91 days, with no significant effect of gender on gestation length (p = 0.6). However, when evaluating the genetic influences on gestation length, we observed significant effects from the sire’s genetic line (p < 0.0001) and the maternal grandfather (p < 0.0001). Notably, longer pregnancies resulted in heavier calves (p < 0.0001). This is the first study to identify the effects of Wagyu breed lines on pregnancy length. Full article

The objective of this study was to explore the relationship between calf birth traits and their susceptibility to diseases before reaching adulthood. A total of 5253 birth traits of Chinese Holstein calves were examined, including gestation length (GL), calf weight at birth (CW), and calving ease score (CES), which ranges from 1 (easy) to 5 (very difficult). Furthermore, monthly medical records were scrutinized for pneumonia and diarrhea in these calves. The study assessed five aspects of disease manifestation in calves: age at first onset, frequency of illness, longest duration of treatment, and total duration of treatment. The link between age at onset and disease manifestation prior to adulthood was analyzed using general linear models and regression models. The GL of calves significantly correlated with the risk of pneumonia, with the risk decreasing as the GL increases. A higher CES was associated with a later onset of diarrhea in calves. Furthermore, the CES was significantly negatively correlated with the duration of diarrhea treatment in calves. These results suggest that implementing different preventive measures for calves with different birth traits and modifying treatment protocols for affected calves could enhance the productivity of dairy cows and reduce losses on farms. Full article

The placenta is a vital organ in bovine reproduction, crucial for blood supply, nutrient transport, and embryonic development. It plays an essential role in the intrauterine growth of calves. However, the molecular mechanisms governing placental function in calves remain inadequately understood. Methods: We established transcriptome and proteome databases for low-birth-weight (LB) and high-birth-weight (HB) calf placentae, identifying key genes and proteins associated with birth weight through bioinformatics analyses that included functional enrichment and protein–protein interactions (PPIs). Both mRNA and protein levels were validated. Results: A total of 1494 differentially expressed genes (DEGs) and 294 differentially expressed proteins (DEPs) were identified when comparing the LB group to the HB group. Furthermore, we identified 53 genes and proteins exhibiting significant co-expression across both transcriptomic and proteomic datasets; among these, 40 were co-upregulated, 8 co-downregulated, while 5 displayed upregulation at the protein level despite downregulation at the mRNA level. Functional enrichment analyses (GO and KEGG) and protein–protein interaction (PPI) analysis indicate that, at the transcriptional level, the primary factor contributing to differences in calf birth weight is that the placenta of the high-birth-weight (HB) group provides more nutrients to the fetus, characterized by enhanced nutrient transport (SLC2A1 and SLC2A11), energy metabolism (ACSL1, MICALL2, PAG2, COL14A1, and ELOVL5), and lipid synthesis (ELOVL5 and ELOVL7). In contrast, the placenta of the low-birth-weight (LB) group prioritizes cell proliferation (PAK1 and ITGA3) and angiogenesis. At the protein level, while the placentae from the HB group exhibit efficient energy production and lipid synthesis, they also demonstrate reduced immunity to various diseases such as systemic lupus erythematosus and bacterial dysentery. Conversely, the LB group placentae excel in regulating critical biological processes, including cell migration, proliferation, differentiation, apoptosis, and signal transduction; they also display higher disease immunity markers (COL6A1, TNC CD36, CD81, Igh-1a, and IGHG) compared to those of the HB group placentae. Co-expression analysis further suggests that increases in calf birth weight can be attributed to both high-efficiency energy production and lipid synthesis within the HB group placentae (ELOVL5, ELOVL7, and ACSL1), alongside cholesterol biosynthesis and metabolic pathways involving CYP11A1 and CYP17A1. Conclusion: We propose that ELOVL5, ELOVL7, ACSL1, CYP11A1, and CYP17A1 serve as potential protein biomarkers for regulating calf birth weight through the modulation of the fatty acid metabolism, lipid synthesis, and cholesterol levels. Full article

After birth, the immune system is challenged by numerous elements of the extrauterine environment, reflected in fluctuations of inflammatory markers. The concentrations of these markers in the first month of life are associated with the future performance of dairy youngstock. It is thought that bacterial genera colonizing the calf intestinal tract can cause inflammation and thus affect their host’s performance via immunomodulation. This study explored how the faecal microbiota of newborn dairy calves were related to inflammatory markers during the first three weeks of life, and if the abundance of specific genera was associated with first-lactation performance. Ninety-five female Holstein calves were studied. Once a week, serum and faecal samples were collected, serum concentrations of serum amyloid A, haptoglobin, tumour necrosis factor-α, and interleukin-6 were measured, and faecal microbiota composition was examined by 16S rRNA gene amplicon sequencing. Faecal Gallibacterium abundance in the first week of age and Collinsella abundance in the second week were negatively associated with inflammatory response as well as with calving–conception interval. Peptostreptococcus abundance in the second week of life was positively associated with inflammatory response and calving–conception interval, and negatively with average daily weight gain. In the third week, Dorea abundance was positively, Bilophila abundance was negatively associated with inflammatory response, and both genera were negatively associated with age at first calving. These bacterial genera may be able to influence the inflammatory response and through this, possibly the future performance of the dairy heifer. Deciphering such microbiota–host interactions can help improve calf management to benefit production and welfare. Full article