Suckling Calves Research Articles

Comparison of suckling and artificial rearing on calf growth and milk requirements in pastoral dairy systems

Context Dairy calf-rearing practises have the potential to influence profitability through milk requirements at rearing, and affect lifetime productivity and market access from an animal-welfare perspective. Aims The aim of this research was to compare calf growth and milk requirements by using conventional artificial rearing (AR) and restricted milk allocation with AR and high milk allocation or suckled calves. Methods Forty-five Friesian × Jersey calves were allocated to be either AR on 6 L/calf.day, (ARC) or 12 L/calf.day, (ARH), or suckled with dams in a cow–calf contact system using partial contact (15 h/day, CCC). AR calves were fed, and intake measured, using an automatic feeder, whereas CCC calves had access to their dams between 1500 hours and 0600 hours. Calves were transitioned off milk, once they reached at least 75 kg liveweight (LW), by gradually reducing their milk allocation (AR) or reducing access to their dam (CCC). Key results Milk consumption for ARH was greater than for ARC calves (382 vs 450 L/calf, P < 0.05), whereas for CCC calves milk-yield difference between dams for the control and suckling groups during the suckling period and over the full season was 706 and 1048 L/cow respectively. There was no difference in weaning weight of calves (87 ± 1.7 kg LW), but, owing to differences in pre-weaning growth rate, age to weaning was youngest (P < 0.05) for CCC (55 days), followed by ARH (62 days) and ARC (73 days). Respective growth rates between birth and weaning (P < 0.001) for CCC, ARH and ARC calves were 0.955, 0.873 and 0.755 ± 0.028 kg/day. Although there was a growth check among CCC calves during the weaning period, there were no post-weaning differences in growth rate among the groups. Conclusions Increasing milk allowance had the benefit of improving calf pre-weaning growth rate, giving the option of weaning calves either earlier or when heavier. However, milk yield losses under suckling systems may be too high to warrant the elevated pre-weaning growth of calves. Implications The costs–benefits of high milk allocation or suckling systems need to be ascertained over the lifetime of the animals to assess long-term survival and productivity outcomes.

Temperament of the dairy cow relates to her maternal behaviour in a pasture-based extended suckling system

Cow-calf rearing is gaining interest in dairy systems as an alternative to calf separation soon after birth. One commonly articulated benefit of these ‘extended suckling’ systems is that they allow expression of highly motivated maternal behaviours. The quality of maternal expression is subject to natural variation, however, and could be influenced by the temperamental characteristics of the dam. This study assessed the relationship between cow temperamental characteristics and expression of maternal behaviours in a pasture-based extended suckling system. Sixteen dairy cows (Bos taurus) underwent social isolation, novel object and novel human tests at 4 months of pregnancy. A principal components analysis (PCA) was used to determine associations between cow responses in these tests. After parturition, the cows entered an extended suckling system (half-day contact) until calves were weaned. Cow-calf interactions at pasture were video recorded for 4 consecutive hours (∼09:00 AM – 1:00 PM) at weeks 3, 6 and 9 post-partum. These data were used to calculate a maternal behaviour score for cows by subtracting the frequency of “negative” maternal behaviours (i.e., agonistic behaviour delivered to own calf, rejecting own calf suckling attempt and rejecting attempted contact by own calf) from the frequency of “positive” maternal behaviours (i.e., nursing own calf, affiliative behaviour delivered to own calf and proximity to own calf). A Pearson correlation was then used to assess the relationship between factors scores and maternal scores. Three behavioural traits were identified from the PCA: boldness, anxiety and sociability. In general, cows delivered more affiliative behaviour to their calves than to other calves and to cows and nursed their own calf more than other calves. The maternal behaviour score varied (mean ± SD, 33 ± 13.4, minimum = 9, maximum = 49). Cows with higher loadings for boldness had a lower maternal behaviour score (p < 0.05). There was no correlation between maternal behaviour score and anxiety or sociability (p > 0.05). The lower maternal behaviour score of bold cows in this study might be influenced by their prioritisation of foraging and exploration over interactions with their calves. Despite the long-standing practice of calf separation soon after birth, the current study demonstrates that maternal abilities of pasture-based dairy dams persist. We conclude that cow temperamental characteristics are related to how the cows interacted with their calves.

PSVII-14 Influence of dam parity and weaning strategy in previous lactation on feedlot performance of Nellore steers

Abstract In tropical beef cattle production systems, the impact of seasonality may be particularly challenging for young cows (primiparous or secondiparous) due to their increased nutritional requirements, encompassing maintenance, growth, gestation, and, in the case of secondiparous cows, lactation. Literature indicates that extending the duration of lactation during gestation is associated with decreased performance of progeny in their postnatal life. Therefore, implementing an early weaning approach can be an effective strategy to alleviate the nutritional demands of lactation in dams, thereby allocating more nutrients for fetal growth. This study aimed to evaluate the effect of early weaning on the feedlot performance of progeny that were in utero at the time of weaning intervention. To create experimental units, secondiparous and multiparous Nellore cows were assigned to one of two weaning strategies, where suckling calves were either; 1) early weaned 150 d (EW); or 2) conventional weaned at 240 d (CW). All calves were weaned at 150 d of lactation in 2022. Three bulls were used: Bull 1: had 13 calves with multiparous cows, had 7 calves with secondiparous cows, comprising 11 EW and 9 CW; Bull 2: had 10 calves with multiparous cows, had 6 calves with secondiparous cows, comprising 6 EW and 10 CW; and Bull 3: had 7 calves with multiparous cows, had 15 calves with secondiparous cows, comprising 11 EW and 11 CW. All cows were managed similarly after weaning, and through parturition, and weaning of subsequent calf, with resulting calves used for the current experiment. Nellore bulls (n = 57) with an initial body weight (BW) of 417.23 ± 9.12 kg and 18 mo of age were allocated to feedlot pens (equipped with Intergado equipment) and fed a common total mixed ration (80:20; concentrate:corn silage) for 97 ± 1.60 d. Bulls were distributed in a randomized complete block in a 2 × 2 factorial arrangement, considering dam weaning strategy in the previous lactation (EW and CW) and dam parity at subsequent calving (multiparous or secondiparous cows, MC and SC, respectively). Data were analyzed using PROC MIXED of SAS 9.4, with a model including the effects of dam weaning strategy, dam parity, and their interaction. Data were considered significant when P values were less than 0.05 and indicated a trend when 0.05 &amp;lt; P ≤ 0.10. There was an interaction between weaning strategy and cow parity, with calves born to SC-CW having reduced initial (P = 0.04) and final BW (P = 0.01) compared with all other groups (Figure 1 and 2). Steers from MC had greater dry matter intake (P = 0.003), and greater biological efficiency (P = 0.03; Table 1). Early weaning improved the final BW of steers born to secondiparous cows, suggesting it could be a strategy to enhance the performance of offspring and the reproductive performance of both secondiparous and multiparous cows.

Respiratory illness in young and adult cattle caused by bovine viral diarrhea virus subgenotype 2b in singular and mixed bacterial infection in a BVDV-vaccinated dairy herd.

Bovine respiratory disease (BRD) is a common global health problem in dairy cattle. The definitive diagnosis of BRD is complex because its etiology involves several predisposing and determining factors. This report describes the etiology of a BRD outbreak in a dairy herd in the mesoregion of Central Eastern Paraná, which simultaneously affected young (calves and heifers) and adult (cows) Holstein-Friesian cattle. Nine biological samples, consisting of five lung samples from two cows and three suckling calves, and four nasal swab samples from heifers, were used for etiological diagnosis. The nucleic acids extracted from lung fragments and nasal swabs were subjected to PCR and RT-PCR assays for partial amplification of the genes of five viruses [bovine viral diarrhea virus (BVDV), bovine alphaherpesvirus 1 (BoAHV1), bovine respiratory syncytial virus (BRSV), bovine parainfluenza virus 3 (BPIV-3), and bovine coronavirus (BCoV)] and four bacteria (Mycoplasma bovis, Mannheimia haemolytica, Pasteurella multocida, and Histophilus somni) involved in the etiology of BRD. All nine biological samples from the animals with BRD tested negative for BoAHV1, BRSV, BPIV-3, BCoV, and H. somni. Therefore, the involvement of these microorganisms in the etiology of BRD outbreak can be ruled out. It was possible to identify the presence of BVDV and M. bovis in singular and mixed infections of the lower respiratory tract in cattle. BVDV was also identified in two nasal swabs: one as a single etiological agent and the other in association with two bacteria (P. multocida and M. haemolytica). The phylogenetic analysis conducted in the nucleotide sequence of the 5'UTR region and Npro gene of the BVDV amplicons demonstrated that the BVDV field strains of this BRD outbreak belong to subgenotype 2b. To the best of our knowledge, this is the first report of BVDV-2b involvement in the etiology of BRD in Brazil. Finally, it is necessary to highlight that the cattle were obtained from an open dairy herd with biannual vaccinations for BVDV-1a and - 2a.

Effect of suckler cow breed type and parity on the development of the cow-calf bond post-partum and calf passive immunity

BackgroundDevelopment of the cow-calf bond post-partum and passive immunity of calves from spring-calving beef × beef (B×B) and beef × dairy (B×D) cow genotypes was determined using primiparous and multiparous (Experiment 1), and primiparous and second-parity (Experiment 2) animals. In Experiment 1, calves either suckled colostrum naturally (‘natural-suckling’) (n = 126), or were fed colostrum, using an oesophageal-tube (‘artificially-fed’) (n = 26), from their dam within 1-h post-partum. In Experiment 2, all calves (n = 60) were artificially-fed colostrum from their dam. Prior to colostrum suckling/feeding, colostrum was sampled for IgG analysis. The cow-calf bond was assessed using CCTV recordings during the first 4-h post-partum. Calves were blood sampled at 48-h post-partum to determine IgG and total protein (TP) concentrations, and zinc sulphate turbidity (ZST) units.ResultsThere was no difference (P > 0.05) in cow licking behaviours and calf standing and suckling behaviours between the genotypes, except in Experiment 2 where B×D calves had more attempts to suckle before suckling occurred (P ≤ 0.05) compared to B×B calves. In Experiment 1, multiparous cows licked their calves sooner (P ≤ 0.05) and for longer (P < 0.01), and their calves had fewer attempts to stand (P < 0.001), stood for longer (P = 0.05), and had fewer attempts to suckle before suckling occurred (P < 0.001) than primiparous cows; there was no parity effect on cow-calf behaviour in Experiment 2. Colostrum IgG concentrations and measures of calf passive immunity did not differ (P > 0.05) between the genotypes in either Experiment. In Experiment 1, colostrum IgG concentrations were greater (P ≤ 0.05) in multiparous compared to primiparous cows and their calves had superior (P ≤ 0.05) passive immunity; no effect of parity was found in Experiment 2. Passive immunity did not differ (P > 0.05) between suckled and artificially-fed calves in Experiment 1.ConclusionsCow genotype had little effect on cow-calf behaviours, but under ‘natural-suckling’ conditions primiparous cows expressed maternal inexperience and their calves were less vigorous than multiparous cows. Colostrum IgG concentration and calf passive immunity measures were unaffected by genotype, but under ‘natural-suckling’ conditions calves from primiparous cows had lower passive immunity.

Foot-and-mouth disease-associated myocarditis is age dependent in suckling calves

Myocarditis is considered a fatal form of foot-and-mouth disease (FMD) in suckling calves. In the present study, a total of 17 calves under 4 months of age and suspected clinically for FMD were examined for clinical lesions, respiratory rate, heart rate, and heart rhythm. Lesion samples, saliva, nasal swabs, and whole blood were collected from suspected calves and subjected to Sandwich ELISA and reverse transcription multiplex polymerase chain reaction (RT-mPCR) for detection and serotyping of FMD virus (FMDV). The samples were found to be positive for FMDV serotype “O”. Myocarditis was suspected in 6 calves based on tachypnoea, tachycardia, and gallop rhythm. Serum aspartate aminotransferase (AST), creatinine kinase myocardial band (CK-MB) and lactate dehydrogenase (LDH), and cardiac troponins (cTnI) were measured. Mean serum AST, cTn-I and LDH were significantly higher (P < 0.001) in < 2 months old FMD-infected calves showing clinical signs suggestive of myocarditis (264.833 ± 4.16; 11.650 ± 0.34 and 1213.33 ± 29.06) than those without myocarditis (< 2 months old: 110.00 ± 0.00, 0.06 ± 0.00, 1050.00 ± 0.00; > 2 months < 4 months: 83.00 ± 3.00, 0.05 ± 0.02, 1159.00 ± 27.63) and healthy control groups (< 2 months old: 67.50 ± 3.10, 0.047 ± 0.01, 1120.00 ± 31.62; > 2 months < 4 months: 72.83 ± 2.09, 0.47 ± 0.00, 1160.00 ± 18.44). However, mean serum CK-MB did not differ significantly amongst the groups. Four calves under 2 months old died and a necropsy revealed the presence of a pathognomic gross lesion of the myocardial form of FMD known as “tigroid heart”. Histopathology confirmed myocarditis. This study also reports the relevance of clinical and histopathological findings and biochemical markers in diagnosing FMD-related myocarditis in suckling calves.

Performance and incidence of diarrhea in suckling Jersey calves supplemented with mineral-vitamin complex and Virginiamycin.

The rearing of calves is an essential activity of a dairy system, as it impacts the future production of these animals. This study aims to evaluate the incidence of diarrhea, performance, and blood parameters of suckling calves that received mineral-vitamin supplementation in milk plus virginiamycin that was offered in milk (via the abomasum) or by esophageal tube (via the rumen). Twenty-seven calves were used, from the first week to 60days of age, submitted to the following treatments: CONTROL, without supplementation; MILK, supplementation of 20g of a mineral-vitamin complex with 100mg of virginiamycin, diluted in milk; RUMEN, supplementation of 20g of a mineral-vitamin complex diluted in milk and 100mg of virginiamycin in gelatin capsules via an esophageal applicator. MILK and RUMEN calves had lower fecal consistency scoring, fewer days with scores 2 and 3 throughout the experimental period, and lower spending on medication compared to the CONTROL animals. Supplemented calves had higher fat and protein intake and reached feed intake of 600g earlier than CONTROL animals, but did not differ in performance and hematological parameters. Supplementation with virginiamycin and vitamin-mineral complex for suckling calves reduced the incidence and days of diarrhea, and reduced medication costs, with no difference in performance, but the supplemented animals had higher initial protein and fat intake and reached targeted feed intake earlier to begin the weaning process.

Effects of Different Sources of Supplemental Zinc on the Performance and Some Blood Parameters of Holstein Suckling Calves

Effects of Different Sources of Supplemental Zinc on the Performance and Some Blood Parameters of Holstein Suckling Calves

Maternal behavior of dairy cows and suckling behavior of dairy calves in different cow-calf contact conditions

Cow-calf contact (CCC) has been suggested as an alternative to the common practice of early separation of dairy cow and calf. Increasing CCC poses challenges by reducing the machine milk yield and increasing separation stress. Part-time CCC may prove more feasible than full-time contact for farmers but may affect the maternal behavior of the cows. Gradually reducing the daily contact could gradually wean the calf off milk, preparing it for separation. This study aims to investigate 1) how cows' maternal behaviors toward their own calf are affected by part-time contact, and 2) whether calves' suckling behavior is reduced by reducing daily cow contact. Fifty-six dairy cows and their calves were assigned to either full-time (23 h/d) or part-time (10 h/d) cow-calf contact for 7 weeks (main rearing period). This was followed by 2 weeks of either reduced contact (50% in wk 8, then 25% of original contact time in wk 9) or unchanged contact. First, the maternal behavior of full and part-time cows was observed for 24 h in the third week of the main rearing period. Part-time cows spent less time nursing and grooming their own calf than full-time cows did. However, the amount of nursing in the inverse parallel position and the probability of a cow nursing a calf other than her own did not differ between the 2 treatments. Second, calf suckling behavior was observed for 24 h in both weeks of the reduced contact period. Averaged across both observations, total suckling time (i.e., time spent suckling any cow) was lower in part-time calves that experienced reduced contact compared with part-time calves with unchanged contact. In wk 9, time spent suckling only the dam was lower for full-time calves with reduced contact compared with part-time calves with unchanged contact. In conclusion, although we found a lower nursing and grooming time in part-time cows compared with full-time, we found no difference between treatments with regards to nursing in the inverse parallel position and nursing a calf other than the cow's own. The effect of gradually reducing cow-calf contact on calves' suckling time requires more research.

The first commercially approved efficacious cryptosporidium vaccine protecting New-Born calves from severe diarrhea

Neonatal calf diarrhea (NCD) is an important cause of morbidity and mortality in calves. Four major pathogens, including Enterotoxigenic Escherichia coli (ETEC), bovine rotavirus (BRV), bovine coronavirus (BCV), and Cryptosporidium spp., are associated with NCD, with Cryptosporidium parvum (C. parvum) recognized as a major contributor. Despite various treatment options available, there is no effective vaccine for bovine cryptosporidiosis yet. In this study, recombinantly expressed C. parvum gp40 was evaluated as a candidate vaccine in pregnant animals. The vaccine was administered to pregnant cows during the last trimester of their pregnancy resulting in highly statistically significantly increased anti-gp40 antibody titers. The resulting anti-gp40 antibodies were transmitted to the calves via colostrum. Both suckling (n = 29; test:14, control:15) and non-suckling (n = 16; 8 per group) calves were challenged with live C. parvum oocysts. The calves that received the colostrum from gp40 vaccinated cows showed a highly statistically significant improvement in health (p < 0.0001), reduced incidence (p < 0.0001), and duration of severe diarrhea (p < 0.001) and increased weight gain in suckling calves (p < 0.0001). This study demonstrates that immune bovine colostrum, induced by immunization of late-gestation cows with C. parvum gp40, provided substantial protection to calves against cryptosporidiosis. These findings suggest that the gp40 vaccine has potential for preventing outbreaks of neonatal diarrhea associated with cryptosporidiosis in calves, thereby improving animal welfare and performance.

Safety evaluation of the food enzyme rennet containing chymosin and pepsin A from the abomasum of suckling calves, goats, lambs and buffaloes.

The food enzyme containing chymosin (EC 3.4.23.4) and pepsin (EC 3.4.23.1) is prepared from the abomasum of suckling calves, goats, lambs and buffaloes by Caglificio Clerici S.p.A. It is intended to be used in the production of cheese. As no concerns arise from the source of the food enzyme, from its manufacture and based on the history of safe use and consumption, the Panel considered that toxicological data were not required and no exposure assessment was necessary. The similarity of the amino acid sequences of the two proteins (chymosin and pepsin A) to those of known allergens was searched and two matches were found with respiratory allergens. The Panel considered that the risk of allergic reactions by dietary exposure cannot be excluded, but the likelihood is low. Based on the data provided, the Panel concluded that this food enzyme does not give rise to safety concerns under the intended conditions of use.

Micellized conjugated linoleic acid as an immune modifier feed additive for suckling calves

This study was attempted to assess the effects of micellized conjugated linoleic acid (CLA) as a feed additive for suckling calves on their growth performance and blood metabolic, oxidative and immune parameters. Forty-eight Holstein calves were divided among four experimental groups (12 calves/treatment) including: 1) calves with no CLA supplementation (CON), 2) calves supplemented with 1 gr CLA/d as micellized form by dissolving 5 mL/d of a CLA contained emulsion in milk (CLA1), 3) calves supplemented with 2 gr CLA/d as micellized form by dissolving 10 mL/d of a CLA contained emulsion in milk (CLA2) and 4) calves supplemented with 3 gr CLA/d as micellized form by dissolving 15 mL/d of a CLA contained emulsion in milk (CLA3). Calves in the CON group received 10 mL of the emulsion medium with no CLA. Feeding micellized CLA via whole milk resulted in a linear increase in blood concentration of glucose on d 40 (P=0.04), and total protein (P

Evaluation and Development of a Nutrition Model to Predict Intake and Growth of Suckling Calves

The objective of this study was to evaluate and develop equations to predict forage intake and growth of calves throughout the suckling period of beef calves grazing on forage or dairy calves fed harvested forage. Milk and forage intake and body weight data for individual animals were collected from published theses (one using bottle-fed dairy calves and one using suckling beef calves). A nutrition model was constructed using milk and forage intake equations and growth equations. Additional datasets were compiled from the literature to develop equations to adjust the original nutrition model for forage digestibility, milk composition, and growth. In general, the original nutrition model predicted the forage intake and body weight of dairy calves with moderate-to-high precision (CCC = 0.234 to 0.929) and poor accuracy (MB = −341.16 to −1.58%). Additionally, the original nutrition model predicted forage intake and body weight in beef calves with poor-to-moderate precision (CCC = 0.348 to 0.766) and accuracy (MB = 6.39 to 57.67%). Adjusted nutrition models performed better with the best model precisely (CCC = 0.914) predicting forage intake and precisely (CCC = 0.978) and accurately (MB = 2.83%) predicting body weight in dairy calves. The best adjusted nutrition model predicted forage intake and body weight with high precision (CCC = 0.882 and 0.935) and moderate accuracy (MB = −7.01 and −7.34) in beef calves. Nutrition models were able to adequately predict the forage intake and growth of calves with adjustments made to standard milk energy concentrations and growth equations.

The Effects of the Environmental Pollutions on the Human Food and Public Health

The environmental pollution Polychlorinated dibenzo-p-dioxins, the polychlorinated dibenzofurans PCDD/F and the polychlorinated biphenyls (PCB) contamination in the food from the animal origin were caused by the industrially produced feed from the free range chicken, sheep, and beef. To elucidate the entry of the the environmental pollution polychlorinated biphenyls (PCBs) and the Polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans PCDD/Fs in the food related to the environmental contamination. The food products from the farm animals are sensitive to the environmental pollution dioxin/ polychlorinated biphenyls (PCB) exposure, the suckling calves and the laying hens housed outdoor at the soil concentrations that have previously been considered as safe. In the beef/veal when the soil is contaminated. The eggs/ the broiler, this can occur. The eggs consumer's especially the young children can easily exceed the health-based guidance values, the tolerable daily intake. The soil, the chicken eggs exposure pathway is probably the most sensitive route for the human exposure to both the environmental pollution dioxin-like polychlorinated biphenyls and the PCDD/Fs from the soil and needs to be considered for the soil guidelines. The calves from the suckler cow herds are the most prone to the impacts of the dlPCB contamination due to the excretion/accumulation via the milk. The environmental pollution polychlorinated biphenyls (PCB) (and the PCDD/F) intake for the free-range cattle stems from the feed and the soil. The sources for the PCDD/Fs and polychlorinated biphenyls (PCBs) relevant to the environmental contamination in polychlorinated biphenyls respect to the food safety. It also includes the considerations on the assessment of the emerging persistent organic pollutants. The major sources of the environmental pollution PCDD/F and the dl-PCB contamination of the food of the animal origin are the soils contaminated from the polychlorinated biphenyls (PCB) and the PCDD/F releases; the polychlorinated biphenyls (PCBs) emitted from the buildings and the constructions; the environmental pollution polychlorinated biphenyls (PCBs) present at the farms. The impacted areas need to be assessed with the respect to the potential contamination of the food producing animals. The livestock management techniques can reduce the exposure to the environmental pollution PCDD/Fs and the environmental pollution polychlorinated biphenyls (PCBs). The control and the reduction measures are recommended for the emission sources and the new listed and the emerging persistent organic pollutants to ensure the food safety.

Impacts of the Environmental Pollution Residues in Human Food on the Public Health

The environmental pollution Polychlorinated dibenzo-p-dioxins, the polychlorinated dibenzofurans PCDD/F and the polychlorinated biphenyls (PCB) contamination in the food from the animal origin were caused by the industrially produced feed from the free range chicken, sheep, and beef. To elucidate the entry of the the environmental pollution polychlorinated biphenyls (PCBs) and the Polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans PCDD/Fs in the food related to the environmental contamination. The food products from the farm animals are sensitive to the environmental pollution dioxin/ polychlorinated biphenyls (PCB) exposure, the suckling calves and the laying hens housed outdoor at the soil concentrations that have previously been considered as safe. In the beef/veal when the soil is contaminated. The eggs/ the broiler, this can occur. The eggs consumer's especially the young children can easily exceed the health-based guidance values, the tolerable daily intake. The soil, the chicken eggs exposure pathway is probably the most sensitive route for the human exposure to both the environmental pollution dioxin-like polychlorinated biphenyls and the PCDD/Fs from the soil and needs to be considered for the soil guidelines. The calves from the suckler cow herds are the most prone to the impacts of the dlPCB contamination due to the excretion/accumulation via the milk. The environmental pollution polychlorinated biphenyls (PCB) (and the PCDD/F) intake for the free-range cattle stems from the feed and the soil. The sources for the PCDD/Fs and polychlorinated biphenyls (PCBs) relevant to the environmental contamination in polychlorinated biphenyls respect to the food safety. It also includes the considerations on the assessment of the emerging persistent organic pollutants. The major sources of the environmental pollution PCDD/F and the dl-PCB contamination of the food of the animal origin are the soils contaminated from the polychlorinated biphenyls (PCB) and the PCDD/F releases; the polychlorinated biphenyls (PCBs) emitted from the buildings and the constructions; the environmental pollution polychlorinated biphenyls (PCBs) present at the farms. The impacted areas need to be assessed with the respect to the potential contamination of the food producing animals. The livestock management techniques can reduce the exposure to the environmental pollution PCDD/Fs and the environmental pollution polychlorinated biphenyls (PCBs). The control and the reduction measures are recommended for the emission sources and the new listed and the emerging persistent organic pollutants to ensure the food safety.

Effects of yeast peptides on the growth, antioxidant and anti-inflammatory capacities, immune function, and diarrhea status of suckling calves.

Yeast peptides, which are small-molecule active peptides extracted from yeast proteins, are known for their antibacterial, antioxidant, and anti-inflammatory properties. However, the effects of yeast peptide on suckling calves remain unclear. In this study, the effects of yeast peptide supplementation on the growth, diarrhea incidence, and immune function of calves during the suckling period were determined. Thirty newborn calves were randomly divided into two groups: the control group (CON) and the treatment group (AP), which received fresh pasteurized milk supplemented with yeast peptides (5 g/day). The experiment lasted for 49 days (7-56 days of age). The dry matter intake, body weight, diarrhea status, immune function, antioxidant capacity, and anti-inflammatory activity of the calves were analyzed. The AP group had higher dry matter intake, daily weight gain, and feed efficiency than the CON group (P < 0.05). Moreover, the duration and frequency of diarrhea were significantly lower in the AP group than in the CON group (P < 0.05). Furthermore, the immune, antioxidant, and anti-inflammatory capabilities of the AP group were significantly higher than those of the CON group (P < 0.05). These findings provide valuable insights for the improvement of early health management during calf rearing.

Effects of dam milk yield and milk composition on birth weight and growth performance of Anatolian buffalo calves

This study was conducted to determine the effects of the dam’s milk yield and composition on birth weight, 6-month, and 12-month live weight (LW) of Anatolian buffalo calves born in 2017 and 2018 years in Çorum province, Türkiye. Calving age had a significant impact on daily milk yield (DMY) (P=0.031), lactation milk yield (LMY) (P=0.048) and solids-not-fat (SNF) (P=0.034). DMY (P=0.022) and fat content (P=0.005) were affacted by calving season. Suckling period and calf sex had no significant impact (P&gt;0.05) on DMY, LMY, fat content, and solids-not-fat (SNF) (P&gt;0.05). The dam’s calving age had a significant impact on birth weight (P=0.029), except for 6-month and 12-month live weight (LW). Calving season affected 6-month (P=0.002) and 12-month LW (P=0.012) without birth weight. The suckling period and calf sex were not significantly affected on the birth weight, 6-month, and 12-month LWs (P&gt;0.05). The highest 6-month LW (P=0.025) was determined in the calves of high DMY buffaloes (&gt;6.50 kg). The DMY of the dam had no effect on the birth weight and 12-month LWs (P&gt;0.05). The calves of buffaloes with the highest LMY (&gt;1300 kg) were observed the highest birth weight (P=0.040) and 6-month LW (P=0.046). The dam’s fat and SNF content had no effect on the birth weight, 6-month, and 12-month LWs. To conclude; “higher milk yield resulted in higher birth weight” means that better dams give better calves, suggesting that buffalo keepers should feed buffalo cows sufficiently to get heavier calves at least.

Characteristics of gut microbiota in captive Asian elephants (Elephas maximus) from infant to elderly

Gut microbiota play an important role in the health and disease of Asian elephants, however, its characteristics at each stage of life have not been thoroughly investigated in maintaining and regulating health of elephants. This study, therefore, aimed to characterize the profiles of the gut microbiota of captive Asian elephants from infants to the elderly. Gut microbiota were identified by 16S rRNA sequencing from the feces of captive Asian elephants with varying age groups, including infant calves, suckling calves, weaned calves, subadult and adult elephants, and geriatric elephants. The diversity of the gut microbiota was lowest in infants, stable during adulthood, and slightly decreased in the geriatric period. The gut microbiota of the infant elephants was dominated by milk-fermenting taxa including genus Bifidobacterium of family Bifidobacteriaceae together with genus Akkermansia. The fiber-fermenting taxa such as Lachnospiraceae_NK3A20_group were found to be increased in suckling elephants in differential abundance analysis by Analysis of Compositions of Microbiomes with Bias Correction (ANCOM-BC). The gut microbiota profiles after weaning until the adult period has been uniform as indicated by no significant differences in beta diversity between groups. However, the composition of the gut microbiota was found to change again in geriatric elephants. Understanding of the composition of the gut microbiota of captive Asian elephants at various life stages could be beneficial for promoting good health throughout their lifespan, as well as ensuring the welfare of captive elephants.

Safety evaluation of the food enzyme rennet containing chymosin and pepsin A from the abomasum of suckling calves, goats and lambs.

The food enzyme rennet containing chymosin (EC 3.4.23.4) and pepsin A (EC 3.4.23.1) is prepared from the abomasum of suckling calves, goats and lambs by GENENCOR INTERNATIONAL B.V. The food enzyme is intended to be used in milk processing for cheese production. As no concerns arise from the animal source of the food enzyme or from its manufacture and based on the history of safe use and consumption, the Panel considered that toxicological data and the estimation of dietary exposure were not required. On the basis of literature data, the Panel considered that the risk of allergic reactions by dietary exposure could not be excluded, but the likelihood is low. Based on the data provided, the Panel concluded that this food enzyme does not give rise to safety concerns under the intended conditions of use.

Training and Adaptation of Beef Calves to Precision Supplementation Technology for Individual Supplementation in Grazing Systems.

Supplementation of beef cattle can be used to meet both nutrient requirements and production goals; however, supplementation costs influence farm profitability. Common supplementation delivery strategies are generally designed to provide nutrients to the mean of the group instead of an individual. Precision individual supplementation technologies, such as the Super SmartFeed (SSF, C-Lock Inc., Rapid City, SD, USA), are available but are generally cost prohibitive to producers. These systems require adaptation or training periods for cattle to utilize this technology. The objective of this research was to assess the training and adoption rates of three different groups of cattle (suckling calves, weaned steers, replacement heifers) to the SSF. Successful adaptation was determined if an individual's supplement intake was above the group average of total allotted feed consumed throughout the training period. Suckling calves (n = 31) underwent a 12 d training period on pasture; 45% of suckling calves adapted to the SSF and average daily intake differed (p < 0.0001) by day of training. Weaned steers (n = 79) were trained in drylot for 13 d. Of the weaned steers, 62% were trained to the SSF, and average daily intake differed (p < 0.0001) by day of training. Replacement heifers (n = 63) grazed tall fescue pastures and had access to SSF for 22 d of training. The success rate of replacement heifers was 73%. For replacement heifers, the daily intake did not differ (p < 0.0001) by day of training. Results indicate production stage may influence cattle adaptation to precision technologies.