Calf Age Research Articles

Faecal prevalence and histopathological evaluation of coccidiosis in bovine calves.

Bovine coccidiois, caused by Eimeria spp. is widely prevalent around the globe and responsible for huge economic losses by causing morbidity and mortality among young calves. The present study was designed to evaluate the prevalence as well as to evaluate histopathological alterations associated with it. The faecal samples were collected from 700 bovine calves upto two month of age from August 2019 to July 2021 and screened for Eimeria oocycts. The intestinal tissue samples of 37 calves were also collected which died during the study period after showing symptoms of diarrhea and examined for histological lesions. The faecal prevalence of Eimeria observed in our study was 2.29% (16/700) while in tissue samples only two out of 37 were found positive for Eimeria infection. Tissue sections revealed various stages of Eimeria gametogony, variable congestion, haemorrhage, and necrosis along with cryptic dilatation and mononuclear cell infiltration. Coccidia was not found to be associated with season, age and sex of calf. Bovine coccidiosis was found to be endemic with low prevalence but severe onset characterized by moderate to severe congestion and inflammatory reaction mainly in the ileum and caecum.

Phenotypic evaluation of pre-weaning growth traits of Akaushi- (Wagyu), Angus- and Brahman-sired calves in tropical conditions

The objective was to assess the effect of sire breed on birth weight, average daily gain from birth to weaning, and actual weaning weight of calves. The calves were produced by AI using semen of five Akaushi (Wagyu), six Angus, and six Brahman bulls. Dams of calves were Beefmaster (n = 60) and Brown Swiss x Zebu (n = 21). The three sire breeds were used on both dam genetic types to produce the calves (45 males and 36 females). Each dam genetic type was raised in two ranches; therefore, all calves were born in four ranches, in the same calendar year. Average age at weaning weight m easurement was 186days. The traits were analyzed with the MIXED procedure of SAS. The statistical model included the fixed effects of sire breed, dam genetic type, calf sex, ranch, and birth season within sire breed-ranch; sire within breed of sire was included as a random effect (except for weaning weight; P > 0.05). In addition, the model for weaning weight included calf age at weaning as a covariate. Birth weights and average daily gains of Akaushi-, Angus- and Brahman-sired calves were similar (P > 0.05). In contrast, Angus-sired calves were heavier (P < 0.05) at weaning than Akaushi- and Brahman-sired calves. Calves out of Brown Swiss x Zebu dams had higher (P < 0.05) pre-weaning average daily gains than calves out of Beefmaster dams. Angus-sired calves performed better at weaning.

A multistate modeling approach to investigate long-term effects of claw horn disruption lesions and early lesion development in dairy cows

Claw horn disruption lesions (CHDL) are a leading cause of lameness in dairy cattle, and the development, effect, and pathology of these lesions remains an open area of interest within dairy cattle health. Current literature typically attempts to measure the effect of risk factors on the development of CHDL over a relatively short time period. Further understanding of the interaction of CHDL and the long-term effect of early CHDL in a cow's life remains an important area of research which is so far mostly unexplored. In this study 57,974 cows from 1,332 herds were selected and their regular claw trimming records containing important claw health information were used to model the long-term effect of lesions in a cow's lifetime in a 6-state multistate model. A multistate model predicts the time before transition from any one state to another and the probability of transition to a future state. The 6 lesion states that were modeled were as follows: never had a lesion, first recorded lesion event, no recorded lesion after first lesion event, second or subsequent recorded lesion event, no recorded lesion after second or subsequent lesion event, and culled. The effect of various cow level covariates on the transition probabilities between various states was tested. For the first time, this study shows the importance and effect of the first lesion and other cow level factors on long-term claw health. Model results showed that the timing and severity of the first recorded lesion event significantly influenced the likelihood of a future lesion being present. Cows with CHDL present within the 180 d of first calving had a short-term increased risk and long-term decreased risk of a future lesion, compared with cows that present with CHDL later than 180 d of first lactation. Moreover, presence of a severe first lesion increased a cow's risk of a future lesion being present. The model was used to evaluate the relative difference between high-risk cows (age of first calving ≥793 d, breeding values in the lowest quartile) and low-risk cows (age of first calving ≤718 d, breeding values in the highest quartile). Our results indicated that these low-risk cows present with a lesion on an average 3 mo later than high-risk cows. Furthermore, results from the model evaluation of a simulated herd with cows with breeding values in the higher quartile indicated that cows present with a CHDL on an average 7.5 mo later compared with a herd where cows have breeding values distributed in a lower quartile.

First report of Cryptosporidium andersoni and risk factors associated with the occurrence of Cryptosporidium spp. in pre-weaned native Korean calves with diarrhea.

Cryptosporidium spp. are important enteric protozoan parasites that infect humans and other animals throughout the world. Cryptosporidium infection in cattle industry leads to substantial economic losses due to diarrhea, growth retardation, weight loss, and possibly death. Most studies have focused on C. parvum, and studies on other Cryptosporidium spp. and calf diarrhea are limited. Therefore, this study aimed to investigate the occurrence of Cryptosporidium spp. in pre-weaned calves, to determine the risk factors for Cryptosporidium spp. infection such as age and season, and to identify subtypes of C. parvum circulating in the Republic of Korea (ROK). A total of 510 fecal samples were collected from calves with diarrhea and divided by age and season. Cryptosporidium spp. were first screened using PCR targeting the small subunit (SSU) rRNA gene and further the 60-kDa glycoprotein gene for subtyping of C. parvum. Out of 510 fecal samples, 71 (13.9%) were positive for Cryptosporidium spp. in pre-weaned calves with diarrhea. C. andersoni (2.8%), C. bovis (30.9%), C. parvum (29.6%), and C. ryanae (36.6%) were identified. C. ryanae was the most predominant in calves in the ROK. Calf age was a significant risk factor for C. bovis (χ2 = 13.83, P = 0.001), C. parvum (χ2 = 7.57, P = 0.023), and C. ryanae (χ2 = 20.18, P = 0.000) occurrence. Additionally, C. parvum was detected 3.1-fold more frequently in pre-weaned calves with diarrhea in fall (95% CI: 1.23-7.81; P = 0.016) than in spring, whereas C. ryanae was 8.9-fold more frequently detected in summer (95% CI: 1.65-48.68; P = 0.011) than in spring. Three subtypes (IIaA17G4R1, IIaA18G3R1, and IIaA20G3R1) of C. parvum were identified. Of them, IIaA17G4R1 was the most common, whereas IIaA20G3R1 was not previously detected in calves in the ROK. To our knowledge, this is the first report of C. andersoni in pre-weaned calves in the ROK. The occurrence of Cryptosporidium spp. appears to be age-dependent in calves. Season had a significant effect on the occurrence of C. parvum and C. ryanae. Taken together, C. bovis and C. ryanae along with C. parvum are detected in pre-weaned calves with diarrhea and these two pathogens should not be overlooked in the diagnosis of calf diarrhea.

The role of anti-E. coli antibody from maternal colostrum on the colonization of newborn dairy calves gut with Escherichia coli and the development of clinical diarrhea

Escherichia coli (E. coli) is an early organism in the colonization of mucosal tissue and has an influence on the development of mucosal and systemic inflammatory responses. To understand the impact of transfer of Immunoglobulin G (IgG), E. coli-specific antibody and general immune factors to the calf on the gut microbiota, an observational study that followed the temporal colonization of the intestine with E. coli as correlated with the total quantity of IgG and the antibody recognizing E. coli, was conducted in newborn Holstein calves. The calves were subjected to the “gold standard” of colostrum management, including dam vaccination prior to delivery to prime colostrum. Twenty Holstein dams, producing an adequate quantity of good-quality colostrum following uncomplicated deliveries of healthy female offspring, were utilized in this study. Each calf was monitored and scored daily for diarrhea. Blood and fecal samples were collected from calves on day (D) D1 (before colostrum intake), then D3, D7, D14 and D28 after colostrum feeding. E. coli isolated from fecal samples of the calves were assessed for virulence genes and the quantity per gram of feces using conventional Polymerase chain reaction and Real-time polymerase chain reaction quantitative, respectively. The total quantity of plasma IgG and the titer of E. coli-binding antibody were measured by enzyme-linked immunosorbent assay. The peak in diarrhea in the calves was observed on D12. No IgG or E. coli-binding antibody were detected prior to colostrum intake (D1). Both total IgG and binding antibody sharply increased by D3. Total and binding IgG declined with calf age. The total number of bacteria (16S rRNA) in feces was similar between D1 and D14. The number of total bacteria increased over the period from D14 to D28. The number of E. coli was minimal on D1. The number of E. coli increased during the period D3-D7. A decrease in the number of E. coli per gram of feces declines between D14and D28. The stable toxin gene was frequently identified in the E. coli isolated from the calves. Further, E. coli K99 was not identified in this study. While the gut was colonized by E. coli early in life corresponding to the peak level of IgG and specific antibody, a decreasing number of E. coli were observed as the passive immunity waned. This suggests that the function of the passive antibody may be to control colonization and seed innate immune function that then stabilizes the level of E. coli in the digestive tract of calves.

Effects of feeding Saccharomyces cerevisiae fermentation postbiotic on the fecal microbial community of Holstein dairy calves

BackgroundThe livestock industry is striving to identify antibiotic alternatives to reduce the need to use antibiotics. Postbiotics, such as Saccharomyces cerevisiae fermentation product (SCFP), have been studied and proposed as potential non-antibiotic growth promoters due to their effects on animal growth and the rumen microbiome; however, little is known of their effects on the hind-gut microbiome during the early life of calves. The objective of this study was to measure the effect of in-feed SCFP on the fecal microbiome of Holstein bull calves through 4 months of age. Calves (n = 60) were separated into two treatments: CON (no SCFP added) or SCFP (SmartCare®, Diamond V, Cedar Rapids, IA, in milk replacer and NutriTek®, Diamond V, Cedar Rapids, IA, incorporated into feed), and were blocked by body weight and serum total protein. Fecal samples were collected on d 0, 28, 56, 84, and 112 of the study to characterize the fecal microbiome community. Data were analyzed as a completely randomized block design with repeated measures when applicable. A random-forest regression method was implemented to more fully understand community succession in the calf fecal microbiome of the two treatment groups.ResultsRichness and evenness of the fecal microbiota increased over time (P < 0.001), and SCFP calves tended to increase the evenness of the community (P = 0.06). Based on random-forest regression, calf age as predicted by microbiome composition was significantly correlated with the calf physiological age (R2 = 0.927, P < 1 × 10−15). Twenty-two “age-discriminatory” ASVs (amplicon sequence variants) were identified in the fecal microbiome that were shared between the two treatment groups. Of these, 6 ASVs (Dorea-ASV308, Lachnospiraceae-ASV288, Oscillospira-ASV311, Roseburia-ASV228, Ruminococcaceae-ASV89 and Ruminoccocaceae-ASV13) in the SCFP group reached their highest abundance in the third month, but they reached their highest abundance in the fourth month in the CON group. All other shared ASVs reached their highest abundance at the same timepoint in both treatment groups.ConclusionsSupplementation of SCFP altered the abundance dynamics of age discriminatory ASVs, suggesting a faster maturation of some members of the fecal microbiota in SCFP calves compared to CON calves. These results demonstrate the value of analyzing microbial community succession as a continuous variable to identify the effects of a dietary treatment.

A randomized controlled trial investigating the effect of transport duration and age at transport on surplus dairy calves: Part II. Impact on hematological variables

Surplus dairy calves often arrive at veal and dairy-beef rearing facilities with health and blood metabolite level abnormalities, which can affect their welfare and performance, predisposing them to future health challenges. The objective of this randomized controlled trial was to investigate the effects of transport duration and age at the time of transport on blood parameters in surplus dairy calves following 6, 12, or 16 h of continuous road transportation. All surplus calves from 5 commercial dairy farms in Ontario were enrolled and examined daily before transport (n = 175). On the day of transportation, calves were weighed, blood sampled, and randomly assigned to 6, 12, or 16 h of transportation. Blood samples were then collected immediately after transportation, as well as 24, 48, and 72 h thereafter. Serum was analyzed at a provincial diagnostic laboratory for nonesterified fatty acids (NEFA), β-hydroxybutyric acid (BHBA), creatine kinase (CK), cholesterol, and haptoglobin. In addition, blood gas and electrolyte values were also assessed at the time of sample collection. Mixed models with repeated measures were used to assess the effects of transport duration, breed, sex, transfer of passive immunity status, weight before transportation, and age at transportation on blood parameters. Immediately following transportation, NEFA and BHBA were greater for calves transported for 12 h (Δ = 0.22 mmol/L NEFA, 95% CI = 0.15 to 0.30; Δ = 0.04 mmol/L BHBA, 95% CI = 0.02 to 0.06) and 16 h (Δ = 0.35 mmol/L NEFA, 95% CI = 0.27 to 0.42; Δ = 0.10 mmol/L BHBA, 95% CI = 0.08 to 0.11) compared with calves transported for 6 h. Glucose was lower immediately following transportation in calves transported for 16 h compared with 6 h (Δ = -15.54 mg/dL, 95% CI = -21.54 to -9.54). In addition, pH and HCO3- were lower in calves transported for 12 (Δ = -0.09 pH, 95% CI = -0.13 to -0.05; Δ = -1.59 mmol/L HCO3-, 95% CI = -2.61 to -0.56) and 16 h (Δ = -0.07 pH, 95% CI = -0.12 to -0.03; Δ = -1.95 mmol/L HCO3-, 95% CI = -2.95 to -0.95) compared with calves transported for 6 h. Calves transported between 15 and 19 d of age had a higher concentration of cholesterol and CK (Δ = 0.27 mmol/L cholesterol; 37.18 U/L CK) compared with 2- to 6-d-old calves, and calves 12 to 14 d old had greater reduction in HCO3- (Δ = -0.92 mmol/L) compared with 2- to 6-d-old calves. These findings show that transporting calves for long distances results in lower glucose concentration and suboptimal energy status, and that this effect varies based on the calf's age.

Host metabolome and faecal microbiome shows potential interactions impacted by age and weaning times in calves

BackgroundCalves undergo nutritional, metabolic, and behavioural changes from birth to the entire weaning period. An appropriate selection of weaning age is essential to reduce the negative effects caused by weaning-related dietary transitions. This study monitored the faecal microbiome and plasma metabolome of 59 female Holstein calves during different developmental stages and weaning times (early vs. late) and identified the potential associations of the measured parameters over an experimental period of 140 days.ResultsA progressive development of the microbiome and metabolome was observed with significant differences according to the weaning groups (weaned at 7 or 17 weeks of age). Faecal samples of young calves were dominated by bifidobacterial and lactobacilli species, while their respective plasma samples showed high concentrations of amino acids (AAs) and biogenic amines (BAs). However, as the calves matured, the abundances of potential fiber-degrading bacteria and the plasma concentrations of sphingomyelins (SMs), few BAs and acylcarnitines (ACs) were increased. Early-weaning at 7 weeks significantly restructured the microbiome towards potential fiber-degrading bacteria and decreased plasma concentrations of most of the AAs and SMs, few BAs and ACs compared to the late-weaning event. Strong associations between faecal microbes, plasma metabolites and calf growth parameters were observed during days 42–98, where the abundances of Bacteroides, Parabacteroides, and Blautia were positively correlated with the plasma concentrations of AAs, BAs and SMs as well as the live weight gain or average daily gain in calves.ConclusionThe present study reported that weaning at 17 weeks of age was beneficial due to higher growth rate of late-weaned calves during days 42–98 and a quick adaptability of microbiota to weaning-related dietary changes during day 112, suggesting an age-dependent maturation of the gastrointestinal tract. However, the respective plasma samples of late-weaned calves contained several metabolites with differential concentrations to the early-weaned group, suggesting a less abrupt but more-persistent effect of dietary changes on host metabolome compared to the microbiome.

Familiarity, age, weaning and health status impact social proximity networks in dairy calves

Social network analysis in dairy calves has not been widely studied, with previous studies limited by the short study duration, and low number of animals and replicates. In this study, we investigated social proximity interactions of 79 Holstein–Friesian calves from 5 cohorts for up to 76 days. Networks were computed using 4-day aggregated associations obtained from ultrawideband location sensor technology, at 1 Hz sampling rate. The effect of age, familiarity, health, and weaning status on the social proximity networks of dairy calves was assessed. Networks were poorly correlated (non-stable) between the different 4-day periods, in the majority of them calves associated heterogeneously, and individuals assorted based on previous familiarity for the whole duration of the study. Age significantly increased association strength, social time and eigenvector centrality and significantly decreased closeness and coefficient of variation in association (CV). Sick calves had a significantly lower strength, social time, centrality and CV, and significantly higher closeness compared to the healthy calves. During and after weaning, calves had significantly lower closeness and CV, and significantly higher association strength, social time, and eigenvector centrality. These results indicate that age, familiarity, weaning, and sickness have a significant impact on the variation of social proximity interaction of calves.

Anticandidal Effects of Zinc Oxide Nanoparticles on Fluconazole-Resistant Candida Isolates Causing Diarrhea in Calves, in vitro.

Gastrointestinal disease in calves may pose a significant threat to the livestock industry. Due to the increased rate of resistance to antifungal drugs and the side effects of these drugs, it is essential to find suitable alternatives, such as nanoparticles, with favorable antifungal effects and few side effects. This study aimed to determine the frequency of yeast causing diarrhea in calves and evaluate zinc oxide nanoparticles' antifungal effects on fluconazole-resistant isolates. Fecal samples from 94 calves (age < three months old) with clinical signs of diarrhea were examined by standard microbiological and biochemical methods. The broth microdilution method evaluated the susceptibility of fungi to fluconazole and the antimicrobial activity of zinc oxide nanoparticles on drug-resistant isolates. Candida albicans (41.63%) were calves' predominant cause of diarrhea. In addition, 51.2% of the C. albicans isolates were resistant to fluconazole. All fluconazole-resistant isolates were eliminated when treated with 119 μg/ml of zinc oxide nanoparticles. The prevalence of diarrhea is relatively high in calves. Considering the predominance of drug-resistant Candida and the favorable in vitro effects of zinc oxide nanoparticles against these isolates, it is recommended to investigate the effects of zinc oxide nanoparticles on these isolates in vivo.

Determination of Direct and Indirect Effects on Milk Yield of Anatolian Buffaloes Using Path Analysis

This study aimed to determine the direct and indirect effects of the independent variables presented by the lactation lenght (LL), age of calving (CAGE), and daily milk yield (DMY) on the dependent variable of lactation milk yield (LMY) in Anatolian buffaloes. In this study, a total of 3761 LMY records of the 834 Anatolian buffaloes calving between 2012 and 2017 in Tokat province and around were used as the research material. In the study, the simple correlation coefficients between the dependent variable of LMY and independent variables were determined positive and significant (P&lt;0.001). The research specified the direct determination coefficients of the independent variables of the LL, CAGE, and DMY on the dependent variable of LMY as 0.378, 0.004, and 0.350, respectively. The path coefficients related to LL, CAGE, and DMY were determined as 0.615, 0.021, and 0.592, respectively. Since the DMY and LL examined in the study had a high direct impact on the lactation milk yield, therefore it could be suggested that using these data as criteria in breeding programs conducted in the herds evaluated in the study will increase the success in the selections applied.

Study of effect of various genetic and non-genetic factors on milk yield in Frieswal cattle

The present study was carried out on data of 3,425 Frieswal cattle (Holstein Friesian × Sahiwal cattle) maintained at Military Farm, Pimpri, Pune, Maharashtra. Total 9,094 lactation records were collected from 3,425 cows born to 239 sires. The data were analyzed using SAS software. The collected data were normalized and utilized for studying effect of genetic and non-genetic factors on milk yield. The PROC GLM procedures of SAS were used to quantify the effect of non-genetic factors on milk yield. The non-genetic factors considered for the present study were period of calving, season of calving and parity whereas, the covariate considered was age at first calving (AFC). The estimated overall least squares mean of lactation milk yield was observed as 3188.65±10.93 kg in Frieswal cattle. The effect of period of calving, and parity was highly significant on lactation milk yield while the season of calving had significantly affected the milk yield. The age of first calving as a covariate had highly significant effect on milk yield. Amongst the genetic factors, the effect of sire was considered and found to be highly significant on lactation milk yield.

Multilocus genotyping of Giardia duodenalis in pre-weaned calves with diarrhea in the Republic of Korea.

Giardia duodenalis is a protozoan parasite that infects humans, companion animals, livestock, and wildlife. Infections in cattle caused by this parasite are often asymptomatic, but such infections can cause diarrhea, reduced weight gain, and ill-thrift in young calves. Although G. duodenalis causes diarrhea in calves, only a few studies have been conducted on calves in the Republic of Korea (ROK). Here, we aimed to determine the prevalence and distribution of G. duodenalis assemblages in pre-weaned calves with diarrhea in the ROK, identify the association between the occurrence of G. duodenalis and the age of calf, and perform molecular characterization of G. duodenalis. We collected 455 fecal samples from pre-weaned native Korean calves (≤60 days old) with diarrhea in four different regions. G. duodenalis was detected using nested PCR targeting the beta-giardin (bg) gene, and positive samples were further genotyped for the glutamate dehydrogenase (gdh) and triosephosphate isomerase (tpi) genes. The overall prevalence of G. duodenalis in calves with diarrhea was 4.4% (20/455) based on the analysis of bg. The highest prevalence was observed in calves aged 11-30 days (7.5%; 95% confidence interval: 3.7%-11.3%), whereas the lowest prevalence was observed in neonatal calves. From the 20 samples that were positive for bg, 16, 5, and 6 sequences were obtained following genotyping of bg, gdh, and tpi, respectively. Sequencing analysis of the bg gene revealed the presence of assemblage E (n = 15) and sub-assemblage AⅠ (n = 1) in the samples. Moreover, we detected mixed infections with assemblages E and A in two calves for the first time. Among the sequences obtained herein, two new subtypes of assemblage E were detected in gdh and tpi sequences each. The results suggest that G. duodenalis is an infectious agent causing diarrhea in calves, and pre-weaned calves are at a higher risk of infection than neonatal calves. Multilocus genotyping should be performed to confirm the presence of potentially zoonotic genotypes. These results highlight the importance of cattle as a source of zoonotic transmission of G. duodenalis to humans.

Effects of alkaline mineral complex supplementation on production performance, serum variables, and liver transcriptome in calves.

Calf diarrhea causes huge economic losses to livestock due to its high incidence and mortality rates. Alkaline mineral complex water is an alkaline solution containing silicon, sodium, potassium, zinc, and germanium, and has biological benefits and therapeutic effects. This study aimed to evaluate the impact of alkaline mineral complex water supplementation on the health of calves and to investigate the effect of Alkaline mineral complex water supplementation on neonatal calf serum variables and the liver transcriptome. Sixty Holstein calves (age 1.88 ± 0.85 days, weight 36.63 ± 3.34 kg) were selected and randomly divided into two groups: the T group (treatment group with alkaline mineral complex water supplemented during the experiment) and C group (control group without alkaline mineral complex water supplementation). Alkaline mineral complex water supplementation significantly increased the body weight for calves aged 60 d and average daily gain during the experimental period (1-60 d). In addition, Alkaline mineral complex water supplementation could significantly decrease the diarrhea rate for calves aged 16-30 d, enhance the T-AOC, IgG, IGF-1, and IGFBP-2 in concentrations. The results of KEGG enrichment analysis in transcriptomics indicate that Alkaline mineral complex water supplementation inhibited the target IL-1B gene of the NF-kappa B signaling pathway of liver. Alkaline mineral complex water supplementation decreased calf diarrhea and improved partial immune function, anti-inflammatory activity, antioxidant capacity, and health of calves. Alkaline mineral complex is a candidate to replace medicated feed additives. Alkaline mineral complex waterAlkaline mineral complex waterAlkaline mineral complex waterAlkaline mineral complex waterAlkaline mineral complex waterAlkaline mineral complex waterAlkaline mineral complex water.

The development of sleep-like posture expression with age in female Holstein calves.

Sleep plays an important role in cattle production and welfare. Therefore, this study aimed to investigate the development of sleep-like posture (SLP) expression in dairy calves from birth to the first calving as an indicator of their sleep behavior. Fifteen female Holstein calves were subjected. Daily SLP was measured eight times (0.5, 1, 2, 4, 8, 12, and 18 months and 23 months or 1month before the first calving) using an accelerometer. Calves were kept in individual pens until weaning at 2.5months old and then kept in the group. The daily SLP time decreased rapidly in early life; however, the rate of decrease gradually slowed and eventually reached a stable level of approximately 60 min/day after 12 months old. The daily SLP bout frequency showed the same change as the SLP time. In contrast, the averaged SLP bout duration slowly decreased with age. Longer daily SLP time during early life in female Holstein calves might be related to brain development. The individual expression of daily SLP time differs before and after weaning. Some external and/or internal factors associated with weaning may be involved SLP expression.

Live Weight and Linear Skeletal Growth from Birth to 14 Months of Age in Holstein Friesian Female Calves

Live Weight and Linear Skeletal Growth from Birth to 14 Months of Age in Holstein Friesian Female Calves

The formaldehyde treated guar meal and prill fat, agro industrial by-products as dietary rumen protected protein and energy source: improves growth performance, feed conversion, nutrient utilization, microbial protein synthesis, blood metabolites and economic efficiency in growing dairy buffalo (Bubalus bubalis) calves.

The study investigated the effects of protein replacement with formaldehyde-treated guar meal (FTGM) and prill fat (PF) in the diet on performance of growing dairy buffalo calves. Thirty-two feedlots Surti breed dairy buffalo calves (age, 7.31 ± 0.34months and body weight, 90.69 ± 6.19kg) were assigned into four dietary treatments (n-8 calves/each): (1) control group, supplied basal diet as per ICAR (2013) nutrient requirements; (2) FTGM group, 30% crude protein (CP) requirement of concentrate mixture (dry matter basis (DMB)) replaced with FTGM in basal diet; (3) PF group, supplied basal diet + 100g PF; and (4) FTGM + PF group, 30% CP requirement of concentrate mixture (DMB) replaced with FTGM in the basal diet + 100g PF for 280days. All the treatment diets were isonitrogenous. Growth performance was improved in FTGM + PF and FTGM groups. Apparent digestibility (%) of CP was increased in FTGM and FTGM + PF diet, while digestibility (%) of ether extract (EE) was increased in PF group. Serum total protein, albumen, urea nitrogen, and creatinine concentrations were higher in FTGM + PF and FTGM groups, whereas total cholesterol and triglycerides levels were greater in FTGM + PF and PF groups. Calculated methane emission had a discernible influence of treatment in FTGM and FTGM + PF. The overall cost of feeding per kilogram gain was lowest in FTGM and FTGM + PF groups. In conclusion, 30% CP replacement with FTGM with or without PF improved the growth performance, feed conversion ratio, and nutrient utilization; supported efficient utilization of resources; and economized the rearing of growing dairy buffalo calves.

Husbandry practice, health, productive and reproductive status of lulu cattle in Mustang, Nepal

Lulu is the only indigenous cattle of taurine (Bos taurus) breed that is reared in northern part of central to western Nepal. There have been no recent studies on husbandry practice, health status, productive and reproductive performance of Lulu cattle in Nepal. Therefore, this study was conducted to know the husbandry practice, health, productive and reproductive status of Lulu cattle in Mustang district. Household survey was conducted in Lulu cattle rearing households (n=183) in Mustang; fecal sample of Lulu cow was collected from each household and examined for endoparasitic infection. Body condition score (BCS), hair coat, anemic and milk production status were recorded only from lactating cows (n=242). All of the respondents kept their cows in loose housing system. Among them, 90.2% grazed their cattle, 21.3% provided some cultivated pastures, 3.3% supplemented commercial feed and none of the farmers fed mineral supplementation to their cattle. All the milk produced was used only for home consumption. Only 22% of respondents dewormed their cattle regularly and 29% never dewormed; only 12% vaccinated against foot and mouth disease (FMD) every year and 25% never vaccinated. Cattle of 79.8% households had endoparasitic infection. Among 242 lactating cows, 13.2% cows had poor BCS (&lt;2.75), 95.5% had rough hair coat and 20.4% had anemic (pale) eye mucous membrane. Total 8.3% cows had the history of abortion. Mean (±SD) peak milk yield and lactation length were 2.01±0.30 liter/day and 9.84±0.86 months, respectively. Most of the cows calved in summer (72%) followed by autumn (12%), spring (11%) and winter (5%). Mean (±SD) age of first calving, calving to conception interval, inter-calving interval, dry period and the number of services per conception were 36.0±0.48 months, 3.99±0.68 months, 12.97±1.34 months, 2.71±0.45 months, and 1.47±0.77, respectively. In conclusion, Lulu cattle has the potentiality to increase its productive and reproductive performance through improved health and husbandry practices.

Estimating reproductive and juvenile survival rates when offspring ages are uncertain: A novel multievent mark‐resight model with beluga whale case study

Abstract Understanding the survival and reproductive rates of a population is critical to determining its long‐term dynamics and viability. Mark‐resight models are often used to estimate these demographic rates, but estimation of survival and reproductive rates is challenging, especially for wide‐ranging, patchily distributed, or cryptic species. In particular, existing mark‐resight models cannot accommodate data from populations in which offspring remain with parents for multiple years, are not always detected, and cannot be aged with certainty. Here we describe a Bayesian multievent mark‐resight modelling framework that uses all available adult and adult‐offspring sightings (including sightings with older offspring of uncertain age) to estimate reproductive rates and survival rates of adults and juveniles. We extend existing multievent mark‐resight models that typically only incorporate adult breeding state uncertainty by additionally accounting for age uncertainty in unmarked offspring and uncertainty in the duration of the mother‐offspring association. We describe our model in general terms and with a simple illustrative example, then apply it in a more complex empirical setting using 13 years of photo‐ID data from a critically endangered population of beluga whales Delphinapterus leucas. We evaluated model performance using simulated data under a range of sample sizes, and adult and offspring detection rates. Applying our model to the beluga data yielded precise estimates for all demographic rates of interest (despite substantial uncertainty in calf ages), including nonbreeder survival and reproductive rates lower than in other beluga populations. Simulations suggested our model yields asymptotically unbiased parameter estimates with good precision and low bias even with moderate sample sizes and detection rates. This work represents an important new development in multievent mark‐resight modelling, allowing estimation of reproductive and juvenile survival rates for populations with extended adult—offspring associations and uncertain offspring ages (e.g. some marine mammals, elephants, bears, great apes, bats and birds). Our model facilitated estimation of robust demographic rates for an endangered beluga population that were previously inestimable (e.g. nonbreeder and juvenile survival, reproductive rate) and that will yield new insights into this population's continued decline.

Feeding behaviors collected from automated milk feeders were associated with disease in group-housed dairy calves in the Upper Midwest United States

Automated milk feeders (AMF) are an attractive option for producers interested in adopting practices that offer greater behavioral freedom for calves and can potentially improve labor management. These feeders give farmers the opportunity to have a more flexible labor schedule and more efficiently feed group-housed calves. However, housing calves in group systems can pose challenges for monitoring calf health on an individual basis, potentially leading to increased morbidity and mortality. Feeding behavior recorded by AMF software could potentially be used as an indicator of disease. Therefore, the objective of this observational study was to investigate the association between feeding behaviors and disease in preweaning group-housed dairy calves fed with AMF. The study was conducted at a dairy farm located in the Upper Midwest United States and included a final data set of 599 Holstein heifer calves. The farm was visited on a weekly basis from May 2018, to May 2019, when calves were visually health scored and AMF data were collected. Calf health scores included calf attitude, ear position, ocular discharge, nasal discharge, hide dirtiness, cough score, and rectal temperatures. Generalized additive mixed models (GAMM) were used to identify associations between feeding behavior and disease. The final quasibinomial GAMM included the fixed (main and interactions) effects of feeding behavior at calf visit-level including milk intake (mL/d), drinking speed (mL/min), visit duration (min), rewarded (with milk being offered) and unrewarded (without milk) visits (number per day), and interval between visits (min), as well as the random effects of calf age in regard to their relationship with calf health status. Total milk intake (mL/d), drinking speed (mL/min), interval between visits (min) to the AMF, calf age (d), and rewarded visits were significantly associated with dairy calf health status. These results indicate that as total milk intake and drinking speed increased, the risk of calves being sick decreased. In contrast, as the interval between visits and age increased, the risk of calves being sick also increased. This study suggests that AMF data may be a useful screening tool for detecting disease in dairy calves. In addition, GAMM were shown to be a simple and flexible approach to modeling calf health status, as they can cope with non-normal data distribution of the response variable, capture nonlinear relationships between explanatory and response variables and accommodate random effects.