Breed Calves Research Articles

TRICHUROSIS EN TERNEROS EN EL DEPARTAMENTO LAS COLONIAS, SANTA FE

Trichuris spp. It is a nematode that affects the mucosa of the cecum and the colon of the ruminates. Clinical cases are rare and occur when the number of adult worms is high. The objective of this work is to report a clinical case of trichurosis in a batch of 40 breeding calves raised in a pen without vegetation cover and with a very humid floor. The food was supplied in feeders, but the animals also consumed the food that fell to the floor. Three animals died from the batch. At necropsy, more than 400 specimens of worms identified as Trichuris were recovered. This case warns of the importance of the diagnosis of parasitosis in intensive breeding.

Pathotyping and antimicrobial susceptibility testing of Escherichia coli isolates from neonatal calves.

Neonatal calf mortality is a major concern to livestock sector worldwide. Neonatal calf diarrhoea (NCD), an acute severe condition causes morbidity and mortality in calves. Amongst various pathogens involved in NCD, E. coli is considered as one of the major causes. The study was targeted to characterize E. coli isolates from neonatal calves for diarrhoeagenic Escherichia coli (DEC) types (pathotyping), antimicrobial resistance (AMR) profiling and to correlate with epidemiological parameters. From neonates, a total of 113 faecal samples were collected, out of that 308, lactose fermenting colonies were confirmed as E. coli. Pathotypable isolates (12.3%) were represented by STEC (6.1%), EPEC (2.9%), ETEC (1.9%), EAEC (0.9%) and EHEC (0.3%). Occurrence of STEC was more in non-diarrhoeic calves, whereas ETEC was observed more in diarrhoeic calves. EPEC occurrence was observed in both diarrhoeic and non-diarrhoeic calves. Fishers extract test showed no significant association for occurrence of DEC types to type of dairies, health status, species, breed, age and sex of neonatal calves. Two hundred and eighty isolates were tested for antimicrobial susceptibility. The isolates showed maximum resistance towards ampicillin (55.4%) followed by tetracycline (54.3%), while minimum resistance was observed towards meropenem (2.5%). Multidrug resistant E. coli isolates were found to be 139 (49.6%), and Extended-spectrum beta-lactamase (ESBL) producers were 120 (42.9%). DEC pathotypes like STEC, ETEC, EHEC and EAEC that are also multidrug resistant present in neonatal calves have zoonotic potential and hence are of public health significance.Supplementary InformationThe online version contains supplementary material available at 10.1007/s11259-021-09857-5.

Prevalence of Calf Mortality in Ethiopia: A Systematic Review and Meta-Analysis.

Background Calf mortality has been a major cause of economic losses in the dairy industry in Ethiopia. The condition results in a significant drop in the number of replacing heifers and bulls for sustainable dairy business. Reports on calf mortality with a wide range of prevalence are rising in the country; however, a pooled prevalence of this condition has not been established. Thus, this systematic review and meta-analysis aimed to quantitatively estimate the pooled prevalence of calf mortality in Ethiopia. Methods Meta-analysis was carried out to obtain the pooled prevalence of calf mortality in Ethiopia. A comprehensive literature search was carried out on PubMed, African Journals Online, CAB, Web of Science Direct, and Google Scholar. Eligible studies were selected based on predefined inclusion and exclusion criteria. Moderators such as the study area, breed of calf, study design, agroecology, and year of study article published were used as a milestone of data extraction. The random-effect model was used to estimate pooled prevalence. Publication bias and the variation in prevalence estimates attributed to heterogeneity were also assessed. Results Twenty-five original research papers on the prevalence of calf mortality in various parts of Ethiopia were included. The reported prevalence of calf mortality was between 0.9% and 37%. The pooled prevalence of calf mortality in the country was 14.79%, and the pooled calf mortality estimate across studies for the entire period regarding 1991 to 2000, 2001 to 2010, 2011 to 2016, and 2017 to 2020 was 26.54%, 17.03%, 14.21%, and 11.23%, respectively. Analysis of study subgroups and location revealed significant variations in prevalence. High heterogeneity was observed in the pooled estimates and even after the subgroup meta-analysis. The funnel plots and Egger's regression asymmetry coefficient (b = −1.0434) (95% CI = −1.49, −0.59; p value of 0.012) did suggest the presence of publication bias. There was also an indication of missing studies that could be incorporated by Duval and Tweedie's trim and fill method where they might fall on a funnel plot and visualize them in an attempt to increase the plot's symmetry. Analyses also suggest that calf breed, sample size, and study location are likely to be moderators of calf mortality prevalence in Ethiopia. Conclusion This finding shows that calf mortality is widespread and could result in considerable economic losses for the dairy industry in Ethiopia. Inevitably, a significant reduction in calf mortality prevalence has been observed in recent years since 2010, but the reduction has not yet reached an economically tolerable level. Calf breed susceptibility contributed to the high prevalence. Therefore, interventions for increasing calf health and performance should be focused on minimizing calf mortality on farm and animal levels.

The Effect of Melatonin Supplementation on Dam Milking Traits and Calf Performance in Beef Cattle

Abstract Melatonin has been documented to alleviate compromised pregnancies and enhance livestock performance traits. The objective of this study was to determine the effect of melatonin supplementation on milking traits in beef cattle dams and subsequent influence on calf performance. Cows (n = 60) were blocked based on embryo transfer donor and sire, potential calf breed and embryo grade. At d190, 220 and 250 of gestation, dams were administered either 2 subdermal ear melatonin implants (preMEL) or no implants (preCON). After parturition, birth weights were recorded and calves randomly received either melatonin implants (posMEL) or none (posCON) on approximately d 0, 30, and 60. At approximately d 60 of lactation, a subset of dams (n = 32) were selected based on age, weight and calf sex for milk collection and analysis. At weaning, calf weight and morphometric data were collected and adjusted according to weaning age. Prenatal melatonin administration did not change calf birth weight (P = 0.956). Milk yield tended to decrease in the preMEL group (P = 0.054) at 2.368 kg ± 0.11 compared to preCON at 2.054 kg ± 0.11. Milk fat percent tended to decrease (P = 0.07) in preMEL at 3.25 ± 0.19 versus preCON at 3.92 ± 0.19. There were no differences in prenatal treatment in respect to milk protein, lactose, solid non-fats, somatic cell count, and urea nitrogen (P > 0.16). At weaning, calf head circumference decreased (P < 0.031) in the preMEL group at 77.92cm ± 0.42 versus preCON at 79.31cm ± 0.45. Otherwise, there were no prenatal or postnatal treatment differences in respect to weaning weight, crown-rump length, hip height and head length (P > 0.12). Previous studies show crown-to-rump length and ponderal index differences. Our lack of differences might be attributed to geographical locations that impact day length or endogenous melatonin status.

Risk factor analysis for beef calves requiring assisted vaginal delivery in Great Britain.

Dystocia has serious consequences for both mother and offspring. This study therefore aimed to identify risk factors for dystocia in vaginally delivered spring born beef calves in Great Britain (GB). Information on calving assistance, calf sex, birthweight, breed, twinning, dam parity and body condition score (BCS) was collected from 1131 calves across 84 GB farms. Variables were modelled against calving assistance as a binary response variable. Twins (Odds Ratio [OR] = 5.45), Charolais calves (OR = 3.24), calves from primiparous dams (OR = 5.75) and male calves (OR = 1.75) were at significantly increased risk of requiring calving assistance across all models. Calves born to cows classed as thin (BCS < 2.5/5) were identified in the univariate analysis and in one of the multivariate models (OR = 1.92) as having an increased likelihood of dystocia. Most beef herds have limited scope to manage cows on the basis of fetal gender and number. However, calf breed, dam body condition and management of primiparous dams can be manipulated to reduce the risk of dystocia and improve supervision. Poor body condition is a novel risk factor for dystocia in beef cows and worthy of further investigation.

Abstracts from the Proceedings of the 33rd Biennial Conference of the Australian Association of Animal Sciences

Encapsulated calcium butyrate (ECAB, ButiPEARL™, Kemin Industries, Inc. Des Moines, Iowa) is a novel and innovative feed technology developed to release butyrate continuously and slowly in the gastrointestinal tract of animals. Butyrate promotes rapid growth and development of rumen papillae for a better absorption of digested nutrients that enables dairy calves to transition smoothly from liquid milk to concentrates with minimal metabolic disorders (Pereira et al. 2017; Eckert et al. 2015; Ferreira & Bittar, 2011). This study investigated the effect of supplementing dairy heifer calves with ButiPEARL™ on average daily weight gain, liveweight and body conformation traits. The study was conducted using forty-eight newly born heifer calves (7 ± 0.4 days old; average liveweight 39.3 ± 5.3 kg) comprising purebred and crossbred Friesians, Jersey and Swedish Red. Calves were kept under the same pasture-based management system and utilised in a complete randomised experimental design for eleven weeks. The treatment groups included the Control (no supplementation), Low (4 kg/t) and High (6 kg/t) doses of ButiPEARL™. Feed intake, liveweight, average daily weight gain and body conformation parameters were subjected to a repeated measures general mixed model (proc mixed) analysis in SAS. Treatment diet, calf breed, dam parity, week of measurement and their first-order interactions fitted as fixed effects, while dam age was fitted as a random effect and all the initial body weight and conformation measurements fitted as covariates. Dose affected liveweight, average daily weight gain, chest girth, withers height, body length and body condition score (P < 0.05). The Low dose resulted in the highest average daily weight gain (0.83 ± 0.03 kg/day), heaviest liveweight (72.08 ± 1.6 kg), widest chest girth (95.94 ± 0.7 cm), longest body length (82.92 ± 0.6 cm) and best body condition score (1.99 ± 0.1; Table 1). Calves assigned to Control and High doses had similar liveweights (65.37 ± 1.4 kg vs 65.74 ± 1.5 kg), average daily weight gain (0.71 ± 0.0 kg vs 0.74 ± 0.0 kg) and chest girth (93.35 ± 0.7 cm vs 92.91 ± 0.7 cm; Table 1). These findings suggest that calf starter rations containing 4 kg/t ButiPEARLTM will improve overall liveweight and body conformation traits of newborn calves in a pasture-based system. Practical implications of supplementing neonatal dairy calves with ECAB is the potential to wean calves early and reduce age at first calving, which has been shown to result in improved lifetime performance. References Eckert E, Brown H, Leslie K, DeVries T, Steele M (2015) Journal of Dairy Science 98, 6315-6326. Ferreira L, Bittar C (2011) Animal 5, 239-245. Pereira GR, Barcellos JOJ, Sessim AG, Tarouco JU, Feijo FD, Neto JB, Prates ER, Canozzi MEA (2017) Revista Brasileira de Zootecnia. 46, 413-420.

Influence of growth hormone gene polymorphism on the productive qualities and the level of toxic elements in the hair of Kalmyk breed calves

The studies were performed on a model of calves of the Kalmyk breed (n = 100) from birth to 14 months of age. The effect of growth hormone polymorphism (rs135322669) on productive qualities, body parameters, and toxic load level is estimated. Blood samples were taken to detect gene polymorphism. DNA samples were isolated from whole blood using a DNA-Extran-1 reagent kit. Primers were developed based on published bGH sequences (Gen Bank Accession NOS. M57764) using Primer3 software. Real-time PCR was performed on an ANK-32 programmable amplifier. The frequency of occurrence of polymorphism in the calves was revealed: 62 % with the CC genotype, 26 % with CG and 12 % with GG. The study of the growth rate of the studied animals from birth to 14 months of age was carried out on the basis of individual monthly weighing. The development was studied on the basis of taking measurements: height at the withers, height at the sacrum, width of the chest, depth of the chest, length of the body, width at the sacrum at 14 months of age. The superiority of calves with CC genotype in live weight starting from 6 months of age over peers with genotypes CG and GG was established. At the age of 6 months it was 5.0–7.0 %, and at 14 months of age 5.0–9.0 %. Calves with the GG genotype were inferior to peers with the CC genotype in height at the withers by 2.3 %, by 2.0 % in the sacrum, by 4.7 % in the chest width, by 5.3 % in the width at the sacrum, by 3.1 % in the chest depth and were inferior to the calves with genotype CG by the width of the chest by 2.3 %. The determination of toxic elements: Al, Cd, Pb, Sn, Hg, Sr, was carried out by atomic emission and mass spectrometry (AES-ICP and MS-ICP). Calves with the SS genotype accumulated less toxic substances in the hair from the withers, so their ∑tox was 52.4-63.1 % lower as compared to their peers with the CG and GG genotypes. This is also confirmed by the correlation analysis, which revealed a reliable relationship between gene polymorphism and ∑tox in wool at the level of r = 0.92.

Study on the causes of calf morbidity and mortality and its associated risk factors in South Omo Zone, South-Western Ethiopia

A cross-sectional and longitudinal observational study with the objectives to identify calf management and husbandry practices and to investigate the major causes of calf morbidity and mortality and its associated risk factors was conducted in South Omo Zone from 2015 to 2016. A total of 85 calf owners were interviewed and 255 calves of those farmers were longitudinally followed for six months from the very first day of their birth. Accordingly, retained placenta 17/85 (20%), narrow pelvic outlet 17/85 (17.6%) and prolonged labour 8/85 (9.4%) were ranked as maternal-related calving problems whereas, ‘navel ill’ 34/85 (40.0%), dead birth 9/85 (10.6%), oversized calve 16/85 (18.8%) and abnormal presentation 9/85 (10.6%) were identified as calf-related problems. The traditional healers 31/85 (36.47%) and veterinarians 24/85 (28.23%) were dominant calving assistants in the study areas. Moreover, bloody diarrhea 24/85 (28.2%), ectoparasites 10/85 (11.8%), pneumonia 7/85 (8.2%) and constipation 3/85 (3.5%) were categorized as the major health problems that frequently affected the calves. From the calves longitudinally followed, 85 calves (33.3%) were encountered different health problems which resulted in calf morbidity and mortality. Identified health problems were not significantly associated (p&gt;0.05) with study sites, sex and breed of calves. According to multiple logistic regression analysis, six variables (calf housing system, dam vaccination history, colostrum feeding frequency, calf house clearing frequency, parity of the dam and calf delivery problem) were significantly associated (p&lt;0.05) with calf morbidity. However, none of the variables was significantly associated with calf mortality. Through six months follow-up, 4.41% crude calf mortality rate was recorded. Sudden death with unknown cause, bloody diarrhea, pneumonia, “evil eye” and physical damages were responsible for 36.36, 18.18, 18.18, 9.09 and 18.18% case fatality and responsible for 1.60, 0.80, 0.80, 0.40 and 0.80% crude mortality respectively. The crude mortality varies among sex; 3.13 and 6.67% respectively in male and female calves. Similarly, it was relatively higher in calves under one week of age (5.73%) and decreasing as the calf’s age increased. It can be concluded that improving herd management and husbandry practices which negatively affecting calf health could minimize calf morbidity and mortality. Moreover, improving the whole herd health system and awareness creation to calve owners to improve the dynamism of their future replacement calve is very important in this area.

Use of chromium nanoparticles as a protector of digestive enzymes and biochemical parameters for various sources of fat in the diet of calves

The gastrointestinal tract acts as a digestive conveyor and carries out a specific stage of food processing throughout its length. A non-traditional approach to feeding cattle unprotected vegetable fats/oils may involve minerals (Ca and/or Mg). In our study, we studied the biological effects associated with the use of chromium nanoparticles at a dose of 200 μg/kg feed, together with soy and sunflower oils, in the diet of 10-month-old Kazakh white-headed breed calves. The calves were surgically fitted with duodenal fistula and pancreatic duct. Results demonstrated that inclusion of chromium nanoparticles in the diet increased the digestibility of crude protein, NDF, ADF and crude fat (p ≤ 0.05). At the same time, inclusion of chromium nanoparticles in the diet led to changes in the blood serum: a 2-fold increase in aspartate aminotransferase (p &lt; 0.05), a 42.2% increase in lactate dehydrogenase and alanine levels similar to control values. We noted that the addition of lipids in the feed led to the mobilisation of triglycerides and cholesterol. At the same time, the inclusion of chromium nanoparticles contributed to a decrease in the level of total lipids in serum and inhibited peripheral metabolic pathways (a 2-fold increase in the de Ritis coefficient). These data may represent additional evidence of the activation of anabolic processes when chromium nanoparticles are introduced into the diet. The increase in the enzyme index was associated with an escalation of lipid peroxidation processes and a decrease in antioxidant defence activity. We showed that vegetable oils enhanced lipolytic and proteolytic activity of pancreatic juice enzymes in the gastrointestinal tract. Adding chromium nanoparticles to the diet reduced lipase activity, especially when used with soybean oil. These data indicate the inhibitory effect of chromium on the activity of pancreatic lipolytic enzymes.

PSV-12 Evaluator effect on the prediction of genetic merit using subjective measures of beef cattle temperament

Abstract The objective of this study was to determine evaluator effect on genetic predictions of docility score (DS), temperament score (TS), and qualitative behavior attributes (QBA; 6 positive and 6 negative QBA). Weaning age calves (n = 1,542) were evaluated using DS, TS, and QBA scores over 4-year period. Fixed effects included evaluator (n = 11 total), primary breed (n = 2), sex (n = 2), and random effect of calf using repeated measure design (across-evaluator model only). Variance components, heritability, and breeding values (EBV) were estimated using pedigree in ASReml 4.2. Evaluator effect on EBV was based on 1) Spearman rank correlation coefficients (rs) and 2) 3-quartiles change in rankings of calves among evaluators per trait. Results showed evaluator scoring was different in DS, TS, and 12 QBA (P &amp;lt; 0.002). Correlations (rs) on EBV across and within evaluators ranged from 0.52 to 0.84 (DS) and 0.53 to 0.87 (TS) (P &amp;lt; 0.0001). For QBA, all rs on EBV were significant (P &amp;lt; 0.05) and ranged from -0.26 to 0.90 (positive) and 0.11 to 0.82 (negative), except on positively occupied and distressed QBAs (P = 0.46 to 0.65). When comparing evaluator specific EBV to across evaluator model, DS and TS had 1.10% and 1.56% 3-quartiles change, whereas comparison of evaluator to evaluator EBV showed 4.54% and 3.76%. For positive and negative QBA attributes, 3-quartiles change ranged from 0% to 35.13% and 0.52% to 3.76% (evaluator to across-evaluator model); and 1.30% to 21.09% and 3.31% to 13.81% (within evaluators). This illustrates that DS and TS had less variability in EBV prediction compared to QBA. Within QBA, negative QBA had less variability compared to positive QBA. In conclusion, evaluators scored differently using these methods. However, in predicting genetic merit, evaluator has negligible effect for scoring systems already implemented by breed associations.

Hepatic ultrasonography in three breeds of healthy calves: Nellore, Curraleiro Pe-duro and Pantaneiro.

An ultrasonography was performed in 21 healthy male calves of Nellore (n=8), Curraleiro Pe-duro (n=7) and Pantaneiro (n=6) breeds, between 8 and 12months, with the objective to display information about size, position and ultrasonographic parenchymal patterns of the liver, in addition to the topography of the gallbladder, right kidney and major vessels. The measurements used were dorsal margin distance (DMD) and ventral margin distance (VMD) of the liver, viewable extension (VE) of the liver, the caudal vena cava (CVC), width (CVCW) and depth (CVCD) and the portal vein (PV), width (PVW) and depth (PVD). The measures DMD, VMD and VE were similar, and the organ's longest visible extension was in 11th ICS. CVC was more frequently observed in the 11th and 10th ICS, despite being visible from the 12th to the 9th ICS in Nellore and still 8th ICS in Curraleiro Pe-duro and Pantaneiro. CVCD was lower in the 10th and 9th ICS in Nellore. The PV presented higher observation frequency in the 10th ICS. The measures PVD and PVW were higher in Nellore in the 11th, 10th and 9th ICS. To our knowledge, this report is the first to document ultrasonographic findings in three healthy calves. Considering the three breeds, the results show no differences in the ultrasonographic features as regard to the measurements and visualization of the position, size and vasculature of the liver and there was no additional information about the topography of the gallbladder and the right kidney.

Relationship Between Metal Load (Selenium, Arsenic, Molybdenum) of Soil, Plant and Serum of Buffaloes

Presence of hazardous minerals in three major components (soil, forage and buffalo serum) was evaluated for determining extent of metal contamination in Sargodha, Pakistan. Ten soil and forage samples for each season were taken from ten randomly selected sites. 30 grazing buffaloes of �niliravi� breed (calves, non-lactating and lactating) were also sampled randomly from these sites for collection of serum. Heavy metal quantification via atomic absorption spectrophotometry was carried out for selenium, molybdenum and arsenic. Non-significant but positive correlation was found for selenium (Se) concentrations in soil, forage and serum and molybdenum (Mo) concentrations in soil and serum. Negative correlation (p]0.05) was obtained for Mo level between forage-serum and soil-forage which was indicative of molybdenum deficiency in the soil. The results suggested that the heavy metals remained below maximum permissible levels and were non-toxic for the ruminants of the study area.

Exploring bacterial pathogens and risk factors associated with the occurrence of navel ill in calves

The study mentioned here was designed to investigate both bacterial pathogens and risk factors associated with the occurrence of naval ill in calves. A total of 350 calves diagnosed to have navel ill formed the population in our study. Incidence density reports representing the period between 2009 and 2018 were obtained from Veterinary Teaching Hospital (VTH), Bangladesh Agricultural University where information about age, sex, breed, seasonal effect was also included. Umbilical swab from each individual suffering from confirmed navel ill was collected for microbiological study. The occurrence of navel ill in the age of &amp;lt;30 days (n = 244, 69.71%) was noted higher compared to the age of ≥30 days (n = 106, 30.29%). Male calves were highly susceptible (n = 192, 54.86%) compared to females (n=158, 45.14%). In cross breed individuals, the occurrence was higher (n = 330, 94.29%) in regard of indigenous calves (n=20, 5.71%). The occurrence of the illness in summer (March-June) was more common (n = 159, 45.43%) in comparison to both rainy (n = 111, 31.71%) and winter (n = 80, 22.86%) seasons. In term of microbiological study, Staphylococcus aureus, E. coli and Proteus spp. were identified and isolated from the infected areas of the calves with the disease. In conclusion, navel ill occurred more commonly in male calves with the age of less than one month. The appearance of navel ill was noted to be more frequently in summer season (March-June) in cross breed calves. The results also demonstrated that the condition is mediated by mixed bacterial infection formed by gram-positive and gram-negative agents which induce the initial inflammation .

Ecologically clean technologies of young cattle development

The article discusses the effectiveness of calf rearing in lightweight buildings in individual cages and in houses for individual keeping from 3 days of his life to 60 days of age. It has shown the advantage of growing young animals using this technology in comparison with the traditional method for group keeping indoors. This method of calf breeding contributes to maintaining the cultivation of full-fledged repair young animals, and ultimately, increasing the efficiency of animal husbandry. Since all experimental groups had a different content system, the dynamics of live weight in age periods helped to reveal the difference in growth rates and developed animals. The data obtained indicate that the weight during the formulation did not differ much in animals of the control I and II of the experimental groups was 36 kg, respectively, 35.7 and 38 kg. At 3 months of age, it amounted to 83, 87.6 and 90.2 kg, respectively. They exceeded their peers in the control group 7.2 kg or 7.99%, 4.6 kg 4.67%, respectively. The average daily increase in 3 months was 626 g, 692 g, 696 g, respectively.

Productive traits of marals of Tenginsky breed type of Altai-Sayan breed

One of the main tasks of the development of the national economics of the Altai Republic is a rapid and signifi cant rise in animal husbandry, both in terms of increasing the number of all animal species, and in terms of increasing the productivity of maral breeding. New methods, new breeds, and highly productive types and lines are needed to solve these complex problems. Any breed is characterized by the unique gene pool and is the result of a long, purposeful and hard work. The scientists had the task of breeding and researching a breed type of maral of Altai-Sayan breed, which is common in some regions of the Republic. The object of the research was marals of the breed type has been bred in the APC BF “Tenginsky”, which were distributed both in the Republic of Altai and in other regions of the Russian Federation. In the sharply continental environments of the highlands animals have been bred that are characterized by a large live weight, high antler productivity and reproductive traits. With regard to the typicality and technological properties of antlers, marals in the APC BF “Tenginsky” occupy the first place in the production of antler products and breeding young animals. A complex evaluation of the method for the distinctiveness, uniformity and stability of breed type of marals has shown that the antler productivity of Tenginsky type antlers has higher indicators not only relative to the marals of neighboring farms, but also higher than the average indicators of the AltaiSayan breed by 30 %. Adult Siberian stags of Tenginsky type have live weight in the range 270–350 kg. Marals of the tengin type belong to large deer with a height of 150–165 cm at the withers. The horns of marals of the Tenginsky type are large in size and have 6–7 appendages. A distinctive feature of the main array of antlers in the Tenginsky type of antlers is the presence of short, but thick in girth trunks. The antler productivity of individual Siberian stags reaches 19,0–23,6 kg of raw antlers. The bred type includes high-class animals (91,6 % elite and class I), which annually produce more than 5,5 t of antlers and at least 350 breeding calves.

Platelet function activity in black-motley calves during the dairy phase

Platelet activity in cattle can change under the influence of many factors. Their assessment in the second phase of their early ontogenesis is of great interest, taking into account the breed of calves. The purpose of the work is to evaluate platelet activity in black-and-white breed dairy calves. The study was conducted on 41 calf of black-motley breed, which was obtained from healthy cows as a result of 2–3 pregnancies. The calves were examined on the 11th, 15th, 20th, 25th and 30th day of ontogenesis. The study used biochemical, hematological and statistical methods. In animals, an increase in platelet aggregation with all tested inductors was detected during the milk feeding phase. The number of discoid platelets in the blood of calves observed during the second phase of early ontogenesis decreased by 10.5 %. Moreover, the total number of active platelets increased by 24.0 %. The levels of small, as well as medium and large aggregates of platelets present in the blood also increased during the milk feeding phase by 28.6 and 27.3 %, respectively. This was achieved in the observed calves by an increase of 9.6 % in the synthesis of thromboxane in platelets due to an increase in the activity of cyclooxygenase in them by 9.4 % and thromboxane synthetase by 9.3 %. This was also influenced by the increase in the platelet content of adenosine phosphates and the increase in their secretion. The levels of actin and myosin in inactive calf platelets increased during the milk feeding phase by 9.7 and 13.2 %, respectively. In animals, an increase in the additional generation of actin and myosin was revealed during platelet aggregation by 11.1 and 9.8 %, respectively. It is clear that calves of the black-motley breed of dairy food are characterized by a certain increase in the activity of platelet aggregation and secretion. This provides them with a high degree of preservation of blood volume in case of damage to blood vessels. The growth of intravascular platelet activity in these calves also contributes to the creation of the necessary conditions to minimize blood loss and ensure homeostasis.

PSVI-24 Evolution and risk factors of pulmonary lesions evaluated with thoracic ultrasonography in pre-weaned beef calves at arrival at the rearing facilities

Abstract Bovine respiratory disease (BRD) is one of the main health problems in in pre-weaning calves at rearing farms. The aim of this study was to evaluate the evolution of pulmonary lesions using a thoracic ultrasonography and its association with predictable risk factors. Thoracic ultrasonography was performed in 811 calves (45–56 kg of BW and 3–4 wk of age) on 5 different rearing facilities at arrival and from d 12 to d 27 after arrival. Thoracic ultrasonography score was classified based on Adams and Buczinski (2016). Weight (light vs heavy), breed (dairy vs crossbred), source (national vs international), season, and number of calves arriving at the facility were recorded and used to evaluate risk factors. Data were analyzed using mixed effects models. At arrival 31% of the calvespresented pulmonary lesions, 21% were mild and 10% severe. After 12–27 d the number of calves without lesion decreased (P &amp;lt; 0.001; 70.3 ± 3.93% vs 34.0 ± 3.93%), number of severe lesions increased (P &amp;lt; 0.001; 8.9% ± 4.78% vs 40.1% ± 4.78%), however mild lesions were constant over time. Percentage of severe pulmonary lesions were greater (P &amp;lt; 0.001) when calves arrived in fall than spring, summer and winter; when calf source (P &amp;lt; 0.001) was international than national; and when their breeds (P &amp;lt; 0.001) were crossbred than dairy. A tendency (P = 0.09) was observed with the increase of severe pulmonary lesions with an increase of animals received by batch. At arrival, calves already had pulmonary lesions that increased in severity over time, therefore current health protocols do not mitigate BRD and more attention should be taken on risk factors such as breed, transport type and season.

The behavior of dairy cattle in late gestation: Effects of parity and dystocia

The aim of this study was to objectively assess, using an automated behavioral monitoring system, any behavioral differences between primiparous and multiparous cows before calving, and to quantify any behavioral differences between assisted (dystocic) and unassisted (eutocic) calvings. Data were collected from 32 multiparous and 12 primiparous Holstein dairy cattle to describe normal calving behavior and parity differences. To quantify behavior related to calving difficulty, the data from 14 animals that had dystocia at calving were matched to cows that had an eutocic calving based on parity, locomotion score, calf breed, calf sex, month, and year of calving. An IceQube (IceRobotics Ltd., South Queensferry, United Kingdom) was fitted to the right hind leg of cows 4 wk before their expected calving date. Data for lying time, standing time, number of steps, motion index (total motion), and the total number of standing and lying bouts (postural transitions) were automatically collected and summed into 15-min blocks. Behavioral variables were summarized into 2-h periods and 24-h periods before analyses. Mixed-effect models were used to analyze cow behavior in the last 4 d before calving (d -4 to -1), and on the day of calving. In the 4 d before calving, compared with multiparous cows, primiparous cows lay down an average 2.8 h/d less, had 9.1 more postural transitions/d (37.7 ± 1.2 vs. 27.6 ± 0.7), walked 172 more steps/d, and had a higher motion index (2,673.2 vs. 1,981.5 units/d). There was an effect of 2-h period on all behavioral variables on the day of calving. No indicator of calving difficulty was found on the day of calving, nor the days leading up to calving. These findings suggest that parity should be considered when predicting the day of calving, and changes in cow behavior on the day of calving could be used to identify calving cows, and to predict the time of calving.

Associations between colostrum management, passive immunity, calf-related hygiene practices, and rates of mortality in preweaning dairy calves

Calves are particularly vulnerable to health issues before weaning and experience high rates of mortality. Poor colostrum quality or substandard colostrum management, combined with poor hygiene, can increase disease susceptibility, contributing to elevated mortality rates. This study aimed to assess colostrum and calf management together with subsequent mortality rates in preweaning calves. Forty-seven Irish spring-calving, pasture-based dairy herds were enrolled in the study. To investigate whether colostrum and hygiene practices change as the calving season progresses, each farm was visited in both the first and last 6 wk of the calving season. The concentration of IgG in 250 colostrum samples and 580 calf serum samples was determined by radial immunodiffusion assay. Mean colostrum IgG concentration was 85 mg/mL, and mean calf serum IgG concentration was 30.9 and 27.1 mg/mL, respectively, in the first and last 6 wk of the calving season. Smaller herd size and younger age at sampling were associated with higher calf serum IgG concentration. Dairy breed calves were associated with higher serum IgG concentrations compared with beef breed calves; no association was detected based on sex. For feeding equipment hygiene, we assessed the presence of protein residues and found that hygiene levels tended to worsen from the first to the final 6 wk of the calving season. We found no association between feeding equipment hygiene and herd size or 28-d calf mortality rate. Colostrum and calf management practices were not associated with either calf serum IgG concentration or 28-d calf mortality rate. We found that IgG concentration in colostrum produced in Irish dairy herds was generally good, although large variation existed, emphasizing the need for assessment of colostrum before feeding. Results also suggested that hygiene practices associated with calf rearing can be improved, particularly in the latter half of the calving season.

Влияние природной минеральной добавки смектитного трепела в составе зерновой кормосмеси на продуктивность телят в молочный период

The effect of smectite tripoli in the grain feed mixture in summer and winter periods was studied via two experiments on the black and motley breed calves in the SEC Agricompany Culture in the Bryansk region. Three groups (each of 10 livestock units) were selected for the trial. The main feed was whole milk. The composition of grain feed in summer included smepitny tripoli in the amount of 15 and 20 g/day per head. In winter, 30 and 40 g of natural mineral additive were included in the grain feed mixture. The results show that in the summer period in the experimental and control groups live weight of calves and average daily gains were almost equal. However, in winter, in the second experimental group that was fed 30 g of natural mineral additive smectite tripoli the average daily gain in calves was more by 5.9%, which allows to conclude that 30 g of smectite tripoli in the grain feed in the winter period is the optimal dose for calves. The analysis of economic efficiency showed that feeding smectite tripoli in the grain feed mixture in the milk period significantly influenced the profit in the second experimental group, where it was 30.6% more than in the control group. In the group that received 40 g of smectite tripoli in the grain feed mixture the profits were less by 6.1%.