Stillborn Calves Research Articles

Taphonomic signatures of early scavenging by black and turkey vultures.

Scavenging is critical for nutrient cycling and maintenance of healthy ecosystems. While there is substantial research into the identification of taphonomic signatures from facultative mammalian scavengers, early stage scavenging signatures by vultures remain unknown. Further, some vulture species are opportunistic predators, highlighting the need to define signatures observed in the course of normal scavenging behavior. We placed stillborn neonatal calves in an unoccupied pasture and used motion-trigger camera traps to quantify scavenging effort, then conducted necropsies to evaluate the effect of black vulture (Coragyps atratus) and turkey vulture (Cathartes aura) scavenging effort on carcass consumption. We measured the order of consumption of different tissue types to delineate which anatomic structures vultures consume first. Scavenging trials with higher numbers of vultures feeding on the carcass for longer were associated with decreased remaining tongue and abdominal viscera, and a larger umbilical wound. Greater maximum flock sizes were associated with decreased remaining tongue and abdominal viscera, a larger umbilical wound, and greater biomass consumption. Black vultures targeted the perineum and tongue earlier, while turkey vultures targeted the eyes, perineum, and tongue. These results are consistent with the idea that vultures prefer tissues that are easy to access and contain high nutrient content. These patterns form a distinctive taphonomic signature that can be used to identify early scavenging by black and turkey vultures. Our results demonstrate that criteria commonly used to identify livestock depredation by black vultures only document vulture presence and not predation. This distinction implies that new and more definitive criteria need to be developed and put into practice for more accurate decision criteria in livestock depredation compensation programs.

Influence of growth intensity of black and white dairy cattle on their reproduction and productivity under free housing

Targeted and economically justified livestock breeding, considering the biological characteristics of growing animals, is a key issue in dairy farming. One of the insufficiently studied aspects of livestock breeding is the period of animal development from the first insemination to the first lactation, which affects their safety, productivity, and reproductive capacity. The study was conducted at the breeding station of the Ukrainian black-and-white dairy breed of the state enterprise "Kutuzivka" in Kharkiv district, Kharkiv region, Ukraine. Animals born in different years differed in growth intensity, reproductive performance, and productivity. At the same time, there was a tendency for the milk yield of first-born heifers to improve with an increase in live weight gain from insemination to the first lactation. According to the results of the correlation analysis, this weight gain had a significant relationship with age and live weight at first insemination, milk yield for 90 days, milk yield for 150 days, milk yield for 305 days of lactation, and live weight at first lactation. The survival rate of all first-born heifers with a weight gain of more than 146 kg was 16–21% higher compared to animals with a lower weight gain. Also, such animals had the highest milk yields for all lactation periods. Their advantage in milk yield was 234 kg for the first 90 days of lactation, 331–381 kg for 150 days of lactation, and 573–675 kg for 305 days of lactation. Groups of animals with different live weight gain after the first insemination also had significant differences in the duration of the service period and the number of stillborn calves. The results of the study concluded that the animals with the highest gain were significantly younger and had a higher live weight at insemination as well as the highest live weight in the first lactation. The early maturation of replacement heifers will contribute to the intensive reproduction of the herd, which will increase the profitability of the dairy industry. Further research is needed to determine the effect of growth intensity on the reproductive performance of second and subsequent lactation cows and calf safety.

Relationship between Pelvic Dimensions and Maximum Traction Forces Required during Parturition in Holstein Cows Using a Biomechanical Obstetric Simulator.

The primary aim of this study was to investigate the effect of the pelvic dimensions of Holstein cows on the traction forces during parturition. Additionally, the relationship between calf measurements and traction forces was explored. For this purpose, a modified in vitro biomechanical model simulating obstetric tractions was used. For the requirements of the experiment, six bone pelvises of deceased Holstein cows were collected based on their estimated pelvic inlet area (EPA) and prepared. Additionally, six stillborn calves were collected based on their body weight (BW). The parameters of the pelvic inlet and cavity were measured using computed tomography (CT). Using the simulator, every calf was pulled in a random order through all pelvises, realizing a total of 36 obstetrical tractions, and the required forces were documented with appropriate software. In each extraction, three peaks of forces were recorded, with the first peak occurring at the entrance of the elbows into the maternal pelvic cavity, the second peak at the entrance of the thorax, and the third at the entrance of the calf's pelvis. Logistic regression revealed an exponential relationship between pelvic parameters and traction forces for the entrance of the elbows and the pelvis, with the recorded forces being higher in the two smallest pelvises and stabilizing at a lower level thereafter, while for the entrance of the thorax, the correlations were either exponential or linear. The adjusted coefficients of determination (r2) were generally above the threshold of 0.5 for the entrance of the elbows and pelvis and lower (0.3-0.4) regarding the thorax and were statistically significant (p < 0.05) in all cases. Regarding the relationships between the calf dimensions and the required traction forces, the types of correlations were primarily linear and of lower magnitude. The combination of pelvic and calf parameters in a multivariate model resulted in an r2 of 0.72 for the entrance of the elbows using the pelvic diagonal and calf's body weight, an r2 of 0.62 using the pelvic area and calf's thoracic circumference, and an r2 of 0.75 using the pelvic diagonal and calf's fetlock joint width. In conclusion, under the conditions of the present experimentation, the applied traction forces were mainly influenced by the pelvic dimensions in an exponential manner, whereas the calf body measurements showed a weaker effect. Based on these findings, critical cut-off points exist, different for every pelvic parameter, below which a significant increase in the required traction forces is expected.

The frequency of bacterial isolation of &lt;i&gt;Clostridium&lt;/i&gt; spp. and their associations in various forms of clostridiosis in cattle

The article presents the results of isolation of Clostridium spp. bacteria and their associations from cattle with different clinical forms of clostridiosis. From 2016 to 2023, 910 samples of biomaterial collected from cows, heifers and calves under 6 months of age, as well as from stillborn calves and aborted fetuses in case of reproductive pathologies in cows were investigated by bacteriological methods. The following species play a major role in the etiology of bovine clostridiosis: C. perfringens, C. septicum, C. novyi (C. oedematiens), C. histolyticum and C. sordellii. C. histolyticum (65.2%), C. septicum (45.6), C. perfringens (29.7) and C. sporogenes (26.1) were isolated most frequently from cows and heifers, while C. sordellii (1.7) and C. novyi (0.9%) were isolated less frequently. Clostridium spp. bacteria of six species were isolated from animals in enterotoxemia and enteritis, and five species in vaginitis and endometritis. In other clinical forms of the disease, bacteria of four species were isolated from cows and heifers. The spectrum of bacteria involved in the development of abomasitis, enteritis and enterotoxemia in calves was similar and represented by four bacterial species: C. histolyticum, C. septicum, C. perfringens and C. sporogenes. Bacteria of five species were isolated from the calves with septicaemic form of the disease. The peculiarities of clinical manifestation and the course of clostridiosis in cattle depended on the species composition of pathogens and their associations. Diseases caused by Clostridium spp. bacteria were acute or subacute, characterized by visible lesions of organs and tissues in a few hours after the animal showed signs of disease and in most cases ended in death.

Congenital localized cutaneous Langerhans cell histiocytosis in a Holstein calf.

Distinct solitary dermal nodules, either covered by an alopecic, or sometimes ulcerated, epidermis, were noticed on the head of a stillborn Holstein calf. The head was submitted for autopsy, and the nodules were found to consist of homogeneous, diffuse pale-yellow, soft-tissue masses with distinct margins that elevated the epidermis above the adjacent skin. Histologically, the dermal nodules were well-delineated on the deep margin approaching the cutaneous muscle and consisted of perivascular neoplastic infiltrates of round cells that in some places coalesced into sheets that extended into the dermis and subcutis. Neoplastic cells separated adnexa and collagen. Immunohistochemistry revealed intense tumor cell expression of vimentin, Iba1, E-cadherin, and CD204; expression of CD18 was faint. The masses were diagnosed as Langerhans cell histiocytosis. Congenital cutaneous Langerhans cell histiocytosis has not been reported previously in cattle, to our knowledge, and should be included in the differential diagnosis of congenital nodular skin lesions.

Early life events associated with first lactation reproductive performance in southwest Victorian pasture-based dairy herds.

This was a prospective cohort study to determine how events from birth until first calving affect reproductive performance in the first lactation in pasture-based dairy herds in Victoria, Australia. Events during the preweaning (0 to 84 days), weaning to first breeding (85 to 473 days) and first breeding to first calving periods (474 to 804 days) were recorded and their association with reproductive performance during the first lactation was quantified. Reproductive performance outcomes included the number of days from first mating start date to first service (MSD-S1) and the number of days from first mating start date to first conception (MSD-CON). Predictors for reproductive performance included: passive transfer status as a calf; season of birth; age and breed of the dam; breed; the presence or absence of dystocia at the time of the heifer's birth; active feeding of colostrum versus being left on the dam for colostrum intake; presence of twinning; the presence or absence of preweaning diarrhoea; preweaning, prepubertal and postpubertal average daily gain; the presence or absence of periparturient disease at first calving; age at first calving; body condition score at first calving; sex of the first-born calf; the presence or absence of a stillborn calf at the first calving and requirement of assistance at first calving. Two Cox proportional hazards regression models were developed: the first for early life event variables associated with MSD-S1 and the second for early life events associated with MSD-CON. Heifers born in autumn and winter had 2.89 (95% CI 1.50 to 5.59, P = 0.002) times and 1.97 (95% CI 1.12 to 3.44, P = 0.018) times the daily hazard of being inseminated compared with heifers born in spring, respectively. For the MSD-S1 analyses heifers that gave birth to a live calf had 1.64 (95% CI 1.14 to 2.36, P = 0.008) times the daily hazard of being inseminated compared with heifers that had a stillborn calf. Increases in weight gain during the first breeding to first calving period by 0.1 kg/day increments increased the daily hazard of first insemination by a factor of 1.10 (95% CI 1.00 to 1.22, P = 0.043). Heifers that experienced periparturient disease had a significantly lower hazard of conception per day compared with heifers that did not experience periparturient disease at the first calving (HR 0.67, 95% CI 0.50 to 0.91, P = 0.009). Increases in weight gain during the first breeding to first calving period by 0.1 kg/day increased the daily hazard of conception by a factor of 1.10 (95% CI 1.01 to 1.21, P = 0.038). We conclude that of all the growth periods assessed in this study, events that occurred during the first breeding to first calving period (474 to 804 days) had the greatest association with reproductive performance in the first lactation. There should be a focus on increasing growth rates during this period and reducing the risk of stillbirth and periparturient disease to improve reproductive performance in the subsequent mating period after calving.

Analysis of Calving Ease and Stillbirth and Their Impact on the Length of Functional Productive Life in Slovak Holstein Cattle.

The aim of the study was to determine the frequency of births according to the categories of calving difficulty and stillbirths and to evaluate the effect of these factors on the longevity of cows. Longevity is one of the traits that affect the overall profit in the dairy industry. A Weibull proportional hazard model was used to evaluate the influence of functional traits such as calving ease and stillbirth. Longevity was expressed as the length of a functional, productive life from the first calving to death or censoring, which was corrected for milk yield. The database included 918,568 calvings, where calving without assistance represented 83.34%, calving with the assistance of one person or the use of a slight mechanical pull represented 14.47%, difficult calving with the assistance of several people, the use of mechanical traction or the intervention of a veterinarian represented 2.16%, and cesarean section represented 0.03%. The mortality of calves, stillborn or dead within 48 h of birth, represented 1.07% and 6.59%, respectively. The frequency of alive female calves was higher (46.84%) than male calves (45.50%). Cows with higher lactations had almost half as many stillborn calves as heifers. The most stillborn calves were found in difficult births (59.48%). In easy calving, this proportion was 2.48%. Using survival analysis, we estimated the significant influence of the factors such as parity, milk production, herd size, age at first calving, herd × year × season, sex of calf, calving ease, and stillbirth on the length of the functional, productive life of cows. The risk of early culling of the cows with moderately difficult calving was 1.259 times higher than in the cows with easy calving. Difficult calving and cesarean section shorten the productive life, and the risk of culling reached 1.711 and 1.894, respectively. Cows that gave birth to a dead calf achieved a 2.939 times higher risk of culling compared to cows that gave birth to a live calf. In this study, a higher risk of early culling was found in cows that gave birth to a male calf. Evaluation of the calving ease and stillbirth can be used as indirect indicators at an earlier age of the animal in the selection process for long-lived animals with good productive and reproductive performance.

KARYOTYPAL VARIABILITY OF UKRAINIAN BROWN DAIRY BREED COWS

KARYOTYPAL VARIABILITY OF UKRAINIAN BROWN DAIRY BREED COWS

THE PRODUCTIVITY OF THE FIRST CALVING COWS OF DIFFERENT CONDITIONS GROWING AND HOUSING

Introduction. The purpose of the work was to study the influence of different conditions of rearing and housing of the first calving cows on their productivity, reproductive capacity and stayability during lactation at the current stage of breeding. Materials and methods of research. The work was carried out based on the data of four breeding plants for the breeding of Ukrainian black and white dairy cows. The data of 3.610 first calving cows that calved during the last six years were analyzed. Statistical processing of the obtained data was carried out by the method of two-factor variance analysis using computer programs. During the analysis, the data were divided by the age of first fertilization and the average daily gain before fertilization. Only animals with a duration of lactation of more than 200 days were selected to determine productivity indicators for lactation. The stayability was determined for the first 10 months of lactation. In determining the probability of abortion and stillbirth, calvings with stillborn calves and abortions after which lactation began are taken into account. Research results. It was established that the live weight of first calving cows, regardless of the housing, increased proportionally to the intensity of their growing. In stall housing, the live weight of first servis that were fertilized at different ages had no significant differences, while in free stall housing, the first calving cows that were inseminated before the age of 470 days had an advantage of 12–19 kg. In terms of milk yield for 305 days of lactation, the first calving cow that were kept tethered and were fertilized at an earlier age exceeded the animals of other groups by 29–148 kg of milk, and those kept without tethering by 564–989 kg. Intensively reared animals produced 244–539 kg of milk more when tethered, and when tethered, this difference was significantly greater and amounted to 530–1081 kg, compared to first calving cow with an increase of less than 800 g. A reading has been established for the trend of increasing the milk yields from the changes in the first fertilization. The intensity of the growth of the heifers before the flooding also has a positive impact on their day milk yield. The probability of unsuccessful calving does not depend on the age of the first insemination in stall housing, but in free housing, animals that were inseminated before 470 days of age had 36–46% more unfavorable results with calving than those that were inseminated in older age The probability of abortion and the birth of a dead calf during stall housing heifers with different intensities of growing before fertilization also had no significant differences, and during free housing heifers with an average daily gain of more than 800 g had 7–9 more cases of unsuccessful calving, calculated on 100 animal compared to heifers with a lower intensity of growing. Conclusions. Increasing the intensity of raising heifers and reducing the age of first insemination contribute to increasing their productivity. It is necessary to carry out constant monitoring of repair youngsters for fatness and to prevent obesity. It leads to a decrease in reproductive capacity, unfavorable calving and, as a result, an increase in the probability of culling in the first lactation, especially in in free housing.

Coxiella burnetii in dairy cattle herd: farming practices and infection dynamics

Abstract Q fever is a widespread disease affecting reproduction in dairy cattle. Several risk factors can increase the possibility of the herd becoming infected and the persistence of infection. The aim of this study was to characterise the dynamics of C. burnetii infection in affected herds and to evaluate reproduction problems and risk factors using a questionnaire within infected and infection-free dairy herds. In total, 25 farms that were serologically positive or shedding C. burnetii DNA in milk and 14 C. burnetii infection-free farms in Latvia answered the questionnaire. Ten positive herds were studied by testing individual blood and milk samples from up to 10 animals at two times separated by 7.5 to 13 months. The number of serologically positive and suspicious animals was higher in the second sampling even though several animals were culled. In the positive herds, the percentage of dystocia, stillborn calves and abortions during the last year was significantly (p=0.001; 0.01; 0.005, respectively) higher than in the negative herds. Several significant factors were found for the presence of Q fever infection, such as the herd size, the regional population density of ruminants, artificial ventilation systems, and frequent farm visitors. Deratisation was less practised in the negative farms and the presence of ticks was observed more often in the negative farms. Only two identified risk factors can be mitigated – the ventilation system and frequent farm visitors. The other factors cannot be changed arbitrarily but they have to be taken into account by decision makers.

Features of pasture nutrition and reproduction as indicators of acclimatization of the Chukchi deer in Yamal

The article presents the results of scientific and production experience in acclimatization and breeding use of reindeer males of the Chukchi breed in the reindeer herding economy of the Yamalo-Nenets Autonomous Okrug. Research and production experience on the acclimatization of Chukotka producers was carried out at the Tazovsky agricultural enterprise of the Yamalo-Nenets Autonomous Okrug, where they were delivered by two groups from the Bilibinsky District of the Chukotka Autonomous Okrug. When assessing the relationship between the origin of the studied animals and the characteristics of the use of pasture fodder, it was found that the ratio of fodder fractions is more influenced by the state of pastures and the grazing season than the breed of deer. the ratio of feed fractions in the rumen of the Nenets and Chukchi deer on average per year did not reveal a statistically significant advantage of any of the studied groups. Timing of the grazing behavior of males of different origins showed that Chukchi deer were more active on pastures, but they spent almost a third of this time looking for food, while local Nenets peers spent half the time on these activities. The time spent directly on the process of feeding in deer of different origins turned out to be almost the same. The results of deer calving showed that the deadness of the breeding stock and the mortality of newborn calves in the experimental herd are lower than in the control herd by 1.1 and 1.0%, respectively. The increased number of stillborn calves is explained by cases of their death in first-calf heifers. The death of live calves during the calving period in both herds is almost the same, but the business yield of calves is higher in the experimental herd by 1.2%. During the first year after the relocation, the Chukchi deer adapted to the conditions of the Yamal forest-tundra and were successfully used as breeding animals.

Cow reproduction rates with varying inbreeding degrees

The evaluation of the breeding work results carried out, the identification of optimal systems for the animals selection, including related ones, have always been relevant. The purpose was to study the influence of various inbreeding degrees on reproductive abilities and their selection and genetic parameters in Holstein cows. The research was carried out on the basis of Pushkinskoe Breeding Plant, Nizhny Novgorod region. At the earliest age, heifers were inseminated in the group with recent inbreeding (14.87 months), for this reason they had the lowest weight at the first insemination - 4 25.7 kg. Cows in the group with recent inbreeding had the shortest service period (108.9 days), the longest service period was in the group with close inbreeding (152.6 days). The variability of live weight during the first insemination and fertilization in all groups was at a low level (Cv = 5,228,25 %). The duration of the service period after first lactation in all groups, except for the group of close inbreeding, had a variation of about 45 %, in the group with close inbreeding it was 1.5 times higher. Despite its small number, the group of close inbreeding turned out to be the most variable in all indicators. An increase in the age of the first fertilization of heifers in the group of close inbreeding leads to an increase in the duration of the service period (r = 0.335). However, there is practically no connection between these indicators in the other groups. Many of the studied indicators had a weak positive or negative relationship with each other. Among the resulting young, more than half were heifers, in groups with different inbreeding degrees this indicator varied from 63.3 to 66.7 %, in the group with outbred animals it was 69.4 %. Twins were registered 2 times and only in the group with a recent inbreeding degree. Stillbirth in all groups was at a fairly low level - 5 .76.7 %, in the group with a close inbreeding degree no cases of stillborn calves were detected. The birth of calves with congenital deformities and pathologies from related mating was not observed. Thus, in the conducted studies, inbreeding had no negative impact on the cows reproductive qualities even to a close degree.

Nucleoside Triphosphate Hydrolases Assay in &lt;em&gt;Toxoplasm gondii&lt;/em&gt; and &lt;em&gt;Neospora caninum&lt;/em&gt; for High-Throughput Screening using a Robot Arm

Protozoan parasites infect humans and many warm-blooded animals. Toxoplasma gondii, a major protozoan parasite, is commonly found in HIV-positive patients, organ transplant recipients and pregnant women, resulting in the severe health condition, Toxoplasmosis. Another major protozoan, Neospora caninum, which bears many similarities to Toxoplasma gondii, causes serious diseases in animals, as does Encephalomyelitis and Myositis-Polyradiculitis in dogs and cows, resulting in stillborn calves. All these exhibited similar nucleoside triphosphate hydrolases (NTPase). Neospora caninum has a NcNTPase, while Toxoplasma gondii has a TgNTPase-I. The enzymes are thought to play crucial roles in propagation and survival. In order to establish compounds and/or extracts preventing protozoan infection, we targeted these enzymes for drug discovery. The next step was to establish a novel, highly sensitive, and highly accurate assay by combining a conventional biochemical enzyme assay with a fluorescent assay to determine ADP content. We also validated that the novel assay fulfills the criteria to carry out high-throughput screening (HTS) in the two protozoan enzymes. We performed HTS, identified 19 compounds and six extracts from two synthetic compound libraries and an extract library derived from marine bacteria, respectively. In this study, a detailed explanation has been introduced on how to carry out HTS, including information about the preparation of reagents, devices, robot arm, etc.

Subclinical Mastitis Detected during the Last Gestation Period Can Increase the Risk of Stillbirth in Dairy Calves.

We hypothesized that subclinical mastitis detected during the last gestation period can increase the risk of stillbirth in dairy calves. The aim was to investigate the relation of subclinical mastitis detected during the last gestation period and its pathogens with the stillbirth of calves. Cows from the 210th day of pregnancy were selected for the study. They were divided into two groups: the first group-subclinical mastitis was confirmed on the farm by the California mastitis test (CMT); the second group of cows-mastitis was not confirmed by the CMT test. Groups of cows were compared according to the results of their calving-the number of stillborn calves. A stillborn calf was defined as a calf that dies at birth or within the first 24 h after calving, following a gestation period of 260 days. Our results suggest that decreasing the incidence of subclinical mastitis during the last gestation period (from the 210th day of pregnancy) can decrease the risk of stillbirth in dairy calves. Further, it is important to identify the pathogen because the highest risk of stillbirth was found in cows with mastitis caused by Escherichia coli, Staphylococcus aureus, Streptococcus agalactiae, pathogenic Staphylococci and other Streptococci. Cows at the first calving had a 1.38-1.65-times higher risk of having stillborn calves than cows of parity ≥ 2. From a practical point, veterinarians and farmers can consider the effect of subclinical mastitis during late gestation on the risk of stillbirth and it could help for strategies of optimizing reproductive performance in dairy cows.

A Heterozygous Missense Variant in MAP2K2 in a Stillborn Romagnola Calf with Skeletal-Cardio-Enteric Dysplasia.

Simple SummarySkeletal dysplasias encompass a clinical-, pathological- and genetically heterogeneous group of disorders characterized by abnormal cartilage and/or bone formation, growth, and remodeling. They may belong to the so-called RASopathies, congenital conditions caused by heterozygous variants in genes that encode components of the Ras/mitogen-activated protein kinase (MAPK) cell signaling pathway. Herein, an affected calf of the Italian Romagnola breed was reported showing a skeletal-cardio-enteric dysplasia. We identified a most likely disease-causing mutation in the MAP2K2 gene by whole-genome sequencing (WGS). The MAP2K2 gene is known to be related with dominant inherited cardio-facio-cutaneous syndrome in humans, but it was so far unknown to cause a similar disease in domestic animals. We assume that the identified missense variant that was predicted to impair the function of the protein, occurred either within the germline of the dam or post-zygotically in the embryo. Rare lethal diseases such as the skeletal-cardio-enteric dysplasia in livestock are usually not characterized to the molecular level, mainly because of the lack of funds and diagnostic opportunities. Precise WGS-based diagnostics enables the understanding of rare diseases and supports the value of monitoring cattle breeding populations for fatal genetic defects.RASopathies are a group of developmental disorders caused by dominant mutations in genes that encode components of the Ras/mitogen-activated protein kinase (MAPK) cell signaling pathway. The goal of this study was to characterize the pathological phenotype of a Romagnola stillborn calf with skeletal-cardio-enteric dysplasia and to identify a genetic cause by whole-genome sequencing (WGS). The calf showed reduced fetal growth, a short-spine, a long and narrow face, cardiac defects and heterotopy of the spiral colon. Genetic analysis revealed a private heterozygous missense variant in MAP2K2:p.Arg179Trp, located in the protein kinase domain in the calf, and not found in more than 4500 control genomes including its sire. The identified variant affecting a conserved residue was predicted to be deleterious and most likely occurred de novo. This represents the first example of a dominant acting, and most likely pathogenic, variant in MAP2K2 in domestic animals, thereby providing the first MAP2K2-related large animal model, especially in respect to the enteric malformation. In addition, this study demonstrates the utility of WGS-based precise diagnostics for understanding sporadic congenital syndromic anomalies in cattle and the general utility of continuous surveillance for rare hereditary defects in cattle.

Using Camera Collars to Study Survival of Migratory Caribou Calves

ABSTRACTMonitoring survival of juveniles in wild populations of vertebrates is challenging because capture and marking of neonates may influence survival and induce biases. Camera collars have proven effective in resource and habitat selection studies, but their effectiveness to assess offspring survival is unknown. Our objective was to monitor the survival of neonates using camera collars installed on 24 preparturient female migratory caribou (Rangifer tarandus) of the Rivière‐aux‐Feuilles herd, from 2016 to 2018, in Nunavik, Canada. Females were captured with a net gun fired from a helicopter and pregnancy was confirmed by ultrasound. Cameras recorded a 10‐second video every 20 min from 1 June until 1 September 2017, when the collar detached automatically. We used Cormack‐Jolly‐Seber models to assess survival and resighting probabilities of calves based on their observation in the videos. Three collars failed, recording less than 30% of the expected videos, including one on a female that did not give birth. Among the 21 females wearing a functional collar, one gave birth to a stillborn calf. We analyzed 25,820 videos recorded from 20 collars. Calf sightings in videos were less frequent as the monitoring period advanced, but we estimated the probability of observing a live calf at 0.77 (SE = 0.42) over the sampling period. Videos indicated a survival rate of 0.67 (SE = 0.11) from birth to 1 September. Our results suggest that camera collars installed on adult females can be used to reliably assess offspring survival, and thus improve our understanding of caribou population dynamics. The application of camera collars should be useful for other large vertebrate species for which the assessment of neonate survival is lacking or difficult to obtain. © 2021 The Wildlife Society.

A dicephalus calf: anatomical, pathological and radiographic aspects

Congenital malformations are morphofunctional abnormalities of tissues and organs that can occur during embryonic or fetal development in all animal species. Among these, dicephalus is characterized by the development of an individual with two heads and two necks, due to the total duplication of facial, cranial, and brain structures. Reports of dicephalus in cattle are scarce and do not normally emphasize radiographic and bone anatomy characteristics. The objective was to describe a case of a stillborn dicephalus calf. The duplication of the head, brain, neck, and two thoracic vertebral columns, isolated from each other, with 13 vertebrae each was verified radiographically. There were 13 pairs of ribs, the ones on the right side articulated with the thoracic spine on the right and the left ones with the spine on the left. Caudally at T13, there was only one lumbar spine, sacral and coccygeal. In the ventrodorsal projection, L1, L2, L3, and L6 had the shape of a butterfly (suggestive of hemivertebrae). At necropsy, in addition to craniocervical and spinal morphological changes, collapsed lungs, duplication of the heart with anastomosis between the aortic arches of the hearts, and duplication of the upper digestive tract were observed. Additionally, there was arthrogryposis of the pelvic limbs. Corpse maceration, followed by the skeletal assembly, showed the bone changes previously observed and confirmed the suspicion of hemivertebrae.

SOME OBSERVATIONS ON THE REPRODUCTIVE PERFORMANCE OF FRIESIAN CATTLE

FIVE-year fertility records of imported Friesian cattle were analysed. The mean monthly distribution of live and still-born calves as well as calf birth weights showed no significant variations. While the overall mean age at first calving was 28.15 ± 4.57 months, the mean age at first calving of heifers born in February — April, May - July, August – October and November – January were 26.09 ± 3.27, 23.91 ± 1.31, 31.71 ± 4.21 and 28.04 ±3.67 months respectively. Some of these observed variations differed significantly (P &lt; 0.01).

De novo ZIC2 frameshift variant associated with frontonasal dysplasia in a Limousin calf

BackgroundBovine frontonasal dysplasias like arhinencephaly, synophthalmia, cyclopia and anophthalmia are sporadic congenital facial malformations. In this study, computed tomography, necropsy, histopathological examinations and whole genome sequencing on an Illumina NextSeq500 were performed to characterize a stillborn Limousin calf with frontonasal dysplasia. In order to identify private genetic and structural variants, we screened whole genome sequencing data of the affected calf and unaffected relatives including parents, a maternal and paternal halfsibling.ResultsThe stillborn calf exhibited severe craniofacial malformations. Nose and maxilla were absent, mandibles were upwardly curved and a median cleft palate was evident. Eyes, optic nerve and orbital cavities were not developed and the rudimentary orbita showed hypotelorism. A defect centrally in the front skull covered with a membrane extended into the intracranial cavity. Aprosencephaly affected telencephalic and diencephalic structures and cerebellum. In addition, a shortened tail was seen. Filtering whole genome sequencing data revealed a private frameshift variant within the candidate gene ZIC2 in the affected calf. This variant was heterozygous mutant in this case and homozygous wild type in parents, half-siblings and controls.ConclusionsWe found a novel ZIC2 frameshift mutation in an aprosencephalic Limousin calf. The origin of this variant is most likely due to a de novo mutation in the germline of one parent or during very early embryonic development. To the authors’ best knowledge, this is the first identified mutation in cattle associated with bovine frontonasal dysplasia.

INFLUENCE OF ARGENTUM NANOPARTICLES ON ECONOMIC AND PHYSIOLOGICAL-BIOCHEMICAL INDICATORS OF LACTATING COWS DURING LONG FEEDING WITH TRADITIONAL AND TRANSGENIC SOYBEAN

Ukraine is among the world's top ten soybean-producing countries. The significant prevalence of Roundup transgenic soybean varieties increases the likelihood of it becoming part of farm animal feed. Accordingly, it is important to study the effect of genetically modified soy on the body of animals and to develop ways to neutralize the deviations caused by its action. A study of the effect of traditional and transgenic soy on reproductive function, physiological, biochemical and economic parameters of lactating cows. Cows' feed intake with the addition of conventional soya had no significant effect on litter size. In the group of animals that consumed transgenic soya, there was a tendency for a reduction in the total number of newborns and an increase in the number of stillborn calves. The use of transgenic soybeans by lactating cows promotes the increase of ALT activity and alkaline phosphatase concentration. Feeding genetically modified soy to cows does not change the chemical composition of milk and does not significantly affect daily milk yield. The addition of Nano argentum citrate to the diet of animals increased the average daily milk yield throughout the experimental period. At 10 days of Nano argentum use, the cows of the experimental group had higher daily milk yields by 10.5 %, and at 20 and 30 days – by 7.5 and 6.4 %, respectively. The corrective effect of the drug Nano argentum on physiological and biochemical parameters in animals that have used transgenic soy for a long time has been established. This indicates the detoxifying properties of the drug and allows to recommend it as a means of preventive protection of animals whose diet may include genetically modified soybeans.