The effect of the feed additive Bioprotectin-KD on the productivity of dairy cows and the correction of the microbiota of calves

The results of tests of a new combined feed additive Bioprotektin-KD based on milk thistle extract with the addition of a complex of bacteria of the genus Lactobacillus and Bifidobacterium to restore intestinal microbiota of animals are presented. Preclinical studies on the effectiveness of the feed additive were conducted on mice with experimental antibiotic-associated dysbacteriosis. Studies on the intestinal microbiota of mice revealed varying degrees of effect of different doses of feed additive on the recovery of resident microflora. The results of pre-clinical studies have proven the harmlessness, non-toxicity and efficacy of the feed additive. Clinical trials of the additive were carried out on productive animals. Its effect on the productivity of black-motley breed cows in a livestock farm in the Belgorod region was studied. The use of the functional feed additive Bioprotectin-KD had a positive effect on the milk productivity of black-motley breed cows. Cows in the experimental groups that received the feed additive had increased their milk yield per lactation by 209.41-499.01 kg compared to the control animals, which was 4.01-8.78%. The quality indicators of milk have increased. The composition of the microflora of the experimental (feed supplement recipients) and control calves was studied. It was found that the quantitative composition of probiotic flora in the intestines of young calves of the control group remained practically unchanged throughout the experiment. The number of indigeneous microflora (lactobacilli and bifidobacteria) increased in the experimental animals. The content of lactic acid microorganisms in the experimental calves began to increase on day 6 of feed supplementation and reached physiological norm on day 30. The safety index of the product has been calculated. The use of the functional feed additive Bioprotektin-KD in conditions of a livestock complex has improved such production indicators as calf survival, average daily weight gain, and milk productivity of cows in the experimental groups of animals as compared to the control ones.

92 Maternal Nutrient Restriction of Primiparous Beef Heifers During Late Gestation Decreases Colostrum Yield and Reduces Calf Vigor

We hypothesized that late gestational nutrient restriction (NR) would reduce colostrum yield and impair offspring transition to postnatal life. Primiparous, fall-calving crossbred beef heifers (BW: 451 ± 28 [SD] kg; BCS: 5.4 ± 0.7) were individually-fed either 100% (control; CON; n = 12) or 70% (n = 13) of NASEM net energy and metabolizable protein requirements for maintenance, pregnancy, and growth from d 160 of gestation to parturition. Delivery duration was determined as minutes from first fetal feet expulsion to birth. Calves were reared naturally by their dams and monitored for times from birth to first sternal recumbency, attempt to stand, and stand; vigor scores (1 = very weak, 5 = extremely vigorous) were assigned at 2, 5, 10, and 20 min of age. Total colostrum from one rear quarter was collected pre-suckling. Calf rectal temperatures were recorded at 0, 6, 12, 24, and 48 h postnatally. Data were analyzed with the fixed effects of treatment (single point) or treatment, hour, and their interaction (over time, using repeated measures). Date of calving was a fixed effect; calf sex was included when P < 0.25. Heifers fed CON had greater (P = 0.04) colostrum weight and volume than NR. Although gestational nutrition did not affect (P = 0.72) calf birth weight, calves born to CON heifers had faster (P = 0.02) times to stand and tended to have faster (P = 0.09) times to attempt to stand. Calves from CON heifers had greater (P = 0.05) 20 min vigor scores. Rectal temperatures at 0 h were greater (P = 0.02) in CON calves, but at 24 h were greater (P = 0.04) in NR calves. These data indicate that heifers nutrient restricted during late gestation have reduced colostrum yield and less vigorous calves, which may influence postnatal calf survival.

Cesarean Section in Cattle: A Review

Cesarean section is one of the oldest surgical procedure performed on cows for delivery of the fetus at parturition. Depending upon the health status of dam and fetus cesarean section has been classified as emergency, non emphysematous and emphysematous procedure. The common maternal indications for performing cesarean section include pelvic fractures, cervical dilation failure and uncorrectable uterine torsion whereas the fetal indication include oversized fetuses and maldisposed calves. Many anesthetic protocols are available for cow however, most cesarean section in cattle can be satisfactorily performed under mild sedation and local infiltration anesthesia using 2% lidocaine. Operative sites for cesarean section in cattle include right and left flank, midline, paramedian, parammary and oblique ventrolateral. The choice of operative sites depends upon facility and patient condition. Peri-operative (before, during and after the operation) care appears to be of utmost significance, post-operative complications of cesarean section include peritonitis, seroma formation, hernia and poor fertility. On the successful outcome of cesarean section in cows in terms of dam and calf survival and future fertility of cows underdoing cesarean section. Previous handling, delay in presentation to referral centers results in poor outcome and thus animal owners must be explained the benefits of prompt presentation of cow to cesarean section for optimal benefits.

Plasticity and repeatability in spring migration and parturition dates with implications for annual reproductive success

Animals are faced with unprecedented challenges as environmental conditions change. Animals must display behavioral plasticity to acclimate to changing conditions, or phenotypic variation must exist within the population to allow for natural selection to change the distribution of trait values. The timing of migration and parturition relative to important annual environmental changes such as snowmelt and vegetation green-up and how they co-vary may influence reproductive success. We tested for plasticity and individual differences in migration and parturition timing as a function of the timing of snowmelt and green-up in a migratory herbivore (caribou; Rangifer tarandus, n = 92) using behavioral reaction norms. We tested whether timing of parturition, plasticity in parturition timing, or timing of green-up were correlated with calf survival. Migration and parturition timing were plastic to the timing of spring conditions, and we found moderate repeatability for migration timing, but no repeatability in timing of parturition. We detected a novel behavioral syndrome where timing of migration and timing of parturition were correlated. Our results suggest that observed shifts in caribou parturition timing in other populations are due to plasticity as opposed to an evolutionary response to changing conditions. We did not detect a correlation between annual reproductive success and either the timing of spring or plasticity to the timing of spring events. While this provides evidence that many populations may be buffered from the consequences of climate change via plasticity, we caution that a lack of repeatability in parturition timing could impede adaptation as climate warming increases.

Temporal kinetics of bovine mammary IgG secretion into colostrum and transition milk

Neonatal calf survival and health is predominantly dependent on sufficient consumption of immunoglobulin G (IgG) and the resulting transfer of passive immunity (TPI). In this study we investigate the potential for continued IgG secretion and temporal kinetics of mammary IgG output in sequential milkings performed at 0, 4, 16, 28, 40 and 52 hours post-calving in Holstein dairy cows. For colostrum (0 hour), we also scrutinize the relationships between IgG concentration, volume, refractometer readings (˚Bx values, Brix ®) and concentration of sugars (lactose and glucose). Mammary transcripts postpartum (0 hour) indicated that active IgG secretion continues beyond the first milking (colostrum; n=4-5). IgG measurements at the different timepoints indicated that colostrum represents only 25.1% of the total IgG produced across the six sequential milking timepoints, with a substantial 48.9% being secreted into transition milk over the next three timepoints (4-, 6- and 28-hour) combined. The differences on the basis of IgG concentrations across 0-, 4- and 16-hour milking timepoints were not statistically significant (p=0.1522; n=9). For colostrum, volume remained highly variable, even with induced let-down prior to milking (n=27). Nonetheless, colostrum IgG secretion was significantly co-regulated with volume (R 2=0.915; p<0.001; n=18), an association that was stronger than that measured for lactose (R 2=0.803; p<0.001; n=18) and glucose (R 2=0.467; p=0.002; n=17). Comparing colostrum ˚Bx values to absolute IgG concentrations showed no correlation (R 2=0.127; p=0.07; n=27); biochemical separation of colostrum components indicated that both proteins and non-protein solutes could affect ˚Bx values (p<0.0001 for both; n=5). This suggests that ˚Bx values do not reasonably indicate IgG concentration to serve as a measure of “colostrum quality.” Additionally, our finding that early transition milk (4-, 6- and 28-hour) can contribute substantially more IgG than colostrum forces a rethink of existing feeding paradigms and means to maximize TPI in calves. Collectively, our results reveal the remarkable value of early transition milk and caveats to colostrum assessments that could advance application in enhancing neonatal calf health.

Veterinary Interventions to Improve Neonatal Survival on British Beef and Sheep Farms: A Qualitative Study

Neonatal lamb and calf deaths are a major issue in UK agriculture. Consistent mortality rates over several decades, despite scientific advances, indicate that socioeconomic factors must also be understood and addressed for effective veterinary service delivery to improve lamb and calf survival. This qualitative study utilised semi-structured interviews with vets and farmers to explore the on-farm mechanisms and social context, with a particular focus on the role of the vet, to manage and reduce neonatal losses in beef calves and lambs on British farms. Data were analysed using a realist evaluation framework to assess how the mechanisms and context for veterinary service delivery influence survival as the outcome of interest. A lack of a clear outcome definition of neonatal mortality, and the financial, social and emotional impact of losses on both vets and farmers, are barriers to recording of losses and standardisation of acceptable mortality levels at a population level. Despite this, there appears to be an individual threshold on each farm at which losses become perceived as problematic, and veterinary involvement shifts from preventive to reactive mechanisms for service delivery. The veterinarian-farmer relationship is central to efforts to maximise survival, but the social and economic capital available to farmers influences the quality of this relationship. Health inequalities are well-recognised as an issue in human healthcare and the findings indicate that similar inequalities exist in livestock health systems.

Effects of β-Mannanase and Bacteriophage Supplementation on Health and Growth Performance of Holstein Calves

The objective of this study was to evaluate the effects of dietary supplementation with bacteriophage and β-mannanase on health and growth performance in calves. Thirty-six pre-weaning male Holstein calves were randomly allocated to one of four dietary treatments with a 2 × 2 factorial arrangement: no supplementation, 0.1% β-mannanase, 0.1% bacteriophage, and both 0.1% bacteriophage and 0.1% β-mannanase supplementation in a starter on a dry matter basis. The experiment lasted from 2 weeks before weaning to 8 weeks after weaning. Twenty-two calves survived to the end of the experiment. No interaction was observed between the two different feed additives. The bacteriophage supplementation tended to increase the odds ratio of survival (p = 0.09). The number of Escherichia coli in feces significantly decreased by bacteriophage supplementation one week after weaning. β-mannanase supplementation increased the concentrate intake (p < 0.01) and tended to increase the final BW (p = 0.08). Analysis of repeated measures indicated β-mannanase supplementation increased weekly body weight gain (p = 0.018). We conclude that bacteriophage supplementation may have a positive effect on calf survival rate, while β-mannanase supplementation may increase the growth rate and starter intake by calves just before and after weaning.

Genetic changes in beef cow traits following selection for calving ease

One approach to reducing calving difficulty is to select heifers with higher breeding value for calving ease. Calving ease is often associated with lower birth weight and that may result in other possible effects on lifetime productivity. Females from experimental select and control calving ease lines within each of the seven populations were compared. Random samples of 720 heifers from lines selected for better calving ease breeding values and 190 heifers from control lines selected for average birth weights were followed through four parities. Select and control lines within the same population were selected to achieve similar yearling weight breeding values. Weights of sampled heifers in select lines were 2.6 kg (P &lt; 0.01) lighter at birth but not different from control lines at weaning. Select lines had significantly shorter hip height, lighter mature weight, and greater calving success at second parity. Their calves were born significantly earlier with lighter weights and less assistance. Significant interactions with parity showed fewer calves assisted and greater calf survival to weaning as heifers but negligible differences with control lines in later parities. Steer progeny sampled from these dams in select lines (n = 204) were not different from steers in control lines (n = 91) for hot carcass weight but had significantly greater fat depth. Two production systems were compared considering the seven populations as replicates. The systems differed in selection history of females (select and control lines) and the use of bulls within their lines as young cows, but used the same bulls in both lines as older cows. Cows were culled after single unsuccessful breeding and kept for up to four parities. Select line cows tended (P ≤ 0.10) to wean more calves and stay in the herd longer. They were assisted significantly fewer times at calving and had greater calf weight gain to weaning when evaluated over their herd life. Mature weights were lighter in select lines, but marketable cow weight from the systems was nearly identical. Control lines did have more marketable young cow weight and select lines older cow weight. Weaned calf weight per heifer starting the system was significantly greater for the select heifer system due to greater survival of calves from heifers and greater calving success at second parity. No important unfavorable effects of genetic differences in calving ease were identified in this experiment.