Dynamic Changes of Intestinal Microbiota and Metabolite Composition in Pre-Weaned Beef Calves

Background: Gut microbes and their metabolites are essential for maintaining host health, but few studies have elucidated the combined effects of microbial and metabolite interactions on the growth and development of pre-weaned calves over time. Therefore, the aim of this study was to explore dynamic changes of intestinal microbiota and metabolites among newborn calves classified as healthy, sub-healthy, and those that died early during their growth and development.Results: 16S rRNA gene sequencing and metabolomics analysis was employed to track the dynamic changes in faecal microflora abundance and metabolite levels (fatty acids and amino acids) in calves before weaning. The results demonstrated that the alpha diversity of the faecal microbiota increased with calf growth and development. Specifically, the abundances of Porphyromonadaceae bacterium DJF B175 and Alistipes shahii gradually increased in healthy calves over time. Inversely, the abundance of Enterobacteriaceae was higher in the sub-healthy group than in the healthy group. Meanwhile, the faeces of calves in the early death group had significantly higher medium-long-chain fatty acid concentration than those in the healthy group. The faecal amino acid concentration decreased significantly with weekly age in the healthy and sub-healthy groups.Conclusions: The study findings provide a new understanding of calf growth and development prior to weaning. Even under the same management conditions, microorganisms and their metabolites interact to play different dynamic regulatory roles in the growth and development of newborn calves. Further studies are warranted to determine the mechanisms involved.

Formation of colostral immunity in calfs on the background of the application of immunostimulators to cows

A scientific and practical substantiation of the need for the timely formation of colostral immunity in calves to create nonspecific protection of the body and adaptation of newborns to new environmental conditions is given, which is the most important problem of modern veterinary science and practice. Colostral immunity is immunity that develops in newborns due to colostral immunoglobulins during the first 24-36 hours of life. For some newborn farm animals (horses, ruminants and pigs), antibodies are transmitted to offspring only through colostrum in the early postnatal period. In order to increase the nonspecific defenses of the body of mothers cows, the formation of colostral immunity in newborn calves and the realization of the biological resource potential of the body, immunostimulants were used, developed by scientists of the Chuvash State Agrarian University: Prevention-N-B-S and Salus-PE.

Efficacy of application of the luteotropic drug for the prevention of intrauterine growth restriction in dairy cows

Purpose: studying the effectiveness of the use of luteotropic action for preventing embryonic development disorders.Materials and methods. The research object is lactating animals in 60-75 days after a selection that manifests sex cyclicity and separated into 4 groups. The first group (n = 11) – in the insemination of parenterally injected the preparation of tautin at a dose of 5 ml. The second group (n = 11) – tautin was administered at a dose of 10 ml on the same time as cows of the first group. The third group (n = 12) – tautin injected 10 ml twice: during seeding and on the 14th day after seeding. The fourth group (n = 12) – was injected with saline per day of seeding and on the 14th day at a dose of 10 ml (negative control). Conducted a transrectal and ultrasound study at the end of the 1st and 2nd month of gestation, in which the size of the yellow body of pregnancy, embryo and the fetus was taken into account. Upon completion of pregnancy, all animals are taken into account: the nature of the flow of labor (physiological flow, objectiveness, fulbirth, detention, postpartum), postpartum period (physiological flow, submissiveness of the uterus, endometritis), the state of newborn calves (gender of the fetus, the time of manifestation of confident poses of standing, sucking reflex, body mass).Results. It has been established that the twofold administration of the tautin during seeding and on the 14th day after a dose of 10,0 ml is accompanied by an increase in fertilization by 19,7-28,8%, a decrease in the delay syndrome of the fetus development of 1,4-4,0 times, Absence of embryonic mortality. The use of the drug Tautin twice in a dose of 10,0 ml is accompanied by an increase in the size of the yellow body of pregnancy in 1,43-2,15 times, in comparison with other modes of its use, cockerel-dump-sized – by 12,9-37,6% and diameter Cases – by 10,1-46,6%. The use of a luteotropic drug is accompanied by a decrease in the incidence of cows to the detention of the last 1,8 times, the submissive of the uterus – 1,8 times, endometritis – by 2,7 times, the time of manifestation of confident posture of the standing of newborns of newborn calves – by 15,6 minutes, a sucking reflex – on 16,5 min and diarrheal syndrome – 2,7 times.Conclusion. The scientific novelty of research lies in the fact that new knowledge is obtained on the effectiveness of the use of the drug of luteotropic action, created using the technology of recombinant proteins, for the prevention of violations of embryonic development in cows.

Supranutritional Maternal Organic Selenium Supplementation during Different Trimesters of Pregnancy Affects the Muscle Gene Transcriptome of Newborn Beef Calves in a Time-Dependent Manner

Selenium (Se) is an essential micronutrient for growth and immune function in beef cattle. We previously showed that supranutritional maternal organic Se supplementation during late pregnancy improves immune function in their newborn calves; however, the effects of maternal organic Se-supplementation on fetal programming during different pregnancy stages have yet to be elucidated. Herein, we investigated the effects of supranutritional maternal organic Se-supplementation in different pregnancy trimesters on their beef calf’s genome-wide transcriptome profiles. Within 12 to 48 h of birth, whole blood and Longissimus dorsi (LD) muscle biopsies were collected from calves born to 40 crossbred Angus cows that received, except for the control group (CTR), Se-yeast boluses (105 mg of Se/wk) during the first (TR1), second (TR2), or third (TR3) trimester of gestation. Whole-blood Se concentrations of newborn calves increased from CTR, TR1, TR2 to TR3, whereas muscle Se concentrations of newborn calves were only increased in TR3 group. We identified 3048 unique differentially expressed genes (DEGs) across all group comparisons (FDR ≤ 0.05 and |log2FC| ≥ 1.5). Furthermore, we predicted 237 unique transcription factors that putatively regulate the DEGs. Independent of supplementation trimester, supranutritional maternal organic Se supplementation downregulated genes involved in adaptive immunity in all trimesters. Dependent on supplementation trimester, genes involved in muscle development were upregulated by TR3 Se supplementation and downregulated by TR1 Se-supplementation, and genes involved in collagen formation were downregulated by TR2 Se-supplementation. Supranutritional maternal organic Se supplementation in the last trimester of pregnancy resulted in upregulation of myosin and actin filament associated genes, potentially allowing for optimal muscle function and contraction. Our findings suggest a beneficial effect of supranutritional maternal organic Se supplementation during late gestation on Se-status and muscle development and function of newborn calves.

Beef productivity of steers of Kalmyk breed of different breeding

The success of the development of beef cattle breeding in the Republic of Buryatia mostly depends on the effectiveness of using animals of Kalmyk breed of different origins in order to increase beef production. The study of the productive traits and expediency of using the gene pool of Kalmyk breed from other regions in comparison with the animals of local selection when breeding beef herds has practical and scientifi c significance. The purpose of the research was to study the productive traits of cattle of Kalmyk breed imported from various climatic zones of Russia. For the experiment, 3 groups of newborn calves of Kalmyk breed of different breeding of 15 heads in each have been selected according to the principle of analogues. The 1st group consisted of steers Kalmyk breed of Buryat breeding, the 2nd – of Kalmyk breeding, the 3rd group – of Rostov breeding. During rearing and feeding, the steers were in the same feeding and housing conditions. During the growth process, the largest live weight at the age of 7 months has been observed in the 1st group of steers received from parents of local reproduction. They surpassed the herdmates of the 2nd group by 3,1 kg or 1,7 %, and the 3rd group by 4,8 kg or 2,7 %. With age the differences in live weight increased at 14 and 18 months the steers of Buryat breeding exceeded their herdmates of the 2nd group by 10,6 kg or 3,4 % and 15,7 kg or 3,8 % (P > 0,95) and the 3rd group by 16,8 kg or 5,4 % (P > 0,95) and 23,5 kg or 5,8 % (Р > 0,99), respectively. A comparative study of the beef productivity of steers of Kalmyk breed obtained under the conditions of the Republic of Buryatia and imported from the Republic of Kalmykia and the Rostov region has shown the advantage of the animals of Buryat breeding, while the herdmates of Rostov selection were the worst, and Kalmyk breeding steers occupied an intermediate position.

The Gut Microbiota of Newborn Calves and Influence of Potential Probiotics on Reducing Diarrheic Disease by Inhibition of Pathogen Colonization

Calf diarrhea is one of the most concerning challenges facing both the dairy and beef cattle industry. Maintaining healthy gut microbiota is essential for preventing gastrointestinal disorders. Here, we observed significantly less bacterial richness in the abnormal feces with watery or hemorrhagic morphology compared to the normal solid feces. The normal solid feces showed high relative abundances of Osllospiraceae, Christensenellaceae, Barnesiella, and Lactobacillus, while the abnormal feces contained more bacterial taxa of Negativicutes, Tyzzerella, Parasutterella, Veillonella, Fusobacterium, and Campylobacter. Healthy calves had extensive bacterial-bacterial correlations, with negative correlation between Lactobacillus and potential diarrheagenic Escherichia coli-Shigella, but not in the abnormal feces. We isolated Lactobacillus species (L. reuteri, L. johnsonii, L. amylovorus, and L. animalis), with L. reuteri being the most abundant, from the healthy gut microbiota. Isolated Lactobacillus strains inhibited pathogenic strains including E. coli K88 and Salmonella Typhimurium. These findings indicate the importance of a diverse gut microbiota in newborn calf’s health and provide multiple potential probiotics that suppress pathogen colonization in the gastrointestinal tract to prevent calf diarrhea.

INFLUENCE OF SUBCLINICAL KETOSIS IN COWS ON FORMATION OF COLOSTRAL IMMUNITY IN CALVES

The health of the newborn depends entirely on the state of the mother’s body throughout the pregnancy. Ensuring optimal conditions for keeping pregnant animals is based, first of all, on adequate feeding and ensuring the sanitary and hygienic conditions of the environment. The cow’s body undergoes a great load during the transition period, which begins 3 weeks before calving and lasts for six weeks. When the technology of feeding and housing is violated, during this period, metabolic disorders often occur in cows, which are manifested by increased production of ketones. It is known that the development of immunity in the early postnatal period in a calf largely depends on the timely feeding of colostrum. Maternal immunoglobulins from colostrum enter the systemic circulation of the newborn in the small intestine through the tubular system of epithelial cells by pinocytosis.The aim of the study is to study the effect of subclinical ketosis in mothers cows on the formation of colostral immunity in calves born from them.For the study, pregnant cows 3-6 years old were selected 3-7 days before delivery. Urine and blood samples were taken from the cows. In order to identify subclinical ketosis in cows, urine was tested for ketones. According to the results of the study, two groups of 10 animals were formed – in the first group (experimental) the level of ketone bodies in the urine ranged from 1.8 to 3.7 mmol/l, in the second group (control) ketones were not found in the urine. Immediately after calving, portions of colostrum were taken from the cows, and blood was taken from newborn calves a day after the first colostrum was fed. The content of immunoglobulins was studied in skim colostrum and in the blood serum of newborn calves. In the blood serum of day-old calves, the content of total protein was also determined by the biuret method, albumin – by the photometric method with bromcresol green.According to the results of the study, a decrease in the classes of immunoglobulins G, M and A was found in the blood serum of cows before calving by 19.1-23.5%, in colostrum – by 23.7-34.4%, and in the blood serum of day old calves – by 21.7-27.6%. The decrease in IgM concentration was determined to the greatest extent. Subclinical ketosis of mothers had practically no effect on the content of albumin in the blood of calves.

EFFICACY OF THE BASED ON THE ASD-2 FRACTION DRUG COMPOSITION FOR CORRECTION OF DYSPEPTIC MANIFESTATIONS IN CALVES

The scientific article is devoted to evaluation of the original author's composition effectiveness for prevention and treatment of dyspepsia in newborn calves from BLV-infected cows. It is shown that use of the composition for prophylactic purposes reduces possibility of dyspepsia development in 20.82 % calves, and for therapeutic purposes reduces the treatment duration of dyspeptic manifestations in 28.35 % of newborn calves up to 3 days and increases the safety of livestock up to 100%. The obtained data are supported by the results of morphological and biochemical analyses of calves' blood, microbiological studies of the intestinal contents, indicating a rapid recovery of the animal homeostasis with opportune use of the composition for preventive or therapeutic purposes. It was found that use of the author's development allows us to keep the weight gain in calves from immunocompromised mothers at the level of intact animals.