The aim of this study was to evaluate the effect of negative energy balance (NEB) on the final growth of the dominant ovarian follicle in Holstein cows. Cows at 14 to 21 d postpartum from an intensive dairy farm were randomly selected and allocated into a positive energy balance group (PEB, with β-hydroxybutyric acid (BHBA) level < 1.2 mmol/L, n = 15) and an NEB group (BHBA > 1.2 mmol/L, n = 15). Plasma samples were collected at 21, 50 and 55 d postpartum to assess the concentrations of energy metabolites, minerals, hormones and cytokines. Ovaries were examined by transrectal ultrasound on days 50 and 55 (120 hours later) to evaluate the diameter of the largest follicle. Compared with PEB cows, there were a more severe body condition loss and a lower milk yield in NEB cows (P < 0.05) and these had greater concentrations of plasma BHBA, non-esterified fatty acids, triglycerides, urea nitrogen, growth hormone, interleukin 6, and fibroblast growth factor 21 and lesser concentrations of plasma glucose, total cholesterol, insulin, insulin-like growth factor 1, insulin-like growth factor binding protein 3, leptin, brain-derived neurotrophic factor and angiopoietin-like protein 8 on d 21 (P < 0.05), while plasma minerals were not affected by energy status (P > 0.05). These changes persisted until the end of the study period (50–55 days postpartum) resulting in a lower follicular growth rate for cows in the NEB than the PEB group. These observations indicate that follicular growth rate is associated with measurable changes in energy metabolite, hormone and cytokine concentrations caused by early postpartum NEB.

Objectives: Aimless use of anti-microbials for the treatment of uterine diseases has driven the rise of safe strains. Subsequently, within the current consider, the viability of post calving tonic (PCT) was assessed in vivo for the treatment of post calving complications in dairy cattle. Materials and Methods: The placentas of 10 chosen post-calved dairy animals with a history of postpartum complications primarily held placentas were drenched with PCT 250 ml twice a day for 2 successive days. The evaluation parameters, viz., time taken for removal of lochia, placenta, involution of the uterus and estrus come back time, body condition score, and milk yield have been analyzed to assess the efficacy of PCT in post calved dairy bovines. Results: The results depicted that following the administration of PCT, the mean time taken for expulsion of uterine discharge (lochia), placenta, time taken for the involution of the uterus, and estrus come back time was 86 and 10 h, 30 and 36 days, respectively. Additionally, the administration of PCT 250 ml twice daily for 2 consecutive days to the post-calved dairy cows caused a significant increase (p < 0.05) in milk yield. Conclusion: It was apparent that PCT encourages the unconstrained removal of held placenta through its ecbolic movement and advances uterine discharge exercises. In addition, PCT supplementation caused augmentation of milk yield in post calved dairy cows. [J Adv Vet Anim Res 2021; 8(4.000): 650-655]

The purpose of this study was to analyze the morpho-functional features of the ovaries and uterus of sows with different genotypes for the estrogen receptor (ESR), prolactin receptor (PRLR), and follicle-stimulating hormone subunit beta (FSHβ) genes associated with reproductive traits. Healthy Large White sows were studied. The genotypic status of the ESR, PRLR, and FSHβ genes was detected by polymerase chain reaction-restriction fragment length polymorphism. The structure of the ovaries and uterus was studied using quantitative assessment of organs and histological research. Sows with the ESR BB genotype significantly exceeded animals with the ESR AA genotype in milk yield (by 0.3 kg) and in the number of piglets at birth (by 0.9 animals) and at weaning (by 0.7 animals). Sows with the ESR AB genotype were midway between those with ESR BB and ESR AA genotypes in terms of these reproductive traits. Animals with the PRLR AA genotype significantly exceeded those with the PRLR BB genotype in the number of piglets born (P < 0.05); the differences in litter weight at birth were not significant. Compared to other genotypes, sows with genotypes ESR BB (P < 0.05) and PRLR AA (AB) (P < 0.05) had larger uteruses and more yellow bodies, tertiary follicles, and primordial follicles in their ovaries. Animals with the FSHβ BB genotype significantly exceeded animals with the FSHβ AB genotype in the length of uterus by 21 cm (P < 0.05).

Aim of the present study was to determine the effect of the lactation number on milk production and to detect the most economical lactation period in Holstein dairy cows. Materials and The animal materials of the study were 392 Holstein dairy cows with a similar dry period and lactation length. The cows were divided into 6 groups according to the number of lactations. The groups were formed as 1st lactation (Group 1; n=67), 2nd lactation (Group 2; n=124), 3rd lactation (Group 3; n=51), 4th lactation (Group 4; n=62), 5th lactation (Group 5; n=41) and 6th lactation (Group 6; n=47).Average lactation milk yields for the 1st, 2nd, 3rd, 4th, 5th, and 6th lactations of the cows used in the study were 7860.03 kg, 9010.02 kg, 10207.15 kg, 10165.89 kg, 8430.57 kg and 8069.78 kg, respectively. It was determined that the highest milk production and highest daily income were obtained during the 3rd and 4th lactation periods (p<0.05).In conclusion, milk production increased in the first three lactations, 3 and 4 lactation remained stable and decreased in 5th and 6th lactations. But, regardless of the number of lactations during the first 6 lactation periods, it is considered economical to use healthy cows for milk production in dairy farms.