Serum albumin concentration of donor cows as an indicator of developmental competence of oocytes

Adequate nutrition is required for maintenance of normal reproduction in cattle. Albumin, the best marker and fundamental part of nutrition, most abundant plasma protein and major component of fetal bovine serum, is the best predictor of malnourishment in South African cattle. The aim of this study was to determine if serum albumin concentrations of donor cows predict the developmental competence of oocytes, and if additional protein supplementation of the in vitro culture media improves embryo outcomes in oocytes from cows with inadequate serum albumin concentrations. Oocytes (n = 1024) were recovered from donors with inadequate (≤35.9 g/L), or adequate serum albumin concentrations (≥36.0 g/L). Four hundred and sixty oocytes originated from cows with inadequate serum albumin and 564 from cows with adequate serum albumin. Oocytes of these cohorts were randomly allocated to a control and supplemented fetal bovine serum in vitro embryo culture protocol. Multiple linear, logistic and Poisson regression analyses were performed to estimate the effects of different covariates on linear, binary and count data respectively. Mixed effects Poisson regression was performed for the number of oocytes that developed into blastocysts by the seventh day of culture. Adequate serum albumin concentration of donor cows independently resulted in 46% increased blastocyst formation in the control protocol (P = 0.02). Although fetal bovine serum supplementation of the culture protocol did not affect blastocyst formation in oocytes originating from cows with inadequate serum albumin, it independently reduced blastocyst formation by 30% in oocytes originating from cows with adequate serum albumin (P = 0.02). Other independent predictors of blastocyst outcome included higher serum urea nitrogen, lower beta (β)-hydroxybutyric acid concentrations and lower fat classification of donor cows. It is concluded that adequate serum albumin of donor cows is a significant predictor of developmental competence of oocytes, and that in vitro supplementation of fetal bovine serum does not improve developmental competence of oocytes and can lead to negative blastocyst outcomes. Further research is required to determine optimal protein supplementation for oocytes originating from inadequately nourished cows.The Department of Production Animal Studies, Faculty of Veterinary Science, University of Pretoria.http://www.theriojournal.com2020-02-01hj2018Production Animal Studie

Reproductive and body size measurements in a cohort of Roan- and Sable antelope (Hippotragus equinus- and niger) in South Africa

The objectives of this study were to provide veterinarians and game breeders with objective body measurements and measurements of the male reproductive system that can act as a guideline for the preforming breeding soundness evaluation’s (BSE’s) in Roan- (Hippotragus equinus) and Sable antelope (Hippotragus niger) that are kept in captivity in South Africa. The later objective was to establish if there are any significant correlations existing between body measurements known to have economic value to the farmer, and measurements that may potentially influence the breeding ability of male Roan- (Hippotragus equinus) and Sable antelope (Hippotragus niger). Captive bred antelope, in Kimberley, Northern Cape area of South Africa were used to collect data from Roan and Sable bulls were darted during the summer (January) and winter (June) periods of 2018, during which each bull’s body measurements (weight, age, body length, length of front leg, horn length, horn rings, horn length tip-tip, horn base circumference) were taken, standard measurements for breeding soundness (scrotal circumference, prostate length and width, testis size, - shape and elasticity) were measured and semen samples were collected for macroscopic (colour, volume, pH, marbling) and microscopic (mass motility, concentration and sperm morphology) evaluation. Body measurements that are potentially associated with economic value such as horn length were, in this study, not correlated with any male reproductive measurements that are potentially associated with the breeding ability of Roan- and Sable antelope kept in captivity. The study also indicated, no strong correlations between physical and reproductive traits that could be confirmed. A weak positive correlation was found between body weight and SC, length of the front leg and SC, mean horn length and length of the front leg and semen concentration and the scrotal circumference. There was no correlation between semen volume and SC in Roan bulls. The Sable bulls showed a correlation between semen volume and SC but it was not significant. However there were increases in SC, semen volume and concentration noted in one bull that was moved to a breeding camp with females after his initial semen collection.Dissertation (MAgric (Animal Production Management))--University of Pretoria. 2020.South African Veterinary Foundation Wildlife PharmaceuticalsAnimal and Wildlife SciencesMAgric (Animal Production Management)Unrestricte