Abstracts Category : Other

Effect of rumen protected vitamin B complex on metabolic parameters, milk production and day 14 conceptus and endometrial gene expression in Holstein dairy cows

by Manveen Kaur

High milk production is associated with sub-fertility in dairy cows due to metabolic demands placed by lactation on the body. The aim of this project was to determine the effects of a rumen-protected vitamin B complex supplementation (VB) compared with a control diet containing no supplementation (CON) on the endometrial gene expression on d 14 of pregnancy. The secondary aim was to look at effect of VB on milk production and components; concentrations of -hydroxybutyric acid, haptoglobin and progesterone in blood; and ovarian dynamics. Fifty-one multiparous Holstein cows from the herd at The University of British Columbia Dairy Education and Research Centre were enrolled into the study three weeks prior to parturition and were randomly assigned to one of the two treatments. Biweekly blood samples, weekly milk samples and daily feed intake were collected. Cows were enrolled onto a double-ovsynch protocol at 333 days post-partum and inseminated by timed artificial insemination (AI). Ovarian structures were monitored and measured using per rectum ultra-sonography. The uterus was flushed on day 14 post AI for conceptus collection and endometrial samples were collected at the same time. Data was analyzed by analysis of variance (ANOVA) using the generalized linear model (GLM) procedure of SAS. Overall, 42 cows were flushed and 13 embryos were collected. VB supplementation had no effect on the size of the embryo, ovulatory follicle size or CL size at embryo collection. Milk production and milk fat values were also similar between the two groups. BHBA and haptoglobin levels between the two groups were also similar. Analysis of expression of genes showed that OXTR, MUC5B, MUC1, IL1, SPP, TRD, FZD8 and FOLR1 genes were significantly upregulated in the VB group. SELL, PLAU and MYH9 genes showed a tendency to be more upregulated in the endometrium of cows in the VB group compared to those in the CON group. In conclusion, expression of genes related to embryo development, immune system, adhesion and regulation of folate transport were upregulated by supplementation. VB supplementation did not affect of production and health outcomes in lactating dairy cows.