Effect of Saccharomyces cerevisiae fermentation product on oxidative status, inflammation, and immune response in transition dairy cattle.

Dairy cattle are subjected to oxidative stress, inflammation, and altered immune function during the transition to lactation. The objective of this study was to evaluate the effects of a dietary Saccharomyces cerevisiae fermentation product (SCFP; NutriTek, Diamond V) on oxidative status, inflammation, and innate and adaptive immune responses during the transition period. Holstein cows were blocked by parity, expected calving date, and previous milk yield and then randomly assigned to treatment within block.

Resynchronizing the first eligible estrus in dairy cattle after a prior insemination and fertility of the prior insemination after gonadotropin-releasing hormone and progesterone treatments.

The hypothesis of this study tested whether application of designed treatments to synchronize estrus in nonpregnant previously inseminated lactating dairy cows increased the proportion of nonpregnant cows in estrus before early pregnancy diagnosis on Day 32 after the previous insemination (Day 0) and increase fertility of the pretreatment insemination. A progesterone insert (CIDR) and GnRH were applied to cows after insemination to resynchronize the returning estrus of cows that failed to conceive on Day 0. The combination of GnRH (Day 14) and a CIDR insert (d 17 through 24) in experiment 1 (n = 347 cows) did not increase (P = 0.

First postpartum ovulation, metabolites and hormones in follicular fluid and blood in transition dairy cows supplemented with a Saccharomyces cerevisiae fermentation product.

We hypothesized that feeding a Saccharomyces cerevisiae fermentation product (SCFP) from -4 through +7 wk (calving = Day 0) facilitates early first postpartum ovulation and alters blood and follicular fluid concentrations of glucose, beta-hydroxybutyrate (BHB), free fatty acids (FFA), and steroid hormones favorable to subsequent fertility. Holstein cows were fed individually a SCFP product (n = 24) or served as controls (n = 23). Blood samples were collected at wk -4 and -2 from expected calving and at 1, 2, 5, and 7 wk postpartum to determine plasma concentrations of FFA and BHB.

Physiologic responses to feeding rumen-protected glucose to lactating dairy cows.

It was hypothesized that rumen-protected glucose (RPG) in diets of dairy cows increases concentrations of insulin resulting in greater blood progesterone concentrations because elevated insulin decreases activity of liver enzymes inactivating steroid hormones. Timing of ovulation was synchronized among 64 postpartum Holstein cows using GnRH and PGF (Day 0 = ovulation). Cows were milked thrice daily and assigned randomly a basal diet supplemented with 0, 1, 2, or 4 kg of an RPG product in place of corn grain, top-dressed in the diet beginning on Day -3.

A shortened resynchronization treatment for dairy cows after a nonpregnancy diagnosis.

We hypothesized that a shortened version of a modified Ovsynch program (OVS: GnRH-1 - 7 d - PGF-1 - 24 h - PGF-2 - 32 h - GnRH-2 - 16 h - AI) that excluded GnRH-1 to resynchronize ovulation in cows bearing a corpus luteum (CL) after a non-pregnancy diagnosis (NPD) or including progesterone supplementation with the OVS treatment for cows without a CL would produce shorter inter-insemination intervals and pregnancy per AI (P/AI) not different from that of cows treated with the OVS treatment. Of the 1697 lactating Holstein cows enrolled in this experiment, complete data were available for only 1584 cows because the remainder was not treated, inseminated per treatment design, left the herd before pregnancy diagnosis, or some other outcome was missing. Cows were enrolled in the study and assigned to either of three treatments at NPD (32 ± 3 d after AI [Day 0]).