| dc.description.abstract | Four experiments were conducted to evaluate: (1) effects of calcium salts of soybean oil (CSSO) supplementation to Bos taurus beef cows post-AI on conception rates and (2) on pregnancy establishment factors; (3) effects of CSSO supplementation to late gestating beef cows on the performance of the offspring; (4) the viability of utilizing low-moisture molasses-based blocks (LMB) as a delivery method for CSSO. In Exp. 1, 1,771 cows were divided into groups, and inseminated on d 0. After AI, groups received CSSO (n = 11), or prilled saturated fat (CON; n = 11) from d 0 to 21. Cows receiving CSSO had greater (P = 0.01) pregnancy rates. In Exp. 2, 90 cows housed in 18 pens were assigned to the same treatments and timed AI program from Exp. 1. On d 15, selected cows were assigned to conceptus collection. On d 20 blood was sampled for RNA extraction. CSSO supplementation increased (P = 0.05) mRNA expression of IFNT by the conceptus, and blood mRNA expression of ISGs. In Exp. 3, cows were assigned to receive: CSSO (n = 52) or CON (n = 52) during late gestation. CSSO cattle had greater (P ≤ 0.02) colostrum and plasma IgG; greater (P ≤ 0.05) expression of adipogenic and myogenic genes; required fewer microbial treatments for BRD (P = 0.05) and had greater LM area compared to CON cohorts. In Exp. 4, 36 cows (n = 9 pens) were assigned to receive: 1) NOSUPP; 2) LMB, 24.7% CSSO; 3) CONC, hand-fed, 24.7% CSSO. Plasma concentrations of linoleic acid, ω-6 PUFA, and total FA were greater (P < 0.01) in CONC and LMB vs. NOSUPP cows. Collectively, these results present CSSO supplementation as a strategy to improve reproductive success in Bos taurus beef cows and productive performance of offspring born from supplemented dams. These results are associated to effects of linoleic acid and its ω-6 derivates. Additionally, the use of LMB seems to be a valid delivery method for CSSO supplementation, and consequently ω-6 FA, to beef cows. | en |
