In a previous study (Peres et al., 2008 Acta Scientiae Veterinariae 36 639), sunflower supplementation during 22 days improved conception rates by 20.4% in Timed AI programs in beef cows. We aimed to evaluate the effects of sunflower seed supplementation on circulating cholesterol (CHOL) and progesterone (P4) concentrations, and the conception rate of recipient beef heifers after timed embryo transfer (TET). Heifers were synchronized using a P4/estradiol-based TET protocol. After device removal (D−2; D0= 2 days after P4 device removal), heifers receive 1.7 kg/animal per day of 40% soybean meal 44% crude protein (CP) and 60% sunflower seed (Sunflower Group; n=106) or 53% of soybean meal with 44% CP and 47% corn (Control Group; n=111) for 22 days (from D−2 to D19), both balanced with 72% TDN and 24% CP. Heifers received an in vitro-produced embryo on D7. Conception rate on D30 was greater (P=0.01) in the Sunflower Group (55.66%) than in the Control Group (36.94%). Greater (P<0.04) CHOL concentration was observed in the Sunflower Group than in the Control Group on D7 (306.0±11.6 vs 277.1±11.9 mg/dl, respectively) and on D19 (260.5±8.0 vs 232.0±8.0 mg/dl, respectively). Plasma P4 concentrations were not different between groups on D7, but were greater (P<0.0001) in the Sunflower Group (5.75±0.39) than in the Control Group (3.48±0.38 ng/ml) on D19. These results indicated that sunflower seed supplementation also increases conception rate in recipient beef heifers after TET.
02 - 04 Sep 2014
World Congress of Reproductive Biology