63 Impact of Supplementing Rumen-Protected Methionine During the Periconceptional Period in Fetal and Postnatal Growth in Beef Cattle

• Published in: Journal of animal science Vol. 100; no. Supplement_3; p. 23
• Main Authors: Heredia, Daniella C, Tarnonsky, Federico, Ojeda, Oscar A A, Rojas, Camila Santos, Fernandez-Marenchino, Ignacio, Luchini, Daniel D, Hansen, Peter J, DiLorenzo, Nicolas, Gonella, Angela M
• Format: Journal Article
• Language: English
• Published: US Oxford University Press 22.09.2022
• Subjects: Oral Presentations
• ISSN: 0021-8812; 1525-3163
• DOI: 10.1093/jas/skac247.043

Abstract Previous evidence has suggested that fertilization and preimplantation embryonic development are sensitive periods that can be influenced by changes in maternal nutrition. We hypothesized that feeding rumen-protected methionine (RP-Met) during the periconceptional period will program bovine gestation in a manner that enhances fetal and postnatal growth. A total of 114 cows were fed a roughage-based diet and randomized to receive corn gluten supplemented with 15 g of RP-Met (RP-Met; Smartamine, Adisseo) or not (Con) from d -7 to +7 relative to artificial insemination (AI) with sex-sorted semen. Estrus synchronization was conducted using the 7-day CoSynch + CIDR protocol. Pregnancy diagnosis, embryo, and fetal morphology were conducted using transrectal ultrasonography 30, and 60 days after AI. After calving, 40 calves (Cont = 19; RP-Met = 21) were considered for birth weight (BW) analysis. Female calves (n=34) were weighed at 2 months of age. Pregnancy per AI at day 30 (Con = 50%, RP-Met = 55%) and day 60 (Con = 50%; RP-Met = 53.4%) were not different between groups (P ≥ 0.05). At 30 days of pregnancy, embryonic vesicle diameter (Con=11.0 ± 0.7 mm; RP-Met =11.6 ± 0.7 mm; P < 0.05) and circumference (Con=0.88 ± 0.09 cm2; RP-Met =0.99 ± 0.09 cm2 P < 0.05) were larger in the RP-Met group but embryo length and abdominal cavity were not different between groups. No difference was observed in fetal morphology at d 60. A treatment by sex interaction was observed (P =0.04). Male calves (n=6) from cows fed RP-Met showed greater BW than those from Con group (Con=31.9 ± 2.3 kg; RP-Met =41.4 ± 2.3 kg) but no difference was observed in females (n=34). There was no difference in BW at 2 months of age between groups. In conclusion, using RP-Met increased embryonic vesicle diameter and circumference, and BW in males.