Implications of Fetal Programming
A dam's nutrition has a direct correlation to her progeny's performance.
SIOUX FALLS, S.D. (Dec. 4, 2012) — “The consequences of nutrient restriction must be considered not only for the individual animal performance, but also for the developing fetus,” Rick Funston, associate professor and beef reproductive physiologist from the University of Nebraska West Central Research and Extension Center, North Platte, told participants of the Applied Reproductive Strategies in Beef Cattle (ARSBC) symposium in Sioux Falls, S.D., Dec. 3-4, 2012.
There is no doubt that feed is the single greatest cost in beef production, he explained. He and his research team wanted to see if management practices could reduce the need for harvested forages and thereby decrease production costs. The challenge, he explained, is that dormant forages don’t meet dietary requirements.
Funston looked at how early weaning calves or supplementing the mothers during gestation affected the performance of progeny, both as replacement females and feeder steers. He said pregnancy rates when rebreeding both groups of cows were the same, though the early-weaned calf was lighter by about 100 pounds (lb.) live weight, and 60 lb. carcass weight. He said it was most profitable to wean later and supplement the cow.
A similar study looked at the effect of dam supplementation on heifer and steer calves in a low-input system. There was no effect of supplementation at pregnancy, but there was a higher percentage of calves weaned on supplemented cows.
There was no difference among heifer calves in age at puberty and percentage cycling, but the heifers of supplemented cows had higher fertility rates. Management was only different before the calves were born.
“These calves are influenced in performance before they are ever born,” Funston explained.
Click here to view larger image of Fig. 1, effects of maternal nutrition on bovine fetal skeletal muscle development.
In steers, those born to unsupplemented dams graded lower than those born to supplemented dams. He reiterated that management of cows before calving affects the performance of calves before they are even born.
Overall, he said, calves of supplemented cows performed better in all aspects except feed efficiency. The calves that were born to unsupplemented mothers adapted to using fewer nutrients, but consequently, suffered in performance.
Funston concluded that maternal nutrition influences fetal organ development, muscle development, postnatal calf performance, carcass characteristics and reproduction. He urged producers to manage their resources during gestation to improve calf performance and health later on.
Funston spoke during Tuesday's session focused on herd fertility and nutrition. Visit the Newsroom at www.appliedreprostrategies.com to listen to his presentation and to view the PowerPoint and proceedings paper submitted to accompany his presentation.
Comprehensive coverage of the symposium is available online at www.appliedreprostrategies.com. Compiled by the Angus Journal editorial team, the site is made possible through sponsorship by the Beef Reproductive Task Force and LiveAuctions.tv.
Editor's Note: This article was written under contract or by staff of the Angus Journal. To request reprint permission and guidelines, contact Shauna Rose Hermel, editor, at 816-383-5270.