Because spring calving season often finds calves hitting the ground with a splash, Chris Zumbrunnen, extension livestock specialist in Milan, Mo., looked into feeding soybeans to improve calve viability and improve cow conception rate upon rebreeding.

Mr. Zumbrunnen's research was initiated as a result of studies by Bob Bellows at USDA research center in Miles City, Mont., that found there is an advantage in calf survivability when the cows were fed high-fat diets prior to calving. Those calves were able to maintain body temperature better once they hit the ground. Researchers concluded that survivability increased because the calves develop higher levels of brown adipose tissue around their internal organs, which allows them to maintain body temperature for longer periods of time when under cold stress.

Unsaturated fatty acids (vegetable oils) have been shown to enhance the reproductive efficiency of beef cattle. While this response has been demonstrated, a major obstacle is the delivery of the unsaturated fatty acids to the small intestine. Rumen bacteria are very effective at hydrolyzing fatty acids from the tryglycerides and then saturating the double bonds present in the fatty acid. The result is an extremely limited unsaturated fatty acid flow to the small intestine where adsorption can occur.

Feeding whole soybeans to ruminants would protect a portion of the fat from degradation in the rumen. The exact proportion is not known, but based on field trials it is known that feeding whole soybeans can be an economical way to increase early conception rates in beef cows.

"In one trial we started feeding cows 45 days before calving was to start," explains Mr. Zumbrunnen. "Nutrient requirements for productive cows dictate that the maximum fat level in the diet is about 5 percent. To reach but not exceed 5 percent fat, cattle in field trials are fed 3.5 pounds of soybeans per day in pasture bunks - along with fescue pasture and brome hay. Total fat levels reach 4.97 in cows weighing 1250 to 1300 pounds."

While average birth weight of soybean fed cows increased 4 pounds, there was no increase in dystocia, no increase in post-calving problems and no udder problems or decline in milk production. However, at rebreeding a 76 percent first-service conception rate was observed on the cows fed soybeans compared to the control group, which had a 62 percent first-service conception. Overall pregnancy was increased by 7 percent. It is important to clarify that once the cows calved, soybeans were no longer fed yet the carry over benefit of the energy enabled higher conceptions rates.

In another trial at the University of Missouri Thomson Research Farm, cows were fed 3.5 pounds of whole soybeans from Dec. 28 to Jan. 28 before calving started. Cows fed whole soybeans achieved an 87 percent first-service conception rate despite being bred by artificial insemination. The control group was fed corn gluten and soybean meal in order to intake the same protein level but half as much fat intake. The control cows first-service conception rate only reached 63 percent.

With soybean prices so low this fall and many planted late, several producers in northeast Missouri are facing a $1.50 dock on immature beans. For these producers, feeding beans for only $2.50 per bushel can be cheap feed. Especially where drought has severely limited forage and hay supplies.