Beans Boost Conception

Feed cows raw soybeans before calving for better pregnancy rates.

I've been feeding whole soybeans to my cows for the past few years; starting about 45 days before calving begins,” says Jim Brinkley, a Sullivan County, MO, Angus producer. “We've noticed a boost in conception and pregnancy rates from feeding just 3.5 lbs. of raw beans/cow/day.”

Brinkley got the idea of feeding whole beans to brood cows from research by Chris Zumbrunnen, Extension livestock specialist; Monty Kerley, beef nutritionist; and David Patterson, beef reproductive physiologist — all of the University of Missouri.

“A few years back, I read a report in BEEF magazine about research with safflower seeds fed to late-gestating beef cows, with a significant increase in conception rates,” Zumbrunnen says. “Could we increase conception and calving rates in northern Missouri and Iowa by feeding whole soybeans?”

“Yes,” the Missouri researchers learned, but some work on the timing was needed. Most response came from feeding 3.5 lbs. of whole soybeans/head/day from 45 days before the start of calving until the cow calved. The regimen resulted in a 76% conception rate on first service, and a 93% overall pregnancy rate. By comparison, feeding combinations of corn gluten and soybean meal resulted in conception rates of 50-62%.

“Soybeans contain a fairly high level of polyunsaturated fatty acids (such as linoleic acid), used to synthesize prostaglandins, which in turn initiate and maintain the reproductive process,” Zumbrunnen notes. “The study females were spring-calving cows in good condition, with an average body condition score of about six.”

Since Brinkley feeds all his cows soybeans, he doesn't have a control group for comparison, but estimates a 20% improvement in conception rate.

“We synchronize heats and breed all cows by artificial insemination,” he says. “My cows are in good body condition at breeding time.”

Some producers are concerned feeding whole soybeans (fat is the most concentrated source of energy) in late gestation might produce heavier birth weights and, with it, more calving problems.

“We've seen a slight increase in calf birth weight,” Zumbrunnen says, “but no increase in calving difficulty as a result of the increased birth weight.”

Other common producer questions:

Q. Aren't raw soybeans toxic to cattle?

A. Overfeeding soybeans can be toxic, but — at 3-3.5 lbs./cow/day — whole soybeans are as safe as feeding low levels of any grain.

Q. Must soybeans be processed into meal or extruded before feeding?

A. Not for cattle. In swine, however, soybeans must be processed or heated to destroy the trypsin-inhibiting agent.

Q. Aren't soybeans too expensive to feed?

A. Over the past four winters of feeding whole beans to cattle, the cost has ranged from 25¢-29¢/cow/day.

“Soybeans here now are just over $5/bu.,” Brinkley says. “That makes the cost under 9¢/lb.”

Q. Can I feed twice as many beans every other day and get the same result?

A. “Normally, about 5% fat is as high as you want to go in a beef cow's diet,” Zumbrunnen says. “Above that, you risk nutritional scours. Adding 3.5 lbs. of soybeans to a grass or hay diet gives a dietary fat content of about 5%. I'd be concerned about going much higher than that in one day.”

Q. What kind of facilities do I need to feed whole soybeans?

A. “I don't use bunks or troughs,” Brinkley says. “I pour the beans right on the grass, and scatter them out so all the cows can get to them.”

Q. Can I feed lower-quality beans and still get good conception response?

A. You can feed small-seeded “BB” soybeans that would incur a market discount and still get the same response. You might not want to feed badly cracked or moldy beans.

“Although last year, I fed damaged soybeans that had been under flood, and I couldn't see any difference in pregnancy rate,” Brinkley says.

“We've consistently seen a 14-23% boost in first-service conception rate by feeding 3-3.5 lbs. of whole soybeans/cow for 30-45 days before calving,” Zumbrunnen adds. “Raw soybeans are a safe, effective way to economically supplement beef brood cows.”

James D. Ritchie is a freelance writer based in Lebanon, MO.