February 6, 2003

With Calving Season Around the Corner, Good Nutrition is Key

Good nutrition for beef cows in the final trimester of pregnancy is key to healthy calves and improves rebreeding, according to a North Dakota State University animal and range scientist.

"The last trimester is critical for the cow and calf," according to Greg Lardy, NDSU Extension Service beef specialist. "The fetus gains 60 to 70 percent of its weight during this period. Regardless of the nutrition the cow is getting, nature is geared toward providing the fetus with all of the nutritional requirements it can. The cow’s body reserves will be sacrificed to ensure the fetus gets nutrients."

One of the concerns this year is that many cattle producers will be feeding CRP hay because of last year’s drought. "Producers who will feed CRP hay need to have it tested," says Lardy. "We tested more than 170 samples and protein levels varied from 3.9 to 16.3 percent. Obviously, supplementation of these hays will differ."

A calf weakened by inadequate nutrition begins life at a disadvantage. "A weak calf won’t suckle properly," says Lardy. "The first few hours are very important, because the colostrum contains immunoglobulins which help the calf combat diseases. The level of immunoglobulins is dependent on the cow’s nutrition. Thin cows produce lower amounts of immunoglobulins in the colostrum. When you consider that the calf should receive 10 to 12 percent of its body weight in colostrum in the first 12 hours of its life, nursing quickly after birth is extremely important."

Poor nutrition can have long-term consequences for cows as well. "The poorer the nutrition of the dam, the longer it will take her to return to estrus," Lardy says. "Ideally, the greater the percentage of the herd that is in estrus early in the breeding season, the better the chances that they will breed and calve early the following calving season. Calves born earlier in the calving season will have heavier weaning weights."

Some producers think that reducing nutrient intake prior to calving results in lower calf birth weights and reduces calving difficulty. "Numerous research trials do not bear that out," Lardy says. "Dams that have not had adequate nutrition are weaker during the birthing process which leads to increased calving difficulty, greater calf morbidity and mortality, and greater incidences of calf diseases."

For most North Dakota producers, calving begins in the later half of February and kicks into high gear in March. Common sense, good nutrition, and clean, dry pens for cow-calf pairs and birthing dams all contribute to a healthy calving season and improve rebreeding success the next summer, Lardy says.

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Source: Greg Lardy, (701)231-7660, gregory.lardy@ndsu.nodak.edu
Writer: Scott Lowell, (701)231-7865, slowell@ndsuext.nodak.edu
Editor: Tom Jirik, (701)231-9269, tjirik@ndsuext.nodak.edu