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Pre-calving nutritional status – impacts on the cow and the calf

Karla Jenkins for Progressive Cattleman Published on 20 December 2018
Cow calf pairs

Calving season is rapidly approaching, so it is time to assess cow body condition and nutrient status and make adjustments if necessary before the onset of lactation.

Assigning a body condition score (BCS) to cows is a way for producers to evaluate the energy balance in the cow. The most common BCS system used in beef cattle is a 1 to 9 scale, with 5 being considered a moderate BCS.

Body condition is much easier to increase before lactation occurs because once lactation starts, the energy demand for the cow may be double what it is for gestation alone. If a cow is thin (BCS of 4 or less) at calving, both the cow and the calf face some challenges that could have been avoided by increasing the cow’s BCS to 5 prior to calving.

Challenges for the cow

The cattle producer’s profit is greatly impacted by the number of calves available to sell each year. Additionally, when calves are born late in the calving season, they tend to be lighter at weaning, thus reducing the pounds of beef sold. Research has indicated cows in a BCS of 4 or less have a reduced conception rate and an increased postpartum interval compared with cows in a BCS of 5 or more.

Challenges for the heifer

Research suggests the BCS for the heifer expecting its first calf should not be below a 6 at calving. The heifer faces several challenges that are not an issue for the mature cow. In addition to the increased energy demands of lactation, the young heifer is still growing and must be able to meet the nutrient demands of growth as well as lactation and subsequent rebreeding. Additionally, because the heifer is not fully grown, it tends to have less rumen capacity than a mature cow and must be able to consume higher-quality feed with a faster rumen passage rate to achieve the daily nutrient intake the heifer’s body demands.

Challenges for the newborn calf

Most producers are well aware the newborn calf must receive colostrum shortly after birth to develop a strong immune system. However, the quality of colostrum the calf has access to depends largely on the nutritional status and management of its dam prior to the calf’s birth. Research studies have reported decreased concentrations of immunoglobulins in the serum of calves 24 hours old under certain conditions. The reduced immunoglobulins were most often noted when calves were born to heifers, in twins, when dystocia occurred and when dam BCS was 4 or less.

Confidently assessing body condition

Maintaining thin cows has certainly been shown to reduce productivity of the cow and jeopardize the health of its calf. However, overfeeding cows to maintain more body condition than necessary is costly as well. While a BCS is a subjective score, there are some objective measures to help producers more accurately assess the body condition of their cows.

Resources such as University of Nebraska’s EC281 Body Condition Scoring Beef Cows can help producers confidently evaluate BCS and make feeding adjustments when necessary. Evaluating BCS of cows and heifers a couple of months before calving allows producers to make nutritional adjustments prior to the onset of lactation to benefit the cow, its newborn and the calf that will be conceived next.

Although managing BCS takes some additional time and resources, the argument could be made the producer’s bottom line depends on it.  end mark

PHOTO: The cow-calf producer’s bottom line has direct correlation with the body condition score and energy balance of the dam. Staff photo.

Karla Jenkins
  • Karla Jenkins

  • Cow-Calf, Stocker Management Specialist
  • University of Nebraska
  • Email Karla Jenkins