September 28, 2012

Early weaning could improve heifer and steer performance


By Sandra Avant / USDA-ARS

When environmental conditions such as drought jeopardize cattle production by reducing calf growth and weaning weights and decreasing cow body condition and body weight, early-weaning management strategies may offer some relief.

Calf weight is critical to the economic viability of a ranch, and reduced cow weight and body condition may negatively impact future production. Animal health and well-being may also be affected in stressful situations created by drought conditions. Agricultural Research Service (ARS) scientists at our Fort Keogh Livestock and Range Research Laboratory (LARRL) in Miles City, Mont., have found that early weaning of spring-born calves improves body weight gain and condition of the cow herd.

Photos provided by the ARS Fort Keogh Livestock and Range Research Laboratory

Animal scientist Richard Waterman and his colleagues at LARRL, along with researchers at Montana State University and the American Simmental Association in Bozeman, Mont., evaluated the early weaning of beef calves and the impact it has on cow, heifer (young female cow) and steer performance.

Scientists compared calves weaned at a traditional age of 215 days to calves weaned early at 80 days of age at two locations—LARRL and a commercial ranch at Judith Gap, Mont. Cows that had their calves removed at 80 days weighed more and were in better body condition going into winter, reducing the amount of harvested feedstuffs required to over winter these cows.

Under some circumstances, early weaning might also increase the likelihood of the cow becoming pregnant earlier in the breeding season, according to Waterman. Heifers that were early weaned reached a reproductive age sooner. Also, early weaning did not impair a heifer’s opportunity to be retained in the herd as a replacement female.

An evaluation of steer calves for body weight gain, feedlot performance and carcass characteristics supported the concept that early-weaned steers reach maturity sooner during the finishing phase, according to Waterman.

However, the research also revealed that if early-weaned steers are not identified prior to entering the feed yard or finishing phase and subsequently harvested at a similar time as traditionally weaned calves of similar genetics and age, early-weaned steer carcasses may be too fat and receive less desirable U.S. Department of Agriculture (USDA) yield grades.  Yet, if early-weaned steers are identified prior to entering the feed yard and harvested at an early age, market premiums can be earned for those carcasses.

ARS is the chief intramural scientific research agency of USDA. These research findings, which were published in Livestock Science, support the USDA priority of promoting international food security.


SCIENTIFIC CONTACT:  Richard Waterman, USDA-ARS Fort Keogh LARRL, 243 Fort Keogh Road, Miles City, MT 59301; phone (406) 874-8208, e-mail


For further reading on this area of research in ARS, you might want to take a look at:

Strategies developed for more efficient beef cattle production

International partners improve cattle here and in South Africa

Eliminating weeds could put more cows on the pasture