This article was originally published in Wisconsin Agriculturist Magazine

Rug up or rugging up is a slang term used in Australia meaning to put on more layers in colder weather. Just like humans need a few extra layers in the winter months, our heifers and cows may need to rug up or add layers now in order to maintain performance through the winter months.

The Body Conditioning Score (BCS) is a tool used to estimate energy reserves, in the form of fat and muscle. Body conditioning score ranges from one to nine with a score of one being extremely thin and nine being very obese. Looking at the back, tail head, pins, hooks, ribs, and brisket of beef cattle can help determine the BCS.

It has long been known that thin cows, with a BCS of 4 or less, produce less colostrum and give birth to calves with lower immunoglobulin levels that are less vigorous at birth. Due to both lower immunoglobin levels and less colostrum consumption, these calves tend to have a harder time overcoming early disease challenges than their peers from cows with a higher BCS. The ideal BCS for a cow going into calving is 5.

Heifers are a little different story as cold temperatures can take a larger toll on their energy reserves. This is because younger animals tend to require more energy to keep themselves warm. If heifers are not receiving the added energy they need from feed, their fat and potentially muscle reserves will decrease. Additionally, heifers should have a BCS of 6 at calving due to the need for additional nutrients to support their growth to mature size along with supporting the calf’s growth.

Nutrient demands are lowest after weaning as the dam no longer requires nutrients to promote calf growth or lactation. This is the most economical time to add weight to your herd if a higher BCS is desirable. If attempts to add weight after weaning were not successful, 90 days before calving is the last time to put weight on at a reasonable cost.  Waiting until your heifer or cow is further into gestation to add some extra layers will result in increased costs and can be very difficult.

After weaning and 90 days before calving are not the only times you should check BCS of your herd. Checking BCS on your heifers and cows should occur at different targets throughout the production season for optimal performance. These target times include late summer or early fall to determine if early weaning is needed; weaning time; 45 days after weaning; beginning of breeding season; 90 days before calving; and calving time.

Next time you head out to check on your heifers and cow, look at their BCS to determine if they need to rug up for the winter months ahead. Then, look at your feed inventory and determine if it contains enough energy, protein, and minerals needed to keep your herd warm in the winter.

Resources

K.G. Odde. 1997. Reproductive efficiency, precalving nutrition, and improving calf survival. Proc. Bovine Connection. 860-092.

Reviewed by Bill Halfman, Extension Monroe County Agriculture Educator; Ryan Sterry, Extension St. Croix County Agriculture Educator; Sandy Stuttgen, ExtensionTaylor County Agriculture Educator; Amanda Cauffman, Extension Grant County Agriculture Educator; and Carolyn Ihde, Extension Crawford and Richland Counties Agriculture Educator.