Body Condition Scoring
November 8, 2023 | View PDF
The last few years have been extremely tough on our cows; extreme low temperatures during the past winter (2022-2023), continued drought and grasshoppers resulting in limited quantity and quality of forages, and high populations of flies caused additional stress to our cattle this past summer. These factors, and others, may result in cows not being in proper condition and in turn having negative implications on breed up.
Beef cows prioritize and partition the nutrients and energy that they consume in a specific way:
1. Basal metabolism
4. Basic energy reserves
7. Additional energy reserves
8. Estrous cycle and initiation of pregnancy
Think about this partitioning of nutrients in terms of a first calf heifer during the breeding season. She has had her first calf, and she has not yet reached her mature size. First, she will take care of her basal metabolism and her maintenance requirements that it takes for basic functions. Most of our cattle are run on extensive rangeland where they must travel to graze and to water, so they will have an activity level that requires nutrients and energy. In terms of this first calf heifer, she is still growing, she is lactating, trying to store basic and additional energy reserves, and then at the end of the day we ask her to breed and maintain the pregnancy. During the breeding season it is typically June-August, depending on your calving date, and the late summer forage is typically of low quality, if all the grasshoppers didn’t already consume it all. This is why first calf heifers are a difficult group to manage, and thinking about this from the mature cow perspective, too, pregnancy, cycling, and initiation of a pregnancy are towards the bottom of the list. This is why cows in lower body condition have a more difficult time initiating and maintaining a pregnancy.
Research has shown that energy reserves at calving have been identified as the single most important factor affecting postpartum interval to estrus and re-breeding success in beef cows. We can use Body Condition Scoring (BCS) to estimate these energy reserves. A BCS of 5 at calving has been shown to be the critical level affecting the following reproductive performance in mature cows. BCS is based on a scale of 1 to 9 with BCS 1 being extremely thin and BCS 9 being extremely obese. The optimal score is a BCS 5 up to a BCS 6. A cow in a BCS 5 would have the hooks, pins, and last two ribs visible, and no fat in the brisket area. The University of Wyoming has an easy 3-Step BCS Guide that can be found at: https://www.wyoextension.org/publications/html/B1294/.
Post-weaning is the most efficient and economical time to put weight and condition on cows that might be thin. Now that they are no longer lactating and they are in mid-gestation, their nutrient requirements are at their lowest of the production cycle. If you have any thin cows, post-weaning would be the time to sort them off and increase their plane of nutrition to put some condition on them. Once they enter the 3rd trimester of pregnancy, their nutrient requirements increase as the calf growth increases exponentially, making it very difficult and not economical to try to increase condition during the last 90 days before calving, and even more important to try to increase condition now to hit that target of BCS 5 at calving.
Call the Richland County Extension Office at 406-433-1206 for more information.