by Dean Kreager
Spring-calving season may seem a long way off, but getting cows in the proper condition needs to start early.
Changing the body condition score on a cow takes time, and entering calving season too thin can have impacts that last well into the next year. Monitoring BCS is a great tool to guide nutrition and prepare cows for calving and breeding.
As many producers transition from grazing to feeding stored forages, they are faced with two major challenges again this year. First is the amount and quality of stored forage, and second is the condition of the cow herd heading into winter.
Drought conditions, for the second year in a row, caused many pastures and forage crops to suffer. With that, the cow herd is likely stressed and heading into winter with a little poorer body condition than ideal. To compound the problem, early wet conditions took a toll on the quality of stored forages. Hay was either rained on or not baled until it was past its prime.
Research by OSU Extension looked at 180 hay samples from 29 counties in Ohio. Of those, only a couple met the needs of a lactating beef cow, and only a few met the needs for both protein and energy of a spring-calving beef cow in her third trimester.
A forage analysis is the best way to determine if supplemental feed will be needed, but BCS can be another important tool. Most producers do not have easy access to scales for monitoring weight of their cows through the winter. BCS is a way of monitoring changes in cows over time to help make decisions on supplying supplemental feed.
BCS can easily be evaluated in the field. Cows are rated on a scale of 1 to 9, with 1 being emaciated and 9 being obese. There are many good guides available to assist with scoring cattle. Your county Extension educator can help with these resources.
More than weight
You will be looking at things like visual presence of the backbone, ribs, hip structures and chest. BCS can be more valuable than just taking weights. BCS considers the condition of the cow regardless of the size of the individual.
A 1,400-pound cow could have a BCS of 3 or 8 depending on her frame size. Ideally, the same person should be scoring each time as not everyone will have the same opinion. Score the cows now to set a baseline and re-evaluate them throughout the winter at four– to six-week intervals.
If body condition scores begin to drop, it is time to begin supplementation or provide a higher-quality forage if it is available. If only a few animals decline, consider ways to separate those so you do not have to supplement the entire herd.
For best performance and health, cows should fall in the 5 to 7 BCS range at time of calving. Spring-calving cows should be at a minimum score of 5 during the winter. Research has shown that BCS below a 5 is associated with decreased colostrum quantity and quality. This can lead to weaker calves that are more susceptible to disease. Additionally, reproductive performance will likely decline.
Reproduction is low on the hierarchy of nutrient use. Cows with BCS under 5 at calving will likely have longer time periods before returning to estrus, which results in later breeding, extended calving intervals and reduced chances of calving early in the breeding season in future years.
Measuring BCS on cows is a low-cost means of monitoring nutritional status over time. Catching downward trends in BCS early will allow nutritional adjustments to be made, which will likely prevent larger problems down the road.
While large increases in feed late in pregnancy can cause problems due to increased calf size, moderate increases in nutrition can result in improved colostrum and calf vigor, which will be more beneficial than a slightly smaller but weak calf. By timely monitoring and adjusting nutritional status using a combination of BCS and forage analysis, many management issues can be avoided.
Kreager is the OSU Extension AGNR educator in Licking County. He is also a member of the OSU Extension Beef Team that publishes the weekly Ohio BEEF Cattle letter, which can be found at beef.osu.edu.