By Ki Fanning, ruminant nutritionist at Great Plains Livestock Consulting
With winter just around the corner and calving season set to start in 60 to 90 days, it’s time to evaluate cows’ body condition. Body condition scoring (BCS) determines the amount of flesh that an animal is carrying. This can be used to evaluate the current feeding regimen. Animals in proper body condition are healthier, take less feed to maintain their body weight (especially in the winter), have increased reproductive performance and wean a larger calf due to age and milk production.
Beef cattle use a 1 through 9 numbering system with 1 being an extremely thin condition without any body fat that can be palpated and near death. A BCS of 9 indicates extreme fat, similar to an animal just prior to slaughter. A cow with a BCS of 5 has a good overall appearance. Upon palpation, fat cover over ribs feels spongy and areas on either side of the tailhead have palpable fat cover. A cow with a BCS of 6 requires firm pressure applied to feel the spinous processes. A high degree of fat is palpable over the ribs and around the tailhead. Cows with a BCS of 7 are considered at the top end of the optimum range for reproduction (5 to 7); however, it is possible that too much money is being spent on feeding these animals and the herd may be more profi table with an average BCS of 6.
Low score, low returns. Cows with a BCS that is not in the 5 to 7 range can experience reduced reproductive performance. When a herd’s BCS average is 6, there should be only a small percentage of cows that are culled each year for being open or late. BCS is a great tool to continually improve the herd’s genetic ability for efficiency of energy utilization.
Before excess body fat can be added, there are eight other metabolic functions that must have their energy requirements met. They are, in order of priority: basal metabolism (including maintaining body temperature); physical activities (including grazing); growth; supporting basic energy reserves; maintaining an existing pregnancy; milk production; adding to energy reserves; and estrous cycling and initiating pregnancy. Once these metabolic functions have their needs met, it takes only small amounts of energy to increase the body condition of an animal.
Research agrees. In my experience, BCS is the single biggest factor affecting conception rates in cattle. Recent research has revealed that cows with a BCS between 5 and 6 will cycle and rebreed sooner than cows with a BCS of 4. In fact, Rick Rasby, a beef specialist at the University of Nebraska–Lincoln, reported cows that cycled at 89, 70, 59, 52 and 31 days postpartum at a BCS of 3, 4, 5, 6 and 7, respectively. Therefore, the cows in greater body condition have the best chance to rebreed and not fall behind in the herd’s calving date. Mike Apley of Kansas State University and Mark Hilton of Purdue University reported the differences in production of heifers with a BCS of 4, 5 and 6. Heifers with BCS 6 had conception rates of 90% by day 40 and 96% by day 60, compared with 65% and 80% for the heifers with BCS 5 and 43% and 56% for the heifers with BCS 4.
The birth weights of the calves averaged 64 lb., 67 lb. and 71 lb. for the heifers with a BCS of 4, 5 and 6; however, there were no differences in the dystocia score. Heifers that calved in the first week of the calving season made $250 per head more compared with heifers that calved in the last week of the calving season, which lost $265 per
head. This loss was due to a lighter calf and a greater chance of the cow falling out of the herd because she was open or late calving.
With the high cost of feed, there is economic advantage to keeping cows in an appropriate BCS to maintain conception rates and profi tability. A body condition scoring chart that gives detailed explanations of what to look for and examples of each BCS can be found at http://beef.unl.edu/learning/condition25.shtml.
- November 2012