Source: Les Anderson, UK extension beef specialist
Early winter is an optimum time to prepare your spring-calving herd for reproductive success. Adequate nutrition from about 50 to 80 days prior to calving is critical to maximizing a cow’s ability to rebreed and maintain a 365-day calving interval. A cow that gets inadequate nutrition or is thin at calving and breeding will take longer to come into heat and will require more services to conceive.
The best method to evaluate the nutritional status of your herd is to do body condition scores. A body condition score is an estimate of the degree of body fatness of an animal, which gives us an estimate of the amount of body energy reserves available to the cow. Scores range from 1 to 9, with 1 meaning a cow is emaciated or extremely thin, while 9 indicates an animal is extremely obese. Beef producers should train themselves to identify cows that are too thin, cows that are marginal and cows that have an optimal body condition score for rebreeding. Body condition scoring is a tool to help plan your supplemental feeding program, so you can maintain adequate productivity in your herd.
You can determine body condition score by looking at the degree of sharpness or thinness in several areas of the cow’s body. The ribs and backbone are two primary regions you need to examine to help establish body condition score. Other important areas are the tailhead, shoulder and brisket regions of the cow. In general, cows with more fat appear smoother in these areas to the point that individual bones are difficult to see.
Cows that are too thin, scores of 3 or less, have easily identifiable fore and rear ribs, sharpness across the backbone, sharpness over the hook and pin bones near the tailhead and sharpness across the shoulders. These cows need to gain approximately 150-200 pounds before calving, if you want them to rebreed in a timely fashion.
Cows that are borderline have a body condition score of 4. These cows have easily identifiable 12th and 13th ribs, but their fore ribs are covered. The backbone and hooks and pins are still prominent but are not sharp in appearance. The shoulders are less defined. These cows need to gain about 75 to 100 pounds before breeding season.
Cows that are in optimal body condition have scores of 5 or 6 and have a good overall appearance. No ribs are visible unless the animal has been shrunk. The backbone, hooks and pins appear rounded and not easily seen, and the area around the tailhead is filled in but not mounded. These cows simply need to maintain their weight until calving.
Research has shown that cows with scores less than 5 at calving have lower pregnancy rates and take longer to rebreed than cows with scores of 5 or higher. The optimum body condition score for mature cows is a 5 or 6. Heifers that are calving their first calf need to have a score of at least 6 to maximize rebreeding success.
The best way to use body condition scoring is to sort cows according to their score at 90-100 days before calving and feed these groups according to their score and nutrient needs to optimize reproduction. Each body condition score typically represents 75 to 100 pounds of body weight. Analyze your feedstuffs so that you can accurately balance rations to meet the needs of each group of cows. This method not only ensures adequate breeding potential of your cowherd, but is also an efficient method of supplying nutrients to your cows.
Educational programs of the Cooperative Extension Service serve all people regardless of race, color, sex, religion, disability or national origin.