Body Condition Scoring of Beef Cows
It is well known that reproduction is the most important factor in determining profitability in a cow-calf enterprise, and the poor reproductive performance is directly linked to body fat in beef cows. In simple terms, body condition scoring is assessing the available fat reserves of the cow, and it is an easy and economical way to help sort cows so that they can be fed according to their nutritional requirements. The nutritional requirement of beef cattle is ordered according to body maintenance, foetal development, lactation, growth and breeding/reproduction and a cows nutrient intake is distributed accordingly and as each of these requirements is filled, available nutrients are obtained from the next lower-level priority. Excess nutrients are stored as body fat, which is mobilised when the nutrient demand exceeds the available intake. In times of severe nutrient restriction, muscle tissue is mobilised when all other nutrient stores have been depleted (Stewart & Dyer, University of Georgia). Body Condition has been directly associated with circulating concentrations of metabolic hormones that are synthesized by hepatic, adipose, and gut tissues and serve as nutritional mediators of reproductive function (Cooke et al., 2021). Research suggests that if the nutritional requirements of the dam are not adequately met during late gestation that long-term health and productivity of her offspring can be negatively influenced through what has been termed foetal programming. Evidence shows that gestational nutrition can alter the offspring’s body composition, growth, hormonal balance, cardiovascular development, metabolic function, neonatal health and organ development and function and even gene expression through epigenetics (Bohnert et al., 2013). Thus, it stands to reason that body condition affects both the performance of the cow and the calf, and poor condition is associated with:
- Reduced income per cow
- Increased post-partum interval (ICP)
- Weak calves at birth
- Low quality and quantity of colostrum
- Reduced milk production
- Lower weaning weights of the calf
In a study done by the University of Florida, they demonstrated that as body condition decreased (on a scale from 1 to 9) from a score of 5 to 4 they noticed reduced pregnancy rates of as much as 30% and an additional loss of 30% in pregnancy rate when an animal dropped from a 4 to a 3. A summary of these results can be seen in the table below.
Similar findings were obtained in a study by Cooke et al., 2021. Where cows with a body condition score of greater than 5 had greater pregnancy outcomes, calved and weaned more calves that weighed more at weaning, and produced more kilograms of calf weaned per cow in the breeding herd compared to cows with a body condition score of less than 5.
Most methods of body condition scoring use a scale of 1 to 9, where 1 is extremely thing and 9 is extremely fat. This system generally focusses on four categories: thin, borderline, optimum and fat.
The following pictures from the Penn State Extension and the University of Minnesota clearly explain how to score cattle for Body Condition (Body Condition Score as a Nutritional Management Tool (psu.edu)).
When to evaluate body condition score
Body condition should be evaluated as often as possible, if body reserves get too low it is very difficult to regain that condition, supplementation is an option, however, it is expensive and requires careful administration to ensure that you do not oversupply. That being said, the most important times to evaluate body condition are before the breeding season, 90-days prior to calving and again at weaning.
Before the Breeding Season: body condition scoring at breeding is crucial because it impacts the female’s ability to get pregnant. Body condition and re-breeding rates can be improved by supplemental feeding prior to the breeding season. It should be born in mind that mature cows will likely respond better to supplementation than first calf heifers. Heifers should come into the breeding season with more condition than cows (BCS around 7), a heifer will place more demand on her body reserves because she needs these reserves for growth, lactation and to maintain the pregnancy. The ideal body condition of a cow at breeding is between a 5 and a 6.
90 Days Prior to Calving and Calving: this is one of the last opportunities to put lost condition back onto cows (cost effectively) before calving. A good practice might be to separate thin cows from cows in better condition and feed them separately and pay special attention to those young cows and heifers. A cow’s nutritional requirement is lowered when not lactating and this should allow the cow to gain adequate body condition before calving, with minimal supplemental feeding, although care should still be taken not to add excessive fat before calving. The ideal body condition of cow 90 days before calving is around a 5 moving towards a 6 and for a heifer around a 6 moving towards a 7. Once the cows and heifers have calved it is very difficult to gain condition due to greater energy requirements of lactation, the cow is recovering from a reduction in body mass and also from fluid displacement.
Weaning: evaluating body condition at weaning can be used to determine which cows or heifers need to gain the most condition prior to calving again, since calves will no longer be suckling from them, they will be able to dry off and add on condition before calving again. The period from weaning to calving is one of the easiest and most economical times for a cow to regain condition, and producers who fail to adjust nutrition levels at this point might have difficulty adding on condition later on in the production cycle (Stewart & Dyer, University of Georgia).
To conclude, body condition scoring is a powerful tool to help better manage the system by matching the feed program to the needs of the cows. It is important to take time to record body condition at the critical time-points during the year in order to adjust the feed program when necessary. Factors affecting body condition play an important role in the economics of a beef cow-calf operation by ultimately affecting the percentage of viable calves each year. Monitoring condition using the nine-point BCS scale can increase the profit potential of the cow-calf enterprise.