Use of Body Condition Scores in Nutritional and Reproductive Management of the Beef Herd
It is difficult to predict how cattle will perform on specific forages. To aid in developing, monitoring, and adjusting a nutrition program for brood cows, you can gain valuable information by evaluating feed and observing the body condition of the cows. The amount of fat on cows and heifers provides a measure of how well the feeding program is meeting the herds nutritional requirements. Fat stores can be estimated by body condition scoring, a technique that is used routinely in managing dairy herd nutrition and one that can be equally valuable for beef cows and calves.
The amount of fat cows carry not only indicates nutritional status, but it also influences rebreeding following calving. If cows are thin when they calve, the period between calving and the start of cycling will be prolonged, and fewer cows will conceive by the end of the breeding season.
Voluntary feed intake is the most difficult nutritional factor to predict. Different classes of cattle require different levels of nutrients, but no matter how high the nutrient content of the forage, it cannot satisfy nutritional requirements if intake is low. Low intake can affect body condition, performance, and profitability.
As part of a routine winter feeding program, samples of forage can be collected and analyzed for crude protein and energy; intake can be estimated, and supplemental protein and energy (grain) can then be added to alleviate deficiencies. In addition to these steps, cows should be observed for changes in body condition that may indicate overnutrition or undernutrition.
When cows are at pasture, it is difficult to evaluate both their intake and the nutritional value of the forage. When pasture growth is reduced during summer droughts, or when cattle are grazing stockpiled forage during the late fall and winter, body condition scoring provides a practical way to judge nutritional status. If body condition declines below the critical level, the producer should provide cows with better grazing conditions or supplemental feeds.
Systems for Body Condition Scoring
There are a number of body condition scoring systems. In North Carolina, the 9-point system is recommended. The scoring system evaluates the amount of fat (condition) a cow carries. On a scale from 1 to 9, 1 represents a very thin, weak cow and 9 represents a grossly obese cow. Almost any cow can score a 1 or a 9 if severely starved or overfed. Condition scores may vary from one evaluator to the next, but if the same person routinely scores the herd, relative changes in condition become apparent with seasonal changes in feed quality and cow requirements.
The figure above shows the body areas that are evaluated in the condition scoring process. Fat on the back; around the tail head; over the pins, hooks and ribs; and in the brisket determine the condition score. To evaluate cows with long hair coats, use your hands to feel for fat cover. Listed below is a description of each body condition score (BCS).
BCS 1. Extremely thin and weak. Severe muscle wasting. Animal is near death.
BCS 2. Extremely thin but not weak. Muscle wasting is evident.
BCS 3. Very thin. All ribs and backbone easily visible and no apparent fat deposits. Some muscle wasting is evident in the hind quarter.
BCS 4. Thin. Ribs and backbone easily visible. No muscle wasting.
BCS 5. Moderate condition. Last two or three ribs are visible and little fat is evident in the brisket or around the tail head.
BCS 6. Smooth appearance. Ribs not easily visible. Only a small amount of fat deposition is evident around the tail head and in the brisket.
BCS 7. Fleshy appearance. Brisket and tail head have considerable fat deposition and the back has a flattened appearance.
BCS 8. Obese. Neck is thickened and appears short. Back is flat with dimples at the backbone. A lot of fat is present in the brisket and around the tail head.
BCS 9. Extremely obese. Appearance is similar to that for a score of 8 but more exaggerated. Brisket is extremely full of fat, and large pockets of fat are evident in the tail head and over the entire body.
Regardless of whether cows calve in spring or fall, they should be scored every 60 days (six times a year) and records should be kept so that changes can be detected. The ideal condition score for cows is 6, but they often increase to 7 when grazing is good and fall to 5 when forages are lower in nutritional value or are limited. Condition scores should not be allowed to fall below 5 or increase above 7. Scores below 5 usually result from severe parasite loads, disease, or malnutrition. Scores above 7 result when cows are barren, severely overfed, or milk production potential is very low.
Other Factors That Influence Scores
Several factors may affect estimates of body condition:
Breed type influences scoring because different breeds deposit fat in different areas.
Muscle thickness affects scores. Heavily muscled cows tend to score higher than thinly muscled cows with the same amount of fat cover.
Cows appear to be thinner when they have not eaten for several hours. Be sure to consider this factor or feed all cows before scoring.
Long hair coats also influence scores. Ribs are not as visible in the winter as they are in the summer when cows shed winter coats.
Critical Body Condition Scores
Cows should maintain a moderate condition (5 to 7) when calving and rebreeding. Excessive loss of body condition to a score below 5 in the first five or six weeks after calving may result in extended periods without estrous cycles or in lower fertility. If mature cows calve in slightly thin condition (at a score of 4), adequate nutrition should be provided to raise their score before rebreeding. Condition at calving is more critical for heaving-milking cows than average cows because they are pulled down after calving and have more trouble rebreeding. Cows can lose some condition after the breeding season but should be back in moderate condition 60 days before calving.
Condition scores vary within cow herd. With a target score of 6, there will always be some cows that score 5 or 7. However, if there is a wide range in condition within the herd, it may be advisable to separate the herd into two groups and feed them differently. For example, the thinner cows may be taken to better pastures or given high-quality hay, supplemental grain, or protein.
The cows that milk heaviest and lose weight easily should also be identified so they can be fed properly to avoid excessive loss of body condition. If forage supplies are low from drought, weaning the current calf crop early allows cows to reach optimum body condition (6) before the next calving and helps ensure successful rebreeding.
Calving heifers at 23 months and rebreeding them in the next 120 days is one of the greatest challenges facing most cow-calf producers. The heifers need extra energy and protein for milk production and growth. Heifers should be bred to calve one month before the cow herd at a body condition score of 6 to 7. They then should receive high quality forage to maintain this condition until they are rebred. A grain and protein supplement may be needed for first-calf heifers unless the forage is of very high quality. This recommendation is similar to that for cows, but the heifers high nutritional requirements make it more difficult to keep condition from slipping. Because of their extra nutritional needs, heifers nursing their first calves should be fed separately from the cow herd. Closely monitoring body condition from calving through the end of the breeding season makes it possible to provide the amount of supplemental feeding needed to keep heifers in moderate condition from successful rebreeding.
Monitoring body condition is useful in the nutritional and reproductive management of brood cows. Maintaining cows between 5 and 7 on a scale of 1 to 9, where 1 is very thin and 9 very fat, will reduce management problems while minimizing the cost of supplemental feeding. If a wide range of body condition exists within a herd, cows should be grouped based on condition and fed accordingly.
Additional information on nutritional programs for beef herds can be obtained from county Cooperative Extension Service agents and from the Southern Regional Beef Management Handbook, available from Extension Animal Husbandry, Campus Box 7621, North Carolina State University, Raleigh, NC 27695-7601.
Published by North Carolina Cooperative Extension Service