We often associate body condition scoring, or BCS, with how fat or thin a cow, sheep, goat or hog might be. But we may need to temper our expectations for maintaining BCS for grazing animals.
Scales for scoring vary depending on the species. For beef cattle, a scale of one to nine is used with one representing very thin animals and nine representing obesity; for sheep, goats and dairy cattle, the scale ranges from one to five and, likewise, one is very thin while five is obese.
In beef cattle, a single point change in scores is approximately 80-100 pounds of live weight, but may range anywhere from 10 to 200 pounds depending on the pregnancy status of a female.
It important to keep in mind that BCS is not associated with total weight of the animal at a single point in time, but rather the distribution of fat. We usually strive for a score in the middle of these scales, typically a five for beef cattle and a three for small ruminants and dairy. Also, keep in mind that the score or target BCS can vary with the age of physiological development.
Body condition is important to track. It often correlates with productivity of an individual as well as reproductive performance, especially during calving and the breeding season. If measuring BCS to gain an idea of rebreeding performance, taking measurements not just at one point in time but during weaning, before and during calving and during breeding can give a better idea of rebreeding performance.
BCS at calving
The most difficult time to obtain a body condition score is during calving when animals are often lactating more and therefore have a higher energy requirement. Periods including late gestation and early lactation will typically be marked by low nutrition and BCS that negatively impacts performance.
In cattle, in order to get from a BCS of one to the desired five at calving, a cow would need to gain an additional 350 pounds – which is likely not feasible 90-100 days prepartum.
To go from a BCS of four to five at calving within the same time range, a cow would need to gain 150-200 pounds. If the cow is at a BCS of five, it would still need to gain additional weight to make up for the weight of the fetus and placenta, about 100 pounds.
For a cow at a BCS of seven, no weight gain would be needed to be in the ideal five-seven range at calving.
Balancing act
Managing body condition is a balancing act. Fat is formed when energy intake exceeds the energy needed for production. While some fat is good — it insulates animals during the winter months and can level out variability in energy intake — too much or too little can be a problem.
BCS should be identified by sorting groups rather than on an individual basis to match feed quality. Thin, moderate and fat are typical classifications used for sorting individuals into groups. Higher quality feeds go to thinner animals while lower quality feeds go to the animals with high BCSs.
Grazing focus
So what does this mean for grazing? When livestock feed on forages, scores for body condition can reflect the quality and quantity of forage that is available to an animal.
Take for instance cattle that feed on two separate bales of hay – one of high energy content and a good relative feed value and the other of poor quality.
Even though each bale may look and weigh the same, an individual feeding on the poor quality bale is not getting enough nutritional value from that bale to meet its energy requirements. Consistently feeding on poor quality hay can lead to lower BCS.
The best way to know whether a bale is good quality or poor is to forage test. The accuracy of these tests depends on how well you sample. Contact your county extension office if you need assistance with collecting forage samples. During the winter months, we often need supplemental feed programs as a primary source of nutrition since crude protein values of forages are often at their lowest point during this time of year. Summer forage conditions are often tied directly to grazing management. Therefore, we can use BCS to inform ourselves how effective our current grazing management system performs.
Resources for further learning:
3 step body condition scoring guide for range cattle: https://www.wyoextension.org/publications/html/B1294/
Body condition score as a nutritional management tool: https://extension.psu.edu/body-condition-score-as-a-nutritional-management-tool
Scoring cows can improve profits: https://ohioline.osu.edu/factsheet/anr-54
Body condition scoring of beef cows: https://go.osu.edu/beefbcsvirginiatech
