Body condition score is the numerical scale (1-9) used to describe the body composition of both fat and muscle of a cow herd. Increasing body condition of a herd requires cattle to consume a diet that is balanced for minerals, vitamins, and protein with excess energy (TDN). Each body condition score is equal to roughly 90 pounds, including some of the fetus and fetal membrane fluids. Additionally, each BCS is about a 4% increase in fat. For example, moving a cow from a BCS 4 to BCS 5 is about 90 pounds with 4% more body fat.
Cows with a thin BCS (< 4) typically take a longer time to cycle back after calving and have lower pregnancy rates compared to better conditioned cows (5 <). This is due to how a cow’s body naturally prioritizes nutrients from the diet. Cows on a negative plane of nutrition, not meeting their requirements, will cause the body to partition nutrients to priority areas such as maintenance for cow survival.