Relationship Between Body Condition Score (BCS) and Feed Efficiency in Lactating Dairy Cattle

Increasing feed efficiency in dairy cattle leads to increased profitability. Feed efficiency in dairy cattle represents the balance between milk production and feed intake. It is desirable if a dairy cow can make more milk with less feed input. There is concern, however, that selecting for a more feed efficient cow might lead to cows that suffer extreme body tissue loss to meet the demands of increased milk production. To research this concern, the relationships between body condition score (BCS) observed during the last 130 days of first lactation and the first 45 days of second lactation and two measures of feed efficiency, residual feed intake (RFI) and gross efficiency (GE), measured during mid-lactation were assessed in 98 first lactation Holstein cows to. Residual feed intake was defined as the difference between the amount of feed an animal is expected to eat and how much they actually consume. No significant differences in BCS at 2nd lactation calving, at approximately 40 days in milk (dim), nor in BCS loss during the first 25 and first 45 dim were observed between the 10 most feed efficient and 10 most feed inefficient cows when either RFI or GE was used as the measure of feed efficiency. Our findings suggest that selection based on RFI as a measure of feed efficiency during mid-lactation should not impact change in BCS during early second lactation.