Effects of feed composition and stage of lactation on the short-term feeding behavior of dairy cows

Twenty Holstein-Friesian cows were assigned to one of four feeding groups t hroughout lactation in a full change-over experiment using two total mixed diets. The low concentrate total mixed diet contained 100 g of concentrate/ kg of fresh matter, and the high concentrate total mixed diet contained 300 g of concentrate/kg of fresh matter. The remainder of the total mixed diet was grass silage. The two changeover groups switched total mixed diets at 153 d of lactation; the other two treatment groups remained on their assign ed diets throughout lactation. For analysis of short-term feeding behavior, four periods of 3 wk each were identified. The midpoints of these periods were -102, -18, 18, and 102 d from the changeover. The concentrate content of the total mixed diet significantly affected dry matter intake and all sh ort-term feeding behavior variables. Cows that consumed the high concentrat e total mixed diet had fewer but longer visits to the feeders and ate more feed per visit than did cows consuming the low concentrate total mixed diet . With one exception, no significant effect of stage of lactation was detec ted for any of the short-term feeding behavior variables. Despite a highly significant decline in dry matter intake as lactation progressed for cows c onsuming the high concentrate total mixed diet, there were no interactions between total mixed diet and stage of lactation for any of the short-term f eeding behavior variables. Large differences in feeding behavior were detec ted between cows consuming the same total mixed diet. These last two findin gs suggest that the use of short-term feeding behavior variables to predict daily intake is unlikely to be successful.