Effect of diet and parity on meal patterns of lactating dairy cows

Abstract

Four multiparous and four primiparous lactating dairy cows housed in stalls were used in a double 4 × 4 Latin square to determine the effect of parity and diet on meal patterns. Cows were fed one of four diets: three total mixed rations containing 40, 50, or 60% barley silage on a dry matter (DM) basis, and a diet in which forage and concentrate were allocated separately (SI) containing 50% concentrate. Dry matter intake was similar for all diets (18.2 ± 0.6 kg d -1 ), as were the number of meals per day (10 ± 1 meals d -1 ) and meal duration (35 ± 3 min meal -1 ). Meal size was larger (5.2 vs. 1.1 or 1.9 kg DM meal -1 ), and eating rate was faster (0.265 vs. 0.053 or 0.034 kg DM min -1 ) when cows consumed concentrate, compared with silage or TMR, respectively. Meal size of TMR, silage or concentrate was positively related to DM intake (r = 0.82, 0.76, and 0.98; respectively). For cows consuming TMR, the number of meals per day was negatively related to DM intake (r = -0.41). Dry matter intake increased when meal size increased, primarily as a result of longer meals and, to a lesser extent, faster eating rate. Feeding management had little effect on meal patterns. Multiparous cows tended to eat more in each meal compared with primiparous cows, but both groups spent the same amount of time eating per meal. Key words: Cows, parity, meal patterns, feeding management