Influence of time and frequency of total mixed ration delivery on feeding behavior, milk production, and ruminal pH of lactating dairy cows

Abstract

The influence of time and frequency of feed delivery on the daily patterns of feeding behavior, milk production, and ruminal pH of lactating cows was evaluated by conducting two experiments. Forty lactating Holstein cows that were housed in free-stall barn were divided into two groups. Cows were milked twice daily at 0530 and 1600. To evaluate the effect of time of feeding, two feeding times were used in the first experiment:(A) feed delivery time that was the same as the milking time and (B) feed delivery at 1000 and 1600 (the same as the second milking time). In the second experiment that evaluated the frequency of feeding, two treatments were conducted with once and twice feed deliveries per day. Milk production and composition were not affected by the diet in both the experiments, although milk urea nitrogen tended to be lower when the feeding time was the same as the milking time, i.e., in A than in B, in experiment 1. In experiment 1, daily eating time in B was longer than that in A (P < 0.05). Furthermore, eating activity was found to be high in the morning, at the 1000 feeding time. In experiment 2, the eating time tended to be longer when feed delivery was once per day than twice per day (P < 0.10). Ruminal pH significantly decreased when the cows were fed twice per day (P < 0.05). These results indicated no negative influence in the productivity of lactating cows when the feed delivery was once per day. Further, the feeding activity increased when the feeding time was apart from the milking time.