The behavior of cows has been studied for many years, but little research has focused on behavior from a nutritional perspective. Research scientists at the University of Guelph and the University of British Columbia recently conducted an experiment to determine how behavior influences nutrition of dairy cattle.
Ensuring adequate feeding time and equal access to the feed bunk by all cows in a group is important as cows have been shown to sort through total mixed rations. The first preference of most cows is the grain concentrate component while leaving the longer forage components.
Sorting of the diet can lead to cows consuming an inconsistent ration which can lead to acidosis. Additionally, sorting by dominant animals leaves an inconsistent remaining ration, especially in the later hours past the time of feed delivery.
Cows that can’t access the feed bunk at peak feeding times may not maintain adequate nutrition to allow for maximum milk production.
It has typically been accepted that dairy cattle consume most of their feed during the day, particularly around sunset and sunrise. However, this observation has been almost exclusively based on observing patterns of grazing animals.
In this experiment, the feeding pattern of group-housed cows fed a total mixed ration was observed. Results showed that cows consumed an average of 7.3 meals per day and had an approximate daily meal time of six hours per day.
The results also showed that the feeding pattern was mostly influenced by the time of feed delivery, feed push-up and milking. The most dramatic peaks in feeding activity occur around the time of feed delivery and the return from milking.
As a follow-up to determine which management functions stimulated cattle to go to the feed bunk, the researchers separated the feed delivery and milking times by six hours. When animals were fed six hours after milking, they increased total daily feeding time by 12.5 percent.
These results indicate that the management practice of feed delivery acts as the primary influence on the daily feeding pattern of lactating dairy cows, and not, as previously thought, the time of day.
One of the most common feeding management practices believed to stimulate feeding activity is feed push-up. As cows sort their total mixed ration, they have a natural tendency to throw feed forward to where it is no longer in reach. For this reason, it is common to push feed closer to cows between feedings to ensure cows have adequate access to feed.
In two separate studies it was determined that pushing feed closer to the cows did little to increase the number of cows eating in comparison to milking on feed bunk attendance. However, this practice is still important so that cows have access to feed when they want to eat.
Because delivery of fresh feed is an important factor in stimulating cows to eat, it would be reasonable to assume that the frequency of feed delivery should influence feeding patterns of lactating cattle.
To test this prediction, researchers designed an experiment to determine what effect increased feed delivery had on feeding patterns of group-housed dairy cows. Feed was delivered to the cows one time per day, two times per day and four times per day. Increasing frequency of feed delivery increased total daily feeding time by 10 to 14 minutes. Frequency of feeding had no effect on the daily lying time or the total number of aggressive interactions at the feed bunk.
However, the results also showed that subordinate cows were not displaced as frequently when fed more often, indicating these cows would have greater access to feed, particularly fresh feed, when the frequency of feed delivery is high.
— Source: Proceedings of the Tri-State Dairy Nutrition Conference, April 2008.