Rory Lewandowski, Extension Educator Wayne County, Ohio State University Extension
The current state of the dairy economy has dairy farm managers looking for ways to improve cow productivity and reduce expenses. One management area that may offer some of these returns is the feed bunk. It is important to work with the herd nutritionist to provide a ration that will allow the dairy cow to produce a high level of milk, but beyond the nutrient composition of the ration, the manager must understand and work with cow feeding behavior to promote maximum dry matter intake (DMI). The following comments are based upon an eXtension article entitled “The Feeding Behavior of Dairy Cows: Considerations to Improve Cow Welfare and Productivity.”
Dairy cows managed in an indoor production system typically spend 4 to 6 hours per day eating, ideally divided into 9 to 14 separate meals or feeding sessions. The delivery of fresh feed is a major stimulus to cow feeding and research demonstrates that the 60 minutes following fresh fed delivery produces a peak feeding pattern. Research has also shown that there is benefit to coordinating the delivery of fresh feed with a return from the milking parlor. Cows that had access to feed after milking stood longer (48 versus 21 minutes) than cows that did not have access to feed after returning from milking. The additional standing time is beneficial from the standpoint of providing adequate time for the teat sphincter muscle to fully close, thus reducing the risk of intramammary infection from exposure to environmental bacteria when cows lie down too soon after milking. Based on this research, adding an additional fresh fed delivery could help to improve DMI intake or, more likely, result in a more even feeding time distribution. Increased feed delivery can reduce diurnal fluctuations in rumen pH and possibly reduce the risk of subacute ruminal acidosis in some situations.
If an additional fresh fed delivery is out of the question, more frequent feed push-up is another management practice that can offer a number of benefits, including higher DMI, greater fat-corrected milk yields, less feed refusal, and an increase in standing time after milking. Typically, sorting occurs by the first cows to eat the freshly delivered feed, which create holes in the feed pile. Cows that eat later do not have the same ration consistency as those first cows. Pushing feed up remixes the feed pile, which provides a better ration to those cows that follow the first eaters. When feed is pushed up, it can also stimulate another feeding session for the cows, creating another meal opportunity. The goal is to get cows to eat more frequent, smaller meals throughout the day. This creates a better pH balance within the rumen as compared to a situation where cows slug feed with fewer, larger meals. Slug feeding can disrupt rumen pH balance and lead to milk fat depression. After the initial feeding period, the feed bunk piles are often scattered, providing a large surface area for oxygen to degrade the forage portion of the ration, in particular ensiled forages. Pushing feed up puts feed back into piles with less surface area, which can help to prevent or reduce heating and reduce feed waste by refusal. If feed is not delivered after milking, then pushing up feed after milking can stimulate cows to eat and increase standing time after milking, allowing more time for the teat canal to close.
A final factor to look at to help improve the DMI and distribution of feeding times and meals for cows is stocking density. The eXtension article says, “recent research suggests that overcrowding at the feed bunk may have deleterious effects on feeding behavior.” In 2000, Batchelder (Proceedings from Dairy Housing and Equipment Systems: Managing and Planning for Profitability, Camp Hill, Pennsylvania) reported that using 30% overcrowding (1.3 cows/headlock) reduced daily DMI and resulted in substantially fewer cows eating during both the hour following milking and following delivery of fresh feed. Other research has shown that in overcrowding situations, cows will stand and wait for a feeding spot. Increased standing times are associated with a higher risk of developing hoof and leg injuries. In addition, some researchers have noted increased aggression in feeding areas when cows are overcrowded and this behavior can lead to higher incidences of hoof lesion development and lameness.
Dairy managers have opportunities to increase productivity and reduce costs by improving feed bunk management to take advantage of cow feeding behaviors. The entire eXtension article is available online at http://tiny.cc/cowfeedingbehavior.