Equal-Opportunity Feeding In The Bunk

Giving cows a few more inches at the feedbunk will help maintain milk production and promote good herd health. They need equal access to the total mixed ration (TMR) formulated for them, because it reduces variation in dry matter intake, says Trevor DeVries.

When there’s too little bunk space, that goal may be thwarted and more-dominant cows will eat more than their share of the TMR, sort for grain and leave the forage.

“There are a lot of producers doing a super job of ensuring good access, but this is not always the case,” adds DeVries, a University of Guelph dairy scientist based in Ontario.

The least dominant and most vulnerable cows – usually transition cows – are most likely to be affected by poor feed access.

“Approximately 30-50% of cows have one or more adverse health events during their transition periods, so any practices that can help reduce metabolic and infectious diseases during this time are tremendously valuable,” he says.

Insufficient bunk space causes a couple of stressful situations. “One, the cows become aggressive to gain access to the feed. They hit one another with their heads to displace each other from the bunk,” says DeVries. “Those cows that remain at the bunk are forced to eat quickly, reducing the amount of chewing time, saliva production and rumen buffering.”

In the second scenario, cows leave the bunk without eating and return later. “By then, the feed’s been picked through, so they’re eating a much different diet than what was originally formulated for them. Or, if the feed is not pushed back, there might be very little left for them to eat at all.”

He offers these strategies to improve access:

• Increase the number of times you feed to more evenly distribute the cows’ feeding activity over a day. “This becomes a time issue for a lot of producers. Feeding them once is viewed as an easier thing to do, but there are some consequences for doing that.”
• Push feed up often enough so the bunk is never empty. “Typically, that means pushing it up a couple of times between feedings if you’re feeding multiple times. If you’re only feeding once a day, it should be done at least every few hours.”
• Increase the amount of space per cow at the feedbunk; transition cows should be allocated 30” each. “If possible, create more space per cow by reducing the number of cows per pen. Producers don’t always have that option, but as decisions are being made to build new barns or additions, adequate space should be a major consideration.”
• To reduce competition, use headlock systems or other types of physical partitions at the bunk.
• Add liquids with caution. Dry feeds are easier for cows to sort than wet feeds, but adding too much water, especially on hot days, can cause feed to overheat.

DeVries also strongly suggests closely matching feed deliveries with milking times, because it takes up to an hour or more after milking for the cows’ teat ends to close.

“You want cows to come back from the milking parlor and have fresh feed in front of them to keep them on their feet,” DeVries explains. If they lie down before then, they increase their chances of picking up udder infections.