One of the key aspects in dairy production is dry matter intake. It is fundamental to ensure cows eat enough feed to maximize production and prevent diseases. This is particularly important when feeding lactating and close-up cows. Several studies show that when cows eat well before calving, they normally tend to perform well after calving.
On the other hand, according to statistics from veterinary studies, the complex of ketosis, fatty liver, and displaced abomasum has emerged as the most frequently investigated herd problem. In these herds, cow behavior and social factors appear to be the primary risk factors.
Dr. Ken Nordlund and his colleagues from the University of Wisconsin say that “where poorly-formulated rations and inaccurate delivery systems were once the primary risk factors, we increasingly see poorly-staged pen moves and overstocking as the key risk factors in our industry today.” According to them, this promotes a disruption of dry matter intake leading to the problems indicated above.
A lot of research has been, and continues to be, done on the nutritional aspects of the diet. Even with advances in this side of the equation, there continues to be research conducted on cow behavior to try to understand which factors promote or discourage feeding activity in dairy cattle, thereby leading to improvements in feeding management practices.
Cows are social animals categorized as allelomimetic, meaning they all want to do the same thing at the same time. They are also described as crepuscular, meaning they are particularly active in the twilight hours of dawn and dusk. This is particularly true for grazing animals.
For housed dairy cattle, according to work from the Animal Welfare Program at the University of British Columbia, times of feeding activity are typically associated with the time of feed delivery and milking, regardless of the time of day at which these occur. These characteristics have consequences on stocking density regarding requirements for stalls and feeding space, because if all animals want to do the same things at the same time, the facilities should have dimensions with this in mind.
Effect of feeding space on aggression and feeding behavior
Modern freestall barns normally have 0.6 meters of feed alley space per cow. The mentioned program from British Columbia University has been actively studying feeding behavior of dairy cows. They conducted a study where they doubled the amount of feeding space from 0.5 meters to 1 meter per animal to see if this would lead to more space between cows at the feeder and fewer aggressive social interactions among cows, allowing cows to increase their feeding activity, particularly at peak feeding times.
They concluded that when provided with more space at the feeder, cows increased distances from their nearest neighbor, reduced their frequency of aggressive interactions, and increased daily feeding time by 14 percent. They also concluded that increasing feeding space to 1 meter per cow allows subordinate cows to increase feeding activity at peak feeding times.
Although research done in 1977 showed that cows can be kept with as little as 0.2 meters of feeding space per cow without adversely affecting DMI or milk production, it also showed that with such a small feedbunk space, many cows may not be able to gain access to feed at peak feeding times, forcing them to shift their feeding times to other parts of the day, including late at night.
According to Dr. DeVries from B.C. University, such a shift in feeding time may be problematic for cows, because sorting of the TMR can reduce the quality of feed for those who do not have access at the time fresh food is provided. Their results indicate that providing more feeding space improves access to fresh feed, particularly for the subordinate cows, which possibly reduces the variation in diet quality consumed by cows.
This can potentially reduce the risk for metabolic problems such as subacute ruminal acidosis and left displaced abomasums. They concluded by recommending an increase on the feeding space over the current industry standard.
Effect of feeding space and feed barrier design on the feeding behavior of dairy cows
On a later date, the team from B.C. University did another study using different feed barrier designs, namely the use of a headlock barrier and a feed stall partition to see if this would provide additional protection while feeding for subordinate cows.
In this same study they also tested different feedbunk space/cow, namely 0.64 meters and 0.92 meters with just a post-and-rail feed barrier and 0.87 meters feedbunk space but with feed stalls separating the cows. Total daily feeding time increased and the frequency of aggressive interactions at the feedbunk decreased when more bunk space was increased from 0.64 to 0.92 meters per cow, confirming previous research.
The addition of feed stalls resulted in even more pronounced effects compared with when cows had 0.92 meters per cow of bunk space. The average number of times a cow was displaced from the feedbunk that had feed stalls was only 45.5 percent of the level seen for the 0.92-meter treatment.
According to this research, as long as we have some kind of separation between cows, like the feed stalls or the headlock barrier, the feeding bunk space can be reduced, allowing for a less costly building. The design of the feed stalls is detailed in Figure 1.
This is very interesting research. Even if one decides not to increase feedbunk space or use feed barriers on every pen, a good place to start would be in the fresh and close-up cow pens. Dry cows are very sensitive to overcrowding: an 11 percent decrease in DMI was observed when numbers went from 88 percent to 93 percent of capacity in a headlock pen, and early-lactation cows often experience difficulty in meeting their nutritional requirements and succumb to disease. PD
References omitted due to space but are available upon request to email@example.com.
—Excerpts from Kenpal Farm Products Dairy Briefs
Pedro Nogueira is a ruminant nutritionist withKenpal Farm Products. Email Pedro Nogureira.