Calf rearing impact lifetime eating behavior
FORT ATKINSON - When it comes to cows, it's not only important what they eat, but how they eat it.
Fortunately, dairy farmers can do a lot to ensure good growth and a lifetime of healthy eating patterns in their calves. That's because critical eating behaviors, such as size and frequency of meals and picky or fast eating, are shaped early on in a cow's life.
"Calves are very impressionable," Dr. Trevor DeVries said during the May Hoard's Dairyman webinar.
His presentation from Guelph, Canada's Dairy University, was co-hosted by Abby Bauer, Hoard's Dairyman, and Mike Hutjens, University of Illinois. It was sponsored by AAS (Advanced Agri Solutions).
The way dairy farmers feed, house and manage their calves impacts the learning and persistence of their feeding patterns, DeVries stressed. These patterns can have immediate consequences, specifically with nutrition consumption and growth, as have long-term implications for production and health.
It's not news that feeding behavior affects the health and productivity of lactating cows. "We know it's not just what we throw in front of them, but how the cow deals with that feed," DeVries noted.
More time and more meals at the bunk equate to greater dry matter intake (DMI), while more sorting at a cow level results in lower milk components.
The big question is what impacts these feeding patterns early in life and whether they persist over time.
For starters, a young calf needs access to milk in sufficient quantities. "Calves will drink much more milk than we have traditionally provided," DeVries pointed out.
Multiple studies show feeding a calf more milk lowers her stress levels, improves her immune function and the efficiency of her feed conversion. It results in higher growth rates, and maintains that weight advantage post-weaning.
Calves fed ample milk diets reach first breeding at an earlier age and demonstrate improved lactational performance, DeVries added, citing 1,550 kg. more milk in the first lactation for each 1 kg difference in average daily gain during the first two months of life.
The key point, DeVries said, is that calves fed high levels of milk consumed their solid feed at a slower rate, in smaller meals, with longer pauses while eating, and with a lesser response to feed delivery.
Solid feed, both starter concentrate and fiber/forage, establishes fermentation in the rumen, which initiates the process of physical and metabolic development.
Research has clarified that forage access early in life does not delay rumen metabolic development. In fact, it promotes solid feed consumption, both before and after weaning, DeVries said.
Just be careful with the type, amount and length of the forage, he cautioned, since the physical form of the forage plays a role in the calf's growth and behavior.
Pre-weaning, calves should be provided with a high quality (20-22 percent protein), palatable starter concentrate. Mix a forage source in with the grain. The best is grass hay or cereal straw, chopped one-inch or less, and limited to about 5 percent of total DMI.
Providing physically-effective forage has been shown to improve gain-to-feed ratios, as well as pos t-weaning feed intakes and total tract nutrient digestibility.
The difference in physically effectiveness of the forage had longer-term effects on sorting, DeVries added. Research comparing TMR vs. top dressed rations after weaning show that slug feeding type eating patterns may be learned.
"Mixed diets fed before and after weaning should promote consistency in intake, in both time and composition", he said.
Social aspects, impact
Another way to promote better eating patterns in dairy calves is to let them keep each other company.
Grouping calves improves both solid food intake and growth, DeVries reported. Studies show calves housed in pairs prior to weaning consumed more concentrate and developed healthier eating patterns, including eating more meals each day.
However, just like cows, they want to be able to feed at the same time, DeVries said, which means another way dairy farmers can set the stage for their cows' future success is by making sure their calves don't have to compete for access to their feed.