There are varied opinions regarding when and how much forage to start feeding young dairy calves. In this ongoing debate, Dr. Alex Bach from Spain recently weighed in his opinion at the recent 25th ADSA Discover Conference on Food Animal Agriculture. The conference focused exclusively on new developments in immunity, nutrition and management of the pre-ruminant calf, and was attended by many of the leading dairy calf researchers from around the world.
Bach, who is a researcher with the Institute for Research and Technology in Agrifood at the Catalan Institution for Research and Advanced Studies, Barcelona, Spain, has performed a number of studies on calf feed particle size and nutrition content, and exhaustively reviewed decades of research by others on the subject.
His conclusion: the industry needs to rethink the current, widespread recommendation to delay forage feeding to calves before two months of age. He adds the important caveat that the first forage provided to calves should be low-quality, so that calves consume enough forage to stimulate the rumination process, but not so much that it displaces starter intake.
"We've conducted studies in which preweaned calves were fed high-quality forages, with disappointing results," says Bach. "They eat and eat and eat the forage, but they don't grow. If the forage source tastes like candy to them, they'll create too much gut fill with the forage and de-select their starter ration, removing important energy and protein content from their diets."
Bach's suggested guidelines for starting calves on forage include:
- Choose a forage source high in fiber but low in nutritive value, such as straw or poor-quality grass hay.
- Chop forage to a particle size of 2 to 3 cm (about 1 inch).
- Feed the forage source at no more than 5% of the total solids ration to avoid gut-fill issues. Ideally, it should be offered free-choice. If it is poor quality, it will not be consumed at more than 3 to 5% of total solid feed consumption.
- Start adding the forage source to calves" diets approximately 2 to 3 weeks of age.
Bach emphasizes that "low-quality" refers to the physical composition and nutritive value of the forage source, but he does not imply that calves should be fed moldy or spoiled feedstuffs.
He contends that calves can experience a growth slump in the weaning transition period. This is especially true for animals that have been on accelerated milk regimens. "If they don't transition well off of the milk diet, calves can lose a considerable amount of the gain advantage they had previously achieved," says Bach. "We need animals to be able to consume and digest forage efficiently before weaning."