While in nature calves transition from a liquid to a solid diet very gradually, often over a period of four to six months, on commercial dairy farms this important process is sped up significantly (see below). As such, great care must be taken regarding the manner in which weaning is accomplished. To identify the best practices in weaning, Dr. Harma Berends and the LifeStart team studied two crucial factors: age at weaning and abrupt vs. gradual weaning.
What they found provides a solid road map for navigating the difficult transition of weaning. Their findings are even more critical for successful calf rearing in commercial settings where neonatal calves are often fed higher planes of nutrition. Why? Higher energy intakes reduce solid feed intakes which in turn slows rumen development. In these circumstances, they found that calves benefit from being weaned later (in this case at eight weeks instead of at six weeks), and more gradually. How so?
They found that calves weaned at eight weeks instead of at six weeks had a substantial increase in starter intake in their final two weeks prior to weaning. This increase in starter better prepared them for the transition to a solid diet, most likely because it led to better rumen development. Thus, waiting an additional two weeks made a big difference in the calves' readiness for weaning.
The LifeStart team also found that weaning over a week or two, compared to doing so in just one day, had multiple benefits. By gradually increasing solid feed intake, growth dips that were normally seen at weaning were prevented. Additionally, since rumen development increases with solid feed intake, weaning more gradually when calves were fed higher levels of nutrition (and thereby had lower intakes of solid feed) created a much smoother and more efficient rumen development in the study.
While higher planes of nutrition are advised for many reasons, including benefits in overall growth and long-term production, Dr. Berends also stresses that it's important to begin providing solid feed, including starter or concentrate feed and roughage, at two weeks of life. "When you include roughage in the diet of a calf, we see that rumen pH increases and that it may prevent acidification," says Dr. Berends. Thus, the inclusion of roughage (particularly straw, as is the preference of the LifeStart team) allows for the maturing rumen to maintain the proper pH required for effective rumination.