Do pre-weaned calves need forage?
Before the 1950s, it was assumed that hay and long forages were necessary to promote rumen development in young calves. However, research conducted during the mid-to-late 1950s demonstrated the importance of grain for rumen development. The digestion of rapidly fermentable carbohydrates (i.e., grain) in the rumen generates the volatile fatty acids propionate and butyrate. Butyrate is the key to rumen papillae development, which is critical for optimal rumen function.
These studies highlighted the significance of starter grain intake of pre-weaned calves and led to the development of the industry standard that suggests that the level of starter grain intake be considered before a calf is weaned. The current standard indicates that a Holstein dairy calf should be consistently consuming at least 2.2 pounds of starter per day before weaning. Although consumption of starter grain is crucial for rumen development, whether forage has a place in the pre-weaned calf nutrition program has been up for debate for decades.