Providing more milk is a great decision for calf welfare and long-term performance, reducing hunger and helping support growth during the critical period of early life. The dairy Code of Practice recommends feeding calves 20% of their body weight in milk. From a health standpoint, there is little need to worry that consuming more milk will cause calf illness or scours. While there have been occasional reports of increased diarrhea in calves provided higher milk allowances, these reports are infrequent and may be due to differences in how fecal scores are evaluated and other variation in feeding practices between studies. It is much more likely that providing more milk will improve calf health. It is well established that improved nutrition and energy intake supports immune function and reduces disease susceptibility. If the calf does become sick, consuming more milk will also help keep her hydrated to better recover from scours.

When increasing milk allowance, it is possible that you may begin seeing slightly looser manure in calves drinking substantially more milk than was previously fed, partly because starter intake is likely to be reduced during earlier weeks of the milk-feeding period. However, if calves are persistently sick and experiencing scours, a veterinarian could confirm what pathogen may be present, and the problem may be related to hygiene and cleaning practices or colostrum quality. While it is also important to check aspects of milk-feeding management, such as correct mixing of milk replacer, the problem will not be due to the amount of milk provided. Calves nursing on the dam consume 20% or more of their body weight in milk, and this volume of milk intake is biologically normal and healthy for the developing calf.

When increasing milk allowance, it is also important to consider a weaning method that will gradually reduce milk intake. If providing milk at a rate of 20% of their body weight, calves should be weaned through a gradual step-down process lasting at least two to three weeks, to encourage starter intake prior to removal of milk. This will ease the stress of this transition and allow calves to maintain nutrient intake and growth, which is also key for their health.