A South Korean study reported in the February Journal of Dairy Science confirms the usefulness of a step-down milk feeding practice used by many calf growers.
During the study, one group of calves received whole milk at the rate of 10 percent of bodyweight for 45 days. A second group of calves followed a step-down method. Those calves received whole milk at the rate of 20 percent of bodyweight for 25 days. Then, between 26 and 30 days of age, researchers gradually reduced the milk-feeding rate from 20 percent to 10 percent by diluting the milk with water at each feeding. This lower feeding rate continued for the next 15 days of the study.
All calves had access to free-choice calf starter, water and chopped grass hay.
At 46 days of age, weaning began. Both groups of calves were weaned gradually by diluting the milk with water. To accomplish this, the researchers increased the amount of water by 10 percent of total volume at each feeding so that on day 50, all of the calves received water only.
Here are some of the results:
- Calves on the step-down method consumed about 62 percent more milk during the entire pre-weaning period than conventionally fed calves.
- Step-fed calves ate less starter and hay between birth and 30 days of age than conventionally fed calves.
- However, the step-fed calves compensated for this by rapidly increasing starter and hay intake after 30 days of age. In fact, the step-fed calves ate about 39 percent more starter between 31 and 50 days of age than conventionally fed calves.
- Step-fed calves gained more bodyweight than conventionally fed calves. For example, the step-fed calves gained nearly 111 percent more bodyweight between birth and 30 days of age than conventionally fed calves. The rate of gain slowed after 30 days, but step-fed calves still gained 41 percent more weight between 31 and 50 days of age than conventionally fed calves.
- Calves on the step method were heavier than conventionally fed calves at 30, 50 and 90 days of age. For instance, the step-fed calves were 32 pounds heavier at weaning at 50 days of age.
- Calves on the step method achieved greater feed efficiency than conventionally fed calves.
The researchers conclude that step-down milk feeding may prevent depressed starter intake in calves fed higher volumes of milk. It also may prevent poor weight gain associated with conventional milk feeding at 10 percent of bodyweight.
Source: February 2007 Journal of Dairy Science