Given the waning days of winter, one may conclude that dairy calves are beyond the added nutritional requirements of cold-weather feeding. Is this the time of the year that calf managers could start saving labor?
The answer is "no."
According to the National Research Council's "Nutrient Requirements of Dairy Cattle," 2001 edition, energy requirements for calves increase below 68 F. In the U.S., nighttime temperatures above 68 F are not the norm; most regions meet this criterion only a few days during the summer. So even though the days are getting warmer, don't be too hasty in reducing those much needed nutrients to calves.
Feeding liquid to calves, whether milk, transition milk or milk replacer, usually is time-consuming and labor-intensive. This can become a significant expense for some dairy producers, particularly if labor is at a premium on the farm. One method for improving labor efficiency in the calf-rearing enterprise is to reduce the number of daily feedings from two to one. In most cases, feeding once a day means combining the amount normally fed twice daily into one feeding.
What effect does once-daily feeding of liquid have on the calf? From the standpoint of digestibility, metabolizability and growth rates, it does not appear to have a significant effect. Researchers in the United Kingdom found feeding frequency (one, two, four or six times daily) had no effect on growth rates or energy balance when calves were less than 28 days of age.
Note, however, that the researchers in these studies fed whole milk or a milk replacer that contained casein and clotted in the abomasum. Clotted casein is released slowly and provides a more continuous source of nutrients throughout the day. Researchers have not determined whether using modern milk replacers based on whey proteins (that don't clot in the rumen) will provide the same nutrient flow during the day when those replacers are fed once daily.
A lack of abomasal clotting may result in a period of nutrient deprivation during the evening. However, using whole or waste milk in a once-daily feeding system has worked satisfactorily, but less so in the winter.
Typically, one feeding of milk or milk replacer is offered in the morning. If calves have been fed twice daily for any length of time, you should expect to hear significant "complaining" when calves are moved to once-daily feeding. Many producers don't feed once daily simply because the calves complain too much.
On the other hand, research at the University of Wisconsin found that calves fed 2.5 pounds of 28 percent protein per day and 20 percent fat milk replacer three times a day instead of twice weighed 10.3 pounds more, were 1.7 centimeters taller and showed greater feed efficiency. The milk replacer powder was diluted to 17 percent solids. These calves were more likely able to obtain higher growth rates and feeding efficiencies due to a more constant source of nutrients throughout the day.