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.
A recent nationwide study by Merck Animal Health found that the number of producers feeding three times a day is increasing. In 2007, the National Animal Health Monitoring System found only 5.4 percent of the calf raisers were feeding three times a day. A more recent study (2010) revealed 8 percent of the calf raisers were feeding three times a day, with 14 percent doing so in the winter.
While both feeding programs have merit, management limitations matter.
Compelling evidence indicates labor cost needs to be considered when thinking about implementing a three-times-per-day feeding system. However, more efficient animals could offset the additional labor cost. Additionally, the Wisconsin study found that calves fed three times per day were more likely to complete the first lactation, potentially reducing future culling costs.
OK, now what? Well, if your management allows it, consider a three-times-per-day feeding program, especially in the winter when calves require a constant source of energy in their liquid diets to sustain maintenance and growth. Note that this concept presents the same allocation of feed, but it is just delivered three times a day. Feeding three times a day will optimize your chance of raising healthy calves that grow into productive, lactating cows.
Nonetheless, feeding three times a day results in a cost of time in the form of labor. To offset that cost, some dairy producers have introduced computerized calf feeders, which allow them to divide liquid diets into multiple smaller meals. Canadian studies have demonstrated that calves will nurse four to eight times daily. Researchers believe that calves instinctively feed more often to maximize nutrient availability. Because automatic calf feeders can produce that level of delivery, they are an option to consider.
Recently, several North Dakota dairy farms installed such systems. During a producer panel session at the last dairy convention, some of these dairy producers noted that to implement this technology successfully, computerized feeding systems require a shift in management priorities, including more frequent observations of calves and the adoption of protocols to monitor the mixing of the powder, temperature calibration and equipment sanitation to make sure they are done correctly.
One final caution: Calves are especially sensitive to the overall level of management. Research has shown repeatedly that calves are healthier when they are monitored frequently. While feeding milk to calves once daily, or investing in a technology and/or letting the computer do it, may not affect the digestibility of nutrients markedly, less monitoring can lead to increased health problems. While both feeding options may save labor, increased morbidity and mortality resulting from decreased observation may increase costs.