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Over the years, the practice of feeding calves through an automatic feeding system has been explored. Even though the conventional way of feeding milk or milk replacer to calves individually 2 or 3 times daily has been proven to result in healthy and profitable calves, some farmers are considering ways to reduce time spent feeding calves. Most automatic calf feeders are programmed to use accelerated calf feeding programs where more total volume of milk is fed per day but in smaller more frequent meals, similar to how a calf nurses its dam. This automatic system identifies a calf through an ear tag or a neck collar and dispenses an amount of milk based on how the system has been programmed, such as based on age, body weight, etc. When managed properly, this feeding system provides for excellent growth of the calf. Additionally, when these systems are used correctly, they can reduce the stress on the calf at the time of weaning. Some key points to remember when weaning calves from an automatic calf feeding system include:
At the time of weaning, calves usually are consuming between 8 to 16 quarts/day of milk or reconstituted milk replacer, depending on how the feeder was programmed and the goals of the operation. These calves usually visit the feeder 4 to 8 times per day and consume around 2 quarts per visit. The computer will then recognize that the calf is at a management-determined age, usually 50 days of age. Now, the computer will start reducing the amount of milk the calf receives during each visit and decrease the number of visits where milk is available to the calf each day. This step-down process is usually done over a week to 10 days. After this time period, the computer will stop providing milk to the calf.
With accelerated calf feeding programs, more milk is fed during the suckling phase than conventional calf rearing methods. Feeding these higher amounts of milk likely means that calves are not eating as much starter as calves that are fed on a conventional system where less milk is fed. To stimulate increased intake of starter, weaning should occur over a 1- to 2-week period whereby the amount of milk fed is slowly decreased. When calves are weaned suddenly over a shorter period, the intake of starter is not sufficient to provide for the energy needs of the calf. Consequently, the calf may not gain weight or may actually lose weight during the weaning phase. By reducing the amount of milk calves receive at each visit, this will promote the calf to consume more starter and increase energy intake from the starter while decreasing energy supplied through the milk. Additionally, this weaning technique will decrease the number of unrewarded visits than if the amount of milk is removed quickly, decreasing the stress to the weaning calf.
Water always should be available and starter should be available after three days of age or when the calf is introduced to group housing. As the calf drops in milk consumption, it will begin to consume more starter to keep from becoming hungry. If adequate amount of starter is not available, behavior changes to show signs of hunger, such as bawling, and more unrewarded visits to the feeder will occur. Water intake is also directly related to feed intake, so the more feed the calf consumes, the more water it will consume. Water provides moisture to rumen bacteria and along with calf starter intake creates a perfect environment for rumen fermentation and the subsequent development of rumen papillae. Additionally, clean water helps prevent diarrhea, even before the weaning process.
It may be tempting to remove the recently weaned calf from the pen right away to provide space for a new calf or to prevent the weaned calf from blocking the feeder from other calves. The weaning period is a big stressor for calves. During periods of stress, animals will reduce feed intake which can decrease average daily gain. Reducing the number of changes that are occurring at a given time should reduce the stress experienced by calves. Once the calf has been successfully weaned, the calf should remain with the group for one to two weeks after weaning. This allows the calf to adjust to only consuming dry feed and should decrease stress before moving to a new pen with differing social interactions.
An automatic feeding system can be a great addition to a calf raising operation. It can provide higher growth rates and a better start associated with accelerated feeding of milk. By being able to decrease the amount of milk and the number of feedings, this system can allow the calf to be weaned slowly and automatically. Properly operated automatic calf feeders can decrease stress, improve starter intake, and decrease the amount of weight loss during the weaning period.
Katie Kelly, University of Kentucky
Donna Amaral-Phillips, Ph.D., University of Kentucky