Automatic calf feeding systems have been adopted by producers across the U.S., and many more are considering them. Following are details about autofeeding that may be helpful in evaluating this technology.
- Age when calves are introduced to the autofeeder system is strongly dependent upon fresh-cow and newborn calf management. Aggressive colostrum management programs are essential to successful adaptation to the autofeeder. Consider routine monitoring of serum proteins during the first week to assess success of the colostrum program. Most farms house calves in individual housing systems for at least the first five days to ensure that the calf is eating well.
- Stocking rates of no more than 25 calves per nipple are advised. A stocking density allowing at least 35 square feet of bedded area per calf also is recommended.
- Milk allowances range from 1.5 to as much as 2.7 lb. (680 – 1225g) of milk solids per calf per day. On a volume basis this amounts to 1.4 to 2.3 gallons (5.3 – 8.7 L) of liquid per day.
- Meal sizes vary from 1 pint to 2.6 quarts (.5 to 2.5 L) each. In many systems, calves must earn enough credits to be able to receive milk or milk replacer from the feeder. As an example, if a calf is allocated 9 liters of “milk” per day, they will earn about .4 liter allocation for each hour of the day. They must accrue enough credits to achieve their minimum meal size specified by the system which might be 1.5 liters. This would mean there must be a minimum of about three hours and 45 minutes between feedings.
- Feeding milk replacer via autofeeders requires powder to be diluted with water to approximately 13-15% solids. Caution is advised when specifying dilution as most autofeeding systems express the grams of milk replacer to add to each liter of water. Therefore 150g added to a liter of water is not 15% solid but 13% (1,000 mL of water + 150 g of powder = 1150 final weight. Therefore 150g of powder/1150g of total weight = 13% solids).
- Number of meals per day varies by the system. Some basic calf autofeeders have a small mixing bowl and provide meals of one pint per visit. In these systems milk allowances exceeding 1 to 1.5 gallons daily require numerous daily visits to obtain the daily allowance (>12). In other systems calves are limited to a maximum amount per visit and the feeder will mix multiple batches of liquid up to the maximum meal size specified. Typically calves nursing from more sophisticated systems consume around four to five meals per day.
- Feeding programs vary considerably depending upon the system. The basic systems are frequently programmed to provide all calves with similar meal sizes and daily allowances, regardless of their age. However, the more sophisticated systems enable feeding a defined feeding program in which milk allowance is gradually increased over several days and then decreases to accomplish a “soft” weaning which is believed to reduce the stress of weaning. In more sophisticated systems, multiple feeding programs can be in effect within one pen so that smaller calves or those of a different breed receive their own, customized feeding plan.