This article is part of our series of original articles on emerging featured topics. Please check here to see other articles in this series.
Automated milk feeding (AMF) systems have been used in Europe for many years, but the usage in the US has increased in recent years. These systems allow for increased social facilitation among calves, redirection of labor from feeding to management of calves, consistency of milk delivery, and consumption of additional milk in smaller meals. Experience with these systems has revealed that the risk of spreading disease in the group housing can be minimized with good management, and non-nutritive sucking is minimized by the higher consumption of milk than is typical with conventional twice-a-day feeding. Some farmers have installed these systems with the idea that labor needs for calves would be reduced; however, use of these systems generally just allows redirection of the labor from feeding to calf management. Perceived benefits of such systems by dairy farmers considering adopting them need to be evaluated based on research and experiences by those using such systems. Thus, many aspects of AMF need to be monitored to optimize calf performance.
As with any indoor calf raising system, ventilation is fundamental for reducing the risk of respiratory and other diseases. Inadequate ventilation has been a common problem in barns where AMF systems have been installed. Farmers should exercise caution when placing these feeders in pre-existing barns without modifications to the ventilation. Increased animal stocking density and inadequate ventilation can cause immediate issues and increase the incidence of respiratory diseases. Whether in a pre-existing barn or a new barn, positive pressure ventilation will most likely be needed. In a University of Minnesota study, researchers observed that barns without such ventilation resulted in about an 80% increase in the likelihood that calves would become sick.
A minimum resting space of 35 sq. ft. per calf is needed, but 40 to 45 sq. ft. of space per calf is recommended, especially for larger breed calves. In the University of Minnesota study, health problems declined as the amount of space per calf was increased. From their study, they suggested 12 to 15 calves per pen because they observed that the number of sick calves increased with larger numbers of calves per pen. Most manufacturers of the AMF recommend one or two nipples per pen, with 25 to 30 calves per nipple. Thus to reduce the risk of disease, generally one nipple should be provided per pen and 20 to 25 calves grouped together. For example, a 30’ x 30’ pen should provide enough space for 20 Holstein calves. However, it has often been observed that calves do not use the allocated space well; they tend to bunch up in certain areas of the pen. Improved use of entire pen can occur with good ventilation (most important), adequate amount of dry bedding, and placement of the water and calf starter away from the nipple. Both water and calf starter need to be provided free choice. The most common method of feeding calf starter is in a raised bunk. Using the bunk tends to encourage calves to eat as a group, thus potentially stimulating greater starter intake.
Calves should not be placed on the AMF immediately after birth. The essentials of dipping the navel and adequate colostrum feeding remain. In general, farmers have found the greatest success when calves are fed individually housed for 7 to 14 days. During this time, they should be fed using a nipple feeder (bottle or bucket) and can be moved to the AMF when they are healthy, have good suckling reflex, and drink all of their milk allowance. Moving calves to group housing too soon can increase health problems. When calves are moved to the AMF, timing within the day for moving the calf should be determined based on when they would be hungry (e.g., typical feeding time in individual housing). Then, they should be led to the feeding station and directly introduced to the nipple by the calf manager.
Once the calves have been moved to the AMF, they should be programmed to have 4 to 8 meals per day with meal sizes of 1.6 to 2.5 liters (0.42 to 0.66 gallons) at each meal; Holstein calves will easily consume 10 liters (2.6 gallons) per day. These systems are designed to use milk replacer, whole milk, or waste milk. Milk pasteurizers can be installed between the milk supply tank and the feeder when using whole or waste milk. The milk replacer should be mixed by the AMF to contain 13 to 15% solids. It is very important to get calves to their peak milk intake as soon as possible, starting them at 4 to 6 liters (1 to 1.5 gallons) and increasing to desired levels over three days. Weaning should be accomplished by reducing the number of meals to 2 per day for 7 days with 1.6 liters (0.4 gallons) per feeding. Additional information about weaning is available in the article “Weaning Calves from an Automatic Feeder”.
As mentioned previously, the labor for calves with AMF should change from that associated with calf feeding to being a calf manager. This means that individuals managing AMF systems need to be well-trained to closely observe animals for early signs of illness and carefully monitor milk intake and speed of drinking. Morbidity, signs of dehydration (such as sunken eyes and skin tenting), labored breathing, and scours can be detected through visual observation. Number of meals, amount of milk allowance consumed, and drinking speed can also be monitored as indicators of illness. Using the information from the computer and walking the pens daily are fundamental to the success of AMF systems. Calves not performing well need immediate attention, and it is sometimes necessary to remove the calves from group housing until their health improves. Cross sucking should also be closely monitored, and the primary instigator may sometimes need to be removed from group housing. With the apparent greater non-nutritive sucking among Jersey than Holstein calves, there may be a higher risk of cross suckling with Jersey calves.
Monitoring the milk dispensing system for proper operation is critical. The calibration of the milk powder delivery needs to be checked according to the manufacturer’s recommendations. Following the cleaning instructions and equipment repair and maintenance are also crucial for proper delivery of powder and keeping bacterial counts low. Bacterial counts have been found to be highly variable with AMF systems. In the University of Minnesota study, Standard Plate Counts with > 100,000 cfu/mL were associated with greater incidence of health problems. Strict adherence to the water temperature and chemicals recommended for cleaning are essential for low bacterial counts and to prevent biofilm development on the surfaces with which milk comes in contact. The temperature of the water for mixing with the milk powder needs to be checked periodically. Inadequate mixing, improper water temperature for mixing and cleaning, and inadequate cleaning of the system all increase the risk for health issues among calves.
In comparison to the conventional system of individually housing pre-weaned calves and feeding milk twice daily, AMF systems facilitate increased milk intake, allow social interaction among the calves, and allow labor to be focused on managing health and behavior of calves. The time which would be used for feeding calves with bottles or buckets and the associated time needed for mixing the milk and cleaning all the equipment in conventional feeding systems can instead be focused on calf management when using AMF. The interest in AMF systems for calves will likely continue to increase, and their use can result in efficient calf performance with minimal disease. However, with any calf feeding system, attention to details and early detection of disease are paramount.
Maurice L. Eastridge
Department of Animal Sciences
The Ohio State University
Earleywine, T., T. Johnson, and E. Stephas. 2010. What we learned from an automatic calf feeder. Hoard’s Dairyman, December 7 issue. http://hoards.com
Endres, M. 2016. Automated calf feeders: What makes them work? Proceedings Four-State Dairy Nutrition and Management Conference. June 15-16, Dubuque, IA. Pgs. 51-54.
James, R. 2017. Group housing systems for calves, facilities, equipment, protocols, and personnel. Western Dairy Management Conference, Feb. 28 – Mar. 2, Reno, NV. http://wdmc.org
Weber Nielsen, M. 2012. Management tips for calves fed with automated milk feeders. Proceedings Tri-State Dairy Nutrition Conference, April 24-25, Ft. Wayne, IN. http://tristatedairy.org