Major Labour Saver
Computerized systems automate calf feeding chore as herds grow larger
As herd sizes increase, preparing milk replacer and feeding a bunch of hungry calves can take up substantial time. The chore becomes even more onerous if your herd size grows to the point where you always have a group of heifers on a liquid diet.
Conventional wisdom suggests raising young calves separately from each other-ideally housed outside in a hutch and fed from individual pails. Some dairy farmers take a different direction. They house calves in a group pen and feed them through an automatic system.
An automatic system can save significant labour. A 1997 study found that managing young animals in hutches required 10 minutes per day per calf. In a group pen fed through an automatic feeder, the time per calf was less than a minute per day.
An automated milk replacer distributor typically consists of a powder hopper, water boiler, mixer and nipple. When a calf enters the feeding station, a computerized system recognizes her, and she receives a portion of the daily ration according to maximum and minimum values set in the computer. A daily report can be printed or viewed from the unit screen to identify calves that did not get their daily allocation.
Field testing indicates the system works best when you control quantities and frequency. Free-choice feeding may lead to problems.
These feeding systems come in different configurations, depending on the number of calves being reared and the penning arrangement. Systems can also be set up to use whole milk instead of powdered replacer.
Recent research has addressed concerns about automatic systems, including:
Limited training is generally needed for the calf to find and use the feeding system. However, group size may affect the time required for all animals to become accustomed to the automatic distributor.
One experiment examined two group sizes. In groups with 15 calves, 90 per cent of the animals were using the system adequately after four days. It took 14 days to get to the same level with a group of 30 calves. Competition and social interaction may explain such a significant difference.
Computer-controlled milk feeders represent a significant investment. An obvious way to make the system more cost-efficient is to maximize the number of calves the feeder nurses. The question then becomes whether 20 or 30 calves per feeder result in a high level of competition for access to the feeder and social pressure on the calves.
For instance, in a 1999 study, with 26 calves per feeder, some calves waited up to an hour for access every day. Furthermore, the increased competition intensified problems with cross-sucking - a redirection of the natural sucking behavior toward other calves.
Calves make two types of visits to the feeder. The rewarded visit gives them a portion of the daily milk replacer allocation. Unrewarded visits occur when they get to the feeder between the programmed schedules.
More animals per feeder increase the occurrence of unrewarded visits. These visits may disturb calves already feeding. They may also block the milk feeder for calves waiting for a rewarded visit, making the problem worse.
To alleviate competition at least partly in larger groups of calves, fewer and larger portions of milk replacer have been shown to be effective. There's still a need to clarify the optimal number of calves that one unit can be nurse. The available data so far tend to indicate it's possibly less than 24.
Another important point to consider is the age of the calves that compose the groups. Avoid housing older calves with young ones since this can substantially increase competition. Groups can be set so that calves from birth to three weeks of age are housed together and remaining animals can be part of the other group. A system with two feeding stalls, one for each age group, is probably the best approach.
When the occupancy of the automatic feeder is monitored over a 24-hour period, peak feeding occurs, on average, from 6 to 8 a.m. and 6 to 9 p.m. Even when the number of animals per group doubles to 24 from 12, peak feeding times over the entire day don't differ. This suggests that the calves are reluctant to feed at less preferred times.
This system's main advantage is reduced labor. However, you can't substitute an automated feeding system for careful management. Build observation time into the schedule since it's a crucial part of any successful rearing program.
Photo shows the drinking nipple. A rectangular reader built into the barriers on either side of the nipple identifies the calf by reading a standard RFID (radio frequency identification) ear tag.
It's been demonstrated that you can successfully rear dairy calves in groups and feed them milk replacer, as well as starter, with a computerized system. However, base a decision to raise them this way on an assessment of herd health status and the ability of the person looking after the calves to closely monitor their wellbeing. Discuss health management with your veterinarian and put a plan in place to prevent potential problems.
The milk dispensing machine mixes a small amount of milk replacer powder with warm water each time the liquid supply to the nipple is depleted. The rectangular data display and entry pad shows the calf identification, whether it's eligible for a drink and the number of meals and refusals, and volume of milk consumed in the last 24 hours.
This article first appeared in the Ruminations column of The Milk Producer Magazine, July, 2005.
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