Principles and Experience
Producers have traditionally raised calves in individual pens or hutches. This rearing system has had advantages of individual feeding, observation and reduced risk of cross-contamination. It is however, still labour intensive. Dairy cattle are naturally group-living animals. Group-housed calves can enjoy an early social interaction and learn to understand group behaviour. Research is now proving that well-managed group housed calf rearing systems can provide advantages for both calves and producers.
Automatic feeding systems for group housing
Group housing often requires intensive management. In non-automated group housing individual intake is difficult to monitor. Moreover, sub-clinical or ill calves may be challenging to identify and therefore treat appropriately.
The new generation of automatic feeding systems (like the Förster-Technik model sold through DeLaval, Lely and Westfalia/GEA) can be easily programmed to effectively feed and monitor calves on an individual basis. There is software available to accumulate a significant amount of information and provide detailed data analysis of individual calves and/or the group for high management control with low labour requirements. An example of data collected includes daily milk replacer intake and number of visits to the feeder. Alarms will be triggered when deviations occur. Individual medication, electrolyte/additive administration programs are also available options.
In conventional feeding by pail, calves are fed limited amounts of milk replacer (i.e.) 2-3 litres (quarts) of milk replacer twice a day, the equivalent of 500-900g (17.6-31.7oz) of solids. For optimal heifer growth and development calf feeding recommendations have increased to 8-10 liters/day, the equivalent of 1200-1500g (42.3-53oz.) of solids, sometimes even more. The advantages of feeding calves more milk are widely published. Areas studied include calf growth, height, starter consumption, medication use/costs, time management, and the increased output of milk during the first lactation (references available upon request). These published advantages examine the economic impacts of feeding more milk replacer. Grober Nutrition, based in Cambridge, Ontario is working in partnership with Förster-Technik, a world leader in automatic calf feeding, to establish further on-farm practice and benefits. The concept of smaller meals being offered more frequently could lead to improved digestion and may also aid in the prevention of severe scouring.
Group feeding experience
Grober Nutrition has been evaluating group housing systems for over 20 years and have more recently collated data from CY Heifer Farms (Elba, N.Y.) and the Grober Young Animal Development Centre (GYADC) (Woodstock, Ont.). The trials were set up to examine and quantify the growth, development, medication usage rate and economics of feeding the same amount of milk to group fed calves compared with individually fed calves. The first data set from CY Farms was evaluated based on 582 calves and concluded no significant difference in live weight and growth rate between the two feeding practices. Group fed calves, however, showed a significantly lower medication cost(P<0.05) during the CY Farms trial period compared to individually fed calves. Computer data analysis allowed for earlier detection of illness and labour was reduced by 52%. The Grober Young Animal Development Centre in Woodstock, Ontario, enables Grober to compare both individual and group housing methods under one roof. This means that nutrition programs, calf-rearing technologies and other calf products can be examined simultaneously under both management systems. Recent data from the Grober Centre shows that calves in groups exceeded average daily gains compared to individually housed calves starting week 5 and continuing past weaning (see Table 1). Table 1. Average Daily Gain (ADG) of calves receiving 6L/day (6quarts/day) of milk replacer as compared between groups and individual pens. (All values reported in kg/day).
|Week 2||Week 3||Week 4||Week 5||Week 6||Week 7||Week 8||Week 9||Week 10|
blue, red columns with different superscripts are significantly different at p<0.05 While ADG often fluctuates due to environmental and health influences there was no significant difference in average body weight until weaning (week 7). Throughout weaning and post-weaning, calves in group housing achieved a significantly higher average body weight (see Figure 1. Improved gains may be attributed to the significant increase (P< 0.05) in starter intake from automatic grain feeders prior to weaning for the group fed calves. However, during weaning, calves in individual pens achieved similar calf starter intake compared to group housed calves.
Group Housing & Health
There are perceived health concerns when calves have nose-to-tail contact. Automatic calf feeding machines are a tool for early detection of illness. Grober Nutrition assessed the cost of medication to evaluate whether group housed calves are more likely to require therapeutic intervention (see Figure 2). The data illustrates that individual calves suffered significantly more illness early on (i.e. scours). During week 4, a significant difference in cost was associated with group calves (respiratory illness). Overall, group fed calves showed a significantly lower medication cost compared to individually fed calves. Age, body weight and a higher plane of nutrition may have accounted for more moderate medication use and cost.
Group Housing Considerations
Selecting calves for group housing with automation requires a thrifty calf with a strong suckling reflex. The calf manager should group calves of similar age and body weight. Group housing of calves has many time and labour saving advantages. It provides improved access to space, allowing for more vigorous activity, and with automation, improves feed consistency and number of feeds. Group housing can facilitate earlier socialization. Moreover, there may be minimization of stress associated with changes in feed and environment post-weaning for calves.