Early pair housing increases solid feed intake and weight gains in dairy calves.

Discipline: calf raising; Key words: weaning, animal welfare, social facilitation, social learning, Holstein.

Individual or group housing for rearing dairy calves has always been a point of debate, but sometimes only a choice of convenience or management history. Both have pros and cons. However, the choice is mostly mixed as calves initially housed individually during the milk-feeding period will be transferred thereafter to group housing. Of late it has been shown that social rearing, that is where a calf is paired with another, is associated with increased solid feed intake and therefore higher weight gains before and after weaning. What is not known is the effect of age at which social housing begins. This then was the objective of a study by Dr J.H.C. Costa and colleagues, the results of which they published in The Journal of Dairy Science, Volume 98 (Issue 9) of 2015, pages 6381 to 6386, with the title:Early pair housing increases solid feed intake and weight gains in dairy calves.

Their aim was to assess the effects of early versus late pairing on feeding behaviour and weight gain before and after weaning. Eight Holstein bull calves were reared individually or paired with another calf at either about 6 days or 43 days of age. All calves were fed 8 litres of milk per day for 4 weeks, 6 litres per day from 4 to 7 weeks, and then milk was reduced by 20% per day until the calves were completely weaned at 8 weeks of age. The calves were given ad libitum access to calf starter and a total mixed ration (TMR). Body weight and feed intake were measured weekly from 3 to 10 weeks of age.

Intake of calf starter was significantly higher for the early-paired (about 6 days) calves than for individually reared and late-paired (about 43 days) calves throughout the experimental period. At 10 weeks of age, starter dry matter intake averaged 2.2, 1.1 and 1.3 kg per day for early-paired, late-paired and individually housed calves, respectively. Intake of TMR did not differ among the three treatments; TMR dry matter intake averaged 3.3, 3.1 and 2.9 kg per day for the same three treatments. Calves in the early paired treatment also showed significantly higher average daily gain over the experimental period (0.9 kg per day vs. 0.8 and 0.7 kg per day for the early-paired, individual, and late-paired calves, respectively).

These results suggest that social housing soon after birth can increase weight gains and intake of solid feed.