Stones a winner as calf bedding

River stones are a satisfactory option for calf bedding, according to a study by DairyNZ and AgResearch.

The use of river stones has been on the rise in recent years, particularly in Southland where more traditional bedding, such as sawdust, is difficult and expensive to obtain.

DairyNZ animal husbandry and welfare team leader Dr Nita Harding said questions about the impact of river stones on calf welfare prompted the study.

‘‘The six-week study showed there are no detrimental effects to calves raised on river stones and that the MAF Animal Welfare (Dairy Cattle) Code of Welfare’s minimum standards for housing calves are met.’’

The study took place on a commercial dairy farm in the South Island in September and October 2011.

The research took rounded river stones, around 3cm in scope, laid out in four calf pens at a depth of 20cm.

Twenty calves were monitored on the river stones and compared with another 20 calves kept on sawdust. Kept at a stocking density of one each 2 sqm, the calves were evaluated at one and six weeks of age.

‘‘We monitored the health and cleanliness of the calves, assessed their behaviour and recorded the temperatures of the calves and the environment,’’ said Dr Harding.

‘‘Both sets of calves grew at the same rate and both bedding materials were relatively dry and clean throughout.

‘‘We now have to go back and investigate the effects of rearing calves on river stones at different stocking rates, as this is likely to be more relevant to commercial conditions. Studies this year will also include more detailed examination of calf behaviour, as well as monitoring health and growth rates.’’

The stocking density used was that recommended for calves reared on river stones.

Dr Harding said while the study provides good information to farmers, it is important to remember that bedding is only one part of a successful system.

‘‘No matter what type of bedding is used, it is important that a plan is in place that takes into account all aspects of calf care,’’ she said.

‘‘This includes making sure staff are adequately trained, calf feeding and health care is adequate, and that calf rearing facilities are well-prepared.’’