Space allowance could be an important variable affecting production, health, reproductive performance and behaviour of dairy cattle. Also, high and low yielding cows may have different ways of coping with insufficient space allowance. The aim of this experiment was to study the influence of space allowance and milk yield level on the performance and behaviour of strawyard housed dairy cows.

The experiment was carried out using 24 Holstein Friesian cows with two groups in early lactation of high (over 30 kg/day milk yield) and two groups in late lactation of low yield (under 25 kg/day milk yield). The groups were allocated to strawyard systems with low stocking density (bed area/cow = 9 m2; pen area/cow = 13.5 m2; feed face width/cow = 1.5 m) or high stocking density (bed area/cow = 4.5 m2; pen area/cow = 6.75 m2; feed face width/cow = 0.75m) conforming to a changeover design with two periods, each of four weeks. The cows were fed a total mixed ration ad libitum and 2kg/cow/day of concentrate in the milking parlour. All animals were milked twice daily.