EFFECT OF DAILY EXERCISE ON PERFORMANCE, FEED-EFFICIENCY AND ENERGY-BALANCE OF TIED DAIRY-COWS

The effect of daily exercise on dairy cows was studied in 65 first and second calvers of the Swedish Red and White breed in a four-year experiment, starting in July 1985. Half of the group walked outdoors 3 km/day from May through October and 400-800 m/day from November through April. From July 1986 the distance walked in the summer period was 2 km daily. Daily exercise did not significantly affect voluntary DM intake, the overall energy consumption or production of milk, ECM, fat or protein. The efficiency of milk energy and protein production did not differ between the treatments in lactations 2-4. Mean energy efficiency in these lactations was 5.6 MJ/kg ECM and mean protein efficiency 1213 g AAT/kg protein. However, in lactation 1 and at restricted feeding, milk energy and protein production was significantly less efficient for exercised cows than for non-exercised cows. The difference was 0.39+/-0.12 MJ/kg ECM (p<0.01) and 132+/-28 g AAT/kg protein (p<0.001). The discrepancy between the Swedish standard for ME in milk production above maintenance, 5.0 MJ/kg ECM, and the results obtained in this and other recent studies are discussed. Concentrations of serum free fatty acids and plasma glucose were measured once a week in lactation weeks 1-8. No significant differences between the treatment groups were observed. Feeding was ad lib. in lactation weeks 4-12. It was noticed that the cows never lay down in the exercise area, which was covered with sand and soil. Behavioural disturbance in the form of tongue rolling was not influenced by exercise.