Effects of daily exercise on the health of tied dairy cows

The effect of daily exercise on tied dairy cows was ied in 65 initially first and second calvers of the Swedish Red and White dual-purpose breed in a 4 year experiment, starting in July 1985. Half of the group walked outdoors for 2–3 km day⁻¹ from May to October and 400–800 m day⁻¹ from November to April. The rest of the cows were constantly tied. Health in general was significantly and positively influenced by exercise, reducing the need for veterinary treatments. Analysis over time, within lactations, showed that the difference in the number of veterinary treatments occured entirely in Weeks 0–2 of lactation. During those weeks, non-exercised (NE) cows were more affected by calving-related diseases, mastitis and leg problems than the exercised (E) cows. The difference between groups increased with increasing lactation number. In addition, somatic cell count in the milk was higher for the NE cows in their first month of lactation. Among feeding-related diseases, the cases of bloat were notably more frequent among NE cows, whereas exercise did not influence the occurence of clinical or subclinical ketosis. Cases of non-infectious leg and hoof disorders were also notably more frequent in the NE group, which also showed a significantly more serious score for skin lesions on the hocks, measured on one occasion. Scores for sole ulcer were significantly higher for the E cows on one occasion of four, at which there were problems with the surface of the exercise area. The causes of exclusions strengthened the differences mentioned for treatments.