Dairy cow performance in mountain pasture : effect of concentrate supplementation level

Abstract

Seventy-nine Tarentaise dairy cows were used in a supplementation trial conducted over 2 years in mountain pastures. During the summer, all animals grazed from a Northern Alps pasture at altitudes between 1650 and 2200 m (strip grazing). Each year and over the whole mountain pasture season, 2 groups were formed : the cows from the High group were given 1.5 kg/day more concentrate than those of the Low group, on average. The effect of the supplementation level was identical during both summers : the High group cows produced 1.1 kg/day more milk than those of the Low group (P<0.01), their protein content was slightly higher (+ 0.8 g/kg) and they gained more liveweight (+ 6 kg) and improved their body score by 0.4 points more than those of the Low group. Body reserve restoration was particularly low in the Low group cows in early lactation at turning to pasture. These results were compared with those obtained in plains, highlands or other Northern Alps mountain pastures.