Dairy cows` pastures. 1. Modelling the grazing management

This compilation of three tests was aimed at measuring the effect on meat quality of differences in growth rate between a period of reduced feeding level during summering on mountain pastures and a period of finishing. A total of 117 Limousin (LI) X Red Holstein(FT) crossbred steers were used for this synthesis comprising various modes and levels of feeding during the finishing period. The animals were divided into four classes based on the average daily growth rate (DGR) between the two experimental periods, 0 – 500 g, 501 – 1000 g, 1001 – 1500 g and 1501 – 2000 g. On average, at slaughter, the carcass weight, the conformation, and the fatteness score were similar. The tissue composition of sirloin was similar. In the longissimus dorsi muscle, the distribution but not the size of the different types of muscle fibres was modified. The greater the difference in DGR, the more fibres were of the rapid contraction and glycolytic type (IIX), the more losses of exudates and the lower the final pH. On the other hand, there seemed to be a positive correlation with tenderness measured by sensory analysis as well as measured by shear force whereas the sarcomere length and myofibrillar fragmentation index remained unchanged.