EFFECT OF EARLY CALVING OF SIMMENTALER HEIFERS UNDER AN EXTENSIVE MANAGEMENT-SYSTEM

Productivity of Simmentaler heifers, first mated at 14 months of age ( 2 M) compared to the traditional system of mating at 26 months of age (3 M), was investigated under extensive farming conditions. Both first calving (60.8 vs. 79.5%) and recalving rates (42.4 vs. 71.2%) differe d (P < 0.01) between 2 M and 3 M heifers, respectively. Although total number of calves born (4.0 vs. 3.2) and weaned (3.3 vs. 3.1) over sev en years differed (P less than or equal to 0.05) between 2 M and 3 M, total weaning weight (669 vs. 645 kg) was not significantly (P > 0.05) influenced. Also, 18.6% of all calves born in 2 M, died at birth. It is concluded that improved productivity is unlikely in an early mating system without additional inputs.