F1 AND 3R CALVES DEVELOPMENT IN AN INTENSIVE DAIRY SYSTEM OF THE HUMID TROPIC, GUALACA-PANAMA

Abstract

Due to the growing climatic variability in the tropics, it is necessary to develop a double purpose animal with greater genetic potential and that adapts to existing and future environmental conditions. The objective of the work was to evaluate the development of F₁ and 3R cattle CALVES in a dual purpose dairy system. Sixty Brahman cows (BR) from the Experimental Station of Gualaca (IDIAP) were used. To produce F₁, Girolando x Brahman (F₁GOBR), Gyr-Dairy x Brahman (F₁GDBR), Holstein x Brahman (F₁HOBR) and Brown Swiss x Brahman (F₁BSBR) were crossed. To produce 3R, F₁GDBR and F₁BSBR were crossed with Holstein and F₁GOBR and F₁HOBR with Brown Swiss. The data was analyzed by descriptive statistics. In F₁, the synthetic breed had a average birth weight of 34,3 kg, where the F₁GOBR was 3,6% higher than the F₁GDBR, while the F₁HOBR dairy breed was superior to the F₁BSBR in 6 and 11% at birth and 60 days respectively; at 240 days the F₁HOBR was superior by 24%. In 3R crosses, the average birth weight was 37,4 kg, which is 10% higher than the F₁. While the heaviest at 60 and 240 days were the 3RPSHO with 81,4 and 143,9 kg, respectively. The reproductive aspects of the weight of breeding (300 kg), was achieved at 20,8 and 18,0 months in the heifers of two and three breeds, and the ageat first calving at 33 and 27 months, respectively; this indicator is reduced by 35% with respect to the national average.