SELEKSI BOBOT BADAN INDUK DAN EVALUASI KESULITAN PARTUS ANAK (Dystocia) SAPI BALI HASIL PERSILANGAN PEJANTAN SAPI LOKAL UNGGUL SULAWESI UTARA

BODY WEIGHT SELECTION AND EVALUATION OF CALVING DIFFICULTY (Dystocia) IN BALI BREED FEMALE CATTLE MATED WITH OUTSTANDING LOCAL BULL OF NORTH SULAWESI. Records on calving performances of 217 parental dams of Bali beef cattle breed including their calves were used to study calving difficulty of Bali beef cattle breed heifers and cows with experiencing in delivery of more than one generation of calving. The difficulties of calving were scored into calving difficulty scores of six scores, initiated at score 0 indicating normal calving to score 5 indicating the most difficult calving delivery requiring surgery. The parental heifers and adult cows as well as their calves grazed onto places within local grass pasture all days starting at 07.00 a.m. to 17.30 p.m. without supplementary feeds of concentrate as the main management system practiced by 104 farmers as the animal owners at rural areas. Differences of calving difficulties in both Bali beef cattle breed groups of heifers and cows were analyzed by nonparametric test of “The Mann-Whitney U testâ€, using ranks of data based on the incidence frequencies of calving difficulty scores. Data of calving difficulty scores of both Bali beef cattle breed heifer group and cow group were ranked in to the numerical rank initiated from the lowest to largest numerical order. The calculated z value in this study indicating the incidence frequencies of calving difficulty in heifer group was significantly higher than those in cow group. Frequencies of calving difficulty on the category score basis in Bali beef cattle breed heifer group were significantly higher compared with those in Bali beef cattle breed cow group. Low live weights and body dimensions of heifer group highly tended to experience in the incidence and severity of calving difficulty compared with those of cow group. Selection of heifers with relatively well developed body dimensions and live weight relative to expected calf birth weight would be recommended to reduce calving difficulty.Keywords: Bali beef cattle breed, dam and calf body measurements, calving difficult