Utilização do Cloprostenol (ICI-80.996) por via intramuscular na sincronização do cio de vacas Nelore

Abstract

Study of the efficiency of Cloprostenol (ICI - 80.996) in the synchronization of the heat and the fertility leved in a Nelore breed herd from Cianorte, Parana State. The animals were distributed at random into three groups of 60 each animals received two doses of 0,5mg of Cloprostenol through intramuscular route II days apart and were inseminated twice at 72 and 96 hours after the second administration, Group II animals were inseminated once, approximately 12 hours after the heat detection. The cows that showed no signs of heat received a second dose 11 days later and were inseminated following the same scheme. Group II animal's heat detection and insemination during 24 days were similar to group H's scheme. The results obtained were as follows: Group I - in the synchronized heat 18 (30%) cows became pregnant. With the second insemination results 68% (41 pregnant). Duration: 37 days. Group II - from 56 cows inseminated in the synchronized heat 25 (44_t6%) became pregnant. After the second insemination, fertility level was 66,0% (37 pregnant). Duration: 37 days, Group III - 51 cows inseminated and 31 (60,7%) pregnant. After the second insemination the fertility level was 72,4% (37pregnant). Duration: 45 days. The conception rale between groups was significantly different (P < 0,01).