INSEMINAÇÃO ARTIFICIAL OVINA COM SÊMEN REFRIGERADO APLICADO EM DIFERENTES VIAS

The aim of this work was to compare in vitro efficiency of 6 extenders in the conservation of ram semen at 5º C for 8 hours. Subsequently, with best in vitro results were used to inseminate 140 ewes. Twenty-three pooled ejaculates were diluted in 6 extenders: Cornell University Extender (CUE), Cornell University - 16 (CU-16), glycine-yolk, citrate-yolk, TRIS-yolk and UHT skim milk-yolk. After 1+3 dilution, the semen samples were cooled during 8 hours at 5º C following analysis of progressive motility, vigor, wave motion, morphology of spermatozoa and thermoresistance test (TT). Citrate-yolk extended semen results were significantly (P0.05). These insemination rates confirmed in vitro performances in which citrate-yolk extended semen demonstrated superiority results. The pregnancy rates of the groups inseminated with cooled semen extended in citrate-yolk, 55-58 hours after pessaries removal were 85.75% and 43.75% for intrauterine and cervical insemination, respectively. There was significant difference (P0,05), nas duas vias estudadas em relação ao CUE. Esses resultados de prenhez confirmam o experimento realizado in vitro, quando se verificou superioridade do diluente citrato-gema. A taxa de prenhez de ovelhas inseminadas com diluente citrato-gema no mesmo horário após a retirada dos pessários, forneceu 85,71% e 43,75% de prenhez nas vias intra-uterina e cervical, respectivamente. A fertilidade foi superior quando se utilizou a via intra-uterina (P<0,05) nos 2 diluentes testados. As inseminações realizadas por via cervical com sêmen refrigerado em citrato-gema às 57 horas e às 49 horas após a retirada dos pessários, obtiveram 43,75% e 21,74% de prenhez, respectivamente. O grupo inseminado às 57 horas, apresentou resultados superiores (P