Effect of ewe breed on the reaction time and semen characteristics in the ram

The aim of this study was to determine the effect of ewe breed on the reaction time and semen characteristics in the ram. For this purpose, from the native sheep breeds in Iran, seven Lory rams and four ewes (two Lory and two Ghezel breeds) were selected. Seven rams were individually subjected to 4 weekly trials in which one of the following two treatments was applied alternately. All of rams were scheduled twice weekly to introduce with the same (Lory) and different (Ghezel) ewe breed individually. In each session, the reaction time and number of mounts before ejaculation were recorded. At two another sessions per week, sperm evaluation was performed in each group after collection of semen by artificial vagina. When the both breeds of the ram and ewe were the same, the mean of reaction time, number of mounts, ejaculation volume, sperm concentration and sperm viability were 44.6 sec, 2.7, 0.97 ml, 4.49 × 109 sperm/ml and 88.9%, respectively and when the breeds were different, the means were 61.5 sec, 2.9, 1.0 ml, 4.52 × 109 sperm/ml and 88.4%, respectively. The reaction time was significantly lower in the first group (P<0.01). However, there was no significant difference in the other parameters between the two groups. It was concluded that during semen collection, when the both breeds of the ram and ewe are the same, the reaction time becomes significantly lower, but the number of mounts and semen characteristics (volume, sperm concentration and viability) did not differ.