Repeatability and relationship with field mating performance of a serving capacity pen test in rams

Two studies were conducted to analyse the repeatability of a serving capaci ty (SC) pen test and to evaluate the correlation of the results of such a t est with field performance. The Laborde SC test, which measures SC by expos ing an individual ram for 40 min to two restrained non-oestrous ewes in a p en was used, in the first study, SC was measured on four and six occasions during the autumn of 1994 and 1995, respectively. The results indicated tha t this test is reliable in measuring SC of rams, since SC was repeatable wi thin, and between, breeding season of consecutive years (p < 0.05). in the second study conducted on two commercial farms, two groups of ewes synchron ised with intravaginal sponges containing medroxyprogesterone acetate, were served by rams of high or low SC. On both the farms, the group of ewes ser ved by rams of high SC had higher pregnancy rates than those served by low SC rams (p < 0.05). The Laborde test proved to be a reliable test for the e valuation of SC in rams and that high SC rams had better field performance. (C) 2000 Elsevier Science B.V. All rights reserved.