Suitability of linear scoring in meat sheep: the practical case of Merinizzata Italiana breed

Linear scoring is widely applied in domestic animal species, mainly in cattle and horses. There are only few cases of linear scoring in sheep, probably because the small body size and the narrow range of the classes make difficult to correctly evaluate the measures. In this paper the results of a linear scoring test carried out on Merinizzata Italiana sheep breed in order to verify the feasibility of this method in sheep, are reported. Twenty untrained people, with three different levels of scoring experience in meat sheep morphology, evaluated 52 pluriparous ewes for body length, chest circumference, chest width, rump height, rump width, and withers height; to check for misclassification, their scores were compared with a reference score, previously obtained measuring the same animals by the suitable tools (measuring tape and a Lydtin stick). The percentage of correct scoring ranged from 44.4% for body length to 61.8% for withers height, and was not affected by the experience of the judge. In all characters, the distance of the class from the trait mean had a significant effect in increasing the intensity of misclassifications; the judge’s experience showed a positive effect in reducing the intensity of the misclassification for body length, that was the hardest trait to score. These results encourage to further verifying in practice the linear scoring in the Merinizzata Italiana sheep and in other meat breeds.