Udder morphology and linear udder scoring as indicators for functional adaptation and selection in Yemeni indigenous sheep breeds

Abstract

Yemeni indigenous sheep are well adapted to various and poor agro-ecological conditions, but there is little information on their characteristic's morphology. The present study evaluated the measurements of the udder and teats, linear udder scores, and their relationships in Yemeni indigenous sheep breeds. One hundred and fifty ewes in their lactating stage belong six indigenous breeds were assessed in semi-extensive conditions. Eight udders' measurements and four linear udder traits (1 9 scale) were recorded. The mean length of the udder, depth, and circumference were 13.49, 12.70, and 24.61 cm, respectively, which showed a significant phenotypic variability. Most of the measures of the udder (P < 0.01) and scores of the linear udder were significantly affected by breed, and only dam age (udder circumference and width) was affected. Udder circumference and udder width had a high positive correlation (r = 0.82, P < 0.01), but distance between teats had negative correlation with distance to the ground (r = -0.49, P < 0.01). Strong correlations were between udder measures and linear scores that proved the reliability of both evaluation methods. In general, the Yemeni indigenous sheep have good and varied udder characteristics that can be put into good use in within-breed selection programs to enhance udder functionality, productivity, and adaptation.