Relationship of Production Traits and Udder Morphometry with Somatic Cell Count in Zaraibi Goats

Abstract

Somatic cell count (SCC) in milk is of interest to dairy goat breeders because of its influence not only on milk production but also on longevity and profitability. This study’s aim was therefore to consider the production traits and udder morphometry relationships between them and SCC. For this purpose, production traits and twelve udder traits were measured from 152 clinically healthy dairy Zaraibi goats at the first four parities of lactations. The examined goats were classified into three categories according to SCC in milk; (≤470x103 cells/ml), (from 471 to ≤500x103 cells/ml) and (>500x103 cells/ml). Results showed that the goats with SCC ≤470x103 cells/ml had significantly the highest values of all studied production parameters. Likewise, the udder and teats measurements showed to be different depending on SCC in milk. However, the studied parameters were with highly significant negative correlations with SCC. The teat position and udder attachment scores were high in goats at SCC ≤470x103 cells/ml, and such scores negatively decreased when SCC values increased. However, the maximum r2 value (62.8%) obtained from regression equation for predicting SCC was by using average daily milk yield, days in milk, udder depth and width traits. In conclusion, including udder depth and width with teats separation and diameter traits in future breeding programs of Zaraibi goats would be useful to ensure that the selection for increased productivity is not accompanied by unwanted deterioration. In addition, these relations could be used as an indirect diagnosis of SCC in Zaraibi goats milk.