Body condition score and body composition of Sarda dairy ewes

This study aimed to assess the accuracy of the body condition score (BCS) method, originally developed for meat and wool breeds, in estimating body reserves in dairy ewes. Twenty-four Sarda dry mature ewes, ranging from 29 to 55 kg of live weight and from 2.00 to 3.25 of BCS (scale 0-5 of Russel et al., 1969), were used to study the relationship between BCS, somatic measuresin vivo, fat depots and chemically-determined body composition. At slaughter, each animal was partitioned into carcass and non-carcass. The fat depots were then separated and weighed. The left side of the carcass and non-carcass were analysed for chemical composition (dry matter, fat, crude protein and ash). The results showed that BCS and chest girth were highly correlated with empty body weight (EBW) (r = 0.80; 0.86 respectively). The regression equation for estimating LW and EBW indicated a change of 13.17 kg of LW and 13.84 kg of EBW per unit of change in BCS. Omental plus mesenteric represented the highest proportion of fat depots. Body fat in EBW linearly increased and body protein linearly decreased as BCS increased until the score 3. Above this level body fat seemed to increase at a lower rate. As BCS increased, the proportion of body fat accumulated in the carcass decreased from 56% (BCS 2) to 30% (BCS 3.25) and conversely increased the fat accumulated into visceral organs and tissues. In conclusion, Sarda sheep had a higher proportion of fat in viscera than in carcass. Differently from what observed in meat breeds, in Sarda sheep BCS did not predict body composition accurately above BCS 3.0.