Relationship between fatty acid composition and softness score of adipose tissue in intensively reared lambs fed with concentrate based on cereals or on beet pulp.

摘要

The aim of the study was to investigate the effect of substituting cereals by sugar beet pulp in the feed on the fatty acid (FA) composition of subcutaneous adipose tissue in indoor lambs. Forty-nine male lambs of the Lacaune dairy breed were fed from 23.6 (+or-4.1) to 41.0 (+or-1.9) kg live weight with hay and a pelleted concentrate containing either 80% of barley and wheat (group C) or 70% sugar beet pulp (group P). The FA composition of caudal adipose tissue sampled at slaughter was determined. The subcutaneous adipose tissue softness was not different between the two groups. The water content and the proportion of odd-numbered (oddFA) and methyl branched-chain FA (BCFA) were high but not significantly different between the two groups (respectively, 22.6% of wet weight, 7.7 and 9.7% of total FA). On the contrary, the proportion of even-numbered saturated FA (ESFA) and especially C18:0 was low but slightly higher in the P group. The proportions of C18:2 and C18:3 were higher in group C than in group P (3.2 vs. 2.2%, P<0.001 and 0.65 vs. 0.48%, P<0.001, respectively). The softness score of adipose tissue was positively related to the water content and proportion of oddFA and BCFA. It was negatively related to the proportion of ESFA, age and live weight at the beginning of the trial. The proportion of unsaturated FA with 18 atoms of carbon did not show any relationship with the adipose tissue softness but it was influenced to some extent by the composition of the diet..