Relationships between the contents of vaccenic acid, CLA and n − 3 fatty acids of goat milk and the muscle of their suckling kids

Abstract

The relationship between goat milk fatty acid composition, especially trans-11 C18:1 (vaccenic acid, VA), conjugated linoleic acid (CLA) and n − 3 fatty acids, and that of the meat from their suckling kids was investigated by feeding the dams a diet supplemented with whole cottonseed (COT) or extruded linseed (LIN). Fifteen Sarda goats, fed 1.2 kg/day per head of concentrate and hay ad libitum, were divided into two groups and supplemented during weeks 4 and 5 post-partum with 32 g/day per head of fat from LIN and COT, which have high C18:3 and C18:2 content, respectively. Fifteen kids were fed exclusively by suckling maternal milk until slaughtering (at 9–10 kg of body weight and approximately 6 weeks of age). Twenty-four hour after slaughter, the longissimus dorsi (LD) muscle was removed from each carcass. Fatty acid profiles of milk and LD were significantly affected by diets. Compared to COT, feeding LIN changed the milk fatty acid profiles by decreasing the proportion of C16:0 and increasing the contents of VA, C18:3 n − 3 (linolenic acid) and total CLA, including cis-9, trans-11-, trans-11, cis-13-, trans-11, trans-13- and trans, trans isomers. The concentrations of VA, cis-9, trans-11 C18:2 (rumenic acid, RA) and linolenic acid in milk and those in kid muscle were strongly correlated. The fatty acid profile of meat from suckling kids was effectively modified by manipulating the diet of the dams.