Dietary conjugated linoleic acid consumption during pregnancy and lactation influences growth and tissue composition in weaned pigs

We evaluated the effects of conjugated linoleic acid (CLA) on growth perfor mance, tissue fatty acid composition and ex vivo lipogenic enzyme activity in piglets (n = 40) reared on sows fed diets supplemented with CLA or linol eic acid (LA). Weaned offspring of both sow groups were offered either a CL A- or LA-enriched starter diet for 35 d. The starter diets were formulated to contain 2 g CLA (containing 58.9 g CLA/100 g total fatty acids) or LA pe r 100 g feed. All piglets were slaughtered at 70 d of age and tissue sample s of the back fat, omental fat and longissimus dorsi were collected. Irresp ective of the dietary fat supplied in the starter period, piglets reared on the CLA sows had greater final body and warm carcass weights (P < 0.01), a nd greater feed intake (P = 0.02) than piglets reared on the LA sows. The d ietary effect on the fatty acid composition was similar for the adipose and muscle tissues. Compared with the LA-enriched diets, CLA increased the lev el of total saturated fatty acids (P ( 0.05), whereas that of monounsaturat ed fatty acids was decreased IP < 0.05). Dietary CLA increased glucose-6-ph osphate dehydrogenase (P < 0.01) and malic enzyme activities (P < 0.06) in the fat tissues, but did not affect fatty acid synthase activity. The shift toward a higher deposition of saturated fatty acids and a lower deposition of monounsaturated fatty acids is the result of down-regulation of Delta9- desaturase activity that was induced by CLA rather than an altered rate of de novo synthesis.