Echium oil and linseed oil as alternatives for fish oil in the maternal diet: Blood fatty acid profiles and oxidative status of sows and piglets1

Abstract

Echium oil (source of stearidonic acid) and linseed oil (source of α-linolenic acid) were evaluated as alternatives for fish oil in the diet of sows to increase the docosahexaenoic acid (DHA) status of the offspring. The hypothesis was that echium oil would be more efficient than linseed oil to increase the DHA concentration, as it bypasses the enzyme Δ6-desaturase. In addition, it was determined whether adding PUFA to the diet affected the plasma oxidative status. Sows were fed either a palm oil diet or a diet containing 1% linseed oil, echium oil, or fish oil from d 73 of gestation and during lactation (n = 16 per dietary treatment). Total oil concentrations in the diets were similar among dietary treatments. Blood samples were taken for fatty acid analysis and oxidative status of sows on d 73 and 93 of gestation and at parturition and the lightest and heaviest piglet per litter at birth and weaning. Colostrum was also sampled. No effect of diet was observed on total number of piglets born (13.7 ± 0.4), number of weaned piglets (10.8 ± 0.4), and gestation length (114.8 ± 0.2 d). Piglets from sows fed fish oil had lighter birth weights (1.41 ± 0.03 kg) than piglets from the linseed oil diet (1.54 ± 0.03 kg; P = 0.006), with no difference between the palm oil (1.45 ± 0.03 kg) and echium oil diet (1.49 ± 0.03 kg). Daily BW gain until weaning was less for piglets from sows fed the fish oil diet (214 ± 5 g) compared with piglets from sows fed the echium oil (240 ± 5 g; P < 0.001) or linseed oil diet (234 ± 5 g; P = 0.02). Compared with the palm oil diet, echium and linseed oil in the maternal diet increased the DHA concentration in the colostrum and the sow and piglet plasma to the same extent (1.1 to 1.4-fold; P < 0.001). On the fish oil diet, 20.7-fold, 10-fold, and 2.4-fold increases in DHA in colostrum, sow, and piglet plasma, respectively, were observed (P < 0.001). At 1% in the maternal diet, echium oil had, thus, no benefit over linseed oil and resulted in a twofold less DHA concentration in the plasma of piglets compared with fish oil. Including n-3 PUFA in the maternal diet did not affect oxidative status of the mother or the offspring.