Effects of linoleic and a-linolenic acid intake on pig behaviour, and its relationship with brain DHA.

Effects of linoleic and a-linolenic acid intake on pig behaviour, and its relationship with brain DHA. J. E. Bolhuis, I. van Kerkhof, and W. J. J. Gerrits*, Wageningen University, Wageningen, the Netherlands. Effects of linoleic acid (LA) and a-linolenic acid (ALA) on behaviour of individually housed pigs (15-30 kg BW) were studied. In a 2×2 factorial arrangement, 32 gilts from 4 litters were assigned to one of four dietary treatments, varying in LA and ALA intake. Differences between low and high intake levels were designed to be identical for LA and ALA: Low ALA and LA intakes were 0.15 and 1.30, and high ALA and LA intakes were 1.45 and 2.60 g/(kg BW0.75.d), respectively. Intakes of saturated and mono-unsaturated fatty acids (FA), and other nutrients were kept constant. Pigs were subjected to an open field test (d 15) and a novel object test (d 16). In addition, behaviour in the home pen was observed using 2-min instantaneous scan sampling for 5 h per day (d 12 and d 18). After 28 d on the dietary treatments, pigs were sacrificed and brain tissues were sampled and analyzed for FA composition. The latencies to approach and touch the novel object were reduced by ALA intake, but at the low LA intake only (LA*ALA, P0.05), DHA concentrations in the frontal cortex were positively correlated with explorative behaviour (r = 0.56, P