Effect of a supplement rich in linolenic acid, added to the diet of gestating and lactating goats, on the sensitivity to stress and learning ability of their offspring

The requirements for polyunsaturated fatty acids during brain development are high and in certain situations supply may be inadequate. Numerous studies in rodents have shown that it diet rich in linolenic acid improves learning ability and modifies emotional reactivity of offspring. Thirty-two goats received from 1.5 months before to 2 months after parturition either a control supplement (C, rapeseed supplement, n = 16), rich in oleic acid (C 18: 1 n - 9) or a test supplement (L, linseed supplement, n = 16), rich in linolenic acid (C18:3n - 3). At birth the profile of fatty acids was measured in blood, mammary secretions and tissue samples from the goats and their kids. After birth the kids were fed a mixture of milk obtained from the same treatment group as their dam and their emotional reactivity and learning ability were studied. The profile of fatty acids was also measured in goat milk and kid plasma. Plasma proportions of linolenic acid, eicosapentaenoic acid (C20:5n - 3) and docosahexaenoic acid (C22:6n - 3) were increased (P < 0.05) and arachidonic acid (C20:4n - 6) decreased (P < 0.01) by L compared to C in goats and kids at birth. At I I days. L kids spent more time sniffing the environment (P < 0.01) and less time immobile (P < 0.05) in a novel environment and passed more frequently next to the novel object (P < 0.05). The kids also tended to spend more time watching the object (P = 0.079) and tended to delay the first vocalisation with mouth open (P = 0.070) compared to C kids. Learning ability in a T-maze test at 46 days and the reaction to a startling stimulus at 48 days were unaffected by treatment. In conclusion, a diet rich in linseed given to gestating and lactating goats seems to increase the attention/exploration of their kids at 11 days without affecting their learning ability. (C) 2008 Elsevier B.V. All rights reserved.