Use of nutraceuticals in organic dairy goat farming: effects of dietary fish oil during the peripartum on colostrum and milk composition

摘要

In organic farming, the prevention of health problems is based upon enhancement of animal natural immunity. Fish oil is a nutraceutical rich in n-3 fatty acids which beneficially influence the immune system. The aim of the study was to evaluate the effects of dietary fish oil during peripartum on colostrum and milk composition, somatic cell count and cell-mediated immunity of dairy goats organically managed. Ten days before expected day of kidding, 36 Saanen dairy goats were divided into 3 groups: C(control diet), UFO (1.25% unprotected fish oil), PFO (2.5% fish oil protected against ruminal biohydrogenation). Dietary treatments continued until 38 days postartum. There were no significant effects on colostrum fat percentage (7.54, 7.64, 8.06%), protein percentage (15.17, 12.72, 14.24%), and somatic cell count (3.59, 3.37, 3.54 log/ml, respectively for C, UFO, PFO). Lactose content of colostrum was higher in the PFO than in the C group (3.16 vs. 2.40%, P<0.05). Milk parameters during the first 38 days postpartum were altered by dietary treatments. UFO and PFO treatments lowered milk yield (4.04, 3.37, 3.39 kg/d, P<0.01) and milk fat percentage (4.68, 3.99, 4.12%, P<0.01). Goats fed UFO and PFO diets had higher milk lactose concentration (4.78, 5.04, 4.99%, P<0.01). There were no significant effects of dietary treatments on milk protein concentration (mean 3.74%). UFO and PFO treatments lowered milk somatic cell count (3.137, 2.829, 2.816 log/ml, P<0.01). In dairy goats fed fish oil, cell-mediatedimmune response at 4 days post-partum was maintained at pre-partum levels.