Supplementation of sow diets with oil during gestation: Sow body condition, milk yield and milk composition

This study aimed to determine the consequences of altering the fatty acid profile of sow diets during gestation. 88 multiparous sows were used to evaluate the effects of fat supplementation during either the first (G1) or second (G2) half of gestation. Sows were allocated to either 3 kg/day of commercial sow pellets (control; C), or an experimental diet consisting of C diet with 10% extra energy in the form of excess pellets (E), palm oil (P), olive oil (O), sunflower oil (S) or fish oil (F). Experimental diets were fed during either the first 60 days of gestation, or from day 61 of gestation until term. All sows were given 3 kg/day of sow pellets as for the C group, during the non-supplemented period. The provision of extra energy resulted in increased fat deposition over the period of supplementation. E G1 and S G1 groups continued to deposit fat at elevated rates during G2. Fat accretion occurred at a much lesser extent in E G2 and P G2 compared to OG2, S G2 and F G2 animals. E G1, S G1 and F G2 mothers mobilized more fat over the lactation period compared to all other groups, except F G1 who mobilized a greater proportion of their fat reserves during lactation than they had accumulated during gestation, resulting in a net loss in back fat depth over the whole production cycle. The timing of supplementation influenced milk yield, and the percentages of fat and protein in the milk but not milk lactose. Milk fatty acid profile reflected the fatty acid profile of the maternal diet during gestation; this effect was most pronounced in the lacteal secretions of sows receiving the F diet. The concentration of immunoglobulins was increased in the colostrum of sows that had received the P and S diets during G1. In conclusion the type and timing of maternal dietary supplementation influences maternal fat deposition and mobilization as well as the fatty acid profile and immunoglobulin concentration of the milk.