妊娠・授乳期ラットにおけるラード及び魚油添加飼料の摂取が仔ラットの油脂摂取嗜好と成長に及ぼす影響

Abstract

To investigate the influence of fat-feeding dams on the food choice and the growth of their pups after weaning two groups of dams were fed a lard diet (LD) or a fish oil diet (FD) during pregnancy and lactation. Immediately after weaning, all pups were placed on two-choice diet program of the LD and the FD for 3 weeks. Although dietary intake during lactation by dams fed the LD was higher than that by dams fed the FD, at the end of lactation, body weight of the LD group was lower than that of the FD group. Body and perirenal fat tissue weights, and plasma leptin and lipid concentrations in suckling pups of dams fed the LD were higher than those in suckling pups of dams fed the FD. These findings indicate that amount of energy transferred to suckling pups from dams fed the LD was higher than that transferred to suckling pups from dams fed the FD. At the beginning of the self-selection period, no significant difference in the amount of the LD and the FD intake was observed between both groups of pups. However, in both groups of pups, the ratio of the LD intake increased and that of the FD decreased from day 3 to 6. After day 6, the ratio of the LD and the FD intake of the pups was about 80% and 20%, respectively. S : M : P and n-3FA : n-6FA in the diet that both groups of pups self-selected after day 6 was 3.3 : 3.9 : 3.0 and 2.9 : 1.0, respectively. These data led us to conclude that rat have an ability to consume essential fatty acid adequately through internal fatty acid metabolism.