離乳直後の仔ラットの脂質し好性に母ラットの脂質摂取量は影響しない

Abstract

We investigated the fat preference of weaning rats born to 8 dams of the Sprague-Dawley strain. The dams had been divided into two groups: one group (LF) was given during pregnancy and lactation a low-fat diet containing 3.5% soybean oil, and the other group (HF) was given a high-fat diet containing 7% soybean oil and 14% lard. After weaning, each pup was given both the high-fat diet and low-fat diet placed in separate cups. The fat preference was determined by measuring the intake of these two diets over 8 days. The respective intake proportions by weight of the high-fat diet were 81% and 88% by the pups from the LF and HF groups, while the respective fat energy ratios of the total dietary intake were 35% and 37%. No significant differences in the body, liver or perirenal fat tissue weights and liver lipid concentrations after self-selection were apparent between both groups of pups, in spite of the large difference in dietary fat level intake by both dam groups. There was no significant difference in the selfselection of dietary fat by the weaning pups. These results suggest that, immediately after weaning, all the rats had a high-fat preference which was not conditioned by the diet of the pregnant and lactating dams, nor by possible nibbling of the dams' diet during nursing.