Effects of dietary protein, fat and restriction on body composition and energy balance in lactating rats.
Isoenergetic diets formulated at three levels of dietary protein using 12,24 and 40% casein and at two levels of fat using 2.26 and 13.82% corn oil were fed at five levels of intake, ad libitum, 75, 62.5, 50 and 37.5% of average ad libitum intake, to 90 lactating rats from d 7 to 14 of lactation. Regression equations developed from lactating rats killed on d 7 of lactation were used to calculate initial body composition and energy of rats killed on d 14 of lactation. Changes in body weight and body water were significantly (P less than 0.05) affected by dietary fat and protein, but change in dry lean body mass was affected only by level of dietary fat, whereas body nitrogen and fat and lean body energy were not affected by level of dietary fat or protein. However, restricted intake significantly increased loss of all these. Likewise, restricted intake decreased milk production. Changes in weights of heart and liver were not affected by diet or intake, whereas intestinal weight decreased with intake restriction. Liver enzyme activities were markedly affected by intake restriction, whereas responses to dietary protein and fat were marginal.
D000818:Animals; D001823:Body Composition / Q000187:drug effects*; D001833:Body Temperature Regulation / Q000187:drug effects; D001834:Body Water / Q000187:drug effects; D001835:Body Weight / Q000187:drug effects; D004041:Dietary Fats / Q000494:pharmacology*; D004044:Dietary Proteins / Q000494:pharmacology*; D004734:Energy Metabolism / Q000187:drug effects*; D005260:Female; D007774:Lactation; D008055:Lipids / Q000172:deficiency; D011247:Pregnancy; D011488:Protein Deficiency / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains
D004041:Dietary Fats; D004044:Dietary Proteins; D008055:Lipids