PubMed1983
Two experiments with male turkeys were designed to study the effects of eating cooked ground beef on plasma lipid and lipoprotein levels. In both experiments, cooked ground beef from forage-finished cattle (F-Bf) and grain-finished cattle (G-Bf) were added at an average of 28.1 and 34.5 g of beef per 100 g of ration in order to provide 40% of the protein requirement. The experimental diets formulated to be isocaloric and isonitrogenous were: 1) basal diet (negative control) in which soybean meal and corn oil served as protein and fat sources, respectively; 2) basal plus crystalline cholesterol (positive control) incorporated at 1 and 2% of the diet in trials 1 and 2, respectively; 3) basal plus F-Bf; 4) basal plus G-Bf. The polyunsaturated to saturated fat ratio averaged 3.45 for diets 1 and 2 and 0.17 for diets 3 and 4, respectively. At 16 weeks, consumption of diets 3 and 4 elevated (P less than 0.05) plasma triglyceride levels and phospholipid levels (trial 1). In trial 2, only diet 4 elevated (P less than 0.05) plasma phospholipid levels. In both trials, the beef diets did not significantly elevate plasma cholesterol and high density lipoprotein (HDL) cholesterol levels above the basal diet. However, the major apoprotein in the HDL fraction, apolipoprotein A-I (apoA-I), was increased (P less than 0.05) in the plasma of male turkeys fed the G-Bf diet in both trials and F-Bf diet in trial 1. Plasma apolipoprotein B (apoB), primarily found in low density lipoproteins (LDL), was increased (P less than 0.05) in one of the two trials by the inclusion of beef in the diet. There were no significant differences in plasma cholesterol, HDL-cholesterol, apoA-I and apoB levels between the types of beef (F-Bf vs. G-Bf).