Dietary cholesterol effects on tissue cholesterol and carcass characteristics of growing pigs selected for high or low serum cholesterol

Abstract

Two groups of 12 pigs genetically selected for either high or low serum cholesterol were used to determine the differences in cholesterol metabolism produced by either high or low cholesterol levels in the neonatal diet. The pigs were fed either a high (.5%) or low (O%) cholesterol diet from birth until 4 weeks. They then were feed the low cholesterol diet until 8 weeks after which they were fed a high (.5%) cholesterol diet until 6 months. Brain (P < .04) and liver (P < .01) were heavier for the high cholesterol diet groups. The brain and heart as a percentage' of live weight were higher due to diet, but liver percentage was not affected by diet. Carcass characteristics showed no significant difference for any of the treatments (P > .05). Back fat at the first rib (P < .01), at the last lumbar vertebrae (P < .05), and at the 10th rib (P < .01), when adjusted for weight, were affected by diet. The four lean cuts, both rough and trimmed, were heavier due to diet, but not genetics. But when data were examined as a percentage of body weight, only the trimmed ham was affected by diet. Brain cholesterol concentration was higher in the high diet groups (P < .03). This finding possibly indicates the ability of cholesterol to cross the blood-brain barrier, but more conclusive evidence is needed. Liver cholesterol was higher in the high diet group. Longissimus dorsi muscle, semitendinosus muscles, and subcutaneous fat cholesterol concentrations showed no relationship to any of the treatments. Mesenteric fat and leaf fat cholesterol levels were statistically higher due to diet. Throughout all variables, no diet x genetic interactions were seen. These data provide evidence that genetically determined high or low serum cholesterol coupled with a high or low cholesterol diet at an early age affects body composition and especially brain size and cholesterol, but has no effect on muscle cholesterol concentration.