THE EFFECTS OF HIGH-FORAGE DIETS WITH ADDED PALM OIL ON PERFORMANCE, PLASMA-LIPIDS, AND CARCASS CHARACTERISTICS OF RAM LAMBS WITH INITIALLYHIGH OR LOW PLASMA-CHOLESTEROL

The objectives of this study were to examine the interaction between a dded palm oil in high-forage diets and initial concentration of plasma cholesterol on performance, plasma lipids, and carcass characteristic s of growing ram lambs. Thirty-two Hampshire-Suffolk ram lambs (initia l BW = 34.4 kg) were assigned to a 2 x 2 factorial design consisting o f diet (basal [NPO] or 10.7% addea palm oil [PO]) and initial plasma c holesterol concentration (high (x) over bar = 50 mg/dL [HC] or low (x) over bar = 38 mg/dL [LC]; SEM = 2; P = .01). The lambs were individua lly fed diets (77% forage-23% concentrate)at contained 16.0% CP, 2.14 Meal of ME/kg (NPO), and 2.62 Meal of ME/kg (PO). Metabolizable energy intakes were adjusted to .20 Mcal/kg of BW.75 for both dietary treatm ents. Lambs were weighed and feed intakes adjusted weekly. Lambs were bled via jugular venipuncture on d 28, 56, and 84 and lambs were slaug htered after they had been fed the diets for 90 d. Plasma concentratio ns of total cholesterol, high-density lipoprotein cholesterol, triglyc erides, and nonesterified fatty acids were increased (P = .01) by feed ing PO. Lamb's fed PO were fatter than lambs fed NPO, as indicated by greater subcutaneous fat thickness and kidney and pelvic fat. Initial plasma cholesterol concentration had little effect on any of the param eters measured. Lambs fed PO had fatter carcasses than lambs fed NPO a t calculated equalized ME intakes, which indicates that energy deposit ion is more efficient in palm oil-supplemented diets.