UTILIZATION OF LODGEPOLE PINE (Pinus contorta) MUKA (FOLIAGE) BY SHEEP

Abstract

Eight sheep were used in two 4 × 4 latin square digestion trials substituting alfalfa meal with unsteamed or steamed muka (foliage) at levels of 20, 40 or 60%. Including muka at all levels depressed (P < 0.05) the digestibility of dry matter, organic matter, crude protein and acid detergent fiber compared with the control alfalfa meal diet. When calculated by difference, the digestibility of muka dry matter and organic matter was not affected (P < 0.05) by either the level of its inclusion in the diets or by steaming. The mean dry matter and organic matter digestibilities of muka were 29.2 and 30.4%, respectively. The protein content of muka was 5.0% and the estimated protein digestibility at the 60% level of inclusion was only 6.6%. With unsteamed muka, the digestibility of acid detergent fiber calculated by difference averaged −11.9%, suggesting the presence of factors which depressed the digestibility of fiber in the basal diet. Steaming appeared to reduce this depression. A growth trial was conducted with lambs where alfalfa meal, as the sole roughage source, was compared to the same diet with 20% of the alfalfa replaced by steamed muka. Growth rates were not different (P > 0.05) being 142 and 138 g/day, respectively. A taste panel evaluation of the carcasses found no adverse effects on flavor due to the inclusion of steamed muka in the diet. Key words: Lodgepole pine muka, nutritive value, sheep