INFLUENCE OF HEMPSEED CAKE ON LIPID FRACTIONS IN BOVINE M. LONGISSIMUS DORSI OF FRESH AND COOKED TISSUE

摘要

IntroductionStrategies to increase the polyunsaturated fatty acid (PUFA) content of beef tissue, while lowering the n-6-3 ratio, have focused on inclusion of forage and lipid sources in the diet. Inclusion of oilseeds, either processed or whole, offer varying degrees of rumen bypass efficiency. Hemp oil consists of 84% PUFA, of which 22% is a-linoleic acid (18:3 n-3) (Callaway 2004). Mustafa et al. (1999) found hemp meal, which contained 32% crude protein and 52% ether extract, to be an excellent source of rumen undegraded protein, with digestion characteristics similar to heat-treated canola meal. Alternatively, feeding full-fat oil seed offers greater protection of lipids from biohydrogenation than if fed as a meal (Aldrich et al., 1997). A feedlot diet (Gibb et al., 2005) containing 14% as-fed whole hemp seed had no adverse effects on daily intake or gain compared to a soybean diet. Fatty acid profile comparison of M. pars costalis diaphramatic indicated a greater proportion of a-linoleic acid in hemp-supplemented animals compared to soybean-supplemented animals (Gibb 2005). Whole hemp seed provides a good source of by-pass protein as well as increasing the content of n-3 FA within the tissue. The objective of this study was to compare the lipid composition of fresh and cooked M. longissimus dorsi (LD) tissue from steers supplemented with either cold pressed hemp cake or soybean meal.