The nutritive value of hemp meal for ruminants

Abstract

Hemp meal (HM) is derived from the processing of hemp (Cannabis Sativa L.) seeds. The objective of this study was to determine the nutritive value of HM for ruminants. Two ruminally fistulated cows were used in a randomized complete-block design to estimate in situ ruminal dry matter (DM) and crude protein (CP) degradability of HM relative to canola meal (CM), heated canola meal (HCM) and borage meal (BM) meal. Intestinal availability of rumen undegraded CP was estimated using a pepsin–pancreatin in vitro assay. Twenty growing lambs were utilized in a completely randomized design to determine total–tract nutrient digestibility coefficients of diets in which HM replaced CM at 0, 25, 50, 75 and 100% as a protein source. Results of the in situ study showed that the soluble-CP fraction of HM was similar to that of HCM and lower (P < 0.05) than those of CM and BM. Rate of degradation of the potentially degradable CP fraction and effective CP degradability of HM was higher (P < 0.05) than HCM and lower (P < 0.05) than CM and BM. Rumen undegraded CP and intestinal digestibility of RUP were highest (P < 0.05) for HM and HCM (average 782.5 and 644.5 g kg–1 of CP, respectively), intermediate for CM (473.9 and 342.9 g kg–1 of CP, respectively) and lowest for BM (401.5 and 242.3 g kg−1 of CP, respectively). However, total available CP was similar for the four protein sources (average 857.8 g kg−1 of CP). Feeding up to 200 g kg−1 HM did not affect voluntary intake or total-tract nutrient digestibility coefficients for sheep fed a barley-based diets. Hemp meal is an excellent source of RUP, with high post-ruminal availability, and may be used to replace CM with no detrimental effects on nutrient utilization by sheep. Key words: Hemp meal, nutritive value, ruminants