The effects of alfalfa particle size and Canola meal treated with hydrochloric acid on physically effectiveness, intake, digestibility and chewing behavior in Zel sheep

This study was conducted to investigate the effects of alfalfa particle sizes (long vs. fine) and treating canola meal with hydrochloric acid solution (with purity of 38 percent and level of 5 percent) on physical effectiveness, intake, apparent total tract digestibility of nutrients and feeding behavior in sheep. Four ruminally cannulated sheep fed with TMR. Experimental diets were including: 1) canola meal treated and long alfalfa 2) canola meal treated and fine alfalfa 3) not treated canola meal and long alfalfa 4) not treated canola meal and fine alfalfa. Obtained data from experiment were analyzed by a 4×4 Latin square experimental design. Particle size distribution was determined by dry- sieving procedure and used to partition of feed component and TMR among percentage of long (larger than 19 mm), medium (between 19 and 8 mm) and small (between 8 and 1.18 mm) particles. According to study results, Reduction of particle size increased daily NDF intake (kg) (P<0.05), but decreased the proportion of physically effective NDF (peNDF) in the ingested rations (P<0.05), however canola meal treatment had no effect on them (P>0.05). Reduction of particle size increased DM intake but decreased digestibility of NDF and OM (P<0.05). Treatment of canola meal with hydrochloric acid solution decreased DM intake but increased CP digestibility (P<0.05). Total chewing activity, rumination and eating time reduced when particle size decreased and canola meal was treated (P<0.05). This study showed that reduction of forage particle size was the most effectiveness factor on DMI and chewing behavior (P< 0.05).