Nutritional evaluation of treated canola straw for ruminants using in vitro gas production technique

The aim of the present study was to determine the chemical composition and estimate the nutritive value of molasses treated with canola straw using in vitro gas production technique with Taleshi native male cattle. Experimental materials were collected from different regions of Parsabad province (Ardabile, Iran). Experimental group were: untreated canola straw (control) and 4% molasses treated canola straw. After providing uniform mix, chemical composition for untreated straw including dry matter (DM), crude protein (CP), ether extract (EE), crude ash (CA), neutral detergent fiber (NDF), acid detergent fiber (ADF) and nonfibrous carbohydrates (NFC) were estimated: 89.66, 2.8, 3.9, 2.4, 79.2, 58.8 and 11.7%, respectively and for molasses treated straw, they were: 66.21, 3.12, 3.9, 3.57, 77.2 57.4 and 12.21%, respectively. Gas production test with mixtures of filtered rumen liquid of two Taleshi native male cattle rumen in time periods of 2, 4, 6, 8, 12, 24, 48, 72 and 96 h was performed. The results show that organic matter digestibility (OMD) and metabolizable energy (ME) for treated canola straw were significantly higher than that of untreated canola straw (control) (p<0.001). Gas productions at 24 h for untreated canola straw (control) and treated canola straw were 20.03 and 27.07 ml, respectively. Overall, it seems that the nutritive value of treated canola straw was higher than that of untreated canola straw (control) for ruminants.   Key words: Nutritive value, canola straw, metabolizable energy, gas production technique.