Analysis on feeding effects of steam explosion and fermentation cotton stalk in sheep

Abstract: In order to investigate the responses of fattening sheep in production performance and blood biochemical parameters to the treatments of steam explosion and fermentation cotton stalk, cotton stalk and corn silage, the whole plant of cotton stalk harvested by self-propelled straw harvester were chopped by grinder, rapid decompression under the 2.5 MPa, 220 ℃ for 2~3 min, then the cooled product was anaerobically fermented for 45 days by adding inoculants. Thirty healthy sheep with 5-month-old were averagely placed into steam explosion and fermentation cotton stalk, cotton stalk and corn silage group according to their body weight. These sheep were fed with different diets according to their nutrients requirements which were added same dry matter proportion of steam explosion and fermentation cotton stalk or cotton stalk or corn silage to the same basal diet during 40-day experimental period. Daily gain, dry matter intake and blood biochemical parameters were analyzed using the GLM model. The results showed that the dry matter intake was significantly different among groups (P<0.01). The daily gain in steam explosion and fermentation cotton stalk group was 49.21% higher than that in cotton stalk group (P<0.05), the daily gain in corn silage group was 44.45% higher than that in cotton stalk group (P=0.06), The ratio of feed-meat was highest in cotton stalk group and lowest in corn silage group. The blood globulin content in corn silage group were 17.02% and 20.01% lower than steam explosion and fermentation cotton stalk group and cotton stalk group, respectively, both showing significant differences (P<0.05). The blood total protein content in corn silage group was 11.90% lower than cotton stalk group (P<0.01), and was 7.86% lower than steam explosion and fermentation cotton stalk group (P<0.05). The ratio of albumin to globulin in steam explosion and fermentation cotton stalk group was 18.68% lower than corn silage group (P<0.05). The glutamic pyruvic transaminase in cotton stalk group was 69.80% and 77.67% higher than corn silage group and steam explosion and fermentation cotton stalk group, the difference were extremely significant (P<0.01). The Blood cholesterol content in corn silage group was 36.13% lower than cotton stalk group (P<0.05). Low density lipoprotein content in corn silage group was 50% lower than cotton stalk group (P<0.05). The results suggested that the feeding quality of steam explosion and fermentation cotton stalk is higher than cotton stalk but lower than corn silage. The steam explosion and fermentation cotton stalk could reduce the damage to animal gut and obtain a daily gain close to corn silage, but its feed efficiency is higher than corn silage and lower than cotton stalk. The steam explosion and microbial fermentation technology cooperative processing could be help to pre-treat cotton straw as roughage for fattening sheep in the cotton growing area.