Effects Of Different Proportions Of Corn Stalk Silage And Rice Straw On The Production Performance, Meat Quality And Blood Biochemical Indexes Of Mutton Goat

Effects of different proportions of corn stalk silage and rice straw on the production performance, meat quality and blood biochemical indexes of mutton goat were studied in the present experiments including 4 parts shown as follows:In experiment one the effect of different proportions of corn stalk silage and rice straw on the growth of mutton goat was studied. Ninty three-month-old boer×Xuhuai goat with similar body weights( 15±2kg) were selected as experimental animals and divided into six groups(15 goats per group) fed with 6 diets different corn silage to straw ratio and forage to concentrate ratio. The 6 diets were: A (roughage/concentration 45:55, silage/straw 85:15, concentrate protein level: 14%), B (roughage/concentration 40:60, silage/straw 75:25, concentrate protein level: 14%), C (roughage/concentration 35:65, silage/straw 70:30, concentrate protein level: 14%), D (roughage/concentration 45:55, silage/straw 85:15, concentrate protein level: 16%), E (roughage/concentration 40:60, silage/straw 75:25, concentrate protein level: 16%), F (roughage/concentration 35:65, silage/straw 70:30, concentrate protein level: 16%). The goats were fed ad libitum. The results showed that in a certain range reducing roughage to concentration and silage to straw ratio could increase the growth of goat and the body size of group D, E and A(concentrate protein level:16%)were higher than groups A, B and C(concentrate protein level:14%). Weight gain of B, D group higher (silage/straw 75/25) than other groups, B>C>A; E>F>D. The increase of concentration to roughage ration from 55:45 to 60:40 could increased the daily gain. However, concentrationto roughage retion increased from 60:40 to 65:35 could decrese the average daily gain of goat. The highest and lowest feed to gain ratios were found in groups A and E, respectively. Group E had the higher economic returns than any other groups.In experiment 2 the effects of different proportions of corn stalk silage and rice straw on goat meat production performance, carcass traits, physical and chemical characteristics of meat, nutritional composition were studied. In concentrate protein level of 14%, with the silage/straw ratio increased, slaughter rate, longissimus muscle moisture and protein, arm triceps moisture, gluteus ash increased; lean rate, longissimus muscle tenderness, pH45min and pH24h, biceps femoris pH24h, longissimus muscle fat, gluteal muscle water decreased. In 16% protein level, with the silage/straw reduced, longissimus muscle moisture, biceps femoris protein gradually increased, while the arm triceps pH24h, biceps femoris fat decreased. The results showed that: in the same concentrate, diary component have influence on the goat meat production performance, it illustrate that silage/straw improved the meat quality, concentrate play a major role in the muscle protein and fat, it have little effects on moisture and ash, silage/straw have greater impact on muscle water and tenderness.In experiment 3 the effects of different proportions of corn stalk silage and rice straw on goat meat amino acids and fatty acid composition were studied. The results showed that amino acid was not significant in different group, but it can improve flavor in mutton. In addition, TAA, EAA, NEAA were not significant in different group. However, with straw and protein decline, TAA increased. In protein level of 16%, EAA increased with straw upward. NEAA along with protein levels increased, it indicated dietary ingredients and nutrition have effects on mutton amino acids. Corn silage/straw have significantly affected on fatty acid composition of different muscles, and show some differences and regularity.In experiment 4 the effects of different proportions of corn stalk silage and rice straw on mutton goat blood biochemical indexes.TP, BUN, TC, BG, AST, ALT, AKP, LDH were not significant in different group, it indicated that silage/straw have little effects on mutton goat blood biochemical parameters.TP were in the normal range( 60.57~74.03 g/L) but group A in 90d were higher than others group.BUN in the range of 4.34~8.08mmol/L, with increased of concentrate protein, BUN and protein utilization declined;and the proteins utilization of group A was lower than others; BG levels in 90d lower than the pre-test, at the same protein level, BG along with roughage/concentration and silage/straw declined, and increase level of protein will reduce BG; TC higher than pre-test, and in the same protein level, the growth rate of TC in roughage/concentration 40:60, silage/straw 75:25 was higher than others group; silage/straw may have positive effects; AST, ALT higher than the pre-test, the initial rise, the late decrease; In addition, in the same protein level, AST, ALT which in roughage/concentration of 40:60 and silage/straw of 75:25 group was higher than other groups. AKP, LDH increase as age increased and then decreased, and protopHase test grew faster, later stage slow, that AKP, LDH was related to the age, and diet composition and nutrient have little effect on them...