Effects Of Whole Cottonseed Supplementation On Growth Performance, Meat Quality And Blood Parameters Of Mutton Sheep In 4-6-Month-Old

Whole Cottonseed (WCS) is a good by-product of processing cotton, and it is a good feed with high energy, protein and fiber. WCS has been used widely thrbugh the foreign country as feed for ruminants. It was reported that WCS has only used in china as feed for dairy and beef cattle, but not for small ruminant especially for mutton sheep. This experiment was designed to study the effect of creasing level of WCS on growth performance, meat quality, blood parameters, and due to determine the level of WCS that could be included in diets for mutton sheep in the year 4-6-month-old. Otherwise, this thesis will provide some practicality informations on the way to save cereal, protein feed and gain the best economy benefit.Thirty 4-month-old crossed sheep of little-tail Han sheep (♀)×Dorset (♂) were divided into five treatments. Single factor design was used in the study with different whole cottonseed levels. Sheep were blocked with the tenet of similar and then assigned at random to one of five diets containing 0, 5, 10, 15 or 20% WCS, as the groupâ… , groupâ…¡, groupâ…¢, groupâ…£or groupâ…¤. WCS was applied as vegetable protein and energy in the diet. CP and ME in concentrations of every group were at the same ratio, but EE, NDF, ADF were increasing.(1) The result of feeding trail showed: The effect of increasing level of WCS on gain was significant (P＜0.01). At the final, the BW of Groupâ…¡and groupâ…¢were heavier (P＜0.01) than the other groups, and there is significant different between the two groups (P＜0.05). The BW of groupâ…¢was the heaviest among all groups, it was improved 17.60%, 13.60%, 19.28%, 20.42% than the other groups. The average daily gain of groupâ…¢was 261.69 g/d, it was heavier significantly (P＜0.01) than the other groups, and there were no difference among the other groups (P＞0.05).The dry matter intake of groupâ… in all experiment period was 1156.90 g/d,it was higher (P＜0.01) than the other groups, but there was no difference (P＞0.05) among all groups. Feed:Gain was no differentce (P＞0.05) among all groups, but its of groupâ…¡and groupâ…¢were lower than groupâ… .The economy benefit of groupâ…¢was the best one, it was increased by 1.14 RMB yuan and 1.09 RMB yuan per head per day than the group V and group I respectively.(2) The results of slaughter trail showed that with the increasing of WCS, the dressing percentage of the group including WCS were decreased than the groupâ… , but the difference was not significant among the groupâ…¢,â…£andâ… (P＞0.05). Rib-Eye Area of groupâ…¢had larger (P＜0.05) than groupâ… andâ…¡, and significantly bigger (P＜0.01) than that of groupâ…£andâ…¤. GR of groupâ… was the best one among all groups, it was bigger (P＜0.05) than that of groupâ…£andâ…¤, but there were no difference (P＞0.05) with groupâ…¡andâ… .There no differences (P＞0.05) among all groups in pH₁, pH₂₄, mature percent on 12h after it was slaughtered, drip loss on 24h after it was slaughtered. Feeding WCS resulted in signifiant (P＜0.01 )decrease intramuscular fat content of all experiment groups.The content of intramuscular fat of groupâ… higher (P＞0.05) than groupâ…¢,but the content of the two groups were higher (P＜0.05) than that of groupâ…¡,â…£, orâ…¤. There was no significant differences (P＞0.05) of TBARS on 24h and 72h after it was slaughtered in all groups, but it has increasing tendency with increasing of WCS. From the score of marbling grade we found that there was no diffemcy (P＞0.05) among all groups. WCS was no effect on flesh color. The content of free gossypol of meat sample was no differency (P＞0.05) among the groupâ… ,â…¡orâ…¢, but they are significantly differency (P＜0.01) with the groupâ…£andâ…¤, and the last two groups were obviously higher (P＜0.05) than that of the others. The content of free gossypol of groupâ…¡was 0.0440 mg/kg, it was the lowest one in all experiment groups.The groupâ…¤was the highest one, it was significantly higher (P＜0.01) than the other groups.(3) The analysis of blood sample showed that blood urine nitrogen (BUN) of groupâ…¢was lower than groupâ…¤(P＜0.05) but no differency (P＞0.05) with the other groups. Addition WCS has no significantly effect (P＞0.05) on Cre, FFA or A/G.Total protein (TP) of groupâ…¤was lower (P＜0.01) than the others, but no differrency (P＞0.05) with groupâ…£. With increasing WCS the ALB was decreased, but there was no differency among all groups. The content of Glu was no regulation and no distinction (P＞0.05) among the experiment groups.(4) The results of digestion trail showed that with the increasing of WCS, apparent digestibility of DM of experiment groups were lower than groupâ… .Among the experiment groups, there was no differency between the first two groups, and significantly higher than that of the last groups. Apparent digestibility of CP was increased from groupâ…¡toâ…¢, but outdo the amount of groupâ…¢it was decreased significantly (P＜0.01).Apparent digestibility of EE was increased from groupâ… toâ…¢, but outdo the amount of groupâ…¢it was decreased (P＞0.05). Apparent digestibility of EE of groupâ…¢was 71.37% which was improved 8.56% than that of groupâ… .And apparent digestibility of EE of experiment groups were increased (P＞0.05) than that of groupâ… . Apparent digestibility of ADF of experiment groups were decreased (P＞0.05) than that of groupâ… . Apparent digestibility of NDF of groupâ…¢was higher (P＞0.05) than that of other groups including groupâ… . (5) Dissecting the sheep, we found that there were no significant swollen or abnormity of colour and lustre in sampling organs. From the observation of histological-pathology of the tissues slice of liver, kidney and lung, we found that there were a few phenomenons of subclinical poisoning. The degree of tissue injury was increased with the increasing of amount of WCS. In all groups, the degree of tissue injury was similitude in groupâ…¡andâ…¢, but theâ…£andâ…¤were aggravated significantly. From the whole circumstances, we found that most metamorphic cells will renew and pathological changes will disappear with removing the factor causing the poisoning.Above all, the experiment shows that:1. The final weight of groupâ…¡and groupâ…¢were higher than the other groups (P＜0.01), so the 10% was the best amount of WCS on diet of mutton sheep in 4-6-month-old. The average daily gain of groupâ…¢was increased significantly (P＜0.01) than the other groups, and the economy benefit of groupâ…¢was the best one.2. With increasing WCS from groupâ…¡toâ…¢there was impoving tend on dressing percentage, Rib-Eye area or GR, but outdo amount of groupâ…¢it was decreased. It was resulted that the best ability of production meat was groupâ…¢.3. There were no effect on tender, mature percent, drip loss, flesh color or pH with increasing WCS, but the content of intramuscular fat was decreased. And the oxidization capability was amplify. The free gossypol of meat in all groups was in the safty range, it was no inderectly harm on peple's body.4. After feeding 60 days, we found that there were a few phenomenons of subclinical poisoning of all groups including the groupâ… . The degree of tissue injury was increased with the increasing of amount of WCS. From the whole circumstances, we found that most metamorphic cells will renew and pathological changes will disappear with removing the factor causing the poisoning. Therefore, WCS was extendable in feed of 4-6-month-old mutton sheep if we mastered the amount and the time of feeding no more than two month.5. There was a decreasing tend of apparent digestibility of CP, ADF or DM with increasing WCS, a increasing tend of apparent digestibility of EE and NDF.