【作者】 沈禹颐；

【导师】 张兆旺；

【作者基本信息】 甘肃农业大学 ， 养殖， 2005， 硕士

【摘要】 为探讨不同类型的饲粮水平对甘肃黄羽肉鸡增重、代谢及屠宰性能的影响,本试验对其上述指标进行了系统的测定和分析。第一期增重试验将甘肃黄鸡在1-4周龄分为三组(高饲粮营养水平组、中饲粮营养水平组、低饲粮营养水平组、),用3种不同营养水平的饲料配方饲喂,结果表明:在4周龄末表现出高组鸡的体重显著高于低组鸡的体重P＜0.05,而与中组鸡的体重无差异P＞0.05。在5—14周龄时分为5组(由中组又分出两组),分别饲喂高饲粮营养水平组、中高饲粮营养水平组、中饲粮营养水平组、中低饲粮营养水平组、低饲粮营养水平组,仍采用3种不同营养水平的饲料配方进行饲喂试验,结果表现出:高组鸡体重显著高于其他4组鸡的体重P＜0.05,其余4组鸡体重之间无显著差异P＞0.05。第二期增重试验在第一期增重试验的基础上选用中饲粮水平的饲粮作为基础日粮,将甘肃黄鸡分为高微量元素组、中微量元素组、低微量元素组三组,添加不同水平的微量元素进行饲喂试验,结果表明,饲喂至3周龄末时中组鸡体重显著高于高组鸡和低组鸡体重P＜0.05,饲喂至10周龄末时3组鸡体重之间无显著差异P＞0.05。增重试验表明:使用中营养水平的饲粮已经能够满足黄羽肉鸡的生长需要,并且经济适用。代谢试验表明:甘肃黄鸡在3周龄、8周龄时对中营养水平饲粮粗蛋白、有机物、干物质、能量的存留率较高,可见,在本次试验中无论是在饲养的前期还是后期,采用中营养水平的饲粮可促进营养物质的消化和吸收,从而有效地提高了饲料的利用率。第一期屠宰试验在试验鸡14周龄末时,选用5组鸡每组公母各5只鸡进行了屠宰性能各项指标的测定;测定结果表明:高组的活重、屠体重、屠宰率、半净膛重、全净膛重、腿重、胸肉重、腿肉重、腹脂重、腹脂率最高,具有较好的屠体品质,和其他各组之间差异显著P＜0.05。但腹脂含量过高,腹脂重为78.67克,腹脂率为5.64%,显著的高于其他各组P＜0.05。第二期屠宰试验在试验鸡10周龄末时选用3组鸡每组公母各5只鸡进行屠宰性能各项指标的测定;在第一期试验屠宰测定项目的基础上增加了胸腿肉失水率、胸腿肉酸度、胸肌面积、胸腿肌干物质等项目的测定。测定结果表明:三组鸡在屠宰率各项指标的测定中,各项指标差异不显著(P＞0.05);胸腿肉酸度在45分及保存24小时之后其PH值,差异不显著(P＞0.05)。三组鸡的腿肌PH值在保存45分、冷藏24小时之后均高于胸肌的PH值。添加中等水平的微量元素即可保持好的肌肉品质。更多还原

【Abstract】 In order to study the effect of different nutrient feed levels on some production performances of Gansu yellow feather broilers,the gain,metabolism and slaughter experiments were conducted respectively.The gain experiments were carried out for 2 phases.In phase 1 study,broilers at 1～4 weeks of age were divided into 3 groups. Group 1 was fed with high nutrient level of feed,group 2—middle nutrient level of feed and group 3—low nutrient level of feed.The results indicated that at the end of 4 weeks of age,the body weight of group 1 was significantly higher than that of the group 3(p＜0.05),but there was no difference between group 1 and group 2 (p＞0.05).During 5～14 weeks of age,the broilers were divided into 5 groups.Group 1 was fed with high nutrient level of feed,group 2—higher middle level of feed,group 3—middle level of feed,group 4—lower middle level of feed,and group 5—low level of feed.The results revealed that the body weight of groupⅠwas significantly higher than that of the other groups(p＜0.05);no difference was found among groups2～5.In phase 2 study,the middle nutrient level of feed was selected as basatl diet.Broilers were divided into 3 groups.Groups 1 was fed with high level of microelements,group 2o—middle level of microelements,group 3—low level of microelements,The results showed that at the end of 3 weeks of age,the body weight of group 2 was significantly higher than that of the group 1 and group 3(p＜0.05);at the end of 10 weeks of age,there were no differences among the 3 groups(p＞0.05);It is suggested that the middle nutrient level of feed satisfied the growth need of yellow feather broilers;and it has the advantages of lower price and practical effect.Metabolism experiment revealed that the retention rate of crude protein,organic matter,dry matter and energy in middle nutrientlevel of feed was higher in broiers at 3 and 8 weeks of age.Therefore,the middle nutrient level of feed could promote the digestion and absorption of nutrient matters and effectively increase the feed utilization rate in broilers during early or later growing stage.The slaughter experiment was carried out for 2 phases.In phase 1 study,at the end of 14 weeks of age,broilers tested were divided into 5 groups of 10 broilers(5 male and 5 female)each.The results showed that the living weight,carcass weight, slaughter rate,half-viscerated weight,whole-viscerated weight,leg weight,chest muscle weight,leg muscle weight,abdominal fat weight,abdominal fat rate in broilers fed with high nutrient level of feed were the highest,when compared to the other groups(p＜0.05),but the abdominal fat was significantly higher than that of the other groups(p＜0.05).In phase 2 study,at the end of 10 weeks of age,broilers tested were divided into 5 groups of 10 broilers(5 male and 5 female)each.Excepting the items tested in phase 1 study,the water loss rate of chest-leg muscles,acidity of chest-leg muscles,chest muscle area,dry matter of chest-leg muscles were added in phase 2 study.The results indicated that in slaughter rate test,all indices were not different (p＞0.05);the water loss rate of chest muscle was not different in 3 groups(p＞0.05),but water loss rate of chest muscle in broilers fed with middle nutrient level of feed was the lowest;water loss rate of leg muscle was signifcantly different among 3 groups (p＜0.05);water loss rate was highest in broilers fed with low nutrient level of feed, and that was lowest in broilers fed with middle nutrient level of feed.The acidity(pH value)of chest -leg muscles was not different after 45 min and storage for 24hr (p＞0.05).The pH value of leg muscle was higher than that of the chest muscle after storage for 45 min and freezing for 24hr.The chest muscle area in broilers fed with middle and low nutrient level of feeds was significantly different when compared to that of the broilers fed with high nutrient level of feed(p＜0.05).更多还原