【作者】 杨开伦；

【导师】 雒秋江；

【作者基本信息】 新疆农业大学 ， 草业科学， 2009， 博士

【摘要】 本文基于近几年新疆农区逐渐兴起的肉绵羊集约化生产方式,研究羔羊月龄、羔羊性别以及不同日粮精粗比等因素对无角陶赛特×小尾寒羊羔羊(简称为陶×寒F1羔羊)产肉性能、肌肉食用品质和肌肉化学成分的影响,旨在进一步全面深入了解集约化全舍饲条件下肉绵羊的产肉性能和肉品质特点,为新疆农区开展和推广肉绵羊集约化生产提供参考和指导。本研究所用的试验绵羊来自完全舍饲的羊群,试验设置了羔羊的屠宰月龄(分别为7月龄、13月龄)、公母、两种精粗比不同的日粮类型(精粗比分别为68:32、35:65)等因素;在研究羔羊屠宰月龄因素的影响时,选择了相同月龄的小尾寒羊羔羊作为比较。在进行屠宰试验测定产肉性能后,进一步测定了肌肉的食用品质和化学成分。结果显示:1、在羔羊产肉性能方面:13月龄的陶×寒F1羔羊屠宰体重、胴体净肉重、瘦肉重、眼肌面积比7月龄时均高出30%以上;7月龄陶×寒F1羔羊的屠宰体重、胴体重、净肉产量、瘦肉产量比7月龄小尾寒羊均高出30%以上;13月龄的陶×寒F1羔羊、小尾寒羊羔羊的绝对产肉性能显著高于7月龄羔羊,但以13月龄陶×寒F1羔羊的绝对产肉性能最高。7月龄陶×寒F1公羔的屠宰体重、胴体重、净肉重均比母羔高出12%以上,肉骨比显著高于母羔,公羔的绝对产肉性能优于母羔。育肥阶段日粮精粗比为68:32时陶×寒F1羔羊的胴体重、净肉重、瘦肉重较精粗比为35:65时高出25%以上,产肉性能显著。2、在羔羊肉食用品质方面:7月龄、13月龄陶×寒F1羔羊背最长肌的胶原蛋白含量、剪切力值均分别低于相同年龄的小尾寒羊,陶×寒F1羔羊背最长肌的嫩度要优于小尾寒羊羔羊。陶×寒F1公羔和母羔背最长肌的食用品质指标之间没有显著差异。育肥阶段的陶×寒F1羔羊饲喂精粗比分别为68:32、35:65的日粮时,羔羊背最长肌的食用品质指标没有显著差异。3、在肌肉化学成分方面:不同月龄、公母、羔羊育肥阶段的日粮精粗比等对陶×寒F1羔羊背最长肌中粗蛋白、钙、磷等常规养分含量均无显著影响;7月龄、13月龄陶×寒F1羔羊的各种氨基酸含量都比小尾寒羊羔羊有所提高,但各种氨基酸的构成比例基本相同;7月龄陶×寒F1羔羊背最长肌中亚油酸的含量比13月龄羔羊高出近45%,13月龄小尾寒羊羔羊背最长肌中亚麻酸的含量较7月龄羔羊高出76.8%,胆固醇含量高出约46%,7月龄、13月龄陶×寒F1羔羊背最长肌中二十碳四稀酸的含量均高于同月龄的小尾寒羊;在陶×寒F1羔羊和小尾寒羊羔羊,铁的含量均表现为13月龄高于7月龄。公羔和母羔背最长肌中各种氨基酸含量、总必需氨基酸含量、总非必需氨基酸含量、总氨基酸含量均差异不显著;公羔背最长肌中亚油酸的含量比母羔高20.3%,胆固醇含量低约32%;7月龄陶×寒F1母羔背最长肌中的铁含量比公羔的高26%左右。日粮精粗比对羔羊背最长肌的氨基酸含量、胆固醇含量、微量元素含量等均没有显著影响;精粗比为68:32时陶×寒F1羔羊的背最长肌中亚油酸、亚麻酸的含量有增加的趋势。本研究表明,采取集约化全舍饲的生产方式,以陶×寒F1羔羊为商品代,饲喂精粗比为68:32的日粮,在7月龄时可形成优质羊肉,是生产优质羊肉的首选生产方式;13月龄屠宰时在羊肉综合品质没有显著下降时可明显提高产肉性能。更多还原

【Abstract】 Based on the increasing intensive production system of meat-produced sheep in farms in Xinjiang, the effects of lamb age, sex, and diet type (concentrate to forage ratio) were studied on slaughter performance, meat characteristics, and muscle chemical components of crossbreed offsprings of Poll Dorset×Small Tail Han Sheep (DHF1). The aim was to get more knowledge on slaughter performance, meat characteristics of meat-produced sheep in intensive production system, and to supply basis for development of intensive production system in Xinjiang.The experiment animals were chosen from the flocks fed in intensive production system. The treatments were slaughter age (7- and 13-month-old), sex, and two diet types (concentrate to forage ratio 68 to32 and 35 to 65). Small Tail Han Sheep (HS) with 7- and 13-month-old age were used as the control group to being compared. The animals were slaughtered for measurement of carcass characteristics and sampling for subsequent meat quality and analysis of muscle chemical components.The results showed that live body weight, meat weight, lean meat weight, and eye muscle area of 13-month-old DHF1 were higher 30% than that of 7-month-old DHF1. Live body weight, carcass weight, meat weight, and lean meat weight of 7-month-old DHF1 were higher 30% than that of 7-month-old HS. The meat production of 13-month-old DHF1 was the highest. Live body weight, carcass weight, and meat weight of 7-month-old DHF1 rams were higher 12% than that of ewes. The meat to bone ratio of rams was significantly higher than that of ewes. The slaughter performance of rams was better than that of ewes. The 7-month-old DHF1 rams fed diet with concentrate to forage ratio of 68 to32 showed higher 25% than that of ratio 36 to 65 in carcass weight, meat weight, and lean meat weight. The collagen content and shear force value in Longissimus dorsi (LD) of 7- and 13-month-old DHF1 were significantly lower than those in LD of HS with the same ages. There was no significant difference in meat characteristics between rams and ewes. The meat characteristics were not affected by diet type. The contents of dry matter, crude protein, crude fat, ash, calcium, and phosphorus in LD were not influenced by age, sex and diet type. The contents of amino acids in LD of 7- and 13-month-old DHF1 were higher to some degree than that of 7- and 13-month-old HS, but corporation of amino acids was similar. The content of linoleic acid in LD of 7-month-old DHF1 lamb was higher about 45% than that of 13-month-old lamb. The content of linlenic acid was increased by 76.8%, but cholesterol higher about 46% in 13-month-old HS lamb than that in 7-month-old HS lamb. Arachiolonic was higher in LD of 7- and 13-month-old DHF1 than that in LD of HS with the same ages. Iron in LD of 13-month-old lambs was higher than that of 13-month-old lambs. There was no significant difference in the contents of various amino acids,total essential amino acids, total non-essential amino acids, and total amino acids in LD between rams and ewes. The content of linoleic acid in LD of DHF1 rams is increased by 20.3%, but cholesterol decreased by 32% compared with DHF1 ewes. Iron in LD of 7-month-old DHF1 ewes was higher about 26% than that of rams. The diet type used in this study did not markedly affect the contents of amino acids, cholesterol, and trace minerals measured. The contents of linoleic acid and linlenic acid in LD of rams fed diet with concentrate to forage ratio of 68 to32 showed the trend of increase.This present study shows that the intensive production system, in which DHF1 rams is finished feeding diet with 68% of concentrate and slaughtered at 7-month-old, is the first selective pattern in Xinjiang lamb production. Both DHF1 rams and HS rams slaughtered at 13-month-old can produce more meat than that slaughtered at 7-month-old but meat quality does not significantly decrease.更多还原