【作者】 徐继成；

【导师】 张伟力；

【作者基本信息】 安徽农业大学 ， 动物营养与饲料科学， 2004， 硕士

【摘要】 美系杜洛克猪引入安徽后由于生态环境，管理方式和饲料营养水平等方面均发生了较大变化，有必要对其现有种质特性进行研究，进一步了解它的生长速度、生长发育水平、胴体组成和肉质性状，为指导杜洛克猪的推广工作提供参考依据。本实验从营养学的角度出发，对美系杜洛克生长性能、胴体品质及肉质做了一整套的测定，初步探讨了屠宰体重，季节，限制饲喂等不同饲养模式在安徽饲养条件下对新引入美系杜洛克生长性能、胴体品质及肉质参数的影响。试验一：新引入美系杜洛克猪在安徽省的性能表现。安徽省畜禽品种改良站2001年从美国引入100头原种杜洛克（85母15公），进行了一年半的扩繁后对原种和695头纯繁一代后裔进行了测定，目前测定的原种成绩为6月龄体长（♂）145±13cm，10月龄体长（♂）153±14cm，18月龄体长（♂）170±13cm，产仔数11.5±2.0头/窝(第二胎)。纯繁一代生长发育成绩为28日龄重8.3±2.1千克，70日龄重33.0±4.5千克，达100千克日龄148.0±13.2天，平均日增重为859克，饲料转化率达2.46：1。肉色L*值达51.70±2.44, 嫩度42.19±4.84N。该测定结果提示，新引进的杜洛克在生长速度、繁殖性能、肉质方面性能优秀，现代美系杜洛克的种质有较明显的改进。试验二：不同屠宰体重对美系杜洛克猪胴体肉质性能的影响。于2001年从美国引进杜洛克原种第二代种猪群中随机抽取28日龄48头杜洛克仔猪，并保育至70日龄，体重达33kg，在生长到肥育阶段饲喂含消化能l3.3~13.1MJ/Kg、粗蛋白质18.01％~16.03％的饲粮。分别在100kg、120kg、150kg体重级别从48头母猪中随机选择12头(4×3，每个体重级别4头)进行屠宰，检测体重和日龄对胴体和肉质的影响。结果表明：当体重从100kg增至150kg时，瘦肉率从66.8％显著降至62.4％，即使在150kg体重，瘦肉率也完全符合市场需求。然而，板油和花油的增加值得注意。此外，肌内脂肪，体重120kg、150kg(3.32％、3.69％)高于100kg(2.86％)。这个结果提示，随着体重增大肌内脂肪提高而改善肉质，但嫩度降低。试验三：季节对美系杜洛克猪胴体和肉质性能的影响。于秋冬季（季节1）与春夏季（季节2）分别在安徽省原种猪场第二代种猪群中选择日龄、体重相近的36头仔猪于28日龄断奶，并保育至70日龄，体重达33kg，在生长到肥育阶段饲喂含消化能l3.3~13.1MJ/Kg、粗蛋白质l8.01％~16.03％的饲粮，自由采食饲喂至100千克活重，再随机选取18头进行屠宰测定并进行肉质参数测定。结果表明：季节对本试验胴体品质无显著影响。在肉质参数中，秋冬季猪肉的红度(6.47±0.73)显著低于春夏季(8.78±0.85)，贮存损失(3.26±0.88)也显著低于春夏季<WP=4>(5.63±0.64)。不同季节猪肉的常规生化指标尚能维持相对稳定，脂肪酸、氨基酸组份合理。试验四：限制饲喂对美系杜洛克猪生长肥育猪生长性能及经济效益的影响。于安徽省原种猪场第二代同胞测定群中选择日龄、体重相近的70日龄肥育猪50头，随机分为对照组与实验组，预试后，对照组按平时自由采食时消耗的饲料量饲喂，实验组饲喂对照组的80%，在相同饲养条件下饲喂至140日龄。试验开始和结束均空腹称重，记录饲料消耗量。实验结果表明：试验组日增重降低了66克，每增重1千克少耗料0.3千克，每头猪净增收入21.08元。更多还原

【Abstract】 Since the importation of American Duroc in 1970’s, the following imported American Duroc of improved genetic background and feeding management have changed a lot , it’s very essential to measure its growth、carcass and meat quality performances for offering a technical reference for Duroc’s production. From the point of view of Animal nutrition, this experiment was focused on the three performance aspects: The effects of different live weights(1)、seasons(2)、and feeding patterns(3) on growth、carcass and meat quality performances of the New American Duroc on the feeding condition of Anhui. Experiment 1：A Report on Growth、Carcass and Meat Quality Performances of the New American Duroc in Ahhui Province. From U.S. Anhui Animal Improvement Station imported 100 American Duroc (15 male, 85 female) and reproduced them for 2 generations. The imported Duroc and the 659 offspring of first generation were tested. The performances of the imported were 145±13cm, 153±14cm, 170±13cm for the male body length at 6, 10, 18 month of age separately. The litter size was 11.5±2.0(the second embryo). The growing performances for the offspring were 8.3±2.1kg and 33.0±4.5kg of body weight at 28 days and 70 days of age separately. The growing days for 100kg body weight was 148.0±13.2 days. The average daily gain was 859g and the feed conversion rate was 2.46:1. As regard to meat quality they had 51.70±2.44 for L* and 42.19±4.84N for shearing force. The results imply that the new imported Duroc have very good capacity of growth, reproduction and meat quality. The genplasma of modern American Duroc has been improved to a certain extent. Experiment 2： Effects on Carcass and Meat Quality Performances of American Duroc at Different Live Weights. 48 Durocs were randomly selected at 28 days of age from the second generation of American Duroc Breeding herd which was imported in 2001 from U.S. The 48 gilts were <WP=6>fed in nursery house till they were 70 days of age at about 33 kg body weight. For the growing-finishing phases the pigs were fed with diets at DE l3.3~13.1MJ/Kg and CP 18.01％~16.03％. Randomly 12 (4×3,4 individuals for each body weight phase) individuals from the 48 Durocs were selected and slaughtered at about 100 kg、120 kg and 150 kg live weight at different growing phases separately to examine the influence of body weight or age on the carcass ad meat quality. The results indicated that the lean percentage decreased significantly from 66.8% to 62.4% when live weight in creased from 100 kg to 150 kg. It means that Duroc gilts are lean enough to current market demands even they are finished as later as 180 days of age at 150 kg live weight. However the increased leaf fat and viscera fat need to be monitored. In addition, higher intramuscular fat percentages were for 120/150 kg live weight (3.32%/3.69%) than that for 100 kg (2.86%). The results imply better meat quality for higher live weight with higher intramuscular fat at the expense of a little worse tenderness. Experiment 3：The Influence of Season on the Carcass and Meat Performances in American Duroc. 36 Duroc pigs of each group were randomly selected at 28 days of age from the second generation of American Duroc Breeding herd in season 1(autumn-winter) and season 2(spring-summer). The 36 Duroc pigs of each group were fed in nursery house till they were 70 days of age at about 33 kg body weight. For the growing-finishing phases the pigs were fed with diets at DE l3.3~13.1MJ/Kg and CP 18.01％~16.03％ till they were 100 kg. Randomly 18 individuals from the each group were selected and slaughtered to examine the influence of different season on the carcass ad meat quality. The results indicated that season had no significant influence on the carcass parameters. As regard to meat parameters, lower a* value(6.47±0.73) and driploss(3.26±0.88) were for the season of autumn-winter than those(8.78±0.85, 5.63±0.64) for the season of spring-summer. Biochemistry parameters of different seasons were relative stabilization. The relative content of Fatty acid更多还原