放牧对育肥后期苏山猪生长性能、胴体性状和肌肉品质的影响

Effects of Grazing on Growth Performance,Carcass Traits and Muscle Quality of Sushan Pigs in Late Fattening Period

本试验旨在研究放牧对育肥后期苏山猪生长性能、胴体性状以及肌肉中氨基酸和脂肪酸含量的影响。选取健康、体重为(75.0±2.0) kg的苏山猪80头(公母各占1/2),随机分为放牧组和对照组,每组2个重复,每个重复20头。放牧组猪群每天11:00—17:00在果园中放牧,自由采食黑麦草、俄罗斯草等青绿饲料。对照组猪群舍饲。预试期7 d,正试期30 d。结果表明:1)放牧组平均日增重和屠宰率均低于对照组,差异达到显著水平(P<0.05);放牧组胴体骨率高于对照组,差异达到极显著水平(P<0.01)。2)放牧组背最长肌失水率低于对照组,差异达到极显著水平(P<0.01);亮度(L^(*))值和红度(a^(*))值高于对照组,黄度(b^(*))值低于对照组,但差异均未达到显著水平(P>0.05)。3)放牧组背最长肌中不饱和脂肪酸含量高于对照组,总饱和脂肪酸含量低于对照组,但差异均未达到显著水平(P>0.05)。放牧组背最长肌中缬氨酸含量高于对照组,胱氨酸含量低于对照组,差异均达到极显著水平(P<0.01)。4)放牧组背最长肌中总必需氨基酸、总鲜味氨基酸和总氨基酸含量均低于对照组,但差异未达到显著水平(P>0.05)。放牧组背最长肌中棕榈油酸含量高于对照组,差异达到显著水平(P<0.05);月桂酸、硬脂酸、花生酸等饱和脂肪酸含量低于对照组,且差异均达到极显著水平(P<0.01)。综上所述,育肥后期苏山猪进行放牧对其生长性能影响不显著,但对其胴体性状和肌肉品质具有一定程度的改善作用,是生产优质猪肉的一种重要养殖模式。

The purpose of this experiment was to study the effects of grazing on the growth performance,carcass traits and the content of amino acids and fatty acids in muscle of Sushan pigs in late fattening period. A total of 80 healthy Sushan pigs(half male and half female)with a body weight of(75.0±2.0)kg were randomly divided into grazing group and control group,with 2 replicates in each group and 20 pigs in each replicate.The pigs in the grazing group grazed in the orchard from 11:00 to 17:00 every day and freely fed on ryegrass,Russian grass and other green feeds. The pigs in the control group were fed in pigsties. The pre-experiment lasted for 7 days and the experiment lasted for 30 days. The results showed as follows:1)the average daily gain and slaughter rate of grazing group were lower than those of control group(P<0.05). The carcass bone rate of grazing group was higher than that of control group,and the difference was very significant(P<0.01). 2)The water loss rate of longissimus dorsi muscle of grazing group was lower than that of control group(P<0.01).lightness(L^(*))and redness(a^(*))values of longissimus dorsi muscle of grazing group were higher than those of the control group,and yellowness(b^(*))value was lower than that of the control group,but the difference did not reach a significant level(P>0.05). 3)The unsaturated fatty acid contents in longissimus dorsi muscle of grazing group were higher than those of control group,and the total saturated fatty acid contents were lower than those of control group,but the difference was not significant(P>0.05). Valine content in longissimus dorsi muscle of grazing group was higher than that of control group,and cystine content was lower than that of control group(P<0.01). 4)The contents of total essential amino acids,total fresh amino acids and total amino acids in longissimus dorsi muscle of grazing group were lower than those of control group,but the difference was not significant(P>0.05). Palmitoleic acid content in longissimus dorsi muscle of grazing group was higher than that of control group(P<0.05). Saturated fatty acids such as lauric acid,stearic acid and arachidonic acid contents were lower than those of the control group,and the differences were very significant(P<0.01). In conclusion,the grazing of Sushan pig in the later stage of fattening has no significant effect on its growth performance,but it can improve its carcass traits and muscle quality to a certain extent. It is an important breeding model for the production of high-quality pork.