新美系猪选育群及其杂交组合的杂交效果分析

试验共设6个组,包括杜、长、大三个纯种组和长×大、大×长、杜×长大三个杂交组,每组选取健康的、体重约25 kg的试验猪12头,公母各半,经过预饲调整后每组选取10头开始正式试验。饲养至组平均体重达100 kg左右时,每组选取4头（2♂2♀）进行屠宰测定和肉质分析,并计算了三个杂交组猪的各主要经济指标的杂优率（H）。结果表明,目前选育群各品种猪的日增重830 g以上,料肉比2.53以下,瘦肉率67%以上,肉质优良。三个纯种组中生长速度以杜洛克为最快,平均日增重达912 g;料肉比以大白猪的最低,为2.35;长白猪的屠宰率、胴体斜长、眼肌面积、瘦肉率最高,背膘厚最薄;6个组中杜×长大商品猪生长最快,平均日增重达977 g,料肉比为2.34,并有较理想的杂优率,而相对于长×大和大×长组合而言,许多重要经济性状,如背膘厚、眼肌面积、后腿比例、脂率、贮存损失等,大×长的杂优率均优于长×大,表明大×长组合也是非常有效的杂交组合,可为筛选新的杂优组合提供参考依据。

Analysis of Growth and Meat Performance and Hybrid Effect on Three Swine Breeding Groups

The swine in this experiment were divided into 6 groups,including 3 purebred groups Duroc（D）,Landrace（L）,Large White（Y） swine and 3 crossbred groups L×Y、Y×L、D×LY.10 healthy 25 kg-pigs were selected to feed in every groups.When their average body weight was 100 kg,4 pigs were picked out to slaughter and studied their slaughtering measurement and meat quality.The results showed that in D,L and Y breeding groups had rapid growth performance,the average daily gain（ADG） above 830 g,and feed conversion ratio（FCR） was under 2.53,they had high lean meat percentage（over 67%） and good meat quality.The ADG of D×LY commercial pig group was 977 g,FCR was 2.34,it had good heterosis.But to L×Y and Y×L cross breed groups,many important economic characters,like the back fat is thick,the eye muscle area,the hind leg proportion,the fat rate,the storing loss and so on,the L×Y are better than Y×L in mixed superior rate,indicated that the L×Y crossbreed is also the very effective hybrid combination,which can provides the reference to screen the new mixed superior combination.