Abstract:

This experiment investigated the effects of alfalfa （Medicago sativa） meal on the production performance， slaughter performance， meat quality， and serum biochemical indicators of different hybrid lines of Liangsan pigs. A two-factor experimental design was adopted， dividing animals into four groups： EGⅠ （Zangliang F₁， fed alfalfa diet）， CGⅠ （Zangliang F₁， fed basal diet）， EGⅡ （Baliang F₁， fed alfalfa diet） and CGⅡ （Baliang F₁， fed basal diet）. Each group consisted of three replicates， with 10 pigs per replicate， and the experiment lasted 49 days. The basal diet was formulated by the experimental farm， and the alfalfa diet was prepared by replacing 9.6% of the basal diet with alfalfa meal. The experimental animals were selected from healthy 8-month-old Liangsan hybrid pigs with good body condition and similar body weight （91.20±10.07 kg）. This study systematically evaluated the effects of the two hybrid combinations and two dietary types on production performance， slaughter performance， meat quality， and serum biochemical indicators， and explored their interactions. It was found that： 1）When comparing hybrid lines， the average daily gain， slaughter rate， lean meat percentage， eye muscle area， glutamic acid content， arginine content， and total antioxidant capacity of group CGⅡ were significantly higher than those of group CGⅠ （P<0.05）. The slaughter rate， ether extract content， and glutathione peroxidase activity of group EGⅡ were significantly higher than those of group EGⅠ （P<0.05）. The crude protein and docosanoic acid content in group EGⅠ were significantly higher than those in group EGⅡ （P<0.05）， while the crude protein and glucose content in group CGⅠ were significantly higher than those in group CGⅡ （P<0.05）. 2） When comparing alfalfa and basal diets the malondialdehyde content in group CGⅡ was significantly higher than that in group EGⅡ （P<0.05）， and the arginine content and total antioxidant capacity in the longissimus dorsi muscle of the EG groups were significantly higher than those in the CG groups （P<0.05）. 3） A significant interaction between diet type and hybrid combination was observed for arginine and α-linolenic acid （P<0.05）. 4） No significant differences were found in the other indicators； however， compared with the basal diet group （CG group）， the alfalfa diet group （EG group） showed a decrease in feed conversion ratio， ether extract content， drip loss， yellowness value， pentadecanoic acid， heptadecanoic acid， docosanoic acid， and tetracosanoic acid content （P>0.05）， while the contents of crude protein， aspartic acid， glycine， alanine， proline， tyrosine， leucine， and butyric acid， as well as the activities of superoxide dismutase and alkaline phosphatase， were increased （P>0.05）. In conclusion， dietary supplementation with alfalfa meal during the late fattening phase reduced the feed conversion ratio， improved feed utilization， enhanced total antioxidant capacity， and effectively improved meat quality in both hybrid lines.

Key words: alfalfa meal, Liangsan pig, growth performance, slaughter performance, meat quality, serum biochemical indexes