Studies On Optimal Levels Of Crude Protein And Lysine For The Sow During Lactation And Observation Of Adaptability In Sweden Landrace

The productive and reproductive performances, and the adaptability of Landrace pig rooted in Sweden were investigated in Shijiazhuang Qingliangshan breeding pig farm. The results showed that the heartbeat rate, respiratory frequency, and body temperature were within the normal ranges. The oestrus cycle, gestation length, total number of piglets born, number of piglets born alive and litter weight at birth were 20.8 d, 115.89 d, 11.33,10.69 and 16.58kg, respectively. Estrus in the gilt and sow lasts 59 and 47 hours, respectively. These sows could reproduce 7 litters under local environment.Age at 100kg weight was 157.26 days , average daily gain was 822.27g, and backfat thickness (probed) at 100kg weight was 10.20 mm, which were all higher than those in Sweden (171.8d, 705.29g and 10.29mm, respectively). These results showed that Landrace pig originated in Sweden could adapt to the natural status and feeding condition of Shijiazhuang Qingliangshan breeding pig farm.In the present, the optimal CP and Lysine levels for lactational sows were determined through a feeding trial. There were four treatments in this trial and the contents of digestion energy (DE) and crude protein (CP) for four treatments were 13.63, 13.63, 13.67, 13.63 MJ/kg and 14.0%, 15.93%,18.4%,20% , respectively , while the Lysine levels of four treatments were 0.756, 0.86, 0.994, 1.080% , respectively. But the CP: Lysine was 0.054 for four treatments. The results showed that the level of CP and Lysine of diets did not affect feed intake and backfat thickness significantly. With CP and Lysine content of diets increased, the weightlessness of lactational sows during lactation became little, which of treatment 3 and 4 is less than that of treatment 1 and 2, but there were no difference between treatment 3 and 4. The interval of delectation to oestrus of the treatment 1 was longest among four treatments, the second was the treatment 2, and the treatment 3 is similar to the treatment 4. The litter weight at 21d of the treatment 3 and 4 was heaver than that of the treatment 1 and 2.,but without significant difference between the treatment 3 and 4. From the above , we considered that the optimal level of CP and Lysine of diets for Sweden Landrace in the farm was 18.4% and 0.994% , respectively.