Study Of Regulatory Mechanism Of CZKJKL On Early Weanling Stress In Piglets

Three experiments were conducted to investigate the regulatory effect of CZKJKL on early weanling stress piglets and the potential mechanism.Experiment 1:[Objective] The experiment was conducted to explore the Effect of CZKJKL on growth performance, serum biochemical parameters and the levels of stress related hormones in early weanling piglets and the optimal dose.[Methods] 48"Duroc×Landrace×Yorkshine" crossbred early weanling piglets [(28±2) d of age] were randomly divided into 4 treatments of 12 piglets each, with 3 replicates in each group and 4 piglets in each replicate. fed with basal diet, basal diet plus 1500mg/kg、 3000mg/kg or 6000mg/kg CZKJKL respectively. The experiment lasted for 14 d.[Result] Adding 3000mg/kg CZKJKL could significantly improve the ADFI and ADG of early weanling piglets (p<0.05),significantly decrease the F/G and diarrhea rates post weanling (p<0.01); significantly improve the levels of TP and AKP in Serum (p<0.01), significantly decrease the levels of BUN、CK、LDH in serum (p< 0.01); significantly improve the levels of IgA and IgG in serum (P< 0.05 or P< 0.01), significantly improve the level of serum IgM in the period of 35～42 days of age;significantly decrease the level of COR in the age of 35d or 42d(p< 0.01),significantly improve the levels of GH、IGF-I、T3、T4 and GAS in Serum(P< 0.05 or P< 0.01). Adding 6000mg/kg CZKJKL could also significantly improve or decrease the above indexes,but the effect is less than the group of adding 3000mg/kg CZKJKL.[Conclusion] The results showed that CZKJKL can efficiently relieves the weanling stress on piglets. In production practice, adding 3000mg/kg CZKJKL in basal diet can obtain the best effect.Experiment 2:[Objective] Based on the earlier study of experiment 1, this study further explored the effect of CZKJKL on growth performance, serum immunological indexes, serum endocrine hormone indexes, serum antioxidant indexes and serum biochemical indexes of early weanling piglets after LPS Immunological Stress.[Methods] 48"Duroc×Landrace×Yorkshine" crossbred early weanling piglets [(28±2) d of age] were randomly divided into 4 treatments of 12 piglets each, with 3 replicates in each group and 4 piglets in each replicate.the four treatments were control group, CZKJKL group, LPS group and (LPS+CZKJKL) group. The piglets in control group and LPS group were fed with basal diet, and the piglets in CZKJKL group and (LPS+CZKJKL) group were fed with basal diet plus 3000mg/kg CZKJKL respectively. The experiment lasted for 14 d. On d 7,piglets were injected intraperitoneally with either 100 μg/kg BW of LPS or an equivalent amount of sterile saline. Blood samples were obtained 3 h after injecting LPS.[Result] (1)Compared to control group, the ADFI and ADG of early weanling piglets in CZKJKL group were significantly increased (p< 0.05), the F/G in the period of 35～42 days of age and 28～42 days of age was significantly decreased(p< 0.01); the levels of IgG,GH,IGF-I,TP in Serum were significantly improved (P< 0.05 or P< 0.01), the activities of T-SOD,GSH-PX, AKP in Serum were significantly improved (P< 0.05 or P< 0.01); the levels of IL-1β,IL-α,TNF-α,ACTH,COR,NOS,MDA and GLU in serum were significantly decreased (P< 0.05 or P< 0.01), the activities of CK,LDH and GOT in serum were significantly decreased (P< 0.05 or P< 0.01).(2)Compared to control group, the ADFI and ADG of early weanling piglets in LPS group were significantly decreased (p< 0.05), the F/G was significantly increased (p< 0.01); the levels of IgG,IGF-I and TP in Serum were significantly decreased (P< 0.01), the activities of T-SOD,GSH-PX, CAT,T-AOC, AKP in Serum were significantly decreased (P< 0.05 or P <0.01); the levels of IL-1β,IL-α,TNF-α,ACTH,COR,MDA,NOS,BUNand GLU in serum were significantly improved (P<0.05 or P<0.01), the activities of CK,LDH and GOT in serum were significantly improved (P< 0.05 or P< 0.01).(3)Compared to LPS group, the ADFI and ADG of early weanling piglets in CZKJKL group were significantly increased (p<0.05), the F/G was significantly decreased (p<0.01); the levels of IgG,IGF-I and TP in Serum were significantly increased (P<0.01), the activities of T-SOD,GSH-PX, CAT,T-AOC, AKP in Serum were significantly increased (P<0.05 or P <0.01); the levels of IL-1β,IL-6,TNF-α,ACTH,COR,MDA,NOS,BUNand GLU in serum were significantly decreased (P<0.05 or P<0.01), the activities of CK,LDH and GOT in serum were significantly decreased (P<0.05 or P<0.01).[Conclusion] Based on the results of this study,we can see that CZKJKL can efficiently relieves the damage of LPS immunological stress and weanling stress on early weanling piglets.Experiment 3:[Objective] Based on the study of experiment 1 and experiment 2, this study further explored the effect of CZKJKL on growth performance, intestinal function,nervous and endocrine and immune network,the mRNA and protein expressions of IL-1β and iNOS in hippocampal tissue of early weanling Wistar rats after LPS immunological stress.[Methods] 72 early weanling Wistar rats at the age of 18 days were randomly divided into 3 treatments of 24 rats each, with 6 replicates in each group and 4 rats in each replicate.The 3 treatments were control group, LPS group and (LPS+CZKJKL group). In the period of 18-24 days of age,the rats in (LPS+CZKJKL)group were fed with 5000mg/kg-BW CZKJKL daily by gavage,the rats in control group and LPS group were fed with equivalent amount of sterile saline.At the age of 21 days, the rats in LPS group and (LPS+CZKJKL)group were injected intraperitoneally with 4mg/kg BW of LPS, the rats in control group were injected equivalent amount of sterile saline. At the time of 4 h after injecting LPS,rats were received D-xylose by gavage to determine the absorption of intestinal tract.Blood and tissue samples were obtained 6 h after injecting LPS.[Result] LPS significantly reduced the ADG, the levels of DAO in mucosa of ileum, the activities of lactase, sucrase and maltase in mucosa of ileum, the activities of SOD and GSH-Px in mucosa of ileum, the D-xylose content in serum, the levels of GAS and MTL in mucosa of ileum (P< 0.05 or P< 0.01). LPS significantly increased the contents of NE and 5-HT in hippocampi,the level of β-EP in hypothalamus, the contents of MDA in mucosa of ileum,the contents of DAO,CCK-8,β-EP,NO,iNOS,IL-1β,IL-6,TNF-α,ACTH and COR in serum, the expression levels of mRNA and protein of IL-1β and iNOS in hippocampal tissue(P< 0.05 or P< 0.01). CZKJKL alleviated significantly the changes of the above indexes induced by LPS(P< 0.05 or P< 0.01).[Conclusion] The results indicate that CZKJKL can efficiently alleviate the damages induced by LPS immunological stress and weanling stress on early weanling rats. It may be paly roles by the following ways as improving the intestinal digestive enzyme activity, enhancing the intestinal digestive and absorptive function, improving the intestinal mucosal antioxidant ability, improving the nervous-endocrine-immune network function.