The Effect Of Extraneous GHRH Gene Plasmid Injection On Growth Performance And Health In Calves

The objectives of the paper were to explore the effect of extraneous GHRH geneplasmid injection on bio-chemical index in blood,the level of growth hormone,immunity and growth performance in calves.Twenty heads of Holstein calves which average body weigh was about 54kg wererandomly dividely into four groups equally and injected the 5ml of 0.9％Nacl solutionrespectively containing 0mg,3mg,6mg and GHRH gene plasmid.The trial results found,the growth hormone levels of every treatments were higher than control,injecting differentdosage of GHRH plasmid, and 6mg treatment arrived the maximum (P＜0.05).In wholetrials average daily gain of every treatments were better than control. Average daily gainof 3mg treatment had a trendency to increase,but the effect was not influencedsignificantly(P＞0.05); Average daily gain of 6mg and 9mg treatments increasedobviously (P＜0.05).Heart girth of 3mg,6mg and 9mg treatments were 5.17％,6.06％and14.08％more than control;And heart girth of 9mg treatment increased significantly(P＜0.05).Body length and height at withers in all treatments were higher than control(P＞0.05). It is obviously that injection of GHRH gene plasmid can improve growthperformance in calvesThe results showed that IgG content of every treatments, injecting different dosage ofGHRH plasmid, had the tendency to increase,and 3mg,6mg treatments hadn't changesignificantly (P＞0.05). Lysozyme concentration of every treatments were better thancontrol, and 6mg treatment arrived the maximum (P＜0.05); The content of superoxidedismutase of 3mg and 6mg treatments didn't increase obviously, and the superoxidedismutase content of 9mg treatment was influenced significantly (P＜0.05).Malondialdehyde content of every treatments had the tendency to reduce,but the effectwas not influenced obviously.And the nitric oxide concentration of every treatments wasnot influenced significantly by the extraneous GHRH gene plasmid injection. So we cansay that injection of GHRH gene plasmid can improve the function of immunity in calves.In whole trial serum albumin content of every treatments was not influencedobviously by the extraneous GHRH gene plasmid injection. The concentration of serum total album and globumin in every groups had a trendency to increased, and serum totalalbum and globnmin of 9mg group arrived the maximum (P＜0.05). The content alkalinephosphatase of 3mag,6mg and 9mg treatments were higher than control,9mg treatmentchange obviously (P＜0.05). The aspartate transaminase concentration of everytreatments,injecting different dosage of GHRH plasmid,had the tendency to reduce,butthe effect was not significantly (P＞0.05);The effect of GHRH plasmid didn't affect thealanine transaminase (P＞0.05).And lactate dehydrogenase was not influenced obviously bythe extraneous GHRH gene plasmid injection (P＞0.05).The whole trials results showed that injection of GHRH gene plasmid not only can'tinfluence the health of calves,but also can improve growth performance and the functionof immunity.