Klindt J, Yen J T, Buonomo F C, Roberts A J, Wise T
Roman L. Hruska U.S. Meat Animal Research Center, ARS, USDA, Clay Center, NE 68933, USA.
J Anim Sci. 1998 Sep;76(9):2368-81. doi: 10.2527/1998.7692368x.
The actions of IGF-I, alone and in combination with porcine growth hormone (pGH), on growth and circulating endocrines and metabolites important in growth were investigated in peripubertal-age Meishan barrows. Pigs were assigned to four treatments: control, buffer; IGF-I, 33 microg rhIGF-I/kg BW injected twice daily; pGH, 33 microg rpGH/kg BW injected once daily; and IGF-I+pGH, 33 microg rhIGF-I/kg BW injected twice daily plus 33 microg rpGH/kg BW injected once daily. Treatments were administered for 28 d. Feed intake, BW, and backfat were recorded and blood samples were collected weekly. At slaughter, organ and primal cut weights were recorded. Offal and half the carcass were ground for chemical analysis. Serum concentrations of IGF-I on d 7, 14, 21, and 28 in the IGF-I, pGH, and IGF-I+pGH groups were increased 60, 107, and 131%, respectively, compared with those of the control group. Administration of pGH increased gain 43%, feed efficiency 60%, carcass protein accretion 88%, and trimmed lean cuts 16%, whereas IGF-I administration increased gain 22%, carcass protein accretion 33%, and trimmed lean cuts 5%. There was little difference in responses to administration of IGF-I+pGH and pGH alone except that coadministration of IGF-I with pGH reduced the ability of pGH to suppress backfat gain (P < .02). Even though administration of IGF-I resulted in a 60% increase in chronic nadir serum concentrations of IGF-I, only a few growth and carcass measures were changed when compared with control pigs. These included increased (P < .05) weight of body, leaf fat, kidneys, and belly. The actions of pGH on growth of pigs were not mimicked, and some were countermanded by administration of IGF-I at a dose that produces significantly increased serum concentrations of IGF-I.
在接近青春期的梅山公猪中，研究了胰岛素样生长因子-I（IGF-I）单独以及与猪生长激素（pGH）联合使用时，对生长以及生长过程中重要的循环内分泌和代谢产物的影响。将猪分为四种处理组：对照组，注射缓冲液；IGF-I组，每天注射两次重组人胰岛素样生长因子-I（rhIGF-I），剂量为33μg/kg体重；pGH组，每天注射一次重组猪生长激素（rpGH），剂量为33μg/kg体重；IGF-I + pGH组，每天注射两次rhIGF-I，剂量为33μg/kg体重，同时每天注射一次rpGH，剂量为33μg/kg体重。处理持续28天。记录采食量、体重和背膘厚度，并每周采集血样。屠宰时，记录器官和主要切块的重量。将内脏和一半胴体研磨进行化学分析。与对照组相比，IGF-I组、pGH组和IGF-I + pGH组在第7、14、21和28天时血清IGF-I浓度分别升高了60%、107%和131%。注射pGH使增重提高43%，饲料效率提高60%，胴体蛋白质沉积增加88%，修整后的瘦肉切块增加16%，而注射IGF-I使增重提高22%，胴体蛋白质沉积增加33%，修整后的瘦肉切块增加5%。IGF-I + pGH组与单独注射pGH组的反应差异不大，只是IGF-I与pGH联合使用降低了pGH抑制背膘增厚的能力（P < 0.02）。尽管注射IGF-I使慢性最低血清IGF-I浓度增加了60%，但与对照猪相比，只有少数生长和胴体指标发生了变化。这些指标包括体重、板油、肾脏和腹部重量增加（P < 0.05）。pGH对猪生长的作用未被IGF-I模拟，并且在产生显著升高的血清IGF-I浓度的剂量下，IGF-I的一些作用与pGH相反。
