Carter S D, Cromwell G L
Department of Animal Sciences, University of Kentucky, Lexington 40546, USA.
J Anim Sci. 1998 Feb;76(2):596-605. doi: 10.2527/1998.762596x.
We investigated the effects of recombinant porcine somatotropin (pST) on the requirement for P to maximize lean tissue accretion and to minimize fat tissue accretion in two experiments using finishing pigs. Corn-soybean meal diets with varying levels of P were fed, and Ca was adjusted to maintain a Ca:P ratio of 1.1:1. In Exp. 1, 96 pigs were fed dietary P concentrations of .35, .45, and .65% from 75 to 109 kg BW. One-half of the pigs were injected daily with 4 mg of pST. Administration of pST increased (P < .05) percentages and accretion rates of lean tissue, bone, skin, water, and protein, but it reduced (P < .05) those of fat tissue and lipid. Increasing dietary P had little effect on chemical composition or accretion rates in untreated pigs, but it increased (P < .05) ash percentage and accretion in pigs treated with pST. Experiment 2 consisted of 66 pigs fed six dietary P concentrations (.35, .50, .65, .80, .95, and 1.10%) from 72 to 114 kg. One-half of the pigs were injected daily with 4 mg of pST. Percentages and accretion rates of lean tissue, bone, skin, water, and protein increased (P < .05) with pST, but those of fat tissue and lipid were reduced (P < .05). Increasing dietary P increased accretion rates of bone and skin (linear, P < .05), lean tissue, water, protein, and ash (quadratic, P <.05), and it reduced (quadratic, P < .05) that of lipid in pigs treated with pST. Dietary P level did not consistently affect percentages or accretion rates of tissues or chemical components in untreated pigs. In most instances, pigs treated with pST required higher dietary P levels and greater daily intakes of P to maximize lean tissue and protein deposition and to minimize fat tissue and lipid accretion than untreated pigs. These results indicate that finishing pigs treated with pST require higher dietary percentages of P to maximize carcass lean deposition as compared with untreated pigs.
我们在两项使用育肥猪的试验中研究了重组猪生长激素（pST）对磷需求的影响，以实现瘦肉组织生长最大化和脂肪组织生长最小化。饲喂含不同磷水平的玉米 - 豆粕型日粮，并调整钙水平以维持钙磷比为1.1:1。在试验1中，96头猪从体重75千克饲养至109千克，分别饲喂含0.35%、0.45%和0.65%磷的日粮。一半的猪每天注射4毫克pST。注射pST提高了（P < 0.05）瘦肉组织、骨骼、皮肤、水分和蛋白质的百分比及生长率，但降低了（P < 0.05）脂肪组织和脂质的百分比及生长率。增加日粮磷水平对未处理猪的化学成分或生长率影响不大，但提高了（P < 0.05）注射pST猪的灰分百分比和灰分生长量。试验2有66头猪，从体重72千克饲养至114千克，饲喂六种日粮磷浓度（0.35%、0.50%、0.65%、0.80%、0.95%和1.10%）。一半的猪每天注射4毫克pST。注射pST后，瘦肉组织、骨骼、皮肤、水分和蛋白质的百分比及生长率增加（P < 0.05），但脂肪组织和脂质的百分比及生长率降低（P < 0.05）。增加日粮磷水平提高了注射pST猪的骨骼和皮肤生长率（线性，P < 0.05）、瘦肉组织、水分、蛋白质和灰分生长率（二次曲线，P < 0.05），并降低了（二次曲线，P < 0.05）脂质生长率。日粮磷水平对未处理猪的组织或化学成分的百分比及生长率没有一致的影响。在大多数情况下，与未处理猪相比，注射pST的猪需要更高的日粮磷水平和更多的每日磷摄入量，以实现瘦肉组织和蛋白质沉积最大化以及脂肪组织和脂质生长最小化。这些结果表明，与未处理猪相比，注射pST的育肥猪需要更高的日粮磷百分比来实现胴体瘦肉沉积最大化。
