Carter S D, Cromwell G L, Colombo G, Fanti P
Department of Animal Sciences, University of Kentucky, Lexington 40546, USA.
J Anim Sci. 1999 Aug;77(8):2163-71. doi: 10.2527/1999.7782163x.
Six sets of four littermate barrows initially averaging 75.5 kg BW were equally fed (within blocks) fortified corn-soybean meal diets (1.30% lysine) containing two concentrations of Ca (.50 and 1.00%) and P (.45% and .90%) in a 34-d test. One-half of the pigs were injected with 4 mg of porcine ST (pST)/d. Following a 7-d adjustment period, total collection of feces and urine was performed during two periods (d 1 to 10 and d 20 to 30) for the determination of Ca and P apparent digestibility (absorption) and retention. Pigs were bled after each period (d 10, 20, and 30) for the determination of serum metabolites associated with Ca, P, and bone metabolism. Feed intake for the 30-d period averaged 2,020 g/d. There were no treatment x period interactions, so the absorption and retention data were pooled across periods. The absorption and retention of Ca and P were greater (P<.01) in pigs fed the higher Ca and P levels. Within each Ca and P level, pST reduced (P<.01) fecal Ca and P excretion. Administration of pST did not affect urinary P excretion, but it increased (P<.03) urinary Ca excretion in pigs fed the low-Ca diet. The absorption and retention of Ca and P were increased (P<.01) by pST; however, the increases in Ca retention and P absorption and retention on an absolute basis (g/d) were more pronounced in pST-treated pigs consuming the higher Ca and P diet (interaction, P<.10). Serum concentrations of 1,25-dihydroxyvitamin D3, osteocalcin, and IGF-I on d 10 and 30 were increased (P<.07) with pST administration. However, the increases in 1,25-dihydroxyvitamin D3 and osteocalcin in pST-treated pigs were more pronounced when the lower dietary Ca and P levels were fed (interaction, P<.08). Urinary excretion of hydroxyproline increased (P<.01) with pST administration, but this effect was more pronounced in pST-treated pigs fed the lower Ca and P diet (interaction, P<.09). These results suggest that pST increases the absorption and retention of Ca and P independent of dietary Ca and P level. However, serum measures associated with Ca, P, and bone metabolism in pST-treated pigs were dependent on the Ca and P content of the diet, suggesting an effect of pST on the homeostatic control of Ca, P, and bone metabolism.
选用六组共24头同窝的雄性仔猪，初始体重平均为75.5千克，在34天的试验期内，按照体重分栏，等量饲喂强化玉米-豆粕型日粮（赖氨酸含量为1.30%），日粮中钙（0.50%和1.00%）和磷（0.45%和0.90%）各有两种浓度。一半的猪每天注射4毫克猪生长激素（pST）。经过7天的适应期后，在两个时间段（第1至10天和第20至30天）收集全部粪便和尿液，以测定钙和磷的表观消化率（吸收率）及潴留量。每个时间段结束后（第10、20和30天）对猪进行采血，以测定与钙、磷及骨代谢相关的血清代谢物。30天试验期内的平均采食量为每天2020克。不存在处理×时间段的交互作用，因此将各时间段的吸收和潴留数据合并。饲喂较高钙和磷水平日粮的猪，其钙和磷的吸收及潴留量更高（P<0.01）。在每个钙和磷水平组内，pST均可降低（P<0.01）粪便中钙和磷的排泄量。施用pST对尿磷排泄量无影响，但在饲喂低钙日粮的猪中，可增加（P<0.03）尿钙排泄量。pST可增加（P<0.01）钙和磷的吸收及潴留量；然而，从绝对值（克/天）来看，在采食高钙高磷日粮的pST处理猪中，钙潴留量以及磷吸收和潴留量的增加更为显著（交互作用，P<0.10）。第10天和第30天时，施用pST可使血清中1,25-二羟维生素D3、骨钙素和胰岛素样生长因子-I的浓度升高（P<0.07）。然而，在饲喂较低日粮钙和磷水平时，pST处理猪中1,25-二羟维生素D3和骨钙素的升高更为显著（交互作用，P<0.08）。施用pST可使羟脯氨酸尿排泄量增加（P<0.01），但在饲喂低钙低磷日粮的pST处理猪中，这种作用更为显著（交互作用，P<0.09）。这些结果表明，pST可增加钙和磷的吸收及潴留量，且与日粮钙和磷水平无关。然而，pST处理猪中与钙、磷及骨代谢相关的血清指标取决于日粮中的钙和磷含量，这表明pST对钙、磷及骨代谢的稳态控制有影响。
