Schlegel Patrick, Gutzwiller Andreas
Agroscope, Swine Research Unit, 1725 Posieux, Switzerland.
Animals (Basel). 2020 Jan 21;10(2):178. doi: 10.3390/ani10020178.
Within the context of maximizing the use of dietary phosphorus, a growing-finishing pig study was conducted to determine the optimal total dietary calcium (Ca) to digestible phosphorus (dP) ratio and to verify the possibility of mineral phosphate removal during the finishing period on growth performance and mineral status. The potential for replacing chemical and mechanical bone properties by dual energy X-ray absorptiometry (DXA) measures on non-dissected feet was also verified. Three Ca to dP ratios (2.2:1, 2.5:1 and 2.8:1) within two dP levels (P+, P-) were fed during 91 days to 84 pigs. The grower and finisher P+ diets contained 3.0 and 2.4 and P- diets contained 2.5 and 1.7 g dP/kg, respectively. Growth performance and blood serum mineral content were independent of treatments, except that 2.2:1 impaired finisher feed conversion ratio compared to 2.5:1 and 2.8:1. Urinary P concentration increased by 37% in 2.2:1 compared to 2.5:1 and 2.8:1. Maximal load on bone and DXA mineral density were reduced in 2.2:1 compared to 2.8:1. Bone ash and volumetric density were reduced in 2.2:1 and 2.5:1 compared to 2.8:1. Diet P- reduced bone ash, maximal load, volumetric density and DXA bone mineral content and density. No interaction was observed between Ca and dP level. Therefore, 2.2:1 was insufficient for an efficient metabolic use of P, 2.5:1 was sufficient to maximize growth performance and 2.8:1 further improved bone mineralization. Increasing dietary Ca did not impair bone zinc content. Diets P- without supplemented mineral phosphates during the finisher period resulted, per pig, in a decrease of its use by 65% and of the calculated P excretion by 41%, without impaired growth performance. Finally, DXA data responded to dietary treatments as did labor intensive chemical and mechanical bone properties.
在最大限度利用日粮磷的背景下，开展了一项生长育肥猪研究，以确定日粮中总钙（Ca）与可消化磷（dP）的最佳比例，并验证育肥期去除矿物磷酸盐对生长性能和矿物质状况的影响。还验证了通过双能X射线吸收法（DXA）测量非解剖足部来替代化学和机械骨特性的可能性。在91天内，给84头猪饲喂了两种dP水平（P+、P-）下的三种Ca与dP比例（2.2:1、2.5:1和2.8:1）。生长育肥期的P+日粮分别含3.0和2.4 g dP/kg，P-日粮分别含2.5和1.7 g dP/kg。生长性能和血清矿物质含量不受处理影响，但与2.5:1和2.8:1相比，2.2:1降低了育肥期的饲料转化率。与2.5:1和2.8:1相比，2.2:1组的尿磷浓度增加了37%。与2.8:1相比，2.2:1组的骨最大负荷和DXA矿物质密度降低。与2.8:1相比，2.2:1和2.5:1组的骨灰和体积密度降低。日粮P-降低了骨灰、最大负荷、体积密度以及DXA骨矿物质含量和密度。未观察到Ca和dP水平之间的交互作用。因此，2.2:1不足以有效代谢利用磷，2.5:1足以使生长性能最大化，2.8:1进一步改善了骨矿化。增加日粮钙不会损害骨锌含量。育肥期不添加矿物磷酸盐的P-日粮，每头猪的矿物磷酸盐用量减少了65%，计算出的磷排泄量减少了41%，且生长性能未受影响。最后，DXA数据对日粮处理的反应与劳动强度大的化学和机械骨特性相同。
