Department of Animal Nutrition, Agricultural University, Peshawar, Khyber Pakhtunkhwa-25000, Pakistan.
Poult Sci. 2011 Sep;90(9):1983-91. doi: 10.3382/ps.2010-01296.
This study investigated the effects of replacing dicalcium phosphate (DCP) with Hazara rock phosphate (HRP) on the growth performance of broiler chickens. The purpose was to determine the maximum level of F that could be well tolerated. The HRP (13.16% P and 2.98% F) was incorporated into a standard corn- and soybean meal-based diet by replacing 0, 25, 50, 75, and 100% of DCP based on P. Each treatment consisted of 5 replicate pens of 10 chicks each. The Ca and nonphytate P contents of all diets were maintained constant at 1.0 and 0.45%, respectively. Replacing 25% DCP with HRP significantly increased average BW gain. Substituting 100% HRP (562 mg of F/kg) decreased (P < 0.05) BW gain. The BW gain was maximized at 63.5:36.5 (DCP:HRP) using a quadratic relationship: BW gain (g) = 1,128.6 + 2.6848 × HRP - 0.0368 × HRP(2). Increasing the level of HRP decreased feed intake: feed intake (g) = 1,987.4 + 2.775 × HRP - 0.0515 × HRP(2). The effect of HRP was not pronounced (significant at P < 0.05) until 75% of DCP was replaced by HRP. Feed intake decreased by an average 3.77 g with each 1.0% increase in the levels of HRP beyond 27% HRP substitution. Replacing DCP with HRP up to 50% caused a significant increase in hot carcass weights. The Ca content of tibia was a quadratic function of HRP and was predicted to be highest at 56% HRP substitution. However, increasing HRP in the diet gradually decreased tibia P content (linear function). Serum Ca was increased by substituting HRP for DCP (linear effect). Increasing HRP in the diet decreased the P content of the serum and was predicted to be lowest (P < 0.05) beyond 50% HRP substitution, suggesting poor P availability at high HRP. In conclusion, growth was maximized by feeding about 36.5% HRP (205 mg of F/kg) and 63.5% DCP as P supplements. Using a multiple range test, it was concluded that between 25 and 50% DCP with HRP replacement (141 and 281 mg of F/kg, respectively) could be used safely without significantly decreasing the growth performance of broiler chickens.
本研究旨在探讨用哈扎拉磷矿（HRP）替代磷酸二钙（DCP）对肉鸡生长性能的影响，以确定肉鸡能够耐受的最大氟水平。HRP（含 13.16%磷和 2.98%氟）通过替代基于磷的基础日粮中 0、25、50、75 和 100%的 DCP 来配制。每个处理组由 10 只小鸡组成的 5 个重复笼组成。所有日粮的钙和非植酸磷含量分别保持在 1.0%和 0.45%。用 HRP 替代 25%的 DCP 可显著提高平均体重增加。用 100%的 HRP（562mgF/kg）替代可降低（P＜0.05）体重增加。使用二次关系，BW 增益最大化至 63.5：36.5（DCP：HRP）：BW 增益（g）=1,128.6+2.6848×HRP-0.0368×HRP（2）。随着 HRP 水平的增加，采食量减少：采食量（g）=1,987.4+2.775×HRP-0.0515×HRP（2）。直到用 HRP 替代 DCP 达到 75%，HRP 的作用才明显（P＜0.05）。超过 27%HRP 替代水平时，HRP 水平每增加 1.0%，采食量平均减少 3.77g。用 HRP 替代 DCP 高达 50%会显著增加热胴体重量。胫骨钙含量随 HRP 呈二次函数变化，在 56%HRP 替代时预测最高。然而，随着日粮中 HRP 的增加，胫骨磷含量逐渐降低（线性函数）。用 HRP 替代 DCP 会增加血清钙（线性效应）。随着日粮中 HRP 的增加，血清磷含量降低，预测在 50%HRP 替代以上时最低（P＜0.05），提示高 HRP 时磷利用率差。总之，用约 36.5%的 HRP（205mgF/kg）和 63.5%的 DCP 作为磷补充料可使生长性能最大化。通过多项范围检验，得出结论，用 HRP 替代 25-50%DCP（分别为 141 和 281mgF/kg）可安全使用，不会显著降低肉鸡的生长性能。
