日粮不同磷水平和钙磷比例对香猪钙磷代谢的影响

３６ 头香猪生长阶段去势公猪，通过３ ×３ 交叉分组设计，随机分配到９ 个处理中，每个处理４个重复，每个重复１ 头猪。试验两个因子中日粮磷３ 个水平分别为０ ．３ ％ 、０ ．６ ％ 和０ ．９ ％ ，日粮钙磷比的３ 个水平为１ １ 、１ ．２５ １ 和１ ．５ １ 。试验基础日粮由玉米、豆粕、血粉和苜蓿粉组成，各处理日粮磷水平和钙磷比用分析纯ＣａＣＯ３ 、Ｎａ２ＨＰＯ４ 和ＣａＨＰＯ４ 调配。两期钙磷代谢试验结果表明，提高日粮磷水平线性增加香猪钙磷采食量、粪钙磷和尿磷（Ｐ＜ ０ ．０１） ，０ ．６ ％ 的日粮磷水平在两期试验中表现出最高的磷存留量和磷表观利用率。随日粮钙磷比增加，钙的采食量、粪钙磷和尿钙逐渐增加（Ｐ＜ ０ ．０１） ，而尿磷逐渐减少（Ｐ＜ ０ ．０１） 。在体重７ｋｇ 时，当钙磷比为１ ．２５ １ 时，钙的表观消化率和表观利用率显著高于１ １组（Ｐ＜ ０ ．０５） 。在体重１７ｋｇ 时，钙磷的存留量、钙的表观利用率和磷的表观消化率在日粮钙磷比１ １ 时表现最大值（Ｐ＜ ０ ．０１） ，并且日粮磷和钙磷比互作效应显著影响粪钙磷、尿磷、钙磷存留量、磷的表观消化率和钙磷表观利用率（Ｐ＜ ０ ．０１）

Effect of Dietary Phosphorus and the Proportion of Calcium to Phosphrous on Its Metabolism in Growing Pig

Thirty-six growing castrated Xiang pigs two metabolism trials based on body weingt 7kg and 17kg.The design of the two metabolism trials used in a 3×3 factorial trial (9 treatments,4 duplicates per treatment,one pig per duplicate and metabolism cage).The basal diet contented 0.29% phosphorus and 0.30% calcium and consisted of corn,soybean,blood meal and alfalfa meal.For 9 treatment diets,levels of phosphorus were 0.3%,0.6% and 0.9% and levels of calcium to phosphorus ratio were 1:1 1.25:1 and 1.5:1.The levels of dietary phosphorus and calcium to phosphorus ratio in the diets were formulated from CaCO\-3,Na\-2HPO\-4 and CaHPO\-4.Calcium and phosphorus intake,fecal calcium and phosphorus and urinary phosphorus showed linear increase of dietary phosphorus level from 0.3% to 0.9%.There was a greater retention and apparent availability of phosphorus which was most evident in 0.6% dietary phosphorus level in two trials(P<0.01).Increasing the ratio of dietary calcium to phosphorus increased gradually in calcium intake,fecal calcium ,fecal phosphorus,urinary calcium and reduced gradually in urinary phosphorus in two trials(P<0.01).For 7kg body weight,the digestibility and availability of calcium was higher with 1.25:1 than 1:1(P<0.05).For 17kg bodyweight ,calcium retention,digestibility and availability wer highest in 1:1 calcium to phosphorus ratio(P<0.01).Statitical analysis of fecal calcium and phosphorus,urinary phosphorus,the retenton of calcium and phosphous,apparent digestibllity of phosphorus and apparent availability of phosphorus and calcium showed there was a significant interaction of phosphorus and the ratio of calcium to phosphorus(P<0.05).