【作者】 孙满吉；

【导师】 王安；

【作者基本信息】 东北农业大学 ， 动物营养与饲料科学， 2000， 硕士

【摘要】 本实验采用玉米—豆饼型试验日粮，对蛋鸡0—60周龄全面系统的进行了高镁实验，实验分高镁组（外加镁6000mg/kg MgO），中镁组（外加镁1200mg/kg MgO），低钙高镁组（含Ca0.72％），低磷高镁组（含P0.572％），对照组（外加镁0.00mg/kg MgO，含Ca0.90％，含P0.70％），本实验从4个方面研究过量镁对蛋鸡胫骨发育及生产性能的影响。实验一.蛋鸡胫骨中矿物元素变化规律的研究 1.蛋鸡胫骨中矿物元素在0—60周龄内变化规律，随着周龄的增加，鲜胫骨长和鲜胫骨重同时增长，胫骨增长和胫骨增重的速度分别在13和20周龄生长曲线趋于平稳。在17—19周龄内胫骨中的钙和磷含量以及胫骨灰重与鲜骨重的比值急剧增加。钙和磷含量的变化曲线相似，只是在纵轴上的截距不同。钠的含量高于镁，在17—19周时，钠和镁的含量急剧增加，在23—24周龄后趋于平稳，钠和镁有相似的变化曲线，只是在纵轴上的截距不同，钾的含量变化不同于钠和镁，随着周龄的增长，钾的含量是降低的，在23—24周龄后趋于平稳，微量元素锰随着周龄的增加而增加，在45周龄后略有下降趋势，铁的曲线变化不规则。实验二.低钙高镁，低磷高镁对蛋雏鸡胫骨发育的影响 2.1低钙高镁对蛋雏鸡胫骨发育的影响 蛋雏鸡采用玉米—豆饼型试验日粮，无论是正常钙（0.90％）还是低钙（0.72％），高镁（外加镁6000mg/kg MgO）时鲜胫骨重量减轻，抗压能力降低，骨灰含量减少，钙:磷，钙:镁，磷:镁的比值降低，但它们之间差异不显著。 日粮中正常钙或低钙，当高镁时，胫骨中镁含量都显著高于对照组，低钙高镁组的镁含量有升高于正常钙高镁组的趋势，但它们之间差异不显著。正常钙高镁组胫骨中钙含量低于对照组，低钙高镁组钙含量又低于正常钙高镁组，三组间差异显著。 2.2低磷高镁对蛋雏鸡胫骨发育的影响 蛋雏鸡采用玉米——豆饼型日粮，正常磷（0.70％）高镁时（外加镁6000mg/kg MgO），胫骨中镁含量显著升高（p＜0.05），钙和磷含量显著低于对照组（p＜0.05），钙和磷的比值显著低于对照组（P＜0.05），鲜胫骨重量显著降低（P＜0.05），胫骨的最大抗压能力和骨灰含量有所降低，但差异不显著（P＞0.05）。 低磷高镁时，胫骨中镁含量显著升高（p＜0.05），钙和磷的含量显著降低于对照组（p＜0.05），低于正常磷高镁组，但差异不显著（p＞0.05），钙与磷的比值低于对照组，但差异不显著（p＞0.05），而钙与磷的比值显著高于正常磷高镁组（p＜0.05）。鲜胫骨长，鲜胫骨最大抗压能力，骨灰含量显著低于对照组（p＜0.05）。一 一…w 3＊镁对蛋雏鸡胚骨发育的影响 蛋雏鸡门J周人添加过量镁（M叨）结果腔骨中镁的含量增加，钙和磷的含量阐氏胚骨中钙：镁，磷：镁，钙：磷的比值减小，X光摄影，骨质疏松。电子显微镜检验，骨组织增生，机械力学法检测其鲜骨的最大抗压能力，胶骨抗压能力 氏。 3．2在育成期（8一8周）高镁转正常日粮，遁oD费骨及溶骨作用，经过较长的时间，胜骨中镁，钙，钠，磷的含量及它们之间的相互比值，因蛋雏鸡（17周）添加过量镁造成的影响都恢复正常。 3．3产蛋鸡（20—60周），外加镁为 we（M刃），结果是高镁组鲜腔骨长和重韶氏于对照组，老龄蛋鸡比新开产母鸡更明显，高镁组胜骨中镁含量升高，骨灰含量阐氏，钙：磷，钙：镁，磷：镁的比值降低。 实验四．蛋鸦时过量侯的反囱四d阴酗中蛋叼囱叫拢盼旧响 4．lgu对日粮镁的反应 iKiK用3i3fC－豆饼型d型日粮，高镁组（We Mh）鸡血液中镁含量显著中＜0．05）高于中镁组＊ Mu和对照组O．m加砂呛 Mu，中镁组与对照组间无显著差异Otoo．05卜而血液中其它矿物元素龌戮间无显著差异…＞OD习．在删中，旅组中磷含量显著低于中镁组和对照组Owto．05卜而中镁组与对照组间无显著差异…＞0．05L其它矿物元素含量描间无显著差异o＞0．05）．在脾脏／舰、觎中镁与其它矿物元素的含量三组间租著差异…＞0．05人肝脏、脾脏、肾脏、翩的鲜重三组间添著差异…＞0·05人 4．2过量镁对产蛋鸡生产性能的影响 产蛋鸡采用I3f6－豆饼型日粮，结果表明，高镁组（外加镁 we MgO）鸡帆【泄物【匕时照组稀，日粮高镁对采食量的影响不显著，高镁组的软破蛋率升高，而老龄时的软破蛋率更高。因此，用石粉作为产蛋鸡饲料的钙源时，应该要求石粉中镁含量低于1．5％。更多还原

【Abstract】 1. With the increase of age. both of tibia length and weight were increased but the increase of length and weight were slower after 13 and 20 weeks. Ca and P contents in tibia, bone ash/fish bone were increased rapidly from the 17th to 19th week.. Changing curves of Ca and P were similar. Na content was higher than Mg content. Na and Mg contents from the 17th to 19th week were increased rapidly. Changing curves of Na and Mg were similar. Changing cwve of K content was not the same as Na and Mg. With the increase of age, K content decreased, after 23?4 weeks the change tended to be smooth, and Mn content increased. but after 45 weeks, Mn content decreased. Changing curve of Fe was irregular. 2. Effects of low dietazy Ca and high Mg on tibia growth of chicks were studied. The results showed that Mg content in tibia was significantly increased, Fresh tibia weight and Ca content in tibia was significantly decreased by high Mg in normal or low Ca diet. Fresh tibia length and weight, compressive strength. content of bone ash were decreased by high Mg in low Ca diet. The ratios of calcium: phosphorus. calcium: magnesium. phosphorus: magnesium were decreased by high Mg in normal or low Cadiet. Effects of low dietaiy P and high Mg on tibia growth of chicks were studied. The results showed that Mg content in tibia was significantly increased, but Ca and P contents, the ratios of Calcium: phosphorus, calcium: magnesium, and phosphorus: magnesium in tibia were significantly decreased. and fresh tibia weight was significantly decreased by high Mg in normal P diet. Mg content in tibia was significantly increased. Ca and P contents in tibia were significantly decreased, and fresh tibia length and weight. compressive strength. content of bone ash were significantly decreased by high Mg in low P diet. 3. Effects of magnesium on tibia of the chick were studied with corn-soybean cake supplemented with magnesium. The results showed that Mg content in tibia was significantly increased, Ca and P contents in tibia were significantly decreased, the ratios of calcium: phosphorus. calcium: magnesium, and phosphorus: magnesium were deceased. Photograph of X-ray showed that bones were loose by high Mg. Electron microscope examination indicated a bone tissue hyperplasia, decreased fresh tibia compressive strength by high Mg (supplement with magnesium 6000mg/kg MgO). Effects of magnesium on tibia of growing chickens were studied with corn-soybean cake supplemented with magnesium. The results showed the decreased sodium, calcium and phosphorus contents and the ratios of calcium: phosphorus. calcium: magnesium and phosphorus: magnesium in tibia caused by high Mg during 1 weeks recovered normal by changing from high Mg to normal diet on growing chickens during 8- 16 weeks.Effects of magnesium on performance of laying hens were studied with corn-soybean cake (supplemented with magnesium 6000mg/kg MgO). The results showed that length and weight of tibia in high magnesium group were decreased. and this was more significant in the old than in the young layer. Magnesium contents of tibia in high magnesium group were high. but ash contents of tibia, ratios of calcium: phosphorus. calcium: magnesium and phosphorus: magnesium were low. 4. The effects of magnesium level (1.Control group 0.00mg/kg MgO, C; 2. Medium magnesium group 1200 mg/kg, MgO, M; 3. High magnesium group 6000 mg/kg, MgO, H) on the chicks were studied with conventional diet. The results showed that magnesium content in blood was higher in H group ti-ian that inC and更多还原