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目的 研究日粮电解质平衡对 2 1日龄肉鸡胫骨软骨发育不良 ( TD)发生、血液酸碱平衡、生长板和干骺端胶原蛋白合成和降解的影响。方法 在玉米 -豆粕日粮中 ,添加 3个水平的Mg O和 ( NH4 ) 2 SO4 ,使日粮中的硫、镁水平分别达到 0 .40 %、0 .65%、0 .90 %和 0 .1 7%、0 .37%、0 .57% ,组成 9个处理日粮 ,饲喂 40 5只 Avian肉用公雏。结果 高硫诱发了肉鸡 TD,日粮中添加镁降低了 TD的发生。日粮电解质平衡与肉鸡 TD发生率呈线性负相关 ( r=- 0 .82 5)。虽然日粮镁、硫水平对血液 p H影响不显著 ,但高硫降低了碱超和碱贮 ( P<0 .0 5) ,酸化了血液 ;高镁则增加了碱超 ( P<0 .0 5) ,起到了碱化作用。日粮高硫降低了血清和生长板酸性磷酸酶 ( ACP)活力 ( P<0 .0 5) ,损害了生长板破软骨细胞的功能 ,降低了胶原蛋白的降解代谢。日粮高镁明显促进了生长板ACP活力以及胶原蛋白的合成和降解代谢 ( P<0 .0 5)。结论 由日粮硫、镁水平调节的电解质平衡可能通过改变血液酸碱平衡 ,影响破软骨细胞的功能及软骨的降解和重吸收 ,最终诱导或制约肉鸡TD的发生。生长板胶原蛋白的降解代谢受阻可能导致 TD生长板软骨滞留的重要原因
Objective To study the effect of dietary electrolyte balance on tibial cartilage dysplasia (TD), blood acid-base balance, growth plate and metaphyseal collagen synthesis and degradation in 21-day-old broilers. Methods Three levels of MgO and (NH4) 2SO4 were added into the corn-soybean meal diet to make the dietary levels of sulfur and magnesium reach 0 .40%, 0.65%, 0 .90% and 0 .17%, 0.37% and0.57%, consisting of 9 treatment diets, feeding 40 5 Avian meat male. The results of high sulfur induced broiler TD, magnesium added to reduce the occurrence of TD. Diet electrolyte balance was negatively correlated with TD incidence in broiler chickens (r = - 0.82 5). Although dietary magnesium and sulfur levels had no significant effect on blood p H, high sulfur reduced alkali and alkali storage (P <0.05) and acidified the blood; while high magnesium increased alkali excess (P <0. 0 5), played a role in alkalization. Sulfur diet decreased the activity of acid phosphatase (ACP) in serum and growth plate (P <0.05), damaged the function of chondrocytes in growth plate and reduced the degradation and metabolism of collagen. Dietary magnesium significantly promoted the ACP activity of growth plate and the synthesis and degradation of collagen (P <0.05). Conclusion Electrolyte balance regulated by dietary sulfur and magnesium may induce or inhibit the occurrence of TD in broilers by changing the acid-base balance of blood, affecting the function of chondrocytes and the degradation and reabsorption of cartilage. Blocked degradation of growth plate collagen may lead to TD growth plate cartilage retention of important reasons