中文摘要：

以低钙、磷水平为基础设计日粮，研究日粮中添加25-OH-D3对42-63日龄黄羽肉鸡屠宰性能、肉品质和VD代谢产物的影响。试验选用42日龄黄羽肉公鸡1200只，随机分成4组，每组5个重复，每个重复60只鸡。处理组1-4中25-OH-D，的添加水平分别为0、50、70和90μg／kg。结果表明，相对于对照组，饲粮中添加不同水平的25-OH-D3对42-63日龄黄羽肉鸡的屠宰性能影响不显著；可提高内脏器官指数，促进内脏器官发育，但90μg，kg剂量对外周免疫器官发育有抑制趋势；25-OH-D，对黄羽肉鸡肉色、系水力和嫩度具有一定的改善作用，对pH值影响不显著；血清和肾脏1，25-（0H）2-D3显著升高，且与25-OH-D3添加量成正相关性，肝脏25-OH-D，含量变化不显著。结果显示，降低日粮钙磷水平，日粮中添加25-OH-D，对后期黄羽肉鸡内脏器官发育和肉品质具有一定改善作用，其中70μg／l（g25-OH-D3添加量的效果最佳。

英文摘要：

This research was intended to use the low calcium and phosphorus levels as foundation to design diet, study the influence from 25-OH-D3 on slaughter performance, meat quality and vitamin D metabolites of 42-63 days-age yellow-feathered broiles. We selected 1200 42-days-age male yellow-feathered broiles, divided into 4 random groups, each group had 5 repeat, each repeat included 60 chicken.25-OH-D3 levels in experimental groups were 0, 50, 70, 90 μg/kg respectively.The results showed that different 25-OH-D3 levels had little influence on 42-63 days-age yellow-feathered broiler＇s slaughtering performance compared with matched group （P〉0.05）; 25-OH-D3 could improve the internal organs index, and promote the development of the internal organs, but 90 p,g/kg dosage had the tendency of inhibiting peripheral immune organ growth; it certainly improved yellow-feathered broiler＇s color of meat, water-holding capacity and tenderness, and had little influence on pH （P〉0.05）; serum and kidney 1,25-（OH）2-D3 increased significantly （P〈0.05）, which showed positive correlations with amount of 25-OH-D3, the content of 25-OH-D3 in liver was not significant （P〉0.05）. The results indicated that when calcium and phosphate levels in diets wei＇e reduced, and 25-OH-D3 added to ration, the growth of internal organ and meat quality had certainly improvement, of which 90 μ/kg 25-OH-D3 dosage got the best results.