Poultry Research Institute, Murree Road, Shamsabad, Rawalpindi, Pakistan.
J Anim Physiol Anim Nutr (Berl). 2010 Oct;94(5):584-93. doi: 10.1111/j.1439-0396.2009.00943.x.
A study was conducted to evaluate four different cholecalciferol levels (NRC; modified), using diets supplemented with 200 (control), 1500, 2500 or 3500 IU/kg of cholecalciferol (VIT-D3). Each treatment was assigned to 3 pens of 17 broiler chicks of a commercial strain grown in an open-sided house with sidewall curtains. At 21 and 42 days, BW and feed conversion (FCR) were determined. At 42 days, five birds per pen were slaughtered to evaluate tibia and toe ash of the right leg, and incidence and severity of tibial dyschondroplasia (TD) of the left tibia and also measured dressing percentage and breast meat yield. Serum calcium and phosphorus concentrations were also determined. Haemagglutination inhibition antibody titre against Newcastle disease virus and lymphoid organs weight/body weight ratio were also determined. At both 21 and 42 days, the BW of birds fed 1500 IU/kg to 3500 IU/kg of VIT-D3 was significantly greater than birds fed 200 IU/kg. Similarly, better FCR was observed in birds those fed diets of high level of VIT-D3. No significant difference was observed for mortality at any age. Better dressing percentage and breast meat yield were noted in birds fed diets containing 2500 or 3500 IU/kg VIT-D3. Both tibia and toe ash contents were increased (p < 0.05) progressively with increased concentrations of cholecalciferol in feed. The incidence of TD (percentage of birds having TD scores greater than zero) was significantly (p < 0.05) influenced by level of 3500 IU VIT-D3/kg at 42 days. The severity of TD in birds fed diets containing 200 IU/kg VIT-D3 was apparently higher than birds fed diets with higher levels of VIT-D3. Concentrations of calcium and phosphorus minerals in the serum increased progressively with the high level of VIT-D3 supplementation to birds at both 21 and 42 days of age. Feeding levels of 1500 or 3500 IU of vitamin D3 did positively affect the immune system within the parameters measured. It may be concluded that performance, bone mineralization, blood chemistry and immunity against disease in broilers could be maintained when supplementing high level of VIT-D3 incorporated in broiler diets.
进行了一项研究，以评估四种不同的胆钙化醇水平（NRC；改良），使用添加 200（对照）、1500、2500 或 3500 IU/kg 胆钙化醇（VIT-D3）的饮食。每个处理组分配给 3 个开放式鸡舍的 17 只商业品系肉鸡笼，鸡舍的侧壁有窗帘。在 21 天和 42 天，测定体重和饲料转化率（FCR）。在 42 天，每个鸡笼宰杀 5 只鸡，以评估右腿胫骨和脚趾灰分，以及左腿胫骨软骨发育不良（TD）的发生率和严重程度，并测量屠宰率和胸肉产量。还测定了血清钙和磷浓度。还测定了新城疫病毒血凝抑制抗体效价和淋巴器官重量/体重比。在 21 天和 42 天，饲喂 1500 IU/kg 至 3500 IU/kg VIT-D3 的鸡的体重均显著大于饲喂 200 IU/kg 的鸡。同样，饲喂高剂量 VIT-D3 日粮的鸡的饲料转化率更好。在任何年龄，死亡率均无显著差异。饲喂 2500 或 3500 IU/kg VIT-D3 日粮的鸡的屠宰率和胸肉产量均较高。随着饲料中胆钙化醇浓度的增加，胫骨和脚趾灰分含量逐渐增加（p <0.05）。42 天时，TD 的发生率（具有 TD 评分大于零的鸟类百分比）显著（p <0.05）受 3500 IU/kg VIT-D3 水平的影响。饲喂 200 IU/kg VIT-D3 日粮的鸡的 TD 严重程度明显高于饲喂高剂量 VIT-D3 日粮的鸡。21 天和 42 天龄时，血清中钙和磷矿物质浓度随着高剂量 VIT-D3 补充量的增加而逐渐增加。1500 或 3500 IU 维生素 D3 的饲养水平确实对所测参数内的免疫系统产生了积极影响。可以得出结论，在肉鸡日粮中补充高水平的 VIT-D3 可以维持肉鸡的生产性能、骨骼矿化、血液化学和对疾病的免疫力。
