Driver J P, Pesti G M, Bakalli R I, Edwards H M
Department of Poultry Science, University of Georgia, Athens 30602.
Poult Sci. 2006 Nov;85(11):1939-46. doi: 10.1093/ps/85.11.1939.
There is considerable data on the effect of reducing inorganic Ca and P in broiler finisher diets on carcass quality. However, there is limited information on the effect of reducing dietary Ca and P during the different phases of growout. Two experiments were conducted from 0 to 35 d in floor pens. In both experiments, at least 4 replicates per treatment (50 chicks per replicate) were used. Corn-soybean meal and soybean oil-based diets deficient in Ca and P were fed. During the starter phase (ST), from 0 to 18 d, chicks were fed a 23% CP diet containing 0.60% Ca and 0.47% total P (tP). During the grower-finisher phase (GF), from 19 to 35 d, birds were fed a 19% CP diet containing 0.30% Ca and 0.37% tP. A combination of 1,000 phytase units/kg of Natuphos phytase and 5 microg/kg of 1alpha-hydroxycholecalciferol (P + 1alpha) was supplemented to some of the feed during the ST and GF. Diets containing adequate Ca and P were also fed during the ST (0.90% Ca and 0.68% tP) and GF (0.80% Ca and 0.67% tP). The level of tibia ash and the incidence of bone disease were measured at 18 and 35 d. At the end of the experiments, birds were processed and evaluated for muscle hemorrhages and broken bones. In both experiments, broilers fed diets that were not P + 1alpha supplemented demonstrated poor bone mineralization, considerable leg problems, and a high incidence of broken bones after processing. Broilers fed P + 1alpha throughout had more broken clavicles and femurs compared with birds fed the adequate diets. Day-18 tibia ash was significantly correlated to broken tibias and femurs during processing. Day-35 tibia ash was better correlated to bloody breast meat than to broken bones. It is concluded that carcass quality depends on the levels of Ca and P fed and the age of the bird. Tibia ash, traditionally used as an indication of bone strength, was better correlated to the incidence of bloody breasts.
关于降低肉鸡育肥期日粮中无机钙和磷对胴体品质的影响，已有大量数据。然而，关于在生长育肥不同阶段降低日粮中钙和磷的影响，相关信息有限。在地面平养条件下进行了两个从0至35日龄的试验。在两个试验中，每个处理至少有4个重复（每个重复50只雏鸡）。饲喂缺乏钙和磷的玉米 - 豆粕及大豆油型日粮。在雏鸡前期（0至18日龄），雏鸡饲喂含23%粗蛋白、0.60%钙和0.47%总磷（tP）的日粮。在生长育肥期（19至35日龄），鸡只饲喂含19%粗蛋白、0.30%钙和0.37%总磷的日粮。在雏鸡前期和生长育肥期，部分饲料中添加了1000单位/千克的耐酶植酸酶和5微克/千克的1α-羟基胆钙化醇（P + 1α）。在雏鸡前期（0.90%钙和0.68%总磷）和生长育肥期（0.80%钙和0.67%总磷）也饲喂了含钙和磷充足的日粮。在18日龄和35日龄时测量胫骨灰分水平和骨骼疾病发生率。试验结束时，对鸡只进行屠宰并评估肌肉出血和骨折情况。在两个试验中，未添加P + 与添加P + 1α的日粮相比，在屠宰后饲喂未添加P + 1α日粮的肉鸡表现出骨矿化不良、腿部问题严重和骨折发生率高。与饲喂充足日粮的鸡相比，全程饲喂P + 1α的肉鸡锁骨和股骨骨折更多。18日龄时的胫骨灰分与屠宰时胫骨和股骨骨折显著相关。35日龄时的胫骨灰分与胸肉出血的相关性比与骨折的相关性更好。得出的结论是，胴体品质取决于所饲喂的钙和磷水平以及鸡的年龄。传统上用作骨骼强度指标的胫骨灰分与胸肉出血发生率的相关性更好。
