Daghir N J, Farran M T, Kaysi S A
Poult Sci. 1985 Jul;64(7):1382-4. doi: 10.3382/ps.0641382.
Single Comb White Leghorn layers raised in floor pens in conventional open housing were used to determine their phosphorous requirement in a semiarid continental climate. Dietary available phosphorous (AP) of .15, .25, .35, and .45% were fed continuously from 26 to 74 weeks of age. Concurrently, diets containing .45, .35, and .25% AP or .35, .25, and .15% AP were "phase fed" during the age intervals of 26 to 42, 42 to 54, and 54 to 74 weeks, respectively. Diets used were corn-soybean diets in which the phosphorous was varied by changing the level of dicalcium phosphate in the ration. Under the conditions of this experiment, hens required a minimum of .25% AP for best egg production, feed consumption, and body weight gain. The AP levels above .35% depressed shell thickness. In a phase-feeding program, when the last phase corresponds with the summer season, AP should not go below .25% for best performance.
采用单冠白来航蛋鸡，在半干旱大陆性气候条件下，饲养于传统开放式鸡舍的地面平养栏中，以确定其磷需求量。从26周龄至74周龄，持续饲喂有效磷（AP）含量分别为0.15%、0.25%、0.35%和0.45%的日粮。同时，在26至42周龄、42至54周龄和54至74周龄期间，分别“阶段饲喂”有效磷含量为0.45%、0.35%和0.25%或0.35%、0.25%和0.15%的日粮。所用日粮为玉米-大豆型日粮，通过改变日粮中磷酸二钙的水平来改变磷含量。在本试验条件下，母鸡产蛋性能、采食量和体重增加的最佳状态需要至少0.25%的有效磷。有效磷水平高于0.35%会降低蛋壳厚度。在阶段饲喂方案中，当最后一个阶段对应夏季时，为获得最佳性能，有效磷含量不应低于0.25%。
