Effects of dietary casein phosphopeptides and calcium levels on eggshell quality and bone status in laying hens
1996
Ashida, K. (Kyoto Univ. (Japan). Coll. of Agriculture) | Nakajima, T. | Hirabayashi, M. | Saito, Y. | Matsui, T. | Yano, H.
This study was conducted to evaluate the effects of dietary casein phosphopeptides (CPP) on eggshell quality and bone status in laying hens fed low or normal calcium (Ca) diets. Sixty laying hens were fed 1.5% or 3.4% Ca diets without CPP supplementation for one week. Then they were fed 3.4% or 1.5% Ca diets containing CPP at 0%, 0.5% or 1.0% for six weeks. In hens fed the 3.4% Ca diet, the supplementation with 0.5% or 1.0% CPP significantly (P0.05) increased tibial ash content and specific gravity. However, CPP supplementation did not affect eggshell quality in these hens. The reduction of dietary Ca to 1.5% decreased the breaking strength, the dry weight, the thickness and the specific gravity of eggshell. Tibial weight, ash content and specific gravity were also reduced by feeding the low-Ca diet. Although CPP supplementation did not affect the tibial parameters in hens fed the 1.5% Ca diet, 0.5% and 1.0% CPP supplied to the 1.5% Ca diet significantly increased the eggshell specific gravity. These results suggested that dietary CPP could increase bone mass and ash content of laying hens fed a normal-Ca diet and improve eggshell quality of those fed a low-Ca diet
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