Levels of calcium and available phosphorus in laying hens during 48 weeks

An experiment was conducted to evaluate levels of calcium (Ca) and available phosphorus (AP) in hens. For this study 300 Leghorn Hy-line W36 hens were used. Five treatments were evaluated, level of Ca and AP in the diet: T1, 4.34 and 0.18%; T2, 4.34 and 0.23%; T3, 4.62 and 0.18%; T4, 4.62 and 0.23% and T5, 3.25 and 0.25% (control). The experiment lasted 48 wk. It was measured feed, Ca and AP consumption, number of eggs, egg mass, feed conversion, egg weight, specific gravity and percentage of eggshell. In feed consumption, number of eggs, egg mass, feed conversion and egg weight, there were no differences among treatments (P>0.05). Higher consumption of calcium (P<0.05) was observed in the hens of T3 and T4 (4.80 and 4.81 g(-1) hen(-1)); in consumption of available phosphorus the hens of T5 consumed more (P<0.05) than the others (0.258 g(-1) hen(-1)). For specific gravity with T1, T3 and T4 (1.0837, 1.0834 and 1.0841) there were better results (P<0.05). In percentage of eggshell were observed better results for T1, T2, T3 y T4 (P<0.05). It is concluded that the concentration of Ca and Pd suggested by the NRC (1994) are not sufficient for maximum eggshell quality.