Calcium and Phosphorus Metabolism and Egg Shell Formation in Egyptian Birds

Salem, Hassan; Reda, Hussien

doi:10.3382/ps.0340197

Cited by 3 publications

(1 citation statement)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The decreasing percent retention of calcium in response to increasing dietary levels of calcium is consistent with findings of Hurwitz and Griminger (1960), Kalango and Ademosun (1973), and Atteh and Leeson (1983); the increase in absolute retention of calcium with increasing levels of calcium is in agreement with findings of Ademosun and Nikolaiczuk (1966) and Kalango and Ademosun (1973). The reduction in phosphorus retention with increasing dietary levels of calcium is consistent with the findings of Tyler (1946) and Salem and Reda (1955); however, it is not consistent with the report of Kalango and Ademosun (1973).…”

Section: Resultssupporting

confidence: 91%

The Effect of Dietary Levels of Calcium and Phosphorus on Performance and Retention of These Nutrients by Laying Hens

Keshavarz

1986

Poultry Science

View full text Add to dashboard Cite

The first experiment utilized three levels of calcium (3.5, 4.5, and 5.5%) and three levels of available phosphorus (.24, .44, and .64%). The birds were 56 weeks old at the beginning of the experiment and were fed the experimental diets for 16 weeks. Egg production, egg weight, feed consumption, plasma calcium and phosphorus, egg shell quality, and tibia ash were not significantly affected by different dietary levels of calcium. Dietary levels of phosphorus did not have a significant effect on the aforementioned parameters, except that feed consumption and plasma level of phosphorus were significantly lower with the lowest level of dietary phosphorus. The absolute retention of calcium was increased but that of phosphorus decreased with increasing levels of calcium. Dietary levels of phosphorus did not significantly affect the absolute retention of calcium or phosphorus.The second experiment used four levels of calcium (3.5, 4.5, 5.5, and 6.5%). The birds were 42 weeks old at the beginning of the experiment and were fed the experimental diets for 20 weeks. Production parameters were not significantly affected by different dietary levels of calcium.The third experiment used three levels of calcium (3.5, 5.0, and 6.5%). Birds were 80 weeks old at the beginning of the experiment and were fed the experimental diets for 16 weeks. Egg production and egg weight were significantly lower with 6.5% than with lower levels of calcium.These experiments suggest that high dietary levels of calcium may affect the performance of old hens. Short duration of high calcium feeding does not seem to affect significantly the performance of younger hens. Absence of a significant interaction between calcium and phosphorus on production parameters indicates that calcium-phosphorus ratio is not as crucial in the laying hens as in the growing chicks. (

show abstract