Calcium and Phosphorus Requirements of Broilers as Influenced by Energy, Sex and Strain

Response of Two Breeds of Chickens to Graded Levels of Dietary Phosphorus

“…The significant P level X breed interaction is not in agreement with Lillie et al (1964), either because the levels of phosphorus used in the present experiments were lower than those they used or the strains they used were more similar in growth rate, feed efficiency, or all three. This interaction also points out that the fast-growing chickens were not able to tolerate a low-phosphorus diet so well as the slow-growing breed.…”

“…Waldroup et al (1963) state that widening the Ca: P ratio at a suboptimal level of phosphorus resulted in lowered body weight or percent bone-ash; whereas, Lillie et al (1964) indicate that increasing the dietary calcium level from 0.9 to 1.2 percent did not show any significant effects at any of the dietary phosphorus levels. Even though the Ca:P ratio did vary among the diets used in these experiments, the comparison of the breeds to these different diets is still valid.…”

Calcium and Phosphorus Requirements of Broiler Chickens

“…In a more recent paper, the Florida group (Waldroup et al, 1962a) takes this into account and propose a phosphorus requirement of between 0.59 and 0.70% for chicks from 0 to 4 weeks of age when "calcium and vitamin D are adequate." Lillie et al (1964) reported maximum growth response at 8 weeks of age from diets containing 0.7% total phosphorus and 0.9 to 1.2% calcium. It is considered probable that the indication of a higher phosphorus requirement resulted from the higher intake of calcium and is an expression of the calcium-phosphorus interrelationship.…”

“…A review of the more pertinent literature by Lillie et al (1964) indicates that the range of discordant values is being narrowed to some extent and that the calcium level recommended by the National Research Council is higher than that which many investigators found to be adequate for optimum growth. The majority of the recent investigations (Formica et al, 1961(Formica et al, , 1962Vanderpopuliere, 1961; Waldroup et al 1962a, b;Simco and Stephenson, 1961;Lillie et al, 1964) have been aimed at refinement of the requirement of the growing chick in the light of current nutritional knowledge. Such was the motive for the experiment reported herein.…”

Calcium, Phosphorus and Vitamin D Requirements of Chickens

“…From a review covering much of the work in this field, it may be noted that wide ranges in calcium and phosphorus levels have been reported as satisfactory for optimum gowth and bone ash (3).…”