B. L. Damron

Beta‐carotene supplementation of Laying Hen Diets

The possibility of beta-carotene affecting production of hens or hatchability of eggs was studied over 252 d with diets based on white maize containing 0, 1.5, 6.75 or 15 mg added beta-carotene/kg. Egg production, food intake, food utilisation, egg weight, and egg specific gravity were not affected significantly by beta-carotene. Egg fertility, hatchability and final body weights of hens were also not significantly influenced. Reflectance measurements showed that dietary beta-carotene resulted in increased deposition and more intense pigmentation in the egg yolk.

Performance of broiler breeder pullets as influenced by composition of grower and layer diets.

Synopsis An experiment was conducted to determine the influence of three grower systems upon the subsequent performance of broiler type breeder pullets. The grower systems were full feeding a 10 per cent protein diet, full feeding a 16 per cent protein diet, and a skip‐a‐day feeding of the 16 per cent diet. One‐third of the pullets fed according to each of the feeding programmes were fed on each of three different layer diets. The use of the low protein and the skip‐a‐day feeding resulted in delaying age at sexual maturity. Total rate of egg production was not affected by the grower diet; however, the number of “ settable “ eggs was increased when maturity was delayed. Performance of the laying hens was not influenced by the composition of the layer diet. Fertility or hatchability was not influenced by composition of either the grower or layer diet. These data would indicate that the low protein diet or the skip‐a‐day feeding system can be effectively used with feeding replacement broiler type birds.

Supplementation of broiler drinking water with liquid ammonium polyphosphate 1

1. In each of two experiments lasting 21 days a commercially available ammonium polyphosphate solution was provided in the drinking water as the sole source of supplemental phosphorus for day-old chicks housed in batteries. 2. In both experiments, similar daily phosphorus intakes either from dicalcium phosphate in the food or from ammonium polyphosphate in the drinking water supported equivalent responses in body weight gains. The same was true for the tibia ash results in experiment 2. 3. Liquid ammonium polyphosphate, while marketed for addition to diets, appears to be also very effective as a waterborne source of phosphorus for broilers.

Utilisation of soft phosphate in diets with and without fish meal or supplemental calcium phosphate 1

Synopsis Two experiments, involving 23 treatments, were conducted with broiler chicks in order to evaluate the utilisation of soft phosphate and calcium phosphate in practical corn‐soybean diets with and without added fish meal. Two levels of fish meal (3 and 6%) were evaluated. Comparable phosphorus and calcium levels were formulated in each of the three basal diets. Phosphorus supplementation was reduced to compensate for the phosphorus content of the fish meal. There was no improvement in body weight when 3% fish meal was added to the diet, but with 6% added fish meal an increase in body weight was obtained as compared with chicks fed on diets containing o and 3% fish meal. Calcium phosphate‐supplemented diets gave better results than soft phosphate diets when fed with the o or the 3% fish meal diet. There was no difference in the performance of the chicks fed two inorganic phosphorus sources in the 6% fish meal diet. Maximum performance was obtained with soft phosphate in combination with 6% fish meal...