عنوان
پدید آورنده
موضوع
رده
کتابخانه
محل استقرار
TLpq304427924
انگلیسی
Dietary animal proteins effect on cholecalciferol requirement and zinc utilization, and corn particle size effect on phytate phosphorus utilization by broiler chicks
[Thesis]
A. B. Kasim
H. M. Edwards, Jr.
University of Georgia
1998
126
Ph.D.
University of Georgia
1998
Previous reports indicate that when soybean protein in the diets of piglets and turkey poults were replaced with purified animal proteins, bone calcification improved. In piglets the dietary requirement for ergocalciferol (vitamin D2) was also lowered. However, there were no reports on the effect of animal proteins on the requirement for cholecalciferol in birds, particularly chickens. Therefore, studies were conducted to determine the effect of using an all purified animal protein (phytate free) diet, and partial substitution of the soybean meal (containing phytate) in a practical corn-soybean meal diet with a purified animal protein mixture (eggwhite, casein and gelatin) or a practical animal protein source (poultry by-product meal). Evaluation of the potencies of several cholecalciferol products using a chick bioassay was also conducted. Effect of increasing dietary cholecalciferol supplementation, dietary cholecalciferol metabolites, and the response of chicks to ultraviolet light irradiation on zinc utilization when fed an all animal protein (phytate free) diet was also studied. The inclusion of purified animal protein or poultry by-product meal in the diet of chicks improved the percent bone ash and reduced the requirement for cholecalciferol by these chicks. However, for both practical corn-soybean meal diet and diet substituted with animal protein, the requirement for cholecalciferol by chicks to eliminate rickets were higher than the requirement for maximum bone ash. Chicks consuming animal protein required lower amount of cholecalciferol to eliminate rickets. The addition of animal proteins to a corn-soybean meal diet may alleviate the appearance of cholecalciferol deficiency symptoms when chicks received marginal cholecalciferol supplementation in the diet. Nine cholecalciferol products were confirmed to have potencies closed to their guaranteed content. The potency results obtained from the chick bioassay indicate that chemical assays done by the manufacturers to measure the activity of the cholecalciferol products were very reliable and truly reflect the potential of the products when given to chicks. An all animal protein diet when fed to chicks will produce zinc deficiency. However, the signs of zinc deficiency were less severe. Supplementation of dietary cholecalciferol, 1 usd\alphausd-hydroxycholecalciferol, or exposure to ultraviolet light to chicks fed all animal protein diet did not influence zinc utilization. Evaluation of the nutrient contents of four different corn sources indicates that there were differences in the ash, phosphorus and phytate phosphorus contents. Chicks fed phosphorus deficient corn-soybean meal diet prepared from the different corn sources indicate that sources of corn influenced calcium, phosphorus, and phytate phosphorus utilization. Sources of corn also influenced metabolizable energy of the diet. Improved retention of calcium, phosphorus, and phytate phosphorus were accomplished when chicks were fed corn-soybeanmeal mash diet containing corn of coarse particle size. Growth performances (body weight and feed efficiency) were not affected by particle size of corn in the diet, indicating that phytate phosphorus retention is the most sensitive criteria to measure phytate phosphorus utilization in chicks.
Biological sciences
Broiler chicks
Cholecalciferol
Corn
Dietary animal proteins
Particle size
A. B. Kasim
H. M. Edwards, Jr.
مطالعه متن کتاب p
[Thesis]
276903
a
Y
