Responses of broilers to dietary zinc concentrations and sources in relation to environmental implications
| Autor: | M.E. Freeman, William A. Dozier, A.L. Burrell, A.J. Davis, T. L. Ward, P.F. Vendrell, M.M. Compton |
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| Rok vydání: | 2004 |
| Předmět: |
Male
Animal feed chemistry.chemical_element Zinc Environment Biology Weight Gain Zea mays Feed conversion ratio Excretion Feces Animal science Animals Dry matter Meal Broiler General Medicine Animal Feed Zinc Sulfate Diet Agronomy chemistry Dietary Supplements Animal Science and Zoology Soybeans Chickens Food Science |
| Zdroj: | British Poultry Science. 45:225-263 |
| ISSN: | 1466-1799 0007-1668 |
| DOI: | 10.1080/00071660410001715867 |
| Popis: | 1. Since high concentrations of zinc are associated with reduced crop yields, environmental concerns are emerging regarding zinc accumulation in areas where poultry production is prevalent. This study investigates growth performance and zinc utilisation during the life cycle of broilers when diets were supplemented with various concentrations of zinc from two different sources. 2. A total of 740 Cobb 500 1-d-old male broiler chicks was randomly distributed into 88 battery cages. Excreta were collected over a 48-h period on d 10, 17, 24, 31, 38, and 45 to measure zinc excretion on a dry matter basis. 3. During the 45-d experimental period, broilers were given a maize-soybean meal basal diet (30 mg/kg zinc) supplemented with 0, 20, 40, and 80 mg/kg of zinc from zinc sulphate, Availa Zn amino acid complex, or an equal combination of zinc sulphate and Availa Zn amino acid complex. 4. Progressive additions of zinc to the basal diet significantly increased body weight gain of broilers, but did not affect feed conversion or mortality. Optimum body weight gain was achieved at 80 mg/kg supplemental zinc, which exceeds the NRC recommendations of 40 mg/kg. 5. During each excreta collection period, increased supplemental zinc concentrations significantly increased zinc excretion. However, the zinc source did not influence zinc utilisation. 6. As compared with zinc sulphate supplementation, the cumulative zinc excretion data indicate that adding zinc to the basal diet in the form of Availa Zn amino acid complex decreased zinc excretion. |
| Databáze: | OpenAIRE |
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