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| Author(s): |
Andréa Luciana dos Santos
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | Pirassununga. |
| Institution: | Universidade de São Paulo (USP). Faculdade de Zootecnica e Engenharia de Alimentos (FZE/BT) |
| Defense date: | 2008-02-15 |
| Examining board members: |
Douglas Emygdio de Faria;
Silvana Martinez Baraldi Artoni;
César Gonçalves de Lima;
José Fernando Machado Menten;
Antonio Celso Pezzato
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| Advisor: | Douglas Emygdio de Faria |
| Abstract | |
This study was carried out to evaluate the performance, growth profile, egg quality, body composition, and bone and reproductive characteristics of hens fed different nutritional programs from day-one to 72 weeks of age. 1656 birds were randomly assigned in a factorial scheme 3x2: nutritional programs (P1 - 95% of the requirements, P2 - 100% of the requirements, and P3 - 105% of the requirements according to Hy-Line Manual) and Hy-Line strains (W36 and Brown), resulting six treatments with six replicates of 46 birds each. To obtain the growth curves was used the equation of Gompertz and multiphase mathematical model. P3 program provided better weight gain in the starter phase (0 - 6 weeks) and, similarly, P2 and P3 programs for the grower phase (7 - 17 weeks). In both phases (starter and grower), feed intake was not influenced by the nutritional programs. However, the Brown pullets showed higher feed intake and weight gain than W36 pullets. It was verified, during the production phase, that egg production, egg weight, and feed conversion were not affected by the nutritional programs. As expected, the Brown hens showed higher values for feed intake, egg production, egg weight, and egg mass than W36 hens. Egg internal (yolk and albumen percentages, Haugh unit, and yolk index), egg external (shell percent, shell thickness, and egg specific gravity), bone (breaking force resistance, calcium and phosphorus concentrations, and bone densitometry), and reproductive characteristics (weight and length of follicles ovarian and of the oviduct segments) were not influenced by the nutritional programs, from 18 to 72 weeks of age. W36 hens showed higher values for yolk percent, bone breaking force resistance, and bone densitometry. On the other hand, Brown hens showed higher values for albumen percent, shell thickness, egg specific gravity, weight and length of magnum, uterus, and vagina. The maximum rates of body growth and nutrients of carcass (protein, fat, ash and water) occurs in different ages. In general, the equation of Gompertz provided better adjust of the data than multiphase mathematical model. It was concluded that the P3 program is indicated for starter phase and P2 program is able to support the nutritional requirements for grower and production phases. The varieties W36 and Brown show different performance, growth, bone strength, reproductive and egg quality profiles. (AU) | |
| FAPESP's process: | 06/01733-8 - Evaluation of growth potential and body composition behavior through mathematical models in pullets submitted to three feeding programs |
| Grantee: | Andréa Luciana dos Santos |
| Support Opportunities: | Scholarships in Brazil - Doctorate |