Trator de galinhas associado à produção de alface

• Ano de defesa: 2010
• Autor(a) principal: Alvaro Luis de Carvalho Veloso
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; UFMG
• Palavras-chave em Português: Agroecologia; Trator de galinhas; Alface; Bem-estar animal; Avicultura alternativa; Ciencias agrarias; Ave Criação
• Link de acesso: http://hdl.handle.net/1843/NCAP-87QFWQ

This experiment aimed to evaluate the effect of rearing laying hens in mobile aviaries on the performance and the internal and external eggs quality, soil fertility and lettuce production comparing to a conventional system of production and to study the behavior and welfare of laying hens kept in mobile aviaries. To evaluate the performance and eggs quality two treatments were used: 1) Mobile aviary measuring 2 m x 1m x 1,2 m (length x width x height) on seedbeds of 1 m width. Eight hens and a rooster were used in each mobile aviary; and 2) Conventional hens cages measuring 50 cm x 39 cm x 43 cm (length x width x height) with four hens per cage; each experimental unit composed by two cages. The treatments were arranged in a completely randomized design, with 6 repetitions, during seven periods of 27 days each. The performance was evaluated in every cycle by means of ration consumption (g/bird/day), egg production (%/bird/day), egg weight (g), egg mass (g/bird/day) and feed conversion (g/g). The eggs internal quality was determined by the Haugh unit, egg yolk and albumen percentage. The quality of the eggs shell was determined through the shell thickness (mm) and percentage of the shell (% of fresh egg) and by the egg specific gravity (g/ml water). The birds raised in mobile aviaries had presented higher production and egg mass, but the ration consumption was bigger and the feed conversion was worse. The cost of the ration was R$ 0,80 per kg, the sale price per dozen eggs was R$ 2,50 for conventional cages system; R$ 3,50 for the mobile aviary system, generating a profitability 46.4% higher for the mobile aviary. The quality of eggs was not affected by the experimental treatments. To evaluate soil fertility and lettuce production two treatments were used: 1) Seedbed measuring 2 m x 1 m (length x width), with mobile aviary measuring 2 m x 1 m x 1,2 m ( length x width x height). Eight hens and a rooster were used in the mobile aviary. The mobile aviary was on the seedbed for nine days and its fertilization was done by the hens; and 2) conventional Seedbed measuring 2 m x 1 m (length x width), fertilized with hens manure. In the conventional seedbed the fertilization was done manually with hens manure collected from a batch of nine hens kept in cages, after a period of nine days. The treatments were arranged in a completely randomized design with 9 replications. Thirty-two seedlings of lettuce grown in greenhouse were transplanted to each seedbed 40 days after the departure of birds and preparation of conventional seedbeds. The lettuce was harvested 32 days after being transplanted. Soil fertility was measured by chemical analysis of pH, Mehlich phosphorus, potassium, aluminum, calcium, magnesium, organic matter and phosphorus balance and physical analysis of thick sand, fine sand, silt and clay in soil samples collected from each seedbed from 0 - 20 cm, before the entry of birds or the manual fertilization and after 40 days. Lettuce production was measured in four plants closest to the average weight of 12 central plants of each seedbed. The characteristics of lettuce evaluated were: number of leaves per plant, diameter of head lettuce, fresh weight of plant, plant dry matter and nitrogen. There was no difference on fertility and physical analysis of soil between the two production systems. But the production rates of lettuce were better for seedbeds fertilized with mobile aviaries. To study the behavior and welfare of laying hens two treatments were used: 1) Mobile aviary measuring 2 m x 1 m x 1,2 m (length x width x height) on seedbeds of 1 m width with eight hens and a rooster; and 2) Conventional bird cages measuring 50 cm x 39 cm x 43 cm (length x width x height) with four hens per cage; each experimental unit composed by two bird cages. The treatments were arranged in a completely randomized design with 6 replications. It was used an ethogram, based on the behavioral needs of poultry with the following behaviors: eating, drinking, investigate feathers, sand bath, comfort movement, scratch, perch, aggressiveness, seated, looking for the nest, posture, standing still, copulation and vocalization. The birds of mobile aviaries and conventional system were observed simultaneously for six consecutive days during the schedules of 7 to 8 hours, 12 to 13 hours and from 17 to 18 hours. The observations were done using the Scan method, that is, at the observation moment the behavior of each one of the birds was written down and passed to the following aviary. The range of observations between the aviaries was 5 minutes and after 30 minutes repeated the same sequence of observations. The thermal evaluation was performed by means of dry bulb temperature and relative humidity. Conclusions: 1) the laying hens raised in mobile aviaries present higher production, worse performance and same quality of eggs compared to the conventional system. However, they generate better economic return due to higher egg prices; 2) the fertilization of the beds with mobile aviaries provides higher production of lettuce and higher content of nitrogen in the plant. As for the levels of the elements assessed in the soil, there is no difference between production systems; 3) the birds in cages are restricted to eating, drinking, investigating feathers, standing still or sitting and laying eggs, while the birds raised in mobile aviaries express all behaviors that are natural to them, displaying improved well-being of birds in this system.