Influência do estresse térmico no nascedouro sobre a imunidade humoral e as características zootécnicas de frangos de corte
Jaboticabal; s.n; 20/02/2006. 33 p.
Thesis
em Pt
| VETTESES
| ID: vtt-9497
Biblioteca responsável:
BR68.1
RESUMO
Dois experimentos foram conduzidos para verificar o efeito da temperatura do nascedouro sobre a imunidade humoral e as características zootécnicas dos frangos. Em cada experimento, embriões distribuídos ao acaso em três grupos foram submetidos à temperatura de 34, 37 ou 39°C (438-508 h de incubação). No experimento 1, os pintainhos foram criados sem vacinação e os títulos de anticorpos maternos contra a Doença Infecciosa da Bursa (VDIB) e a Doença de Newcastle (VDN) foram quantificados semanalmente até 42 dias, pelo método de ELlSA. No experimento 2, medidas morfométricas da bursa foram realizadas em 15 aves recém-eclodidas e as outras foram distribuídas em cinco parcelas por tratamento, de 30 aves cada e vacinadas contra VDIB (9° e 21° dia) e VDN (4° e 16° dia) e determinaram-se os títulos de anticorpos como no experimento 1. Características de desempenho e composição bromatológica foram determinadas. O peso e a área da bursa não foram afetados, entanto que, as áreas folicular, medular e cortical e a espessura do epitélio foram afetadas pelos tratamentos (pABSTRACT
Two experiments were carried out to verify the temperature effects in the hatcher on humoral immunity and performance of broiler chickens. In each experiment, the embryos were randomly distributed in three temperature 34, 37 or 39°C (438-508 h of incubation). In the experiment 1, the chicks were reared without vaccination and the maternal antibodies titers against Infectious Bursal Disease Virus (IBDV), and Newcastle Disease Virus (NDV) were weekly assessed up to 42 days of age, by ELlSA method. In the experiment 2, bursa morphometric measures were done on hatch in 15 chicks per temperature. The other chicks were randomly distributed in five pens (30 birds each) per temperature and were vaccinated against IBDV (9th and 21st day of age) and NDV (4th and 16th day of age) and the antibodies titers were determined like in the experiment 1. Performance and body chemical composition were determined. Bursa weight and area were not affected, while follicular, medullar and cortical areas and the epithelium width were affected by temperature (p<0.05). There was not interaction between temperature and chicks age, nor temperature effect on maternal and after vaccination antibodies titers (p>0.05). The body dry matter was smaller in the 7th day of age to embryos exposed to 39°C in relation to 34°C. The feed intake was lower and feed conversion better up to 7 days of age and body weight was lower up to 21 days of age, to embryos exposed to 39°C. From 1 to 42 days of age performance was not influenced by temperature. It was concluded that heat stress in the hatcher 1) reduces the bursa follicular development at hatch, however, it does not influence after vaccination immune humoral responses, 2) the maternal antibodies transferences and decline of its levei was not affected, 3) the heat stress impairs performance from 1 to 21 days, but not from 1 to 42 days of age
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Base de dados:
VETTESES
Idioma:
Pt
Ano de publicação:
2006
Tipo de documento:
Thesis