Exposição de ovos de matrizes pesadas à luz monocromática durante a incubação artificial

• Autor(a) principal: Mesquita, Mariana Alves
• Data de Publicação: 2017
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Repositório Institucional da UFG
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tede/7783
• topic: Desenvolvimento embrionário; Fotoestimulação; Frangos de corte; Embryo development; Photostimulation; Broilers; CIENCIAS AGRARIAS::ZOOTECNIA

Two experiments were conducted at North Carolina State University to elucidate the hypothesis that exposing broiler embryos to monochromatic lights during incubation period may influence embryonic growth and development, improving incubation traits and posthatching period. In the first experiment, intermittent green light, continuous green light, intermittent red light and dark were evaluated. In addition, the influence of egg position in the tray was also tested. In the second experiment, monochromatic green light exposure was evaluated during different phases of incubation period. Treatments were: 1) 21d of incubation in the dark; 2) 21d of incubation with green light; 3) dark until E5 and continuous green light until hatch; 4) continuous green light until E5 and dark until hatch; 5) dark until E18 and continuous green light until hatch; 6) continuous green light until E18 and dark until hatch. Machine temperatures were adjusted daily in order to obtain optimal eggshell temperature (99,5 a 100,4°F) during the whole incubation period. In the first trial, embryo mortality in intermediate phase was higher in the group exposed to intermittent green light. Relative proventriculus weight was influenced by light stimuli, and the group that was not exposed to light showed the greatest organ development. Feed intake was also influenced by light treatments at 21 d of age. In the second trial, exposing embryos to continuous green light at different moments during incubation period affected the percentage of hatch and hatch of fertile. In addition, dead pipped was higher in the group exposed to light until E18. Liver weight was higher in chicks incubated in the dark during 21 d. Feed conversion ratio at 35 and 42 days was also influenced by light treatments, and the group that was not exposed to light during the whole incubation period had the lower feed conversion ratio. Significant interaction was observed between light stimuli and sex for breast yield. Male chicks that were light stimulated until E18 had the lowest breast yield. Comparing sexes, the highest breast yield was observed for females that were light stimulated until E18 during incubation. In conclusion, with incubation conditions that were established during the experiments, exposing broiler embryos to monochromatic lights did not promote benefits in incubation traits and also did not influenced chick growth and development in posthatching period.