Programas de luz sobre o desempenho e parâmetros seminais de galos semi-pesados.

This study aimed to evaluate the influence of different lighting programs on the performance and semen parameters of semi-heavy cock strain. Twenty four roosters, aging 19 weeks, of the Lohman Brown strain were used, and submitted to three treatments: 1) continuous lightning programs 2) intermittent lightning programs and 3) increasing natural lightning programs. The animals were distributed into a completely randomized design, with 8 replicates being the experimental unit constituted of 1 animal. The experimental period lasted 140 days and the evaluated variables were: feed intake (g/chicken/day), body weight (g), semen production (ml), motility (%) and vigor (0 to 5) of the sperm, spermatic concentration (cells number × 109), total spermatic cells (NCT-volume x concentration) and spermatic morphology (head, tail and total alterations). The semi-heavy roosters submitted to continuous and intermittent lightning programs presented greater semen production and greater NCT (P<0,05). There was no significant influence (P>0.05) of the treatments on the other variables. It was concluded that the programs of continuous and intermittent light can be used for semi-heavy cocks during the breeding season, without sacrificing performance and sêmen parameters. [ABSTRACT FROM AUTHOR]