Effect of intermittent lighting, light intensity and source on the performance and welfare of broilers

Abstract

Broilers are currently reared under nearly continuous lighting (CL) schedules. However, the suitability of such lighting regimens may be questioned in terms of performance and welfare. This paper reviews the literature concerning the effects of intermittent lighting (IL) schedules on these issues. Final body weights at market age of broilers reared under IL schedules are equal to, or even higher than, those of broilers reared under CL schedules. However, endogenous (genotype and sex) and exogenous (dietary composition, feeder space, etc.) factors may interact with the lighting schedule. In contrast, feed conversion is consistently improved with IL, partly as a consequence of a more concave growth curve (initial growth depression followed by compensatory growth). Inconsistencies in the literature concerning the effect of IL on (abdominal) fat content and dressing yield are caused by interactions with other factors. However, it is clearly demonstrated that IL reduces leg abnormalities, in particular the incidence of twisted legs. Additional welfare benefits of IL are found in reduced physiological stress and improved eye condition. An increase in the amount of catching damage has been observed with IL, but this may be avoided by modifying light management before commencement of the catching operation. The importance of light is not restricted to the lighting schedule; aspects of the light quality are also important. Although the data related to light intensity are conflicting, it is generally recommended that an intensity of 51ux should be provided. Whilst fluorescent light does not affect broiler performance adversely, its lower use of electricity compared with incandescent lighting does reduce input costs. More research is needed to evaluate the impact of these qualitative aspects of lighting on poultry welfare.

Curtain color and lighting program in broiler production: II. carcass and parts yield and abdominal fat deposition

“…Renden et al (1996) applied four different photoperiods: 1) 23L:1D; 2) 16L:8D; 3) 16L:3D1L:4D; 4) 16L:2D:1L:2D:1L:2D, where L = hours of light; and D = hours of darkness and did not find any influence of photoperiod on abdominal fat, wings, or thighs yields. However, Buyse et al (1996), when evaluating abdominal fat deposition in broilers submitted to intermittent (1L:3E) or nearly continuous (23L:1E) lighting programs found that the intermittent lighting program reduced broiler abdominal fat deposition at 28 and 41 days of age. These authors concluded that adipose tissue deposition was postponed due to a change in the slope of the growth curve imposed by intermittent lighting.…”

Curtain color and lighting program in broiler production: I - general performance

“…These results are partially consistent with the findings of Classen (1992), quoted by Rutz et al (2000), that continuous lighting programs allow consistent access of the birds to the feed during the whole day, thereby promoting maximum feed intake and weight gain due to feed ingestion stimulation. Buyse et al (1996) evaluated the live performance of broilers submitted to intermittent (1 hour of light and 3 hours of dark) or nearly continuous (23 hours of light and 1 hour of darkness) lighting programs and showed that, up to 28 days of age, broiler body weight was higher with nearly continuous lighting program, but at 41 days, this difference disappeared and bird performance was similar at both programs. Renden et al (1996) observed an effect of the lighting program on weight gain, but not on the feed efficiency of 49-day-old broilers submitted to four different lighting programs.…”

Análise de diferentes sistemas de iluminação para aviários de produção de ovos férteis

“…A importância da luz nos aviários não está restrita apenas à duração da iluminação: intensidade da luz, fonte de luz, freqüência, comprimento de onda do pico de radiação, comprimento de onda espectral, composição espectral e a distribuição espacial das lâmpadas no galpão, também afetam os resultados finais, em termos da qualidade e da quantidade de produção (Buyse & Simons, 1996;Lewis & Morris, 1998).…”