Effect of light-emitting diode vs. fluorescent lighting on laying hens in aviary hen houses: Part 1 - Operational characteristics of lights and production traits of hens

Effects of LED Lights with Defined Spectral Proportion on Growth and Reproduction of Indigenous Beijing-You Chickens

Light presents an important exogenous factor for poultry. This study examined effects of LED lights with different defined spectrums on growth and reproduction of indigenous Beijing-You chickens. A total of 576 one-day old female chicks were divided into 16 rooms, and each were exposed to four different lights: LED A (21% green light, 30% blue light, 24% yellow light, and 25% red light), B (35%, 35%, 18%, and 12%), C (27%, 30%, 22%, and 21%), or compact fluorescent lamps (CFL, 15%, 28%, 41%, and 16%). Results showed that feed intake and feed conversion ratio were comparable among treatments throughout the 17 week rearing period (p > 0.05). LED C showed similar body weight gain with CFL, but higher than LED A and B. The CFL birds start to lay on 132.25 d, while LED B did not lay until 148.25 d. The age at 50% egg production did not vary among groups (p = 0.12). Total egg number until 43 week of LED B was higher than others (p < 0.05). Therefore, LED lights with defined spectral proportion have different effects on chickens' growth and reproduction. The LED C promotes the prepubertal growth, and the LED B provides proper sexual maturation age and better egg-laying persistence.

The effect of linear lighting systems on the productive performance and egg quality of laying hens

The low uniformity in light distribution provided by conventional lighting systems installed in laying poultry can compromise the productive performance and egg quality of laying hens. Thus, the aim of the current study is to evaluate the effect of a linear lighting system with light-emitting diode (LED strip) on the productive performance and egg quality of laying hens, by comparing it to the conventional LED lamp lighting system. The study used Hy-Line Brown hens from a commercial production unit. Hen-day egg production (%), mortality rate (%), egg weight (g), albumen height (mm), Haugh unit, eggshell thickness, eggshell strength, and thermal-environment conditions were evaluated from the 19th to the 48th wk of age. The results have shown that LED strips were capable of improving egg production (P < 0.05) in comparison to LED lamps. Egg quality was not affected (P > 0.05) by the evaluated lighting systems throughout the experimental period. Results of the current study indicate that the homogeneous illuminance distribution provided by the linear LED strip lighting system at different cage floors improved egg production in comparison to the conventional LED lamp lighting system.

Effects of LED Light Color and Intensity on Feather Pecking and Fear Responses of Layer Breeders in Natural Mating Colony Cages

Simple Summary

Commercial breeder farms are moving forward using colony cages due to high efficiency, low energy input, clean production, and as a result of the rising public concerns with respect to the welfare of hens in conventional cages. Compared with conventional cages, layer breeders in colony cage are the parent-stock of laying hens and are confined together with roosters. However, the use of colony cages is still in a preliminary stage due to behavioral issues such as feather pecking (FP) and cannibalism. These behaviors can cause poor health, poor welfare, and economic problems. It is necessary to identify effective and proximal management practices to alleviate the damage that is caused by FP and cannibalism in such colony cage systems. This study aims to mitigate the problems of FP and cannibalism by utilizing light environment regulation. Results of this study indicates that red light and low light intensity could effectively alleviate FP and cannibalism during the laying period. Such knowledge might help to understand FP behavior and stress susceptibility of hens in this system and will provide a basis for the optimization of the cage equipment and the regulation of light environment.

Abstract

Natural mating colony cages for layer breeders have become commonplace for layer breeders in China. However, feather pecking (FP) and cannibalism are prominent in this system. The objective of this study was to investigate the effects of four light-emitting diode (LED) light colors (white: WL, red: RL, yellow-orange: YO, blue-green: BG) with two light intensities for each color, on FP, plumage condition, cannibalism, fear, and stress. A total of 32 identical cages were used for the eight treatments (four replicates for each treatment). For both light intensities, hens in RL had a lowest frequency of severe FP, whereas hens in WL had the highest frequency of severe FP. Hens in RL and BG had better plumage conditions than in WL and YO. Compared with RL and BG treatments, hens treated with WL and YO had a significantly longer tonic immobility (TI) duration. Hens treated with RL had a higher concentration of 5-hydroxytryptamine (5-HT), a lower concentration of corticosterone (CORT), and a lower heterophil to lymphocyte ratio than WL and YO. Furthermore, RL could significantly reduce mortality from cannibalism. Overall, hens treated with RL and low light intensity showed a lower frequency of severe FP, less damaged plumage, were less fearful, had lower physiological indicators of stress, and had reduced mortality from cannibalism. Transforming the light color to red or dimming the light could be regarded as an effective method to reduce the risk of FP and alleviate the fear responses of layer breeders.

Effects of litter floor access and inclusion of experienced hens in aviary housing on floor eggs, litter condition, air quality, and hen welfare

With different cage-free (CF) housing styles and management schemes, retailers have developed their own CF criteria. One highly debated aspect is if hens may be kept inside the system for part of the day—during the first few hours after lights-on. Research is lacking regarding the impacts of such a practice on hen welfare, incidence of eggs laid on the litter floor, litter condition, and air quality. This 14-mo field study was conducted to help assess such impacts. Hens (Dekalb White) in an aviary house (50,000-hen nominal capacity) were allowed to have full litter access (FLA) vs. part-time litter access (PLA) from 10:50 am to 9:00 pm, coupled with the absence or presence of experienced hens (1.5% of the population), hence a 2 × 2 factorial arrangement. The measured variables included a) incidence of floor eggs, b) percentage of birds remaining on litter floor at night, c) mortality, d) body weight (BW) and BW uniformity, e) litter condition (depth, moisture content, texture, amount removed, and bacteria concentration), f) environmental conditions, and g) welfare conditions (10 variables). Compared to FLA, PLA had a significantly lower incidence of floor eggs (1.4 ± 0.1 vs. 12.6 ± 1.1 eggs per hen housed as of 76 weeks of age (WOA), i.e., approximately 89% reduction), less manure deposition on the floor (0.53 ± 0.02 vs. 1.05 ± 0.04 kg/100 hens/d, dry basis, i.e., approximately 50% reduction), and lower ammonia concentrations due to drier litter (averaging 22% lower). Inclusion of 1.5% experienced hens in the young flock did not show benefit of reducing the incidence of floor eggs (P = 0.48). The percentage of hens remaining on the floor at night was low (< 0.01%) in all cases from 24 WOA onward. No differences were detected between FLA and PLA in hen welfare conditions, mortality, BW, BW uniformity, bacteria concentration in the litter, air temperature, or relative humidity.

Effects of light-emitting diode light v. fluorescent light on growing performance, activity levels and well-being of non-beak-trimmed W-36 pullets

More energy-efficient, readily dimmable, long-lasting and more affordable light-emitting diode (LED) lights are increasingly finding applications in poultry production facilities. Despite anecdotal evidence about the benefits of such lighting on bird performance and behavior, concrete research data were lacking. In this study, a commercial poultry-specific LED light (dim-to-blue, controllable correlated color temperature (CCT) from 4500 to 5300 K) and a typical compact fluorescent light (CFL) (soft white, CCT=2700 K) were compared with regards to their effects on growing performance, activity levels, and feather and comb conditions of non-beak-trimmed W-36 pullets during a 14-week rearing period. A total of 1280-day-old pullets in two successive batches, 640 birds each, were used in the study. For each batch, pullets were randomly assigned to four identical litter-floor rooms equipped with perches, two rooms per light regimen, 160 birds per room. Body weight, BW uniformity (BWU), BW gain (BWG) and cumulative mortality rate (CMR) of the pullets were determined every 2 weeks from day-old to 14 weeks of age (WOA). Activity levels of the pullets at 5 to 14 WOA were delineated by movement index. Results revealed that pullets under the LED and CFL lights had comparable BW (1140±5 g v. 1135±5 g, P=0.41), BWU (90.8±1.0% v. 91.9±1.0%, P=0.48) and CMR (1.3±0.6% v. 2.7±0.6%, P=0.18) at 14 WOA despite some varying BWG during the rearing. Circadian activity levels of the pullets were higher under the LED light than under the CFL light, possibly resulting from differences in spectrum and/or perceived light intensity between the two lights. No feather damage or comb wound was apparent in either light regimen at the end of the rearing period. The results contribute to understanding the impact of emerging LED lights on pullets rearing which is a critical component of egg production.

Status of Solid State Lighting Product Development and Future Trends for General Illumination

After decades of research and development on fabrication of efficient light-emitting diodes (LEDs) throughout the visible spectrum, LED-based lighting has reached unparalleled performance with respect to energy efficiency and has become the light source for virtually all new lighting products being designed today. The development of the core light sources and their subsequent integration into lighting systems continue to present unique challenges and opportunities for product designers. We review these systems and the current development status, as well as provide context for the trends in solid state lighting that are leading to the development of value-added lighting solutions that extend the domain of lighting beyond light generation, into fields as diverse as communications, healthcare, and agricultural production.