Effects of colour and intensity of artificial light produced by incandescent bulbs on the performance traits, thyroid hormones, and blood metabolites of broiler chickens

Effect of a gradual increase in the intensity of lighting on the physiological performance of broilers

Birds are exposed when the light is turned on by using the gradual increase of the light system. This study used 224 chicks (Ross 308) at one day old. Those chicks were randomly distributed into four treatments with four replicates for each treatment, i.e. (14 chicks/replicate). The treatments include the following: T1 the lighting program according to the guide for 308 ROSS company (Control Treatment), T2 the lighting program according to the guide with a gradual increase of lighting intensity every 20 minutes, T3 used the same method with an increase of lighting intensity every 40 minutes, T4 used lighting program with a gradual increase of lighting intensity every 60 minutes. The blood biochemical and hematological characteristics of 22 and 37 days of the age of chicks were studied. The results showed that females of T2 and T3 were significantly superior in blood sugar levels over the females of T1 and T4. Besides, it was observed that there was a significant decrease in the value of ALP enzyme in the blood of chicks males of all treatments compared with the control treatment. The H/L stress indicator was significantly decreased in T2, T3 and T4 compared with the control treatment. At the same time, there were no significant differences in other blood characteristics among all treatments. Finally, at the age of 37 days, it was noted that there was no significant difference among all blood characteristics at this age. It can be concluded that there were no significant effects of the gradual lighting intensity on the physiological performance of broilers. Still, at the period of 22 days, there was a reduction in stress levels, particularly H/L and very low-density lipoproteins. This experiment was conducted in the College of Agriculture, the University of Anbar's poultry fields for (37 days) the period from 18/10/2021 to 21/11/2021. the research was undertaken to reduce the effect of stress resulting from the sudden and high light intensity that birds are exposed to when the light is turned on by using the gradual increase of the light system. This study used 224 chicks (Ross 308) at one day old. Those chicks were randomly distributed into four treatments with four replicates for each treatment, i.e. (14 chicks/replicate). The treatments include the following: T1 the lighting program according to the guide for 308 ROSS company (Control Treatment), T2 the lighting program according to the guide with a gradual increase of lighting intensity every 20 minutes, T3 used the same method with an increase of lighting intensity every 40 minutes, T4 used lighting program with a gradual increase of lighting intensity every 60 minutes The blood biochemical of 22 and 37 days of the age of chicks were studied. The results showed that females of T2 and T3 were significantly superior in blood sugar levels over the females of T1 and T4. Besides, it was observed that there was a significant decrease in the value of ALP enzyme in the blood of chicks males of all treatments compared with the control treatment. The H/L ratio stress indicator was significantly decreased in T2, T3 and T4 compared with the control treatment. In comparison, there were no significant differences in other blood characteristics among all treatments. Finally, at the age of 37 days, it was noted that there was no significant difference among all blood characteristics at this age. It can be concluded that there were no significant effects of the gradual lighting intensity on the physiological performance of broilers. Still, at 22 days, there was a reduction in stress levels, particularly H/L ratio and very low-density lipoproteins. Keywords: Broiler ; ROSS 308 ; Light Intensity ; Lux; Blood characteristics

Light regimen on health and growth of broilers: an update review

The importance of lighting regimen is increasing with the industrialization of poultry production, as lighting has been intimately associated with not only the establishment of rhythm and synchronous physiology of broiler chickens, but also the secretion of hormones associated with broiler maturation and growth. In recent years, increasing attention has been paid to the effects of lighting management on growth performance, immune status, and welfare of broilers. An appropriate lighting regimen, including proper source of lighting, intensity, duration, and wavelength (color) of light, is crucial to improve the growth performance and welfare of broilers. In this review, we updated the impacts of different light regimens on health and growth performance of broilers.

Effects of lighting source as an environmental strategy for heat stress amelioration in growing Californian rabbits during summer season

The current work investigated the influences of different light sources on growth performance, carcass characteristics, blood biochemicals, physiological status and health aspects. One hundred and twenty growing California rabbits were assigned into four empirical collections in an experiment of completely randomized design. Rabbits of the first collection were reared under incandescent light bulbs (control), while the second, third and fourth collections were reared under fluorescent, saving light and LED light bulbs, respectively. The results indicated that rabbits reared under incandescent and LED had the heaviest body weight at 16-weeks-old. Rabbits reared under LED recorded the greatest gain during 14-16 weeks of age and 6-16 weeks of age. The lowest feed conversion ratio was observed in rabbits reared under LED lighting, during 14-16 weeks of age, and during the whole period without significant variations. Fat percentage (%) was low in rabbits exposed to fluorescent and LED. Rabbits grown under LED showed the lowest albumin/globulin and the highest glucose concentration. Rabbits kept under LED showed the lowest rectal temperature, mortality and health risks %. Conclusively, LED lighting source might be appropriate for alteration of incandescent and fluorescent light sources in rabbit farms to improve growth performance without compromising rabbit's carcass and welfare.

Evaluation of light colour manipulation on physiological response and growth performance of broiler chickens

Artificial illumination, including light quality, is crucial in modern broiler management. The aim of this study was to examine the effect of a switch in light colour on the performance of broiler chickens in tropical environments. A total of 280 1-day-old Arbor acre male chicks were used for this study and were weighed and assigned to different light environments viz. white (WH), green (GR), blue (BL), GR switched to BL at 14 days (GB), BL switched to GR at 14 days (BG), BL switched to GR at 28 days (BGG) and GR switched to BL at 28 days (GBB) having four replicates of ten birds each. Body weight, weight gain, feed intake and feed conversion ratio were recorded weekly. Blood samples were collected from 2 birds per replicate weekly for the determination of plasma triiodothyronine (T₃), haematology and serum biochemical parameters. The experiment was laid out in a completely randomised design. Results showed that the final body weights of the birds in GBB and GB were comparable but higher than those of the other treatment groups. Feed intake of the chickens in WH was similar to that of BG but higher than those of the other treatment groups, while FCR of the birds in WH was higher (P < 0.05) than the other treatment groups. Plasma T₃ of the birds in GR was comparable to that of birds in BL but significantly higher than those of the birds in WH and a similar trend was also observed at weeks 1 and 2. Heterophil/lymphocyte ratio (H/L) of the birds in WH was significantly higher than those of BL and GR whose values were similar to those in GB and BG. Heterophil/lymphocytes of the birds in WH was higher than those of BG, GR, BGG, GB and GBB but similar to those of BL. The breast muscle of the birds in GBB and GB was similar to those of BGG and GR and significantly higher than those of WH, BL and BG. Based on the results obtained in this study, it was concluded that the use of green light up to 28 days in combination with blue light stimulated the growth of broiler chickens and manipulation of light colours can be used to improve the welfare and performance of chickens.

Impact of Housing Environment on the Immune System in Chickens: A Review

During their lifespan, chickens are confronted with a wide range of acute and chronic stressors in their housing environment that may threaten their welfare and health by modulating the immune system. Especially chronic stressful conditions can exceed the individual's allostatic load, with negative consequences for immunity. A fully functional immune system is mandatory for health and welfare and, consequently, also for high productivity and safe animal products. This review provides a comprehensive overview of the impact of housing form, light regime as well as aerial ammonia and hydrogen sulfide concentrations on the immune system in chickens. Certain housing conditions are clearly associated with immunological alterations which potentially impair the success of vaccinations or affect disease susceptibility. Such poor conditions counteract sustainable poultry production. This review also outlines current knowledge gaps and provides recommendations for future research.