Effect of night light regimen on growth performance, antioxidant status and health of broiler chickens from 1 to 21 days of age

The effect of light regime and time of slaughter in broiler on broiler performance, liver antioxidant status, and expression of genes related to peptide absorption in the jejunum and melatonin synthesis in the brain

This study aimed to assess the effects of light regime and time of slaughter on primal cut and organ weights, peptide transporter 1 (PEPT1) gene expression in the jejunum, arylalkylamine N-acetyltransferase (AANAT) gene expression in the brain, and liver oxidant/antioxidant status in broilers aged 37 days. The experiment was conducted in a factorial completely randomized design, with two light regimes (intermittent light varying according to bird age and continuous light under an 18 h light/6 h dark photoperiod) and four times of slaughter (2:00, 8:00, 14:00 and 20:00 h). There was an interaction effect on PEPT1 and AANAT expression, lipid and protein oxidation and superoxide dismutase (SOD) activity. In both light regimes, PEPT1 expression responded cubically to slaughter time. In the continuous light group, PEPT1 expression was highest in birds slaughtered at 2:00 and 14:00 h, whereas, in the intermittent light treatment, expression was highest at 8:00 h. In the continuous light regime, AANAT expression had a cubic relationship with time of slaughter, with the greatest values recorded at 20:00 h. In the intermittent light regime, slaughter time showed a cubic effect on lipid oxidation, which was highest at 8:00 h. In the continuous light group, there was a cubic effect on nitrite concentration, lipid oxidation, protein oxidation, and SOD activity; nitrite levels, lipid oxidation, and protein oxidation were highest and SOD activity was lowest in birds slaughtered at 14:00 h. Time of slaughter influenced catalase activity, which responded cubically; catalase activity was lowest at 8:00 and 14:00 h. This study is the first to demonstrate that PEPT1 expression in the jejunum of broilers follows a diurnal rhythm and varies according to light regime. The results also suggest that mainly continuous lighting and slaughter at 14:00 h when the animals are possibly more active may be more stressful to broilers.

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

Adverse effects of heat stress during summer on broiler chickens production and antioxidant mitigating effects

Broiler chicken meat is a good source of protein consumed universally, and is one of the most commonly farmed species in world. In addition to providing food, poultry non-edible byproducts also have value. A major advantage of broiler chicken production is their short production cycle, which results in a greater rate of production in comparison to other species. However, as with any production system, there are constraints in broiler production with one of the most pressing being energy requirements to keep the birds warm as chicks and cool later in the growth cycle, as a result of the cost needing mechanical heating and cooling. While this is feasible in more advanced economies, this is not readily affordable in developing economies. As a result, farmers rely on natural ventilation to cool the rearing houses, which generally becoming excessively warm with the resultant heat stress on the birds. Since little can be done without resorting to mechanical ventilation and cooling, exploring the use of other means to reduce heat stress is needed. For this review, we cover the various factors that induce heat stress, the physiological and behavioral responses of broiler chickens to heat stress. We also look at mitigating the adverse effect of heat stress through the use of antioxidants which possess either an anti-stress and/or antioxidant effects.

Effects of the circadian rhythm on milk composition in dairy cows: Does day milk differ from night milk?

Metabolism in most organisms can show variations between the day and night. These variations may also affect the composition of products derived from livestock. The aim of the present study was to investigate the difference in composition between the day milk and night milk of dairy cows. Ten multiparous Holstein cows (milk yield = 25.2 ± 5.00 kg/d) were randomly selected during mid lactation. Milk samples were collected at 0500 h ("night milk") and 1500 h ("day milk") and analyzed to determine their composition. Mid-infrared spectroscopy was used to analyze macronutrient content of milk. Metabolomics and lipidomics were used to detect and analyze small molecules and fatty acids, respectively. An automatic biochemical analyzer and ELISA kits were used to determine biochemical indicators, as well as antioxidant and immune parameters in the milk. Though milk fat, protein, lactose, and total milk solids were not different between day milk and night milk, small molecules, metabolites and lipids, and hormones and cytokines differed between day milk and night milk. Regarding biochemical and immune-related indicators, the concentrations of malondialdehyde, HSP70, and HSP90 in night milk were lower than that in day milk. However, interferon-γ levels were higher in night milk. Additionally, night milk was naturally rich in melatonin. Lipidomics analyses showed that the levels of some lipids in night milk were higher than those in day milk. Metabolomics analyses identified 36 different metabolites between day milk and night milk. Higher concentrations of N-acetyl-d-glucosamine, cis-aconitate, and d-sorbitol were observed in day milk. However, the other 33 metabolites analyzed, including carbohydrates, lipids, AA, and aromatic compounds, showed lower concentrations in day milk than in night milk. The present findings show that the composition of night milk differs considerably from that of day milk. Notable changes in the circadian rhythm also altered milk composition. These results provide evidence to support the strategic use and classification of day milk and night milk.

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.