Effects of Light Sources and Intensity on Broilers Grown to Heavy Weights: Hematophysiological and Biochemical Assessment

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.

Effects of dietary Original XPC on selected blood variables in layer pullets challenged with Mycoplasma gallisepticum,. Poult Sci 2020;99:4373-4383. [PMID: 32867981 PMCID: PMC7598016 DOI: 10.1016/j.psj.2020.06.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

Effects of dietary Original XPC (XPC) on 17 selected blood variables in commercial layer pullets challenged with the virulent, low-passage R strain of Mycoplasma gallisepticum (R_lowMG) were investigated. Hy-Line W-36 pullets sourced from M. gallisepticum–clean layer breeders were fed a basal diet with XPC (1.25 kg/metric ton) or without from hatch until 12 wk of age (woa). At 8 and 10 woa, half of the birds in each dietary treatment were challenged with R_lowMG. Blood samples were taken immediately before the initial R_lowMG challenge at 8 woa and again at 12 woa (4 wk after challenge). At 8 woa, blood pH was lower and glucose concentration was higher in the preassigned challenge treatment groups. At 12 woa, the concentration of oxygen dissolved in the blood was significantly lower in the R_lowMG-challenged group than the unchallenged group of birds regardless of dietary treatment. The R_lowMG challenge significantly increased blood carbon dioxide partial pressure, calcium, sodium, anion gap, osmolality, glucose, and corticosterone levels but significantly decreased blood oxygen partial pressure, oxyhemoglobin concentration, concentration of oxygen dissolved in the blood, chloride, and pH levels. Because blood pH and glucose concentration at 8 woa were examined before challenge, their baseline values were biased with respect to challenge treatment before treatment was applied. However, the lack of a significant main effect due to diet at 8 woa for blood pH and glucose concentration, along with the other 15 blood variables, indicate that the baseline data with respect to dietary treatment were unbiased, allowing for real dietary effects to be accurately assessed. In conclusion, layer pullets challenged with R_lowMG undergo a stress response associated with changes in various physiological blood variables, and a decrease in pH and increase in carbon dioxide partial pressure, in association with a lack of change in bicarbonate, indicates that the stress response caused by the R_lowMG challenge was associated with respiratory acidosis. Nevertheless, feeding XPC did not influence the effects of challenge treatment on these postchallenge physiological blood values.

Impact of lighting color and duration on productive performance and Newcastle disease vaccination efficiency in broiler chickens

Background and Aim

Manipulating lighting colors and regimens is considered an effective mean for improving broiler productivity. The influence of red, blue, and white light-emitting diode (LED) was investigated using three different regimens of lighting and darkness; continuous 23 h light (L):1 h dark (D), continuous 18 h L:6 h D, and intermittent 16 h L:8 h D hours on the performance, carcass weight (CW), feed and water intake (WI), serum glucose (GLUCO), triglycerides (TG), and cholesterol (TC), intestinal bacterial load, growth and metabolic hormones, and efficiency of Newcastle disease (ND) vaccine.

Materials and Methods

A total of 252 1-day-old Ross broilers on deep litter were divided into nine groups. The 1^st, 4^th, and 7^th groups were exposed to continuous 23L:1D, the 2^nd, 5^th, and 8^th groups were exposed to continuous 18L:6D, and the 3^rd, 6^th, and 9^th groups were exposed to intermittent 16L:8D (4L:2D, 4 times) lighting regimen using red, blue, and white LED lights, respectively. A total of 1350 samples (225 sera, 225 swabs, and 900 organ samples) were collected.

Results

Blue LED group revealed a highly significant increase (p<0.01) in live body weight, body weight gain, performance index, CW, spleen, heart, and liver weights, and anti-ND antibody titer, as well as a highly significant decline (p<0.01) of feed intake, WI, GLUCO, TG, TC, growth hormone, insulin, tri-iodothyronine (T3), tetra-iodothyronine (T4), total bacterial count (TBC), and total Enterobacteriaceae count compared to red and white LED lights in all tested lighting regimens. Continuous 23L:1D and 18L:6D regimens were significantly (p<0.01) superior to intermittent 16L:8D in their influence on the performance, CW, biochemistry, hormonal profile, and bacterial load.

Conclusion

The blue LED light associated with continuous 18L:6D or 23L:1D h regimen is highly recommended in broiler houses for their enhancing the productive performance, growth, and immunity.

Effects of light-sources and photoperiod on hemato-physiological indices of broilers grown to heavy weights

We evaluated the influence of light sources and photoperiod on blood physiological variables in four trials. In each trial, 720 1-d-old Ross × Ross 708 chicks were randomly distributed into 12 environmentally controlled rooms (30 males/30 females/room). The experimental design was a 4 × 3 factorial treatments consisting of four light sources [incandescent (ICD, standard), compact fluorescent, neutral light emitting diode, and cool poultry-specific-filtered LED] and three photoperiods [long/continuous (23L:1D), regular/intermittent (2L:2D), and short/non-intermittent (8L:16D)] from d8-d56 at 50% relative humidity. Birds were fed the same diet, while feed and water were provided ad libitum. Blood samples were collected from the brachial wing vein on d 14, 28, 42, and 56 of age and analyzed immediately. Light sources had significant (P ≤ 0.05) effects on body weight (BW), and some of the selected blood physiological indices except Hb, Hct, Ca2+ angap, glucose, and corticosterone. Also, the photoperiods had significant (P ≤ 0.05) effects on BW and most of the selected blood physiological indices except HCO3-, angap, glucose, corticosterone, and T4. However, all these changes were still within the normal acid-base homeostasis and physiological ranges of this species. Acid-base regulation during the short photoperiod exposure had not deteriorated despite higher pCO2 that consequently decreased blood pH, due to a respiratory acidosis. Plasma corticosterone and glucose concentrations were not affected by treatments, suggesting an absence of physiological stress. It was concluded that the three LED light bulbs evaluated could be suitable for replacement of ICD along with the regular/intermittent photoperiod. Commercial poultry facilities can thereby reduce energy costs and optimize production efficiency without compromising the welfare of broilers grown to heavy weights (>3 kg).