The effect of 580 nm-based-LED mixed light on growth, adipose deposition, skeletal development, and body temperature of chickens

Effects of intermittent lighting program and light colour on ocular health variables as welfare indicators in broiler chickens

1. The objective of the present study was to examine the effect of lighting programs and light colour on ocular health variables as welfare indicators in Ross 308 broilers.2. A total of 384, male, one-d-old broiler chickens (Ross 308) were placed in a completely randomised design with a 2 × 2 factorial arrangement of lighting program (continuous or intermittent) and light colour (white and green LED light). Ross 308 broilers under restricted lighting had 18 h of light (18 L:6D), while those under intermittent lighting had cycles of 17 L:3D:1 L:3D throughout the experimental period, which lasted 42 d.3. At the end of the experiment, all eyes of birds (n = 96 birds) underwent a complete ophthalmic examination, which included the Schirmer tear test I, intraocular pressure and eye dimensions. In addition, 32 broilers (eight birds per trial groups) aged 42 d underwent ophthalmic examination to include assessment of ocular ultrasound biometry.4. Light colour had a significant influence on the mean intraocular pressure (p < 0.001). The Ross 308 broilers kept with intermittent lighting had lower eye weights (2.29 g; p < 0.05), palpebral fissure length (14.39 mm; p < 0.01), eye dorsoventral diameter (17.46 mm; p < 0.05), anteroposterior size (13.70 mm; p < 0.01) and corneal dorsoventral diameter (7.81 mm; p < 0.05) compared to those reared under restricted lighting.5. In conclusion, these values for Ross 308 broilers may be applied in poultry ophthalmology to detect early eye disease symptoms and to help the diagnosis of tear disorders that could cause economic losses and welfare issues. Intermittent lighting and green LED light may help reduce eye health problems thus contributing to improved welfare in broilers.

In vivo prediction of abdominal fat and breast muscle in broiler chicken using live body measurements based on machine learning

The purpose of this study was to predict the carcass characteristics of broilers using support vector regression (SVR) and artificial neural network (ANN) model methods. Data were obtained from 176 yellow feather broilers aged 100-day-old (90 males and 86 females). The input variables were live body measurements, including external measurements and B-ultrasound measurements. The predictors of the model were the weight of abdominal fat and breast muscle in male and female broilers, respectively. After descriptive statistics and correlation analysis, the datasets were randomly divided into train set and test set according to the ratio of 7:3 to establish the model. The results of this study demonstrated that it is feasible to use machine learning methods to predict carcass characteristics of broilers based on live body measurements. Compared with the ANN method, the SVR method achieved better prediction results, for predicting breast muscle (male: R² = 0.950; female: R² = 0.955) and abdominal fat (male: R² = 0.802; female: R² = 0.944) in the test set. Consequently, the SVR method can be considered to predict breast muscle and abdominal fat of broiler chickens, except for abdominal fat in male broilers. However, further revaluation of the SVR method is suggested.

Interactions between color and intensity of LED light on growth performance, serum biochemical profile, immune response variable, and nutrient apparent utilization in broiler chicken

This study investigated the effects of light-emitting diode (LED) color and intensity of broilers. One-day-old Cobb-500 broilers (n = 648) were fed nine groups with six replicates; three light colors (white, blue, & green) and intensities (for 1 to 7 days, viz., 20, 40, and 60 lx; for 8 to 42 days, viz., 5, 10, and 15 lx) were applied. Test lasted for 42 days. Results indicated that compared with blue light, 60-lx white light for 1 to 7 days increased the average daily gain (ADG) and average daily feed intake (ADFI) of broilers (p < 0.01). In the 10-lx light groups, the levels of interleukin-2 (IL-2) and the concentrations of albumin (ALB) (p < 0.05) increased. Moreover, the nutrient apparent utilization for ether extract (EE) under 10-lx green light was higher than that under 15-lx blue light (p < 0.01). The interaction effects of light intensity and light color had an extremely significant influence on the ADG for 1 to 7 days, IL-2 level, ALB content, and EE apparent utilization rate (p < 0.01) and had a significant influence on the ADFI and F/G for 1 to 7 days (p < 0.05). The production performance of broilers reared in three-layer cage could be improved by using 60-lx white LED light for 1 to 7 days and 5- to 10-lx green LED light or 10-lx white LED light for 8 to 42 days.

A specialized pore turret in the mammalian cation channel TRPV1 is responsible for distinct and species-specific heat activation thresholds

The transient receptor potential vanilloid 1 (TRPV1) channel is a heat-activated cation channel that plays a crucial role in ambient temperature detection and thermal homeostasis. Although several structural features of TRPV1 have been shown to be involved in heat-induced activation of the gating process, the physiological significance of only a few of these key elements has been evaluated in an evolutionary context. Here, using transient expression in HEK293 cells, electrophysiological recordings, and molecular modeling, we show that the pore turret contains both structural and functional determinants that set the heat activation thresholds of distinct TRPV1 orthologs in mammals whose body temperatures fluctuate widely. We found that TRPV1 from the bat Carollia brevicauda exhibits a lower threshold temperature of channel activation than does its human ortholog and three bat-specific amino acid substitutions located in the pore turret are sufficient to determine this threshold temperature. Furthermore, the structure of the TRPV1 pore turret appears to be of physiological and evolutionary significance for differentiating the heat-activated threshold among species-specific TRPV1 orthologs. These findings support a role for the TRPV1 pore turret in tuning the heat-activated threshold, and they suggest that its evolution was driven by adaption to specific physiological traits among mammals exposed to variable temperatures.

Interactive effects of light-sources, photoperiod, and strains on growth performance, carcass characteristics, and health indices of broilers grown to heavy weights1

Effects of light sources, photoperiods, and strains on growth performance, carcass characteristics, and health indices of broilers grown to heavy weights (>3 kg) were evaluated. The experimental design was a 4 × 2 × 2 factorial treatments consisting of 4 light sources [incandescent (ICD, standard), compact fluorescent light, neutral light emitting diode (Neutral-LED), and cool poultry specific LED (Cool-poultry specific (PS)-LED)], 2 photoperiods (regular/intermittent [2L:2D], and short [8L:16D]), and 2 strains (A, B). In each trial, chicks of 2 different strains from different commercial hatcheries were equally and randomly distributed into 16 environmentally controlled rooms at 1 D of age. Each room was randomly assigned one of 16 treatments from day 1 to 56 D of age. Feed and water were provided ad libitum. Birds were provided a 4 phase-feeding program (starter, grower, finisher, withdrawal). Birds and feed were weighed on 1, 14, 28, 42, and 56 D of age for growth performance. On day 56, a total of 20 (10 males and 10 females) birds from each room were processed to determine weights and yields. The BW, BW gain, live weight, and carcass weight of birds reared under PS-LED were higher (P < 0.05) in comparison with birds reared under ICD, but feed intake, feed conversion ratio, mortality, and carcass characteristics were not affected by treatments. Also, broilers subjected to the short/non-intermittent photoperiod had the lowest (P < 0.05) growth performance and carcass characteristics compared with values obtained for regular/intermittent photoperiods. In addition, strain was significant (P < 0.05) for most of the examined variables. Feed conversion, fat, tender, and yield were not affected by treatments. There was no effect of photoperiod, light sources, or their interactions on mortality. This study shows positive impacts on alternative light sources when compared to ICD along with regular/intermittent photoperiod in commercial poultry facilities rearing the 2 strains used in this study, thereby reducing energy costs and optimizing production efficiency without compromising the welfare of broilers grown to heavy weights.