Effects of different light-emitting diode light on hatch performance, embryo development, eye structure, and plasma melatonin in layer incubation

Light intensity, wavelength, and photoperiod have a combined effect on chicken incubation. This study was conducted to evaluate the effect of 12-h light, 12-h dark (12L:12D) photoperiod of white light (380-780 nm, WL), blue light (455/447.5-462.5 nm, BL), and green light (525/515-535 nm, GL) in chicken perceived light intensity during layer incubation on hatching performance, embryo development, eye structure, and melatonin concentration. Three batches of eggs from Jinghong No. 1 layer breeder were used in this experiment. Light stimulation had no effect on hatchability, and no consistent effect on embryo weight and newly hatched chick weight. However, the average hatching time of white light group and green light group was 7.3 h and 5.5 h later than that of the control group. Therefore, the holding period of chicks was significantly shortened (P = 0.001) in these 2 light groups. Light stimulation had a significant effect on the thickness of retinal layers (P < 0.05), retinal layers of white light group was thicker than that of the other 3 groups. Melatonin levels of chicks hatched in the green light and blue light were significantly higher than that of chicks hatched in the white light and darkness (P < 0.05). It indicated that the monochrome green and blue light promoted the expression of melatonin in chicken embryos. No significant diurnal rhythms were found at the level of plasma melatonin in 4 groups on d 21 using cosine analysis. It was concluded that green light has a positive effect on embryo development and melatonin secretion, while white light probably has positive effect on eye development. Furthermore, both green and white light stimulation resulted in late hatch for layer egg incubation. The obtained results are important in determining the light protocol for chicken incubation.

Effect of photoperiod during incubation on embryonic temperature, hatch traits and performance of two commercial broiler strains

Provision of light during incubation has shown the potential to enhance hatching traits and affect posthatch productivity, physiology, and behavior. In this study, 2 repeated trials were conducted to investigate the effect of photoperiod and strain on the embryo temperature, hatching traits and posthatch growth performance of 2 commercial strains of broilers (Ross 308 and Cobb 500). In each trial, hatching eggs were randomly distributed into 6 incubators with 3 photoperiod treatments: blue LED light for 12 h d^-1 (12L:12D) or 18 h d^-1 (18L:6D) during entire incubation were compared with no illumination condition (DARK). Data were analyzed as a 3 × 2 factorial arrangement with the trial as the blocking factor. Embryos incubated under 12L:12D and 18L:6D had lower air cell temperature (P < 0.05) than the DARK embryos from d 13 of incubation onward except on the day of candling. The response of air cell temperature to periodic illumination differed between 2 strains. Cobb embryos had lower air cell temperature in 12L:12D than those incubated with 18L:6D from d 16 of incubation onward, whereas lower air cell temperature was found in Ross embryos when illuminated with 18L:6D photoperiod compared to those under 12L:12D. The 12L:12D treatment was associated with improved (P < 0.05) navel closure condition of hatchlings. There were no differences in hatchability, embryo mortality, body weight, or length at hatch among photoperiod groups or its combination with strain. No differences in production parameters were found between DARK and illuminated groups. However, 12L:12D had heavier (P < 0.05) body weight on d 14 of age and higher (P < 0.05) body weight gain than 18L:6D from d 7 to 14 of age. The results of this study indicate that providing blue LED light up to 18 h d^-1 has no detrimental effect on production of broilers, however, 12L:12D light regime improved chick quality at hatch compared to DARK and resulted in heavier birds by d 14 compared to 18L:6D.

Pre-Incubation and Turning During Long Storage as a Method of Improving Hatchability and Chick Quality of Japanese Quail Eggs

In this study, we investigated the effect of modification of 12 d storage conditions of quail eggs from two flocks: at 17–20 weeks of life (A) and 36–39 weeks of life (B) on the incubation time, hatch window (HW), hatching results and chicks quality. The eggs were divided into experimental groups: COI = no pre-incubation (PI); SPIDES = were treated with 4 h PI, delivered at 4, 6, 8 and 10 d of storage; EG SPIDES = were treated with variable time of PI according to the scheme 5 d – 2 h, 7 d – 3 h, 9 d – 5 h and 11 d – 6 h. In addition, in each group, half of the eggs were turned (T) every 12 h, which is indicated as COI T, SPIDES T and EG SPIDES T. Pre-incubation was conducted at 37.8°C and 50–55% RH. It has been demonstrated that both storage profiles contribute to shortened incubation time, yet the HW is deteriorated if T is not applied. The benefits resulting from the EG SPIDES profile is an increase of 2.3 points in the “average score of all chicks” index compared to the COI group. In summary, the use of PI and T, and in particular the EG SPIDES profile with the concomitant use of T during long storage of quail eggs is recommended to obtain a considerable improvement of hatching results and chick quality.

Effect of heat treatment on pre-stocking of Turkey eggs and its impact on incubation and hatching

Egg stocking is used to meet housing demands in the hatchery industry. Stocking periods longer than 10 days of occur commonly, despite the fact that this practice causes productive losses during the incubation process. To minimize these losses, eggs are heated before incubation to stimulate the embryo, thereby reducing the range of birth intervals. The objective of this study was to determine whether heat treatment (37.5 °C) prior to incubation would improve hatching rates. We also determined the heat-exposure time necessary to improve productivity. We stored 5376 Nicholas pedigree eggs, aged between 40 and 51 weeks, for seven days. These eggs were distributed in three groups: groups 1 and 2 received 4 and 6 h of heat treatment, respectively; group 3 was used as control (no heat treatment, remaining at 17 °C). After heat treatment, the eggs were stored for 7 days at 17 °C, together with eggs from the control group. We found significant variation in the cumulative dispersion of birds born during the hatch window; greater numbers of birds were born in group 1 that underwent the 4-h heat treatment with a 24-h hatch window and in group 3 that underwent the 6-h heat treatment with a 12-h hatch window. Hatch rate, yolk retention and the relationship between average chick weight/average egg weight did not differ between treatments. These data suggest that heat treatment modulates the hatch window; nevertheless, the treatment did not influence the average weight the chicks, the number of chicks born, the percentage of hatching or yolk retention.

Hatch rate of laying hen strains provided a photoperiod during incubation

Implementing a photoperiod during incubation has been shown to be a potential next step to removing one more stressor for newly hatched poultry species. The distribution of hatch over time is a parameter that may be influenced by photoperiod that could benefit from a photoperiod but has not been studied at this time and is the objective of this paper. The impact on hatch rate for three strains of chicken, Barred Plymouth Rock (BR), Lohmann Brown (LB) and Lohmann Lite (LL), was measured following the provision of a 12L : 12D (12 h light : 12 h dark) photoperiod starting at 0, 9 or 17 days of incubation and compared with incubation in the dark. The cumulative number of chicks hatched eggs at four points in time (489, 498, 507 and 516 h of incubation) was analysed using repeated measures analysis in a 3 × 4 factorial arrangement of treatments. Repeated measures analysis was done to determine the main and interaction effects of photoperiod and bird strain, and a regression analysis was used to determine how these effects evolved over time. Lohmann Brown embryos provided a 12L : 12D photoperiod throughout incubation were first to reach 50% of total chicks hatched and rate of hatch from 50% to 75% of total chicks hatched as well. As the LB chicks did not begin to hatch earlier or finish later, the LB strain was the most synchronised when provided a 12L : 12D photoperiod from the beginning of incubation. Similar results were found for LL, but no difference on the percentage hatched over time was found when provided the 12L : 12D photoperiod at the beginning of incubation or at day 9. The BR strain only showed a significant difference in hatch window synchronisation when provided a 12L : 12D photoperiod at day 9 of incubation. These results indicate that the strain of chicken impacts the hatch window, and each strain responds to a photoperiod during incubation differently. This information could be useful for hatchery managers to deal with different strains of chicken for incubation.

Bioenvironmental Zonal Controlling of Incubated Avian Embryo Using Localised Infrared Heating

The main objective of any bioenvironmental controller is to create favourable bioenvironmental conditions around the living-system. In industrial incubation practice of chicken embryo, it is sometimes difficult to fill large incubators with uniform eggs, which leads to suboptimal results. The ideal incubation solution is a machine that is capable of coping with all sorts of variabilities in eggs. This can be realised in practice by creating different zones of different environmental conditions within the same machine. In the present study, a two-levels controller was designed and implemented to combine both convective and radiative heating to incubate eggs. On the higher level, three model-predictive-control (MPC) constrained controllers were developed to regulate the power applied to nine IR-radiators divided into three zones based on continuous feedback of the eggshell temperatures in each zone. On the lower level, a PID controller was used to maintain the air temperature within an experimental incubator at a fixed level (34 °C) lower than the standard incubation temperature. Four full incubation trials were carried out to test and implement the developed zonal controllers. The implementation results showed that the developed controllers were able to follow the reference trajectory defined for each zone. It was possible to keep the eggshell temperatures within the middle region (zone) different from the sidelong regions (zones) while the air temperature kept constant at 34 °C. The average hatching result (HOF) of the four full incubation trial was 84.0% (±0.5). The developed two-levels control system is a promising technique for demand-based climate controller and to optimizing energy use by using multi-objectives MPCs with constraint on total energy consumption.

Effect of embryonic thermal manipulation on heat shock protein 70 (HSP70) expression and subsequent immune response to post-hatch lipopolysaccharide challenge in Pekin ducklings

During the course of multi-stage incubation, small locational differences in incubation temperature within a machine are not uncommon and so the goal of this study was to study the immune response of ducklings exposed to thermal manipulation during incubation. Commercial Pekin duck eggs (n = 200) were distributed among four treatment: SS-Control (37.5°C from embryonic day [ED] 1 to 25); SS-LPS (37.5°C from ED1 to 25 + LPS at D0 [hatch]); HH-LPS (38°C from ED1 to 25+ LPS at D0); SH-LPS (37.5°C from ED1 to 10 and 38°C from ED 11 to 25 + LPS at D0). At D0, ducklings received a lipopolysaccharide (LPS) injection. At D1 and D5, the HH-LPS treatment significantly reduced body weight (P ≤ 0.05). At D1 and D3 post-LPS injection, the SH-LPS and HH-LPS treatments significantly reduced splenic and bursal heat shock protein 70 (HSP70), mRNA abundance, and macrophage nitric oxide production compared with the SS-LPS treatment (P ≤ 0.05). At D1, the HH-LPS and SH-LPS treatments had increased splenic IL-10 mRNA and lower MHC I mRNA compared with the SS-LPS treatment (P ≤ 0.05). At D1, the HH-LPS treatment increased splenic IL-6 mRNA and bursal IFNγ mRNA transcription while the SH-LPS treatment reduced splenic IL-6 mRNA compared with the SS-LPS treatment (P ≤ 0.05). The HH-LPS treatment reduced thymocyte proliferation efficiency, while at D1, D3, and D5, the SH-LPS treatment increased thymocyte proliferation efficiency compared with the SS-LPS treatment (P ≤ 0.05). Ducklings in the HH-LPS treatment had a higher splenic CD8+/CD4+ ratio compared to the SS-LPS treatment at D3 post-LPS injection (P ≤ 0.05). In summary, the HH-LPS treatment compromised immunocompetence via decreased NO production and thymocyte proliferation efficiency, while the SH-LPS treatment increased body weight and thymocyte proliferation and reduced IL-6 mRNA abundance. This suggests that an embryonic temperature stress during the latter half of incubation may prime the immune system which may be beneficial during secondary post-hatch inflammatory challenges.

Effect of Newcastle disease virus level of infection on embryonic length, embryonic death, and protein profile changes

Background and Aim

Newcastle disease virus (NDV) is an obligate intracellular parasite. Virus can only live on living cells. The embryonated chicken eggs (ECEs) are one of the growth media of virus that is a cheap, easy to do, and accurate for showing patterns of virus change in the host. Higher virus titers indicate the higher number of viruses and more virulent to infect host. This research aimed to investigate the effect of different level of NDV titer infection in ECEs on protein profile, embryonic length, mortality, and pathological change.

Materials and Methods

The study used a completely randomized design of six treatments and seven replications. The treatments were different level of NDV titer infection in allantoic fluid (AF) of 9-11 days ECEs, i.e., P1=2⁰, P2=2⁶, P3=2⁷, P4=2⁸, P5=2⁹, and P6=2¹⁰ hemagglutination unit (HAU). All samples were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Data were analyzed using one-way ANOVA with p=0.05 for length of the embryo and descriptive analysis for embryo mortality, pathology change, and protein band.

Results

The result showed that protein profile of NDV-infected ECEs of all different levels is more complex than protein profile of no NDV-infected ECEs. NDV infected of all different levels showed longer size embryo, higher mortality embryo at the first 2 days, and higher occurrence of hemorrhagic in all part of bodies of embryo than those of no NDV infected.

Conclusion

It was concluded that NDV infection of all different level decreased health conditions of chicken embryo of ECEs of 9-11 days old. Different level of NDV infection of ECEs of 9-11 days old showed no significantly different embryo profiles. However, all of the NDV-infected embryos were shorter, death on the 2nd day, and suffered more hemorrhage on all body surfaces than uninfected NDV embryos.

Physiological response of broiler embryos to different incubator temperature profiles and maternal flock age during incubation. 1. Embryonic metabolism and day-old chick quality

Broiler strain, maternal age, and incubation temperature influence embryo metabolism. Hatching eggs were obtained from young (Y; 28 to 34 wk, $\bar{\rm x}$ = 31.2 wk), mid (M; 36 to 45 wk, $\bar{\rm x}$ = 40.5 wk) and old (O; 49 to 54 wk, $\bar{\rm x}$ = 51.4 wk) Ross 708 (n = 88; Experiment 1) and Ross 308 [(n = 45; Experiment 2: (Y; 25 to 34 wk, $\bar{\rm x}$ = 30.5 wk), (M; 35 to 44 wk, $\bar{\rm x}$ = 40.2 wk), and (O; 49 to 54 wk, $\bar{\rm x}$ = 51.6 wk)] breeders. Eggs were stored for 2 to 4 d (18°C, 73% RH), and incubated for 14 d at 37.5°C and 56% RH. At 15 d (E15), 8 fertile eggs per flock age were incubated in individual metabolic chambers at 36.0, 36.5, 37.0, or 37.5°C until E21.5. Each temperature was repeated one additional time. O2 consumption and CO2 production were used to calculate embryonic heat production (EHP). Embryo temperature was measured as eggshell temperature (EST). Initial egg weight was used as a covariate; significance was assessed at P < 0.05. In Ross 708, daily EHP tended to be higher in M and O than Y treatments at E16; EHP of M was higher than Y and O eggs at E18; M and O were higher than O eggs at E19. Incubation at 37.0°C resulted in the highest EHP from E15 to E21, except at E17. Embryos at 37.5°C had reduced EHP beyond E17. Daily EST from E15 to E21 was higher at 37.5 and 37.0°C than at 36.0 and 36.5°C. In Ross 308, daily EST was highest at 37.5°C except at E20. Incubation temperature and EST were highly correlated (R2 = 0.90 to 0.89; P < 0.001). Ross 708 chicks were longer and hatched earlier at 37.0°C than at 36.0 and 37.5°C. EST and EHP increased with incubation temperature in Ross 708. In Ross 308, maternal flock age and incubation temperature did not impact EHP. However, EST was highest at 37.5°C except at E20. Ross 708 was more sensitive to incubation temperature than Ross 308.

Effect of a photoperiodic green light programme during incubation on embryo development and hatch process

This study was conducted to evaluate the effect of a 12-h light, 12-h dark (12L : 12D) photoperiod of green light during day 1 to day 18 of incubation time, on embryo growth, hormone concentration and the hatch process. In the test group, monochromatic light was provided by a total of 204 green light-emitting diodes (522 nm) mounted in a frame which was placed above the top tray of eggs to give even spread of illumination. No light-dark cycle was used in the control group. Four batches of eggs (n=300/group per batch) from fertile Ross 308 broiler breeders were used in this experiment. The beak length and crown-rump length of embryos incubated under green light were significantly longer than that of control embryos at day 10 and day 12, respectively (P<0.01). Furthermore, green light-exposed embryos had a longer third toe length compared with control embryos at day 10, day 14 and day 17 (P=0.02). At group level (n=4 batches), light stimulation had no effect on chick weight and quality at take-off, the initiation of hatch and hatch window. However, the individual hatching time of the light exposure focal chicks (n=33) was 3.4 h earlier (P=0.49) than the control focal chicks (n=36) probably due to the change in melatonin rhythm of the light group. The results of this study indicate that green light accelerates embryo development and alters hatch-related hormones (thyroid and corticosterone), which may result in earlier hatching.

Physiological status of broiler chicks at pulling time and the relationship to duration of holding period

Newly hatched chicks may be held longer than 48 h and experience long periods of fasting in commercial hatcheries. Limited information is known about the physiological status of chicks in such situations, due to the difficulty of precisely recording time of hatch. This study investigated the effect of the time from hatch to pulling (holding period) on physiological measures/parameters in 109 broiler chicks. Fertile Ross 308 eggs were incubated in a custom built small-scale incubator. The individual hatching time of each focal chick was determined using eggshell temperature monitoring. At 'pulling' (512 h of incubation time), the quality of focal chicks was assessed using the chick scoring method and physiological parameters were measured including BW, organ (heart, liver and stomach) weights, blood values and plasma corticosterone level. The time from hatch to pulling varied from 7.58 to 44.97 h. Egg weight at setting was significantly correlated with chick BW and weight of organs at pulling, but had no effect on chick quality, blood values and plasma corticosterone. Relative BW at pulling was negatively associated with the duration of holding period (P=0.002). However, there was a positive correlation between relative stomach weight and the duration of the holding period (P<0.001). As the holding period duration increased, there was a trend that blood partial pressure of oxygen, haematocrit and haemoglobin also increased, and blood partial pressure of carbon dioxide, total carbon dioxide and bicarbonate decreased (P<0.05). A wide range of plasma corticosterone was observed from chicks that had experienced different durations of holding period. We conclude that shortening the hatch window and minimising the number of chicks that experience a long holding period before pulling may improve chick quality and physiological status, which may be due to unfavourable environmental conditions that include feed and water deprivation.

An insight into the heat and mass transfer mechanisms of eggshells hatching broiler chicks and its effects to the hatcher environment

Thermodynamic study of incubated eggs is an important component in the optimisation of incubation processes. However, research on the interaction of heat and moisture transfer mechanisms in eggs is rather limited and does not focus on the hatching stage of incubation. During hatch, both the recently hatched chick and the broken eggshell add extra heat and moisture contents to the hatcher environment. In this study, we have proposed a novel way to estimate thermodynamically the amount of water evaporated from a broken eggshell during hatch. The hypothesis of this study considers that previously reported drops in eggshell temperature during hatching of chicks is the result remaining water content evaporating from the eggshell, released on the inner membrane by the recently hatched wet chick, just before hatch. To reproduce this process, water was sprayed on eggshells to mimic the water-fluid from the wet body of a chick. For each sample of eggshell, the shell geometry and weight, surface area and eggshell temperature were measured. Water evaporation losses and convection coefficient were calculated using a novel model approach considering the simultaneous heat and mass transfer profiles in an eggshell. The calculated average convective coefficient was 23.9 ± 7.5 W/m(2) °C, similar to previously reported coefficients in literature as a function of 0.5-1m/s air speed range. Comparison between measured and calculated values for the water evaporation showed 68% probability accuracy, associated to the use of an experimentally derived single heat transfer coefficient. The results support our proposed modelling approach of heat and mass transfer mechanisms. Furthermore, by estimating the amount of evaporated water in an eggshell post-hatch, air humidity levels inside the hatcher can be optimised to ensure wet chicks dry properly while not dehydrating early hatching chicks.