The Behavioral and Productive Characteristics of Japanese Quails (Coturnix japonica) Exposed to Different Monochromatic Lighting.

The purpose of this study is to examine the impact of monochromatic illuminations at wavelengths of white (400-700 nm), green (560 nm), yellow (580 nm), blue (480 nm), and red (660 nm) on the performance and behavioral traits of Japanese quails throughout their fattening period. A total of 300 quails in five lighting experimental groups were housed in their conventional rearing cages. Weekly live weights of quails were measured individually, developmental stability was determined, and behavior and fear tests were performed. The body weight averages of quails exposed to blue, green, and yellow light were determined to be greater than those exposed to white and red light (p < 0.05). In terms of the mature weight parameter and the weight of the inflection point of the Gompertz growth model, the averages of the quails exposed to green and blue monochromatic lighting were higher (p < 0.05). The most negative findings on aggressive behavior were observed in birds exposed to monochromatic yellow and red light. Although the body weight of quails exposed to yellow monochromatic lighting was similar to that of quails exposed to green and blue monochromatic lighting, green and blue monochromatic lighting produced the best results in terms of growth, behavior, and developmental stability characteristics. Consequently, it is believed that consistently using green or blue monochromatic lighting programs when raising Japanese quails may provide economic advantages to the producers.

Effects of Species-Specific Auditory Stimulation on Broiler Embryos on Hatchability, Developmental Stability, Behavior, and Performance Characteristics.

The aim of this study is to expose broiler embryos to species-specific sounds from the 444th and 468th hours of incubation until the end of incubation and, thus, to determine the effects of these stimulations on their hatching characteristics, performance traits, developmental stability, and behavioral characteristics. Auditory stimulation sounds are a total of 5 min of recording consisting of sounds made by embryos during and after internal piping and response sounds made by the broody hen at that time. The auditory stimulation pattern was created as 5 min of recording and 5 min of silence for a total of 20 min of recording, and this sound pattern was played continuously with 65 dB sound intensity and 800 Hz sound frequency. A total of 750 Ross 308 broiler hatching eggs were equally divided into three groups (AS1: auditory stimulation from hour 444, AS2: sound stimulation from hour 468), and two stimulation groups and a control (silent) group were incubated in three homologous incubators. Due to auditory stimulation, the hatching window in embryos exposed to species-specific sounds beginning at the 444th hour of the incubation period was determined to be 28 h in this study. Auditory stimulation was late in the embryos exposed to species-specific sounds from the 468th hour of incubation, and the incubation windows in this group and the silent (control) group were determined to be 36 h and 40 h, respectively. The chicks that were exposed to early auditory stimulation during incubation exhibited a higher average Tona score (99.03) in comparison to the other groups (p < 0.05). Additionally, the number of chicks discarded was comparatively higher than the others (p < 0.05). Auditory stimulation during incubation had no effect on live weight, Gompertz growth curve parameters, feed conversion ratio, slaughter-carcass characteristics, behavioral traits, or developmental balance characteristics. Consequently, it was determined that the incubation window and the number of marketable chicks were both substantially impacted by the implementation of species-specific auditory stimulation. However, further research is required to ascertain the precise timing of this auditory stimulation.

Genetic Parameter Estimates of Growth Curve and Feed Efficiency Traits in Japanese Quail.

This study aimed to estimate heritabilities for weekly body weight traits, the Gompertz growth curve parameters, and feed efficiency characteristics, as well as genetic correlations among characteristics. A total of 700 Japanese quails with pedigree records were used in this study. Body weight and feed consumption were measured individually on a weekly basis. Using weekly body weight data, the growth model parameters were estimated for each bird using the Gompertz nonlinear regression model. Multi-trait variance-covariance matrices were obtained with Bayesian inference using the Gibbs sampler. While estimates of high heritability (0.59 to 0.61) were found for weekly body weight traits, estimates of moderate heritability (0.23 to 0.37) were determined for feed intake and feed conversion efficiency traits. The estimated heritabilities for the parameters of the Gompertz model and inflection point coordinates were moderate (0.37 to 0.47). While genetic correlations between feed intake and body weight characteristics were positive and moderate (0.28 to 0.49), the genetic correlations between feed conversion efficiency and body weight traits were positive and strong (0.52 to 0.83). It has been concluded that the moderate negative genetic relationship between feed conversion efficiency and body weight may constrain selection studies. Due to the weak genetic correlation between the asymptotic body weight parameter of the Gompertz model and the feed conversion efficiency, it is thought that the total genetic gain will be greater if the mature weight parameter is also used as a selection criterion in genetic improvement studies.

The effects of exposure to cold during incubation on developmental stability, fear, growth, and carcass traits in Japanese quails.

The aim of this study was to determine the effects of 6 h/day cold (35.0 °C) acclimatization between the 9th and 15th days of incubation of Japanese quail embryos on hatchability, livability, chick quality, developmental stability, fear response, live weight, and slaughter-carcass characteristics. Two homologous incubators and a total of 500 hatching eggs were used in the study. Randomly selected half of the eggs were exposed to cold according to the eggshell temperature. The cold acclimation of Japanese quail embryos had no adverse effects on all mentioned traits, except for chick quality. Chicks in the control group had higher Tona scores (99.46) than those exposed to cold (99.00) (P < 0.05). In addition, there were differences among the treatment groups in terms of the parameters of mature weight (ß0), instantaneous growth rate (ß2), and inflection point coordinates of the Gompertz growth model (P < 0.05 for all). It was found that exposing embryos to cold during the incubation changed the shape of the growth curve. As the development of embryos exposed to cold slows down, a compensatory growth occurs in the early posthatch period. Thus, the growth rate increased in the period before the inflection point of the growth curve.

Influences of Dietary Supplementation with Maca (Lepidium meyenii) on Performance, Parameters of Growth Curve and Carcass Characteristics in Japanese Quail.

Maca plant contains rich nutrients and in addition, it has various bioactive substances (N-benzyl-palmitamide, benzyl isothiocyanate, glucosinolates and phenolics). It is used to improve reproductive properties and has antioxidant effects for both humans and animals. The aim of this study was to determine the effects of adding maca plant powder to the ration at different levels on growth, slaughter carcass, partial egg production and some reproductive characteristics in Japanese quail (Coturnix coturnix japonica). The experimental groups were formed by adding 0% (control), 0.05% and 0.1% maca powder to the diet, and a total of 300 birds were used. Growth (weekly body weights, parameters of Gompertz growth function), feed efficiency and carcass characteristics of quails in the 42-day fattening trial were determined. Reproductive characteristics were measured up to 22 weeks of age. Addition of maca powder to the diet increased the feed consumption (p < 0.05) but did not affect body weights at 35 and 42 days of age, ß0 and ß1 parameters or point of inflection weight of the Gompertz model, carcass traits, partial egg production or fertility. It may be advisable to add 0.1% maca powder to the diets of breeders. Besides, maca powder reduced embryonic deaths and improved chick quality (both p < 0.05). It is thought that different results for reproductive traits can be obtained if maca powder is used for a longer period in the diets of breeder quail flocks.

Effects of monochromatic light stimuli during embryogenesis on some performance traits, behavior, and fear responses in Japanese quails.

Lighting is crucial in poultry rearing and the subjects with light intensity, source, and color having been addressed in numerous studies. Numerous studies with monochromatic light from light-emitting diode (LED) bulbs have been reported. In the current study, fertile Japanese quail eggs were exposed to a dark environment (Control) or monochromatic green (560 nm) and blue (480 nm) lighting throughout incubation. There were no significant differences in hatch weight, hatchability, total embryonic mortality, hatch time, growth performance, and slaughter-carcass traits in the study (P > 0.05). Furthermore, the lowest mean in terms of early embryonic mortalities (12.37%) was determined in the group treated with green LED lighting (P < 0.05), whereas it was discovered that the lowest mean in terms of late embryonic mortalities (13.59%) was in the group treated with blue LED lighting (P < 0.05). During the test time, the green LED group showed higher averages in terms of the number of peeps and first defecation time as response to environmental stimuli (P < 0.05). The highest mean for jumping (7.6 times) was detected in the group treated with blue LED lighting (P < 0.05). In conclusion, it was revealed that the blue and green LED lighting applied to the Japanese quail eggs in incubation had no effects on incubation traits, growth, and slaughter-carcass traits but had positive effects on some behavioral traits.

Effects of Multi-Trait Selection on Phenotypic and Genetic Changes in Japanese Quail (Coturnix coturnix japonica).

The present study in Japanese quail was aimed to develop multi-trait genetic selection program for a meat type sire line utilizing the mixed-model methodology. In total, 2000 pedigreed quail were formed the basis of the research where a multi-trait animal model was performed. A flock consisting of a total of 160 families (1 male: 3 female) was developed from the initial flock (base population of sire line), so as to obtain a selection flock sire line. Body weight at 5 weeks of age was chosen as a primary selection criterion in flock. The age at point of inflection derived from Gompertz growth curve, feed conversion ratio between 3 to 5 weeks of age, and carcass yield at 5 week of age were determined as selection criteria. Multi-trait BLUP methodology was carried out for genetic improvement of birds. In flock, 25 percent of males and females with highest breeding value were selected to produce next generation. Genetic parameter estimates, realized genetic parameters, selection responses, and genetic trends were obtained. Significant (P<0.01) selection responses for body weight, age at point of inflection, feed conversion ratio, and carcass yield traits on generations were observed. The results of the study revealed that the negative genetic relationships exhibited between some studied traits had overcame by modern poultry breeding methods such as selection via multi-trait BLUP.

Effects of slaughter age and mass selection on slaughter and carcass characteristics in 2 lines of Japanese quail.

The aim of this study was to evaluate the relationship between slaughter age and slaughter-carcass characteristics in 2 quail lines. With this aim, a Japanese quail flock subjected to mass selection to increase BW for 4 generations and a control flock that randomly mated for 4 generations were used. Birds of both lines were slaughtered at 4, 5, 6, 7, and 8 wk of age. Weights of carcass, breast, leg, wing, edible inner organs, and abdominal fat, and their percentages in BW were measured. Short-term mass selection for increased BW resulted in an increase for all slaughter and carcass traits, except edible inner organ percentage. Slaughter age had a significant effect on the studied traits, indicating that the BW and weight of carcass, carcass parts, abdominal fat, edible inner organs, and percentage of abdominal fat increased with increased slaughter age. Conversely, the carcass yield and percentages of carcass parts and edible inner organs were decreased with an increase in slaughter age. The present study showed that deterioration in carcass quality occurred with an increase in slaughter age. Furthermore, the differences between the carcass weights over the different ages ranged between 16.83 to 22.45% in favor of the selection line after a short-term mass selection.

Genetic parameter estimates of growth curve and reproduction traits in Japanese quail.

The goal of selection studies in broilers is to obtain genetically superior chicks in terms of major economic traits, which are mainly growth rate, meat yield, and feed conversion ratio. Multiple selection schedules for growth and reproduction are used in selection programs within commercial broiler dam lines. Modern genetic improvement methods have not been applied in experimental quail lines. The current research was conducted to estimate heritabilities and genetic correlations for growth and reproduction traits in a Japanese quail flock. The Gompertz equation was used to determine growth curve parameters. The Gibbs sampling under a multi-trait animal model was applied to estimate the heritabilities and genetic correlations for these traits. A total of 948 quail were used with complete pedigree information to estimate the genetic parameters. Heritability estimates of BW, absolute and relative growth rates at 5 wk of age (AGR and RGR), ß0 and ß2 parameters, and age at point of inflection (IPT) of Gompertz growth curve, total egg number (EN) from the day of first lay to 24 wk of age were moderate to high, with values ranging from 0.25 to 0.40. A low heritability (0.07) for fertility (FR) and a strong genetic correlation (0.83) between FR and EN were estimated in our study. Body weight exhibited negative genetic correlation with EN, FR, RGR, and IPT. This genetic antagonism among the mentioned traits may be overcome using modern poultry breeding methods such as selection using multi-trait best linear unbiased prediction and crossbreeding.

Japanese quail meat quality: characteristics, heritabilities, and genetic correlations with some slaughter traits.

The aim of this study was to evaluate the genetic parameters of several breast meat quality traits and their genetic relationships with some slaughter traits [BW, breast yield (BRY), and abdominal fat yield (AFY)]. In total, 1,093 pedigreed quail were slaughtered at 35 d of age to measure BRY, AFY, and breast meat quality traits [ultimate pH (pHU), Commission Internationale d'Eclairage color parameters (L*, lightness; a*, redness; and b*, yellowness), thawing and cooking loss (TL and CL, respectively), and Warner-Bratzler shear value (WB)]. The average pHU, L*, a*, and b* were determined to be 5.94, 43.09, 19.24, and 7.74, respectively. In addition, a very high WB average (7.75 kg) indicated the firmness of breast meat. High heritabilities were estimated for BW, BRY, and AFY (0.51, 0.49, and 0.35). Genetic correlations of BW between BRY and AFY were found to be high (0.32 and 0.58). On the other hand, the moderate negative relationship between BRY and AFY (-0.24) implies that selection for breast yield should not increase abdominal fat. The pHU was found to be the most heritable trait (0.64), whereas the other meat quality traits showed heritabilities in the range of 0.39 to 0.48. Contrary to chickens, the genetic correlation between pHU and L* was low. The pHU exhibited a negative and high correlation with BW and AFY, whereas L* showed a positive but smaller relationship with these traits. Moreover, pHU exhibited high negative correlations (-0.43 and -0.62) with TL and WB, whereas L* showed a moderate relationship (0.24) with CL. This genetic study confirmed that the multi-trait selection could be used to improve meat quality traits. Further, the ultimate pH of breast meat is a relevant selection criterion due to its strong relationships with either water-holding capacity and texture or low abdominal fatness.

Nonlinear mixed effects modeling of growth in Japanese quail.

The aim of this study was to examine the use of a nonlinear mixed modeling approach to growth studies of Japanese quail. Weekly BW measurements of 89 female and 89 male quail were used in the study. A well-known logistic growth function was used in the analysis. The function was expanded to include a sex effect and random bird effects in ß0 and ß2 parameters. Analyses were performed via SAS 9.2 software. The performance of 3 models, a fixed effects model (model 1) including only sex effect, a mixed effects model (model 2) including sex effect in ß0 and ß2 parameters and random bird effect in ß0, and a mixed effects model (model 3) including sex and random bird effects in ß0 and ß2 parameters, was compared. The minimized value of -2 times the log-likelihood, Akaike information criterion, corrected version of Akaike information criterion, and Schwarz information criterion values indicated a better fit of model 3 relative to other competitive models. Furthermore, the error variance reduction in model 2 and model 3 compared with model 1 was 60 and 65%, respectively, indicating the better fit of the mixed effect models. Significant differences between sexes were also determined in ß0 and ß2 parameters, in which the males, on average, had lower ß0 and higher ß2 parameters than females.

Investigation of nonlinear models to describe long-term egg production in Japanese quail.

In this study, long-term egg production was monitored in a Japanese quail flock, which had not undergone any genetic improvement, for 52 wk as of the age of sexual maturity. The study aimed to detect some traits with respect to egg production, to determine the cumulative hen-housed egg numbers, and to compare goodness of fit of different nonlinear models for the percentage of hen-day egg production. The mean age at first egg was 38.9 d and the age at 50% egg production was 45.3 d. The quail reached peak production at 15 wk of age (wk 9 of egg production period) when the percentage of hen-day egg production was found to be 94%. The cumulative hen-housed egg number for 52 wk as of the age of sexual maturity was 253.08. The monomolecular function, a nonsigmoid model, was used in the nonlinear regression analysis of the cumulative egg numbers. Parameters a, b, and c of the monomolecular model were estimated to be 461.70, 473.31, and 0.065, respectively. Gamma, McNally, Adams-Bell, and modified compartmental models, widely used in hens previously, were used in the nonlinear regression analysis of the percentages of hen-day egg production. The goodness of fit for these models was compared using the values of pseudo-R², Akaike's information criterion, and Bayesian information criterion. It was determined that all the models are adequate but that the Adams-Bell model displayed a slightly better fit for the percentage of hen-day egg production in Japanese quail than others.