Egg Production In Japanese Quail Research Articles

Arginine requirement for egg production in Japanese quail

The objective of this study was to determine the ideal arginine intake for egg production in Japanese quail using the dilution technique. A completely random design was used, with 8 treatments (seven concentrations of arginine plus a control diet) and ten replicates, totaling 80 Japanese quails. The digestible arginine levels included in the study were 0.361%, 0.603%, 0.843%, 1.084%, 1.204%, 1.311%, and 1.460%. The variables analyzed were feed intake, egg production (EP), egg weight, egg output (EO), feed conversion ratio, and body weight were performed using a mixed model. When the effect of arginine levels (P ≤ 0.05) was detected, the model's broken line linear-plateau (BL), quadratic-plateau (BLq), and the first intercept of the BLq in the plateau of BL were adjusted to determine the ideal arginine intake. It observed that the arginine levels modified the quail responses (P < 0.001). Egg production was 10% with the 0.361% arginine in diet and recovered (97%) with the 1.311% arginine diet. The BL and BLq models estimated 232 mg/quail per day and 351 mg/quail per day for EO, respectively. The first intercept obtained was 290 mg/quail per day or 1,411%, which was considered the optimum level arginine intake for EO in Japanese quail.

Growth response, carcass characteristics and egg laying performance of Japanese quail (Coturnix coturnix japonica ) fed diets containing varying levels of fermented cassava (Manihot esculenta ) peel meal

A two phased experimental study was conducted on 300, two-weeks-old Japanese quails to determine the effect of feeding diets containing varying levels of fermented cassava (Manihot esculenta ) peel meal on the growth performance, carcass characteristics and egg production of Japanese quail ( ). Japanese quails with mean initial body weight of 26.67 g and of mixed sexes were used. Fermented cassava peel meal (FCPM) was prepared by soaking fresh cassava peels in water (that is twice its weight) for three days. Thereafter, the peels were put in a jute bag and kept for 12 hours under a hydraulic press; sundried for a few days and milled using an attrition mill. During the growing phase, the birds were randomly allotted to four dietary treatments with 75 birds per treatment, each replicated three times, with the diets containing FCPM replacing 0, 25, 50 and 75 % maize to form diets T , T , T and T respectively. The diets were isonitrogenous, containing 24 % crude protein, and fed to the experimental birds for six weeks. Data were collected on feed intake, growth performance and carcass characteristics. The laying phase involved 120 female quails from he growing phase that were sexed to retain only the females. They were then allotted to four dietary treatments of three replicates per treatment; with 10 birds per replicate. The birds were fed the experimental diets containing FCPM replacing 0, 25, 50 and 75 % maize for eight weeks, and data were collected on egg production and egg quality parameters. Results show significant (p&lt;0.05) differences in daily feed intake and nutrient digestibility among the treatments, while daily weight gain and feed conversion ratio (FCR) were not significantly (p&gt;0.05) different, during the growing phase. For the laying phase, there were no significant (p&gt;0.05) differences in daily feed intake, hen day production (HDP) and all the egg quality traits determined. Therefore, it can be concluded that dietary maize could be replaced with FCPM up to 50 % and 75 % in growing quails without any deleterious effects on growth performance and carcass characteristics respectively; whereas it can replace up to 75 % in the diet of laying Japanese quails without any adverse effect on egg production and egg quality traits.

Effect of papaya leaves (Carica Papaya) suspension on Japanese quail (coturnix Japonica)

Introduction: The experiment was aimed to investigate (i) the comparative efficacy of papaya leaves suspension (PLS) and doxycycline on bacterial load and blood constituents on E. coli inoculated Japanese quail, (ii) the effect of PLS on live body weight, egg production and egg quality (Egg weight, egg shape index, shell plus membrane weight, shell plus membrane thickness, haugh unit, albumen index and yolk index) of Japanese quail. Materials and Methods: 120 female Japanese quails ten days old were randomly assigned into four groups with three replications and grouped as control group (T0), E. coli treated group (T1), E. coli plus PLS (0.25%) treated group (T2) and E. coli plus doxacil-vet powder (1g/2lit) treated group (T3) for the aim (i). Ten days old 60 female Japanese quails were randomly assigned into two groups named T0 (control diet) and T1 (0.25% PLS) with three replications to fulfill the aim (ii). Result: (i) microbial load significantly (P2 & T3 group where significantly (P0 and T1 group. TEC, Hb, PCV & ESR in different treatment groups were almost similar and the differences were statistically non-significant (P>0.05) except TLC which was statistically significant (P2 group. (ii) The body weight of T0 and T1 at 65th day were 164.95 and 182.32 g respectively which was statistically significant (P0 and T1 group respectively which statistically significant (P0.05). Conclusion: It may concluded that papaya leaf (Carica papaya) suspension have antimicrobial effect and effect on blood constituents, growth performance and egg production of Japanese quail. Keywords: Coturnix japonica, Carica papaya, E. coli, Hematology, Body weight and egg production.

Revisiting the Avian Eco-SSL for Lead: Recommendations for Revision.

The avian ecological soil screening level (Eco-SSL) for Pb (11 mg/kg) is within soil background concentrations for >90% of the United States. Consequently, its utility as a soil screening level is limited. Site-specific ecological risk-based remedial goals for Pb are frequently many times greater. Toxicity reference values (TRVs) play a major role in defining Eco-SSLs. The Pb Eco-SSL TRV is driven by reduced egg production in Japanese quail (Coturnix japonica), which displays effects at doses both substantially lower and greater than other tested species. High variability in egg production in Japanese quail has also been observed for other contaminants. Japanese quail egg production may therefore be too variable and unreliable an effect endpoint upon which to base regulatory screening criteria. Toxicity data supporting the Eco-SSL were reevaluated and only studies reporting both no and lowest observed adverse effect levels (NOAELs and LOAELs) for reproduction, growth, or survival were considered. Dose-response data were extracted from 10 studies both as concentrations and doses. Dose-response relationships were developed using the US Environmental Protection Agency (USEPA) Benchmark Dose Software for dietary concentrations and doses for egg production in Japanese quail and chickens. Effect levels (of 10%, 20%, and 50%) were extracted from the dose-response analyses. Species sensitivity distributions and dose-response data indicated reproduction was most sensitive to Pb and survival was least sensitive, with growth intermediate. Limited data for ringed turtle doves (Streptopelia risoria) and American kestrels (Falco sparverius) suggest lower sensitivity than chickens to Pb. The ED10 and ED20 thresholds for chickens were 4.4 and 9.8 mg·kg-1 ·d-1 , respectively. Avian Pb Eco-SSLs were recalculated based on the chicken ED10 and ED20, with and without a bioavailability adjustment. Revised avian Pb Eco-SSLs for the most highly exposed species (American woodcock), based on the ED10 and assuming 100% and 50% bioavailability, were 36.3 mg/kg and 43.7 mg/kg, respectively. Integr Environ Assess Manag 2019;15:739-749. © 2019 SETAC.

An Effect of Dietary Supplementation of Chlorella Vulgaris (Green Microalgae) on Egg Production of Japanese Quail

An Effect of Dietary Supplementation of Chlorella Vulgaris (Green Microalgae) on Egg Production of Japanese Quail

Genetic analyses of partial egg production in Japanese quail using multi-trait random regression models

ABSTRACT1. The aim of the present study was to estimate genetic parameters for average egg weight (EW) and egg number (EN) at different ages in Japanese quail using multi-trait random regression (MTRR) models.2. A total of 8534 records from 900 quail, hatched between 2014 and 2015, were used in the study. Average weekly egg weights and egg numbers were measured from second until sixth week of egg production.3. Nine random regression models were compared to identify the best order of the Legendre polynomials (LP). The most optimal model was identified by the Bayesian Information Criterion. A model with second order of LP for fixed effects, second order of LP for additive genetic effects and third order of LP for permanent environmental effects (MTRR23) was found to be the best.4. According to the MTRR23 model, direct heritability for EW increased from 0.26 in the second week to 0.53 in the sixth week of egg production, whereas the ratio of permanent environment to phenotypic variance decreased from 0.48 to 0.1. Direct heritability for EN was low, whereas the ratio of permanent environment to phenotypic variance decreased from 0.57 to 0.15 during the production period.5. For each trait, estimated genetic correlations among weeks of egg production were high (from 0.85 to 0.98). Genetic correlations between EW and EN were low and negative for the first two weeks, but they were low and positive for the rest of the egg production period.6. In conclusion, random regression models can be used effectively for analysing egg production traits in Japanese quail. Response to selection for increased egg weight would be higher at older ages because of its higher heritability and such a breeding program would have no negative genetic impact on egg production.

Genetic analysis of partial egg production records in Japanese quail using random regression models

The main objectives of this study were to detect the most appropriate random regression model (RRM) to fit the data of monthly egg production in 2 lines (selected and control) of Japanese quail and to test the consistency of different criteria of model choice. Data from 1,200 female Japanese quails for the first 5 months of egg production from 4 consecutive generations of an egg line selected for egg production in the first month (EP1) was analyzed. Eight RRMs with different orders of Legendre polynomials were compared to determine the proper model for analysis. All criteria of model choice suggested that the adequate model included the second-order Legendre polynomials for fixed effects, and the third-order for additive genetic effects and permanent environmental effects. Predictive ability of the best model was the highest among all models (ρ = 0.987). According to the best model fitted to the data, estimates of heritability were relatively low to moderate (0.10 to 0.17) showed a descending pattern from the first to the fifth month of production. A similar pattern was observed for permanent environmental effects with greater estimates in the first (0.36) and second (0.23) months of production than heritability estimates. Genetic correlations between separate production periods were higher (0.18 to 0.93) than their phenotypic counterparts (0.15 to 0.87). The superiority of the selected line over the control was observed through significant (P < 0.05) linear contrast estimates. Significant (P < 0.05) estimates of covariate effect (age at sexual maturity) showed a decreased pattern with greater impact on egg production in earlier ages (first and second months) than later ones. A methodology based on random regression animal models can be recommended for genetic evaluation of egg production in Japanese quail.

An evaluation of inorganic toxicity reference values for use in assessing hazards to American robins (Turdus migratorius).

When performing screening-level and baseline risk assessments, assessors usually compare estimated exposures of wildlife receptor species with toxicity reference values (TRVs). We modeled the exposure of American robins (Turdus migratorius) to 10 elements (As, Cd, Cr, Cu, Hg, Mn, Pb, Se, Zn, and V) in spring and early summer, a time when earthworms are the preferred prey. We calculated soil benchmarks associated with possible toxic effects to these robins from 6 sets of published TRVs. Several of the resulting soil screening-level benchmarks were inconsistent with each other and less than soil background concentrations. Accordingly, we examined the derivations of the TRVs as a possible source of error. In the case of V, a particularly toxic chemical compound (ammonium vanadate) containing V, not normally present in soil, had been used to estimate a TRV. In the cases of Zn and Cu, use of uncertainty values of 10 in estimating TRVs led to implausibly low soil screening values. In the case of Pb, a TRV was calculated from studies demonstrating reductions in egg production in Japanese quail (Coturnix coturnix japonica) exposed to Pb concentrations well below than those causing toxic effects in other species of birds. The results on quail, which were replicated in additional trials, are probably not applicable to other, unrelated species, although we acknowledge that only a small fraction of all species of birds has been tested. These examples underscore the importance of understanding the derivation and relevance of TRVs before selecting them for use in screening or in ecological risk assessment. Integr Environ Assess Manag 2017;13:352-359. © 2016 SETAC.

Increased Egg Production of Japanese Quail (Cortunix japonica) by Improving Liver Function Through Turmeric Powder Supplementation

Increased Egg Production of Japanese Quail (Cortunix japonica) by Improving Liver Function Through Turmeric Powder Supplementation

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.

The effects of vitamin C and E supplementation on heat shock protein 70 response of ovary and brain in heat-stressed quail

1. The effects of vitamin C (L-ascorbic acid) and vitamin E (α-tocopherol acetate) supplementation on egg production and heat shock protein 70 (Hsp70) response of ovary and brain in the Japanese quail (Coturnix coturnix japonica) exposed to high ambient temperature were evaluated. 2. The birds (n = 540; 55 d old) were randomly assigned to 18 groups consisting of 3 replicates of 10 birds each in a 2 × 3 × 3 factorial arrangement of treatments. Birds were kept in wire cages in a temperature-controlled room at either 22°C (thermo-neutral, TN) or 34°C (heat stress, HS) for 8 h/d (09:00 to 17:00 h; until the end of the study) and fed on a basal diet or the basal diet supplemented with either three levels of vitamin C (0, 250 and 500 mg of L-ascorbic acid/kg of diet) or three levels of vitamin E (0, 250 and 500 mg of dl-α-tocopheryl acetate/kg of diet). 3. Feed intake and egg production were not affected by vitamin C and E supplementation under thermo-neutral conditions. However, feed intake and egg production were increased with the vitamin C or E supplementation either singly or in combination in heat-stressed quail. When vitamin was added, feed intake and egg production of quails under TN were different from those raised under HS. However, in the absence of supplemental vitamins, feed intake and egg production at TN and HS were no different. 4. Heat exposure increased serum corticosterone levels and Hsp70 expression. Serum corticosterone level was significantly decreased by vitamin C or E supplementation in HS groups for quail. Ovary and brain Hsp70 expression linearly decreased as dietary vitamin C or vitamin E supplementation increased in heat-stressed groups. However, Hsp70 expression of ovary and brain was not affected by vitamin C or E supplementation under thermo-neutral conditions. 5. The present study showed that a combination of dietary vitamin C (500 mg) and E supplementation (500 mg) may alleviate some heat stress effects of heat shock proteins of ovary and brain and egg production of Japanese quail.

The effect of long-term feeding of conjugated linoleic acid on fertility in Japanese quail

The objective of this study was to determine the effects of the long-term feeding of conjugated linoleic acid (CLA) on laying hen performance, egg fertility and hatchability of fertile eggs of Japanese quail (Coturnix coturnix japonica). One hundred and sixty 7-day old Japanese quail chicks were randomly assigned to four groups (40 birds per group) and fed for five weeks on a commercial diet supplemented with either 0.5% hazelnut (Group A), 0.5% sunflower oil (Group B), 0.25% CLA (Group C) or 0.5% CLA (Group D). The birds received water and feed ad libitum during the study. At the end of the five weeks the birds were sexed, and 21 females and seven males from each group were selected. For a further six weeks these selected birds were fed a layer diet supplemented with their respective sources of oil. Eggs were collected daily and incubated weekly. The fertility rate was determined by visual inspection at the end of the incubation period. Dietary CLA at the inclusion level of 0.5%, but not at 0.25%, caused a significant decrease in percentage hatchability of the fertile eggs compared to Groups A and B. Hatchability of fertile eggs from Groups A, B, C and D was 74, 80, 72 and 70, respectively. Fertility rates between Groups A, B, C and D did not differ significantly, and were 64.4, 56.4, 66.0 and 62.8%, respectively. Hen-day egg production of Groups A, C and D were similar, but in weeks 3, 4, 5 and 6, hens in Group B had a significantly lower hen-day egg production (%) compared to Group A. Also, in weeks 3, 4, 5 and 6, egg size in Group B was significantly lower than that in the other groups. From this study it is concluded that dietary CLA at inclusion levels of 0.25% or 0.5% did not influence egg fertility, egg weight and egg production in Japanese quail. South African Journal of Animal Science Vol. 36(2) 2006: 99-104

Role of nitric oxide in ovarian follicular development and egg production in Japanese quail ( Coturnix coturnix japonica)

Role of nitric oxide (NO) in regulating the reproductive functions at hypothalamo-hypophysealovarian axis in Japanese quail was studied. In first experiment, metabolites of NO, i.e. nitrite and nitrate (NO 2 and NO 3) were estimated together in hypothalamus, serum and ovarian follicles of good and poor layers. In the second experiment, different NO modulators such as l-arginine ( l-Arg), sodium nitroprusside (SNP) and N G-nitro- l-arginine methyl ester, HCl ( l-NAME) were administered to the birds. In the first experiment, significantly higher ( P < 0.01) NO 2 and NO 3 levels in serum, hypothalamus and largest ( F 1) ovarian follicles were observed in good layers as compared to poor layers. Higher ( P < 0.05) NO 2 and NO 3 concentration was observed in F 1 follicles than smaller follicles ( F 2) only in good layers. The NO 2 and NO 3 concentration was significantly reduced ( P < 0.05) in post ovulatory follicles (POFs) in comparison to F 1 and F 2 follicles. In the second experiment, the serum NO 2 and NO 3 concentrations were higher ( P < 0.05) in the SNP, lower ( P < 0.05) in the l-NAME group and unchanged in the l-Arg treated group in comparison to control group. Compared to control, l-Arg and SNP increased ( P < 0.05) the hypothalamic NO 2 and NO 3 concentration where as l-NAME reduced ( P < 0.05) these levels. The NO 2 and NO 3 concentration was increased ( P < 0.05) as the follicle size increased and it was significantly reduced ( P < 0.05) in POFs. The higher ( P < 0.05) follicular NO 2 and NO 3 concentration was observed in l-Arg group in comparison to control group. Egg production was also found to be higher ( P < 0.05) in l-Arg group whereas it was not different ( P > 0.05) in SNP and l-NAME treated groups. The yolk weight and yolk to albumin ratio was reduced ( P < 0.05) in l-NAME group in comparison to control group. It may be concluded from the present study that NO plays a key role in regulating follicular development, ovulatory mechanisms and egg production in Japanese quail.

Effect of chronic progesterone injection on egg production in Japanese quail

Young laying turkey hens ceased laying and developed a polycystic ovarian follicle (PCOF) syndrome 3 wk after injections of progesterone (P4) ceased. It was hypothesized that laying Japanese quail chronically injected with progesterone (P4) would respond with reduced or arrested egg production and altered ovarian morphology similar to that seen in turkeys expressing the PCOF syndrome, and could thus serve as a model to study the PCOF syndrome. To test these hypotheses, 6 trials were conducted with young photosensitive Japanese quail photostimulated to induce sexual maturity with either 24L:0D or 14L:10D at 6 or 8 wk of age, and used after 3 to 5 wk of egg production. The quail were injected once daily at dosages of 0, 0.17, 0.33, 0.5, 1.5, 3.0, or 4.5 mg of P4/kg per d, or twice daily at dosages of 0 and 1.5 mg of P4/kg for 8 to 14 d and were then necropsied 1 d after the last injection or after waiting an additional 8 to 14 d. During the injection period, egg production was not different among P4 dosages <1.5 mg of P4/kg per d, but decreased at dosages of 1.5 mg of P4/kg per d or greater. A decrease in egg production was found with twice daily injections of 1.5 mg of P4/kg. The decrease in egg production rate ceased and egg production resumed 5 to 7 d after the last injections of 3.0 and 4.5 mg of P4/kg per d or twice-daily injections of 1.5 mg of P4/kg. Compared with control hens, a high percentage of hens (from 12 to 75%) held a hard-shelled egg in the uterus during single daily injections at dosages of 3.0 and 4.5 mg of P4/kg per d and twice daily injections of 1.5 mg of P4/kg. Ovary and oviductal weights, and number of hierarchical follicles were not changed after chronic P4 injection, but more atretic follicles were found in hens at the end of 8 to 12 d of P4 injection. In conclusion, a decreasing egg production rate was induced by chronic P4 injection, but the decrease ceased and egg production resumed 5 to 7 d after the last injections in laying Japanese quail. Young quail hens, unlike young turkey hens, did not develop a PCOF-like syndrome after P4 injection.

T-maze behavior and early egg production in Japanese quail selected for contrasting adrenocortical responsiveness

Broiler chicks that traverse a T-maze quickly to reinstate contact with their companions (HP, high performance) are known to grow faster, be more social, and exhibit a reduced plasma corticosterone (B) response to acute stress than slower (LP, low performance) chicks. Genetic lines of Japanese quail selected for reduced (LS, low stress) or exaggerated (HS, high stress) plasma B response to brief restraint also differ in sociality and performance. In the present study, we asked if divergence in early T-maze behavior was associated with differential attainment of puberty and early egg production in these lines. At 3 d of age, LS and HS quail were categorized as HP or LP birds based on running times in a T-maze. Thus, there were four treatment combinations: HP-LS, HP-HS, LP-LS, and LP-HS birds. Daily egg records were kept for 8 wk. The average ages at first egg lay (FIRST), at 25% egg production (A25% EP), and weekly and cumulative hen-day egg production (HDEP) where calculated. Daily egg weight (EWT) data were also collected, and BW measures were made at the end of the trial. Mean FIRST and A25% EP responses were lower (P < 0.02) and cumulative HDEP was greater (P < 0.04) in HP than in LP quail. Despite considerable numerical reductions in FIRST and A25% EP, as well as 5% elevation in cumulative HDEP in LS quail, line differences in these variables were not significant. On the other hand, FIRST and A25% EP were reduced (P < 0.05) in HP-LS quail when compared to LP-HS ones, whereas HP-HS and LP-LS quail showed intermediate and similar responses that did not differ from the other two treatment groups. Mean cumulative HDEP findings for the interactive effect of performance category with line mimicked these puberty findings. EWT and BW measures were not affected by any of the treatments or their interactions. Our results suggest that rapid negotiation of the T-maze by quail chicks is associated with accelerated puberty and increased HDEP in quail of two genetically diverse lines. This effect is particularly evident in quail selected for reduced adrenocortical responsiveness, suggesting possible additive effects.

Retinoic acid accelerates the development of reproductive organs and egg production in Japanese quail (Coturnix coturnix japonica).

The effects of retinoic acid on the development of reproductive organs and egg production in female Japanese quail (Coturnix coturnix japonica) were investigated. Female quail were fed a diet containing retinoic acid at 4 mg/kg (RA) or two diets containing retinyl acetate at 5000 IU/kg (VA1) or 14 000 IU/kg (VA2) after being fed a vitamin A-free diet for 2 wk (experiment 1). The oviduct and ovary grew more rapidly (P < 0.05) in RA-treated quail than in VA-treated quail at 5 wk of age. In addition, the body weight of RA-fed quail was also greater (P: < 0.05) than that of VA-fed quail at 5 wk. The RA-treated quail laid their first eggs approximately 5 days earlier (P < 0.05) than the VA-treated quail. Furthermore, these RA-fed quail laid more eggs (P < 0.05) than those VA-fed quail during the experimental period. To confirm the results of experiment 1, a similar experiment was conducted to record the first egg and total eggs laid by quail fed VA2 or RA (experiment 2). The early onset of oviposition was again observed in the RA-treated group (P < 0.01). These results suggest that retinoic acid has a stimulating effect on the reproductive system of female Japanese quail, as has been previously shown in the reproductive system of male Japanese quail.

Changes in heterosis under within‐line selection or reciprocal recurrent selection: an experiment on early egg production in Japanese quail

IntroductionIn much animal production, commercial animals are crossbreds from closed lines or breeds under long‐term directional selection. Therefore it is desirable to be able to predict heterosis gains over the generations as it is done for genetic progress under within‐line selection. However, heterosis is the phenotypic expression of a complex phenomenon which may involve several types of genetic effects like dominance and epistasis. In animal breeding, basic quantitative genetics theory indicates that heterosis should be proportional to (squared) differences in gene frequency between populations (e.g. F alconer and M acK ay 1996), and it has been found approximately correct, so it is commonly used for planning crosses. Under that type of heterosis, however, selection towards the same objective in two populations should bring gene frequencies closer, and therefore it should eventually decrease heterosis. On the other hand, reciprocal recurrent selection designed to increase genetic distance between lines should eventually achieve maximum heterosis (O llivier 1982). Some experiments reviewed by brun (1982) have already compared genetic progress under within‐line and reciprocal recurrent selection, but they did not focus on comparing the trend of heterosis with generations between the two selection methods. Also, heterosis was monitored periodically in some selection experiments on poultry, and results were reviewed by F airfull (1990). They were somewhat contradictory, but they generally failed to relate genetic progress to loss of heterosis under within‐line selection. Moreover, in commercial production, as purebreds and crossbreds are not contemporaries and are generally maintained under very different management systems, estimations of heterosis and of the evolution of crossbred advantage over the generations may be difficult to obtain.Using the Japanese quail as an experimental animal, the present work was initiated specifically to follow the changes in heterosis brought about by selection for a single heterotic trait, early egg production (M invielleet al. 1995). For that purpose, two selection methods expected to have opposite effects on heterosis, directional within‐line (or individual) selection and reciprocal recurrent selection, were applied for 13 generations in four quail lines started from two different origins, and trends of heterosis in the selected character and in weight and egg traits were evaluated.

Changes of Protein Polymorphism in Selection Program for Egg Production in Japanese Quail, Coturnix coturnix japonica. 2. Gene Constitutionof 8th and 13th Generations.

Changes of Protein Polymorphism in Selection Program for Egg Production in Japanese Quail, Coturnix coturnix japonica. 2. Gene Constitutionof 8th and 13th Generations.

Changes of Protein Polymorphism in Selection Program for Egg Production in Japanese Quail, Coturnix coturnix japonica. 1. Gene constitution of Initial Generation.

The present study was done to evaluate and compare the genetic variability at initial generation in an experiment which was conducted to evaluate the heterosis effect in lines under different modes of selection for egg production using Jouy and Tours strains maintained in INRA. Genetic variability was analyzed for 6 lines (lines 1, 2, 3, 4, C and D) of the both strains by 10 protein loci (Hb-1, Alb, Tf, Es-D, Es-2, 6PGD, ADH, Acp, Prt and Amy). The values of Ppoly were calculated as 0.500-0.600 in Jouy strain and 0.70 in Tours strain. The values of H varied from 0.182 to 0.193 in Jouy strain and from 0.220 to 0.232 in Tours strain. Coefficients of gene differentiation (GST) among line was calculated as 0.019. This values suggests that genetic differentiation among the 6 lines is small. Based on genetic distance data, dendrograms were drawn by unweighted pair group method. Six lines were clustered in two groups. One group is composed of line 1, line 3 and line C, and the other group is composed of line 2, line 4 and line D. Based on 9 loci except Prt locus, genetic relationship among 6 lines in INRA and 6 laboratory populations in Japan was investigated. Genetic distances were calculated as 0.001-0.009 within INRA, 0.029-0.089 within Japanese stock and 0.081-0.184 between INRA stock and Japanese stock. GST calculated from gene frequency of 12 quail lines in INRA and Japan was estimated as 0.191 which is higher than the value among lines within INRA. This results suggest this genetic differentiation between INRA and Japan is larger than between lines in INRA stock and between laboratory lines in Japan. A dendrogram composed of the 12 quail lines showed two different clusters of six lines of INRA and 6 laboratory lines in Japan. These results suggest that gene constitution between quail lines in France and in Japan widely different.

Multiphasic Analysis of Egg Production in Japanese Quail

A multiphasic function that considers egg production of individual hens to result from more than one phase was used to describe egg production for Japanese quail. Each phase is determined by number of eggs within a clutch, including internally laid eggs, and pause between clutches. Cumulative egg production was fitted by using a function (Koops and Grossman, 1992) expressing time in terms of cumulative egg number. Data from nine hens over a 31-day period were analyzed to estimate parameters for lag and delay. The data were preadjusted for internal laying. Lag ranged from −1.14 to .19 h. Unlike chickens, there was no clear relationship between lag and average clutch length in Japanese quail. Average delay was about 21.6 h and seemed to be longer than that in the chicken. Furthermore, the residual standard error for delay was higher in Japanese quail than in the chicken.