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

1. 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 evaluation of weekly body weight in Japanese quail using random regression models.

1. A total of 11 826 records from 2489 quails, hatched between 2012 and 2013, were used to estimate genetic parameters for BW (body weight) of Japanese quail using random regression models. Weekly BW was measured from hatch until 49 d of age. WOMBAT software (University of New England, Australia) was used for estimating genetic and phenotypic parameters. 2. Nineteen models were evaluated to identify the best orders of Legendre polynomials. A model with Legendre polynomial of order 3 for additive genetic effect, order 3 for permanent environmental effects and order 1 for maternal permanent environmental effects was chosen as the best model. 3. According to the best model, phenotypic and genetic variances were higher at the end of the rearing period. Although direct heritability for BW reduced from 0.18 at hatch to 0.12 at 7 d of age, it gradually increased to 0.42 at 49 d of age. It indicates that BW at older ages is more controlled by genetic components in Japanese quail. 4. Phenotypic and genetic correlations between adjacent periods except hatching weight were more closely correlated than remote periods. The present results suggested that BW at earlier ages, especially at hatch, are different traits compared to BW at older ages. Therefore, BW at earlier ages could not be used as a selection criterion for improving BW at slaughter age.

Genetic evaluation of carcass traits in Japanese quail using ultrasonic and morphological measurements.

1. A study was conducted to evaluate the carcass composition of 1083 live birds using ultrasonic and morphological measurements and to estimate the genetic relationship between predicted and dissected carcass composition in Japanese quail. 2. Birds were reared for 35 d, and morphological measurements consisting of the length and width of breast muscle were recorded for all birds using a digital caliper. After slaughtering, the weight and percentage of carcass traits were measured on chilled carcasses. The dimensions of breast muscle were measured in 638 birds with an ultrasound scanner before slaughter at 35 d of age. 3. Genetic parameters from univariate and bivariate analyses were obtained by restricted maximum likelihood using ASREML software. 4. Genetic correlations between body weight at 35 d (BW35) and the percentage of carcass traits were low. Therefore, selection for BW35 may not effectively improve the yield of carcass components in Japanese quail. 5. High genetic correlations between carcass traits and ultrasonic measurements compared to morphological measurements suggest that the ultrasonic technique is a better method to improve breast weight and yield in Japanese quail.

Genetic parameters for feed efficiency and body weight traits in Japanese quail.

1. The objectives of the present study were to estimate heritability and genetic correlations for feed efficiency and body weight (BW) in Japanese quail. 2. Recorded traits during different weeks of the growing period were BW from hatch to 35 d, feed intake (FI), feed conversion ratio (FCR) and residual feed intake (RFI) from hatch to 28 d of age. 3. Genetic parameters were estimated by restricted maximum likelihood method using ASREML software. The results showed that heritability estimates for BW ranged from 0.11 to 0.22, and maternal permanent environmental effect was the highest at hatch (0.45). FCR, RFI and FI showed moderate heritabilities ranging from 0.13 to 0.40. 4.Genetic correlations of BW28 with FI0-28 (0.88) and RFI0-28 (0.1) and genetic correlation of FI0-28 with FCR0-28 (0.13) and RFI0-28 (0.52) were positive. A negative genetic correlation was found between BW28 and FCR0-28 (-0.49). There was a high positive genetic correlation (0.67) between RFI0-28 and FCR0-28. 5. In conclusion, selection for increased BW and reduced FI in a selection index could be recommended to improve feed efficiency traits including FCR and RFI in Japanese quail.

Genetic evaluation of meat quality traits and their correlation with growth and carcase composition in Japanese quail.

1. Estimates of heritability, genetic and phenotypic correlations of performance and meat quality traits were obtained in a population of Japanese quail using restricted maximum likelihood (REML) procedures. 2. The heritability estimates for body weight (BW) traits ranged from 0·15 at hatch to 0·42 at six weeks. For carcase composition traits, heritability estimates ranged from 0·12 for carcase yield to 0·26 for abdominal fat yield and for meat quality traits they ranged from 0·18 for drip loss to 0·54 for yellowness of the meat. 3. Negative genetic correlations were found between BW and carcase traits with ultimate pH and drip loss ranging from -0·01 (BW at hatch) to -0·40 (skin yield). Redness and yellowness showed negative genetic correlations with BW and carcase traits, whereas the genetic correlations with lightness were positive (from 0·04 to 0·43). 4. Shear force and cooking loss showed positive genetic correlations with carcase, breast, abdominal and skin yield. 5. In conclusion, meat quality traits have the potential to be improved through genetic selection but selection for higher BW and carcase composition may reduce the meat quality of Japanese quail through reducing redness, ultimate pH and intramuscular fat and increasing lightness, shear force and cooking loss of the meat.

Genetic properties of egg quality traits and their correlations with performance traits in Japanese quail.

1. Performance traits were measured on 1908 Japanese quail and egg quality traits assessed on 1800 eggs at 10 wk of age. 2. Genetic and phenotypic correlations were estimated using a bivariate animal model with restricted maximum likelihood using ASREML software. 3. Body weight at different ages showed positive genetic correlations with egg weight and most of the internal egg quality traits, whereas their genetic correlations with eggshell thickness, eggshell strength and eggshell percentage were negative. 4. Genetic correlations of age at sexual maturity and egg number with most of external and internal traits were negative. 5. It was concluded that selection for higher body weight will result in heavier and better quality eggs. Because of the negative genetic correlation between BW and egg shell quality, a selection index including BW and eggshell strength would be the best breeding strategy for genetic improvement of egg quality in Japanese quail.

Genetic evaluation of carcass composition and fat deposition in Japanese quail.

Current research was conducted to estimate heritability and genetic correlations for carcass composition and fat deposition in Japanese quail at 42 and 91 d of age. Studied traits were BW at 42 and 91 d of age (BW42, BW91), carcass weight and percentage, breast meat weight and percentage, thigh weight and percentage, abdominal fat weight and abdominal fat percentage (AFP), skin weight and skin percentage (SP) as a measure of subcutaneous fat, and the percentage of breast intramuscular fat (IFP). Genetic parameters were estimated by restricted maximum likelihood using ASREML software. The heritability estimates of BW and the weight of carcass traits were higher (from 0.45 for BW42 to 0.63 for breast meat weight) than the percentage of carcass traits (from 0.11 for thigh percentage to 0.19 for breast meat percentage). The heritability estimates for SP, AFP, and IFP as fat deposition tissues were 0.17, 0.26, and 0.20, respectively. There were high genetic correlations between BW42 with the weight and percentage of carcass components (from 0.65 to 0.98). Body weight at 42 d of age also showed positive genetic correlations with skin weight and SP (0.80 and 0.23, respectively), abdominal fat weight and AFP (0.44 and 0.21, respectively), and IFP (0.28). A positive genetic correlation between SP and AFP (0.51) was observed. Present results indicated that the percentage of breast intramuscular fat is a heritable trait and selection for increasing BW and decreasing abdominal and subcutaneous fats will improve carcass composition and breast meat quality in Japanese quail. In addition, selection against abdominal and subcutaneous fat does not change intramuscular fat and the quality of breast meat.

Coupling of TLC and UV-measurement for quantification of naproxen and its main metabolite in urine.

A simple sensitive method of high specificity and selectivity for quantitative determination of the non-steroidal anti-inflammatory drug naproxen and its main metabolite, 6-demethylated derivative, in biological specimens is described. Like naproxen, its metabolite absorbs maximally at 232 nm; this makes their simultaneous quantification, via direct UV-measurements at lambda max, in biological fluids quite impossible. Simple TLC-separation on silica gel F254 using chloroform + methanol (85:15, v/v) achieved the best fractionation of the unchanged drug and its metabolite from the matrix-contents of urine. UV-quantification of fractionated components could reach concentration levels of 0.2-3.0 micrograms ml-1 (ppm) in worked up urine samples. Varying levels of unchanged antiinflammatory drug and the phenolic metabolite could be accurately traced in urine samples following a 2.9 mg/kg oral dose after different time-intervals. Synthetic preparation of the metabolite by demethylation of naproxen is briefly mentioned.

Spectrophotometric determination of tranexamic acid with chloranil.

Tranexamic acid is reacted with aqueous alcoholic chloranil, buffered at pH 9, to give a complex with maximum absorption at 346 nm and with an apparent molar absorptivity of 15.7 x 10(3) l.mole(-1).cm(-1). A(max) is linearly related to concentration over the range 2-10 mug ml . When applied to tablets labelled as containing 500 mg each, the mean found was 496 +/- 4 mg. The results were comparable with those of the traditional formol titration method for amino-acids.

Conductimetric determination of methimazole.

Methimazole, a thyroid inhibitor, is a weak acid. In this communication, its authentic powder and its tablets (Tapazole) are assayed via its acidic property in aqueous medium. The equivalence point is determined conductimetrically. The average percent recovery for its authentic powder and tablets were found to be 99.30 +/- 1.30 and 98.27 +/- 1.81 respectively. The method, proposed in this study, is simple, rapid and can be adopted for routine analysis in quality control laboratories.