In recent years, quail meat has gained popularity among consumers and several lines, breed and varieties have been developed for different production purposes. Anyway, the available information in literature are still very scarce. In light of this, the aim of the current study was to evaluate the effect of different lines (meat type and egg type quails), cross (meat type x egg type quails; F0 x F1) and gender (males and females) on growth performance, carcass and meat quality traits in Japanese quail (Coturnix japonica). Current research was a part of a larger research project whose main aim was the detection of quantitative trait loci (QTLs) and their linkage with phenotipical traits (meat and egg quality traits), in order to study the genetic structure at the basis of the variability of the quantitative traits. Also, verify and demonstrate, on the basis of information on the QTL, if quail could be considered as an “Animal model” for chicken with interesting economic implications. The experiment was performed with two Japanese quail (Coturnix japonica) population (meat type and egg type) reared at the Didactic Experimental Station of the University of Life Sciences in Lublin (Poland). Forty-four quails (generation F0), 22 Pharaoh (F-33) meat type males and 22 Standard (S-22) laying type females, were reciprocally crossed to produce the F1 hybrids generation. F2 generation has been created by mating one F1 male with one F1 female, full siblings. The birds, randomly chosen from F0 (22 males and 22 females), F1 (22 males and 22 females) and F2 (84 males and 152 females) were raised to 20 wk of age in collective cages (F0 and F1: 6 birds in each 6 cages and 4 birds in each 2 cages; F2: 6 birds in each 38 cages, 4 birds in each two cages) under continuous lighting (natural and artificial). Quail were fed ad libitum commercial diets according to age. The diet containing 28 % CP and 3,000 kcal of ME/kg for the first week, then till 28 days it containing 24 % CP and 2,900 kcal of ME/kg; the finisher ration had 20 % CP and 2,800 kcal of ME/kg. Birds had free access to water during the experiment. At slaughter (20 weeks of age), all birds were individually weighed (after a fasting period of 12 h), stunned and decapitated, according to the EU regulations on the protection of animals at the time of killing (European Communities, 2009). After plucking and eviscerating, carcasses were weighted and dissected (leg, breast, giblets, abdominal fat; theirs percentages were calculated based on hot carcass weight) and, in addition, dressing percentage (without giblets) was calculated. After the refrigeration period (24 h at 4°C), the right Pectoral muscle (PM) pH (pH24) was recorded and the left PM was removed, vacuum packaged, and stored frozen (− 40°C) for analyses of intramuscular collagen (IMC) properties, cholesterol content and fatty acid composition. Data were evaluated by one way analysis of variance (ANOVA; SPSS Inc., 2010) and Scheffé’s test was applied to compare the mean values among the three generations. Quails of meat line (F-33) were significantly heavier than those of the egg line (S-22) and they had higher carcass weight, carcass yield and abdominal fat percentage; differently, giblets percentage and meat pH were higher in egg type quails. The IMC amount did not differ significantly between the two lines; however, meat of the egg line had a slower collagen maturation (hydroxylysylpyridinoline crosslink/collagen). Breast meat of S-22 quails had higher total saturated fatty acid (SFA) amount, but also higher total polyunsaturated fatty acid (PUFA) content compared with F-33 quails; on the contrary, the latter had higher (+ 11.5 %) total monounsaturated fatty acid (MUFA) amount. The ratio between polyunsaturated to saturate fatty acids (P/S) and muscle cholesterol were similar between lines, even if meat line quails supplied meat with lower atherogenic index (AI) and thrombogenic index (TI). The F1 and F2 generations showed an evident sexual dimorphism and an additional effect could be due to hybrid heterosis. Both females of F1 and F2 generations were heavier than males and had higher giblets percentage, while males showed a higher carcass yield and abdominal fat percentage. The IMC amount was not influenced by gender in both generations, even if meat from F1 females had higher degree of collagen maturation. In the F2 generation, a significant hatch-effect was found for the IMC amount and the degree of collagen maturation. In the F1 generation the fatty acid composition and the relative ratios, as well as the muscle cholesterol content, were similar between sexes. On the contrary, in the F2 generation females were characterized by higher total PUFA content and consequently higher P/S ratio, but lower muscle cholesterol content compared to males. The comparison of performance traits among the three generations showed an evident phenotypic variation. The cross between two genetically distant lines as well as the cross between full siblings hybrids did not influence the body weight of hybrid males but had a negative effect on their carcass weight. Instead, hybrid females were heavier than parental line (S-22): F1 hybrid had an increase of body weight of 23.9 %, while F2 showed an increase of 31.4 %. The total content of SFA was lower in muscle hybrid females (F1 and F2) compared to female of parental line, while the SFA amount between males was similar among the three generations. The total MUFA amount was higher in both F1 males and females, suggesting a positive heterosis in the F1 generation, especially for females. On the contrary, the total PUFA content, as well as the total n-6 fatty acids amount were higher in F2 hybrids in both sexes. The P/S ratio was highest in F2 quails, while both F1 males and females were characterized by the highest n-6/n-3 ratio. Hybrid females (F1 and F2) showed a significant lower AI and TI compared to parental line. Interestingly, both F1 and F2 females and only F1 males showed a considerably lower muscle cholesterol content compared to parental lines. Overall, the results obtained at the end of this study have provided information regarding three generation cross of two types (meat line and egg line) of Japanese quail which could be used in the future in poultry breeding industry.
|Titolo:||Effect of cross-breed of meat and egg line on productive performance and meat quality in Japanese quail (Coturnix japonica) from different generations|
Fatty acid composition
|Data di pubblicazione:||1-apr-2014|
|Appare nelle tipologie:||8.2 Tesi di dottorato (Ex-ROAD)|