GENETIC STUDY ON THE PERFORMANCE OF JAPANESE QUAILS
| dc.contributor.advisor | RAMESH GUPTA, B(MAJOR) | |
| dc.contributor.advisor | GNANA PRAKASH, M | |
| dc.contributor.advisor | RAJASEKHAR REDDY, A | |
| dc.contributor.advisor | SUDHAKAR REDDY, K | |
| dc.contributor.author | PUNYA KUMARI, B | |
| dc.date.accessioned | 2018-10-05T10:55:51Z | |
| dc.date.available | 2018-10-05T10:55:51Z | |
| dc.date.issued | 2007-09 | |
| dc.description.abstract | ABSTRACT : The present investigation was carried out on the Black (3237) and Brown (3376) Japanese quails (Coturnix coturnix japonica) maintained at the Poultry Experimental Station (PES), Department of Poultry Science, Rajendranagar, Hyderabad under the selection for high 4-week body weight in generations 5, 6, 7 and 8 to study the influence of various genetic and non-genetic factors on body weights, average daily gains (ADG), age at first egg (AFE), egg production (EP), carcass traits and egg quality traits. The genetic parameters and response to selection were estimated for various traits. Selection indices were developed utilizing the genetic parameters estimated. The overall least squares means for body weights at day-old, 1, 2, 3 and 4 weeks of age were 9.75, 37.09, 77.55, 126.41 and 170.95 g, respectively. The effect of strains and generations was significant on body weights at all the ages, while the influence of sex was evident from 2 to 20 weeks of age. Hatch effect was significant on body weights upto 4-weeks age, but not beyond. The birds belonging to 7th generation were consistently weighed heaviest. Sexual dimorphism in favour of the females was evident by their higher body weights ranging from 1.29 to 45.14 g over the males, from 2 to 20 weeks of age, respectively. The overall least squares mean ADGs during 1, 2, 3, 4, 5 to 8, 9 to 12, 13 to 16 and 17 to 20 weeks of age were 3.91, 5.78, 6.98, 6.36, 2.73, 0.55, 0.34 and 0.30 g, respectively. Strain and hatch effect was significant on ADGs at all ages with an exception to that of 9 to 12 weeks of age, whereas generations exhibited significant influence on ADGs during the entire period of study. Sex of the chick affected this trait during 2 to 8 and 13 to 20 weeks of age. The highest ADGs of 6.86 and 7.10 g were obtained in males and females, respectively, during 3 weeks of age. . The overall least squares means for age at first egg and cumulative egg production up to 12, 16 and 20 weeks of age were 55.18 days, 19.80, 38.52 and 57.53 eggs, respectively. The effect of strains, generations and hatch were significant on AFE and egg production. The overall least squares means for pre-slaughter weight and weights of dressed, carcass, wings, neck, legs, thighs, drumsticks, breast and back were 221.61, 137.75 g 12.38, 5.91, 33.15, 19.63, 13.61, 55.08 and 29.84 g, respectively. Significant influence of strains, generations, sex and hatches was found on majority of the carcass traits studied. The Black Japanese quails exhibited higher means for almost all carcass traits than those of Browns. The chicks of 7th generation recorded highest means, while a majority of the carcass characters studied was higher in females than in males. The overall least squares mean dressing percentage was 62.22 and the wings, neck, legs, thighs, drumsticks, breast and back formed 9.01, 4.29, 24.21, 14.30, 9.94, 40.70 and 21.76 percent of dressed carcass respectively. The overall least squares means for egg weight, shell weight, shell thickness, albumen weight, yolk weight, shape index, albumen index, yolk index and Haugh unit score were 13.71 g, 1.17 g, 0.21 mm, 7.80 g, 4.74 g, 79.23, 0.13, 0.45 and 58.27, respectively. The albumen, yolk and shell weights constituted 56.83, 34.61 and 8.56 percent of the egg weight, respectively. Almost all the egg quality traits were significantly influenced either by strains or generations. Medium to high heritability estimates within the normal range were obtained for the body weights from 1 to 4 weeks of age in Black and Brown Japanese quails by half-sib as well as full sib methods. The estimates based on sire component were higher than those based on dam component body weights at majority of the ages. . The heritabilities of ADGs estimated by half-sib method ranged from low to high, but, majority of estimates from 1 to 4 weeks of age were moderate, in magnitude, while the estimates based on full sib analysis varied from low to medium. The heritabilities of age at first egg (AFE) by half-sib method varied from moderate (0.27) to high (0.79) and by full sib method (sire + dam component) ranged from low (0.16) to high (0.39). The heritabilities of egg production by half-sib method varied from 0.46 to 0.68 in Black and 0.55 to 0.97 in Brown strains, while these estimates based on sire + dam component ranged from 0.32 to 0.39 and 0.21 to 0.34 in Black and Brown strains, respectively. Heritability estimates for various external and internal egg quality traits and quality indices in Black and Brown Japanese quails were mostly medium but ranged from low to moderate, respectively. The estimates of genetic, phenotypic and environmental correlations for body weights in Black and Brown Japanese quails in all four generations varied from moderate to high in magnitude, but positive in direction. The genetic and phenotypic correlations for ADGs were moderate to high and low to medium in magnitude, respectively. The genetic, phenotypic and environmental correlations among BW4, AFE, and EP varied from -0.59 to 1.00, -0.35 to 0.89 and -0.58 to 0.81 in Black Japanese quails and the correlations in the same order for Brown Japanese quails were -0.84 to 0.96, -0.51 to 0.81 and -0.37 to 0.50. The correlations on genetic, phenotypic and environmental scale among the various carcass traits and external, internal egg quality traits and quality indices exhibited considerable variation in magnitude and direction. The response to selection in body weight at 4-weeks age among the four generations 5 to 7 varied from 6.03 to 30.93 g in Black males; 6.84 to 14.24 g in Black females; 2.67 to 6.90 g in Brown males and 2.20 to 6.41 g in females. The cumulative response to selection in generations 5 to 8 was 53.31, 40.21, 18.85 and 15.05g in Black males, Black females, Brown males and Brown females. Out of seven selection indices constructed based on the genetic parameters obtained in the present study, the index I2 consisting of body weight at 4-weeks (BW4), age at first egg (AFE) and egg production upto 16 weeks of age (EP16) was found to be the best with RIH value of 35.50% in Black Japanese quails. This index was expected to fetch a desirable increase of 0.7399 g in BW4, decrease the AFE by 0.0056 days and increase 0.2656 eggs upto 16 weeks age per 1% increase in RIH value. In Brown Japanese quails, the index I3, with a moderate RIH value (25.11%) was expected to improve BW4 by 0.5153 g, EP20 by 0.5302 eggs and reduce AFE by 0.0455 days and considered to be satisfactory. | en_US |
| dc.identifier.uri | http://krishikosh.egranth.ac.in/handle/1/5810074840 | |
| dc.keywords | JAPANESE QUAILS;GENETIC STUDY;PERFORMANCE | en_US |
| dc.language.iso | en | en_US |
| dc.pages | 182 | en_US |
| dc.publisher | SRI VENKATESWARA VETERINARY UNIVERSITY TIRUPATI - 517 502. (A.P.) INDIA | en_US |
| dc.sub | Animal Genetics and Breeding | en_US |
| dc.subject | null | en_US |
| dc.theme | GENETIC STUDY ON THE PERFORMANCE OF JAPANESE QUAILS | en_US |
| dc.these.type | Ph.D | en_US |
| dc.title | GENETIC STUDY ON THE PERFORMANCE OF JAPANESE QUAILS | en_US |
| dc.type | Thesis | en_US |