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ThesisItem Open Access GENETIC STUDIES ON THE PERFORMANCE OF CERTAIN BROILER RABBIT BREEDS(SRI VENKATESWARA VETERINARY UNIVERSITY TIRUPATI - 517 502. (A.P.) INDIA, 2007-10) ANITHA, K; GNANA PRAKASH, M(MAJOR); RAMESH GUPTA, B; RAJASHEKAR REDDY, AABSTRACT : The present study was conducted on New Zealand White (NZW), Grey Giant (GG), Soviet Chinchilla (SC), Flemish Giant (FG), Californian White (CW) purebreds and two synthetics - APAU Fawn (FN) and APAU Black (BL) bunnies born during November 2006 and July 2007 in the “Rabbit Production for Meat” scheme, Department of Animal Genetics and Breeding, College of Veterinary Science, Hyderabad. Bunnies were reared under cage and deep litter system. The overall least-squares mean litter size at birth and weaning and litter weight at birth and weaning were 6.18 ± 0.28 and 3.75 ± 0.23 bunnies and 305.16 ± 13.75 and 1190.93 ± 56.92 g, respectively. Winter proved to be the favorable season of birth for litter traits. The overall least-squares mean body weights were 50.00 ± 0.59, 104.52 ± 1.89, 175.10 ± 3.28, 239.50 ± 6.11 and 354.07 ± 9.19 g at birth, 1 2, 3 and 4 weeks age, respectively. In general, BL bunnies and those born in rainy season recorded significantly higher pre-weaning body weights. Mean body weights from birth to 3 weeks of age declined as the LSB increased. The overall mean body weights at 6, 8, 10, 12, 14 and 16 weeks of age were 551.89 ± 16.84, 684.30 ± 19.68, 856.37 ± 23.33, 1018.79 ± 28.83, 1207.18 ± 31.98 and 1352.84 ± 37.93 g, respectively. The FG rabbits have recorded significantly higher weights up to 8 weeks age. Post weaning body weights of bunnies born in winter were higher. The litter size classes 1-3 and 4-6 recorded higher body weights. The overall least square mean ADGs during 5-6, 7-8, 9-10, 11-12, 13-14 and 15-16 weeks were 17.55 ± 1.04, 9.06 ± 0.73, 10.91 ± 0.80, 10.46 ± 0.94, 14.47 ± 0.90 and 10.98 ± 1.0 g, respectively. Genetic group, rearing system and season had significant influence. The overall least-squares mean lactation milk yield was 1116.21± 98.28 g. Does kindled during February and those with a LWB of >250 g. recorded significantly higher milk yield. The mean daily milk yield ranged from 61.2 ± 2.1 to 73.3 ± 2.1. The effect of genetic group and season of birth was significant on feed intake and feed efficiency but not on weight gain. The overall least-squares means for pre-slaughter weight, dressed weight, dressing percentage, forecut, midcut, hindcut, head and feet, pelt, edible offals, inedible offals and length of caecum were 1451.14 ± 63.04 g, 695.33 ± 39.18 g, 46.69 ± 0.86, 245.73 ± 12.14 g, 174.41 ± 12.95 g, 275.19 ± 14.81 g, 193.79 ± 6.33 g, 141.11 ± 8.93 g, 57.44 ± 2.81g, 303.19 ± 11.47 g and 43.38 ± 0.85 cm, respectively. Length of caecum was significantly lower in CW rabbits. Most carcass traits studied were significantly higher in males and in those born in winter season. Rearing system had a significant influence on the length of caecum only. The overall least-squares means for dry matter, total ash, protein, fat and cholesterol in rabbit meat were 24.3%, 1.3%, 20.3 g%, 4.1% and 0.1mg%, respectively. Heritability estimates for litter traits were beyond the normal range. Heritability estimates of the pre and post weaning body weights, post weaning ADGs and carcass traits that could be computed varied from 0.11 ± 0.69 to 0.98 ± 1.94. The genetic and phenotypic correlations ranged from -0.04 ± 1.75 to 0.98 ± 0.02 and 0.45 to 0.97 among post weaning body weights, -0.21 ± 0.33 to 0.54 ± 0.27 and -0.09 to 0.25 among post weaning ADGs, respectivelyThesisItem Open Access GENETIC STUDY ON THE PERFORMANCE OF JAPANESE QUAILS(SRI VENKATESWARA VETERINARY UNIVERSITY TIRUPATI - 517 502. (A.P.) INDIA, 2007-09) PUNYA KUMARI, B; RAMESH GUPTA, B(MAJOR); GNANA PRAKASH, M; RAJASEKHAR REDDY, A; SUDHAKAR REDDY, KABSTRACT : 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.ThesisItem Open Access CYTOGENETIC CHARACTERIZATION OF JAPANESE QUAILS(SRI VENKATESWARA VETERINARY UNIVERSITY TIRUPATI - 517 502. (A.P.) INDIA, 2007-06) SRIDEVI, B; Gnana Prakash, M(MAJOR); Ramesh Gupta, B; Ravinder Reddy, VABSTRACT : Fifteen male and fifteen female black Japanese quails and 45 embryonated eggs obtained from the stocks maintained at Poultry Experimental Station, College of Veterinary Science, Rajendranagar, Hyderabad, were utilized for the present study. The chromosome number was obtained by counting the chromosomes from the metaphases obtained by leucocyte culture technique, bone marrow preparation and embryonic tissue preparations. The chromosome number varied from 76 to 81 with a modal chromosome number of 78. Five pairs of autosomes were macrochromosomes, while the remaining were microchromosomes. All the macrochromosomes were sub-metacentric whereas the morphology of the microchromosomes could not be ascertained. The Z-chromosome was identified as the fifth largest unpaired bi-armed chromosome in females and paired chromosome in males, while the W-chromosome was identified as the microchromosome in the size class of 7 to 8 chromosomes. The sex of the bird and the technique of obtaining metaphases had significant effect on the morphometric measurements of some chromosomes. The overall means of relative length, arm ratio, centromeric index and morphological index based on re-transformed data for the autosomes ranged from 0.95 + 0.0004 to 10.58 + 0.0015 percent, 1.20 + 0.02 to 2.38 + 0.07, 0.54 + 0.005 to 0.70 + 0.007 and 5.98 + 0.14 to 7.90 + 0.24, respectively. The mean relative lengths of Z- and W-chromosomes were 4.66 + 0.0006 and 2.47 + 0.0005 percent, respectively. The arm ratio, centromeric index and morphological index of the Z-chromosome were found to be 1.04 + 0.01, 0.51 + 0.002 and 7.14 + 0.19 respectively. Among the autosomes, the five macrochromosomes contributed 36.08 per cent to the genome.ThesisItem Open Access GENETIC ANALYSIS OF THE PERFORMANCE OF “FRIESWAL” CATTLE(SRI VENKATESWARA VETERINARY UNIVERSITY TIRUPATI - 517 502. (A.P.) INDIA, 2007-03) SHUBHA LAKSHMI, B; Ramesh Gupta, B(MAJOR); Gnana Prakash, M; Sudhakar, KABSTRACT : Data on various grades of Holstein Friesian × Sahiwal cattle maintained at Military Dairy Farm, Bowenpally, Secunderabad, over a period of 19 years (1988 – 2006) were analyzed for studying their mean performance and for the estimation of genetic parameters of various production and reproduction traits of the FS genetic grade cows. The genetic grades studied, included Sahiwal cows with Holstein Friesian inheritance of 3/8 (35.9375% to 39.0625%), 7/16 (40.625% to 46.875%), 5/8 (53.125% to 68.75%), 3/4 (71.875% to 78.125%), 7/8 (81.25% to 87.50%), 15/16 (90.625% to 93.75%) and FS (about 55% to 75%). The overall least-squares means of body weights at birth, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 15, 18, 21, 24 and 27 months of age were 26.08, 36.74, 51.04, 67.06, 83.02, 98.73, 113.35, 130.10, 141.21, 153.23, 164.25, 175.87, 188.21, 221.82, 253.85, 292.09, 316.06 and 336.28 kg, respectively. Genetic grades significantly affected the body weights at birth, 1, 2, 3, 21, 24 and 27 months of age, whereas period of birth significantly affected (P<0.01) the body weights at all the ages studied. Season of birth significantly affected the body weights at 3, 4, 5, 6, 10, 11, 12 and 21 months of age only. The overall least-squares means for total lactation milk yield, 300-day lactation milk yield, lactation length, peak yield, milk yield per day of lactation and milk yield per day of calving interval were 2864.32 kg, 2593.84 kg, 329.03 days, 13.30 kg, 8.69 kg and 6.40 kg, respectively. Genetic grades, period of calving and parity significantly affected all the production traits studied. Season of calving significantly affected (P<0.01) all the production traits studied except for the lactation length. The overall least-squares means of age at first service, age at first calving, service period, number of inseminations per conception, gestation period, dry period, calving interval and breeding efficiency were 640.24 days, 983.14 days, 183.28 days, 2.34, 275.93 days, 127.85 days, 450.42 days and 73.45%, respectively. Genetic grades significantly affected (P<0.01) age at first service, service period, number of inseminations per conception and calving interval, while period of calving significantly affected (P<0.01) age at first service, age at first calving, service period, dry period, calving interval and breeding efficiency. Season of calving had significant influence on service period, gestation period, dry period and calving interval. Significant effect (P<0.01) of parity was observed on service period, number of inseminations per conception, dry period and calving interval while sex of calf significantly affected number of inseminations per conception and gestation period only. The genetic analysis of adjusted data of FS grade cows revealed that the heritabilities of body weights ranged from 0.08 + 0.08 at birth to 0.99 + 0.32 at 18 months of age. Genetic correlations among the body weights at various ages ranged from -0.14 ± 0.12 (between birth weight and 6 months weight) to 0.97 ± 0.01 (between body weights at 12 months and 15 months of age). The phenotypic correlations ranged from 0.09 (between birth weight and 12 months weight) to 0.88 (between body weights at 12 and 15 months of age). The estimates of heritability for total lactation milk yield, 300-day lactation milk yield, lactation length, peak yield, milk yield per day of lactation, milk yield per day of calving interval, age at first calving, service period, gestation period, dry period, calving interval and breeding efficiency were 0.20, 0.18, 0.06, 0.16, 0.27, 0.17, 0.60, 0.03, 0.05, 0.02, 0.07 and 0.06, respectively. Total lactation milk yield was found to be genetically positively correlated with all the other traits studied except with gestation period, while 300-day lactation milk yield and lactation length were positively correlated with all the other traits studied. Peak yield and age at first calving were positively correlated with all the other traits except with gestation period and dry period. Service period was also positively correlated with all the other traits except with gestation period while gestation period was negatively correlated with all the traits except with lactation length and calving interval. The phenotypic correlations were positive among majority of the traits studied. The estimates of repeatability for total lactation milk yield, 300-day lactation milk yield, lactation length, peak yield, service period, gestation period, dry period and calving interval were 0.13, 0.56, 0.50, 0.12, 0.04, 0.07, 0.03 and 0.07, respectively. The Most Probable Producing Ability (MPPA) of the cows was computed based on total lactation milk yield and 300-day lactation milk yield. The results of the present study revealed that Frieswal cows of G3 genetic grade (5/8) outperformed the other grades in their overall performance. The genetic variation existing in the body weights, production and reproduction traits offered good scope for further genetic improvement through selection of the sires.