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Subject: Animal Genetics and Breeding × Author: KAU × End date: 2001 × Start date: 2001 ×
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    ThesisItemOpen Access
    Chromosome architecture of desi pigs of Kerala
    (Department of Animal Genetics and Breeding, College of Veterinary and Animal Sciences, Mannuthy, 2001) Jayan, K C; KAU; Raghunandanan, K V
    A cytogenetic analysis of the chromosomes of black desi pigs of Kerala was carried out. Fifty four black desi pigs housed at the AICRP on pigs: centre for Pig Production and Research, Mannuthy formed the material for study. Forty five Large White Yorkshire pigs were also studied for comparison of the chromosome architecture. Metaphase spreads were obtained by peripheral blood leukocyte culture in RPMI 1640 medium. A combination of pokeweed nitrogen and phytohemagglutinin was used for initiating mitosis. The metaphase spreads were G-banded by incubating them in 2 x SSC containing trypsin solution for 45 minutes at 60°C. The number, morphology and morphometric measurements of chromosomes were studied. The distinct visible bands observed in G-banding was compared to that of the standard G-banded karyotype of pigs. The karyotype revealed in desi pigs a chromosome diploid number of 38 (2n = 19). This consist of six pairs of submetacentric chromosomes, four pairs of metacentric chromosomes, six pairs of acrocentric chromosomes and a pair of sex chromosomes, either XX or XY. The X-chromosome was submetacentric and Y-chromosome metacentric. In Large White Yorkshire pigs included in the present study also the diploid number of chromosomes is 38, with similar morphological characteristics for the chromosomes as that of the desi pigs. Thus in morphology and number of chromosomes, the desi pigs maintained a similarity to that of large White Yorkshire pigs. The relative length of the largest chromosome which was a submetacentric one in both breeds was 11.69 ± 0.19 in desi pigs and 11.35 ± 0.37 in large White Yorkshire pigs. The Y-chromosome was the smallest chromosome in desi and large White Yorkshire pigs. The Y-chromosome had a relative length of 1.95 ± 0.12 in desi pigs and 1.7 ± 0.07 in large White Yorkshire pigs. The relative length of X-chromosome of desi and large White Yorkshire pigs were 4.63 ± 0.25 and 5.01 ± 0.22 respectively. The arm ratio of the submetacentric chromosomes was highest for chromosome 2 in both the breeds. The arm ratio was lowest for chromosome 8 in desi pigs and chromosome 5 in large White Yorkshire pigs. The ann ratio of the X-chromosome was 1.97 ± 0.08 for desi pigs and 1.81 ± 0.15 for the large White Yorkshire pigs. The centromeric index measurements varied from 23.06 ± 0.84 to 42.68 ± 0.71 for desi pigs and 26.2 ± 0.89 to 39.45 ± 1.51 for large White , Yorkshire pigs. The centromeric index value was highest for chromosome 8 and lowest for chromosome 2 in both breeds. The X-chromosome had a Centromeric Index of 32.09 ± 1.17 in desi pigs and 36.33 ± 1.64 in large White Yorkshire pigs. The bands obtained by G-banding of the chromosomes of desi pigs were comparable to the standard G-banded karyotype of pigs.
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    ThesisItemOpen Access
    Comparative evaluation of litter traits in desi, large white yorkshire and their crossbred pigs
    (Department of Animal Breeding and Genetics, College of Veterinary and Animal Sciences, Mannuthy, 2001) Gopinathan, A; KAU; Usha, A P
    The present study was undertaken to compare and evaluate litter traits in Large White Yorkshire, Desi and their Crossbred pigs and to decide a breeding strategy. The data on 20-25 farrowings were collected from Centre for Pig Production and Research, Mannuthy for Large White Yorkshire, Desi and Crossbred pigs. A random sample of eight animals from each genetic group was selected and maintained from weaning to eight month of age to study the growth, feed conversion efficiency and- carcass characteristics. The average birth weight and weaning weight, litter size at birth and weaning, litter weight at birth and weaning, pre-weaning mortality for each genetic group were calculated. Large White Yorkshire was found to be superior for all traits followed by Crossbred and Desi pigs. Crossbred pigs had lowest pre-weaning mortality while Desi pigs had highest litter size at birth. Analysis of variance showed that the effect of genetic group was found to be highly significant for all litter traits except litter size at birth and weaning. The data were analysed using least squares analysis of variance to study the effect of different factors on birth weight and weaning weight in all three genetic groups. Least squares analysis of variance for birth weight revealed that the effect of sire and litter size at birth was highly significant in all three genetic groups. Sex had significant effect only in crossbreds. For weaning weight, the effect of sire and litter size at birth were found to be highly significant while sex did not show a significant effect on weaning weight in all three genetic groups. The effect of genetic group was found to be highly significant for third, fifth and eighth month body weight. But there was no significant effect noticed between Large White Yorkshire and Crossbred pigs during third month. The average daily gain and feed conversion efficiency was highest for Large White Yorkshire followed by Crossbred and Desi pigs from weaning to eight months of age. In carcass traits like back fat thickness, loin eye area, dressing percentage and carcass length, Large White Yorkshire averaged better than Desi and Crossbred pigs. The effect of genetic group was found to be highly significant for all carcass traits.
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    ThesisItemOpen Access
    Association of bodyweight and milk production in Vechur and other dwarf desi cattle of Kerala
    (Centre for Advanced Studies in Animal Genetics and Breeding, College of Veterinary and Animal Sciences, Mannuthy, 2001) Bindya, Liz Abraham; KAU; Sosamma, Iype
    The present work is a study on the association between body weights, lactation milk yield and age at first calving in Vechur and other dwarf desi cattle maintained at Kerala Agricultural University. This information can be utilized in the selection programme to evolve a small cow weighing around 125kg and yielding 800 kg milk per lactation. The average body weights at birth, three, six, nine, twelve months and at adult stage for males of Vechur were 11.2 ± 0.2 kg, 28.7 ± 0.7 kg, 44.2 ± 0.8kg, 63.9 ± 4.0 kg, 76.1 ± 1.9 kg, 173.6 ± 6.9 kg and those for Kasargod, 11.1 ± 0.3 kg, 33.5 ± 3.0 kg, 49.5 ± 4.6 kg, 80.4 ± 6.8 kg, 86.8 ± 11.2 kg and 194?"3 ± 19.9 kg respectively. The corresponding estimates for females of Vechur were 10.2 ± 0.2 kg, 28.3 ± 0.7 kg, 43.3 ± 0.8 kg 52.7 ± 1.3 kg, 69.5 ± 1.2 kg and 138.5 ± 2.3 kg and those for Kasargod, 9.5 ± 0.4 kg, 29.1 ± 1.8 kg, 49.5 ± 2.7 kg, 54.3 ± 3.0 kg, 61.1 ± 3.8 kg and 147.7 ± 5.1 kg respectively. The average gain in weight for the four periods i.e., months 0-3, 3-6, 6-9 and 9 -6;12 when expressed as a percentage of initial weight for males of Vechur were 149.0, 54.7, 39.7, 25.3 and those for Kasargod, 198.4, 62.5, 59.5, 17.0 per cent respectively. The corresponding estimates for the females of Vechur were 178.1, 55,8, 31.8, 27.1 and those for Kasargod, 169.1, 58.4, 20.0, 13.3 per cent respectively. Male calves of Vechur gained 6.7 times and those of Kasargod 7.8 times the birth weight by twelve months of age. Males and females differed in body weight only at adult stage. Between breeds, male calves at nine months and female calves at twelve months differed. The average age at first calving and lactation milk yield of Vechur were 1080.3 ± 33.6 and 579.6 ± 35.7 kg and those of Kasargod were 1147.5 ± 68.0 days and 298.3 ± 35.6 kg respectively. The means for milk yield differed significantly. Weight at three months had a heritability of 0.61 and adult body weight, 0.81 in Vechur. The heritability for milk yield and age at first calving were 0.1 and 0.06 respectively. Estimation of phenotypic correlations in Vechur revealed that birth weight had a correlation of 0.446 with twelve months weight. Body weights at the adjacent stages had correlations ranging from 0.36-0.77. Age at first calving had correlation only with weight at nine months (0.668) and milk yield had only with adult body weight (0.406), 11 In Kasargod, body weight at different stages upto 12 . months had correlations around 0.8 but not with adult body weight. Adult body weight and milk yield were found to have a correlation of 0.918. Genetic correlation In Vechur for weight at three months and adult weight was 0.683, but that between adult weight and milk yield was not significant. The annual genetic gain from selection was estimated to be -4.35 kg and 12.968 kg for adult body weight and lactation milk yield respectively. Considering a take off time of five years, it would be possible to achieve the target of 800 kg per lactation from the present 579.5 kg, in a time period of 22 years. Vechur is the smallest breed not only of India, but probably of the wor ld is the highest milk yielder among the very light breeds with the lowest age at first calving among all Indian breeds. Kasargod males have the highest growth rate upto one year among all Indian breeds. The potential of the Vechur cow for milk and the Kasargod bull calf for meat can be advantageously utilized at present and improved with selection in the future.