Browsing by Author "Usha, A P"

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Biochemical polymorphism in broiler rabbits
(Department of Animal Breeding, Genetics and Biostatistics, College of Veterinary and Animal Sciences, Mannuthy, 1990) Usha, A P; Mukundan, G
Blood samples collected from rabbits maintained in the rabbit breeding farm of Kerala Agricultural University formed the materials for this study These blood samples were typed employing horizontal polyacrylamide gel electrophoresis to study the polymorphism of transferrin post transferrin and haemoglobin A total of 152 rabbits comprising of 50 Soviet Chinchilla 52 Newzealand White and 50 local rabbits were involved m the study Genetic inter relationship among growth traits and survivability were studied In all the genetic groups two transferrin variants the faster Tf and slower Tf with two phenotypes TfAA and TfAC were observed The gene frequency of Tf and Tf were 0 7500 and 0 2500 in Soviet Chinchilla 0 8300 and 0 1700 m Newzealand White and 0 8100 and 0 1900 m local rabbits The frequency of TfA allele was higher in all the populations The phenotype TfCC was not observed in any of the genetic groups Three post transferrin phenotypes Ptf FF Ptf FS and Ptf SS were detected and found to be controlled by two F S co dominant alleles Ptf and Ptf The fast moving F variant was designated as Ptf and the slow moving migrant S F was designated as Ptf The gene frequency of Ptf was 0 7400 0 8500 and 0 7600 m the three genetic groups and e that of Ptf was 0 2600 0 1500 and 0 2400 in Soviet Chinchilla Newzealand White and local rabbits respectively Haemoglobin was found to be monomorphic in all the three genetic groups studied The allelic frequencies of transferrin and post transferrin were suggestive of Hardy Weinberg equilibrium in the populations of three breeds No significant diversity was found to exist between genetic groups analysis of segretation pattern observed in pedigrees revealed the autosomal codominant mode of inheritance for transferrin and post transferrin alleles The absence of TfCC phenotype in the whole population of rabbits may be due to its unfavourable influence on the viability
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; 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
Evaluation of microsatellite markers for paternity testing in cattle
(Department of Animal Breeding and Genetics, College of Veterinary and Animal Sciences, Mannuthy, 2004) Preethy, M S; Usha, A P
A study was undertaken to evaluate the efficiency of microsatellite markers for paternity testing in cattle of Kerala. Genomic DNA was isolated from whole blood, fresh and frozen semen samples using phenol: chloroform method. DNA samples from 100 genetically unrelated animals were used to determine the polymorphisity of the markers and samples of known pedigree was used to test the inheritance of markers. The mean yield of DNA obtained from 5 ml of whole blood was 388.2 ± 14.3 µg, from fresh semen was 181.15 ± 6.2 µg/400 million sperms and from frozen semen was 116.95 ± 25.2 µg/150 million sperm cells. The optical density ratios (260/280) ranged from 1.64 to 1.81, 1.42 to 1.73, 1.54 to 1.76 and for DNA obtained from blood, fresh and frozen semen respectively. Three microsatellite markers viz., DRB3, ETH131 and FSH out of a panel of tested markers were chosen for the study based on their polymorphicity and ease of typing. The forward primer of each primer pair was end-labelled with  32P-ATP. PCR parameters varied between the primers with respect to annealing temperature (60°C for DRB3 and FSH; 55°C for ETH131) and MgCl2 concentration (1.25 mM for DRB3 and FSH; 1.5 mM for ETH131). The amplified products fractionated by denaturing polyacrylamide gel electropheresis were visualized by autoradiography. The number of alleles was counted and allele sizes assigned by comparison with sequences of M13 DNA run along with PCR products. The frequency of each allele was worked out. Seventeen alleles with sizes ranging from 138-192 bp were identified for DRB3, 11 alleles of size ranges 134-168 bp for ETH131 and nine alleles of size ranges of 184-214 bp were observed for FSH. The heterozygosity values obtained for each locus were 0.8938, 0.8385 and 0.8519 for DRB3, ETH131 and FSH respectively. DRB3 was highly informative with PIC value of 0.8864 followed by FSH (0.8392) and ETH131 (0.8151). The probability of exclusion of incorrect sire was calculated independently for the three markers and the values were 0.7913, 0.6787 and 0.7035 for DRB3, ETH131 and FSH respectively. The combined probability of exclusion obtained with DRB3 and ETH131 was 0.9329 and DRB3 and FSH was 0.9381 and that with ETH131 and FSH was 0.9047. The three markers together yielded a cumulative exclusion probability of 0.9801. Thus the exclusion probability was found to increase with the number of markers. The inheritance pattern of these markers was tested on known sire families. All the three markers agreed with each other in identifying the correct sire and excluding the incorrect one. Though the efficacy of the three markers for paternity testing was found satisfactory, it was concluded that one or two similarly polymorphic markers have to be used along with the markers studied to obtain maximum probability of exclusion of 0.99.
Microsatallite marker based characterization of indigenous pigs of Kerala
(Department of Animal Breeding and Genetics, College of Veterinary and Animal Sciences, Mannuthy, 2006) Ariprasath, K; Usha, A P
The study was undertaken to assess the genetic diversity among four indigenous pig population of Kerala using microsatellite markers. The animals were selected from various part of Kerala, population I included the conserved Angamali pigs from university farm, Mannuthy, population II consisted of animals from Koothattukualm, population III were the animals from Ollur and animals from border districts of Kerala formed the population IV. Genetic analysis was carried out using five polymorphic microsatellite markers. Blood samples were collected from 100 unrelated indigenous pigs from all four populations and DNA was isolated. The phenol-chloroform method of extraction yielded 224.35±9.86µg/5ml of blood. PCR conditions were standardized for all five selected markers namely, S0005, S0101, SW1026, SW2517 and S0008. The forward primer of each marker was endlabelled with γ32 P-ATP as source of radio signal. The M13 single strand DNA was sequenced and used as a size standard. Autoradiography was employed to visualize the results. A total of eight alleles were detected in S0005 and S0101, five alleles in each of SW1026 and S0008, and six in SW2517. The heterozygosity varied from 0.7747 in SW2517 to as large as 0.8475 for S0005. The heterozygosity values for S0101, SW1026 and S0008 were 0.7774, 0.7672, and 0.7424 respectively. The PIC values ranges from 0.6974 for S0008 to 0.8291 for S0005. The PIC values for S0101, SW1026 and SW2517 were 0.7483, 0.7284 and 0.7381 respectively. The allele frequencies were used to estimate the Nei’s standard genetic distance among the populations. The distance measure ranged from 0.5704 to 0.7161, with the highest value noticed between population II and IV and the lowest between population I and III. A dendrogram was constructed using the POPGENE version 3.2 program which grouped the population I and IV in one cluster and II and III populations in another cluster.