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Sri Venkateswara Veterinary University, Tirupati

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  • ThesisItemOpen Access
    POLYMORPHISM OF IFNA16 AND CAST GENES IN SWINE POPULATION OF ANDHRA PRADESH
    (SRI VENKATESWARA VETERINARY UNIVERSITY, TIRUPATI - 517 502. (A.P.) INDIA, 2024-02) PRIYANKA PATI; VINOO .R (MAJOR); SUDHAKAR .K; KALYANA CHAKRAVARTHI .M
    A total of 218 pigs namely LWY and SVVU T-17 were randomly selected and blood samples were collected to determine genetic polymorphism of CAST and IFNA16 genes by using PCR-RFLP method. The genomic DNA was amplified by PCR and product size of 376bp for CAST and 237bp for IFNA16 gene was obtained. The PCR products of CAST and IFNA16 genes were digested with HinfI restriction enzyme which recognizes the SNP 76872 G>A and 413G>A respectively and incubated at 37o overnight. The restriction fragment sizes of 376, 247, 129 bp (3 bands), 247, 129(2 bands) and uncut fragment of 376bp were observed for CAST/HinfI locus, whereas IFNA16/HinfI (rs701706389) genotyping revealed that two genetic groups were monomorphic with A allele. Three different types genotypes were identified (AA, GA and GG) based on the different patterns and two alleles namely A and G. For CAST gene the genotypic and allelic frequencies of AA, GA, GG and A and G were found to be 0.39, 0.49, 0.12 and 0.63, 0.37 (LWY); 0.008, 0.47, 0.522 and 0.24, 0.76 (SVVU T-17). The Chi-Square value for CAST locus revealed significant difference (P<0.01) in SVVU T-17, whereas it was non-significant for LWY. Chi-Square differences in genotypic and allelic frequencies at CAST/HinfI locus between LWY and SVVU T-17 shown significant differences (P<0.01) between them. The observed heterozygosity (Ho) values ranged from 0.47 to 0.49 and the expected heterozygosity (He) values ranged from 0.37 to 0.46 for CAST gene. The Polymorphic Informative Content (PIC) value was medium and ranged from 0.29 to 0.36 for CAST gene. The Fixation index (FIS) value were found to be negative for two genetic groups and ranged from -0.27 to -0.06. The results revealed the existence of polymorphism for CAST gene and it could be a marker to establish association with meat quality traits.
  • ThesisItemOpen Access
    POLYMORPHISM IN GENOMIC REGIONS LINKED TO RESISTANCE AGAINST BRUCELLOSIS IN CATTLE AND BUFFALO
    (SRI VENKATESWARA VETERINARY UNIVERSITY TIRUPATI - 517 502. (A.P.) INDIA, 2023-04) GANADAYA CHOPPARA; VINOO .R (MAJOR); SUDHAKAR .K; VENKATA SESHAIAH .CH
    Brucella abortus causes bovine brucellosis, a prevalent reproductive disease with high zoonotic potential where the host immune response plays a critical role in disease prevention. Toll-Like Receptors (TLRs) are the type of receptors that serve as the body's first line of defense against pathogens thus conferring resistance to various diseases. They distinguish invading pathogens as well as endogenous substances from damaged cells and are critical in bridging the gap between innate and adaptive immunity. The current study sought to identify genetic polymorphisms in TLR1 and TLR2 and their association with natural resistance to brucellosis. Mutations in the coding regions of TLR1 (+1380 G/A) and TLR2 (T385G) were used to identify the polymorphism in 362 samples of cattle and buffalo using PCR-RFLP. To know the association of SNPs with the disease, a case-control study has been made with 222 samples of which 41 samples resulted as positive (case) and 181 as negative (control) in both RBPT and ELISA. In TLR1/AciI locus, the “GG” genotype was predominant in Murrah, Holstein Friesian crossbreds, and Jersey crossbreds while indigenous cattle solely genotyped to “GG”. In the TLR2-EcoRV locus, “GG” genotype was prevalent in Murrah and indigenous cattle breeds, whereas the “TT” genotype was prevalent in crossbred cattle. Murrah buffaloes in TLR1 and TLR2, and Ongole cattle in TLR2 had deviated from the Hardy-Weinberg equilibrium (P<0.01). The logistic regression analysis for TLR1 could not be performed; however, for the TLR2 (T385G) locus, the Odds Ratio (OR) of T/T against G/G - G/T was 0.17 (0.02-1.46; 95% CI), indicating that the ‘T’ allele had a lower relative risk of brucellosis incidence than the ‘G’ allele. The odds ratios of HF crossbreds and Ongole were 0.43 and 0.23, respectively, indicating that they were brucellosis-resistant, but it was observed that Punganur cattle had a significant risk of infection (OR=1.71). In the present investigation, selection against TLR2(T385G) may reduce the risk of brucellosis in bovine herds however, due to the small sample size of Jersey crossbred and Punganur the computed estimates were not reliable.
  • ThesisItemOpen Access
    EVALUATION OF PUTATIVE POLYMORPHISM IN GENES UNDERLYING THE NATURAL RESISTANCE AGAINST BOVINE BRUCELLOSIS
    (SRI VENKATESWARA VETERINARY UNIVERSITY TIRUPATI - 517 502. (A.P.) INDIA, 2023-04) CHANDANA YADAGIRI; SUDHAKAR .K (MAJOR); VINOO .R; VENKATA SESHAIAH .CH; SRINIVASA RAO .T
    Brucellosis, caused by Brucella abortus is a disease of livestock that is of major economic importance worldwide, as well as zoonotic. A total of 362 samples were collected from Murrah, Holstein Friesian crossbred, Jersey crossbred, Ongole, Gir and Punganur maintained at different organised farms in Andhra Pradesh to determine the polymorphism of Solute carrier family 11-member 1 (SLC11A1) and Receptor Protein Tyrosine Phosphatase (PTPRT) genes and to investigate their association with resistance or susceptibility to bovine brucellosis. The PCR-RFLP analysis on SLC11A1 (rs109453173) with PstI on 374 bp amplicon revealed all three genotypes in the genetic groups studied, except Punganur where fixation of C allele was noticed. The higher frequency of C allele was observed in HF crossbred, Jersey crossbred and Ongole whereas higher frequency of T allele was noticed in Gir and Murrah. PTPRT/BglII (rs110465273) digestion revealed all three genotypes with higher frequency of T allele in all the genetic groups except Jersey crossbred where the frequency of C and T alleles were similar. PTPRT/DpnI (rs132841890) genotyping revealed that all the genetic groups were monomorphic with C allele. At SLC11A1/PstI locus, moderate genetic diversity in cattle genetic groups and low in Murrah buffaloes were noticed. At PTPRT/BglII locus, moderate level of genetic diversity with heterozygote excess was noticed in Murrah buffaloes and cattle genetic groups except in Ongole cattle. In a total of 222 sampled for case-control association by conducting RBPT and whose results were confirmed by iELISA 41 samples were confirmed as cases based upon the Odds Ratio (OR) values. Among cases, Murrah buffaloes and crossbred cattle were monomorphic at SLC11A1/PstI locus with GG and CC genotypes whereas in indigenous cattle all the three genotypes were observed with high frequency of GG. At PTPRT/BglII locus, none of the animal had CC genotype in cases. In Murrah buffaloes and crossbred cattle, a higher frequency of TT genotype was noticed whereas it was CT in indigenous cattle, The data upon analysis with SNPStats revealed that SLC11A1/PstI locus was non significantly (P=0.68) associated with bovine brucellosis where the odds ratio of CG versus CC-GG (overdominance inheritance model) was 0.65 (0.07-5.72) indicating that there is a heterozygote advantage and PTPRT/BglII locus was near significantly (P=0.07) associated with brucellosis with OR of TT versus CT-CC was 0.52 (0.26-1.07) suggesting TT had higher odds of bovine brucellosis (dominance model). The results from this study are suggestive of genetic predisposition for resistance against bovine brucellosis warranting studies on larger population for a valid conclusion.
  • ThesisItemOpen Access
    IDENTIFICATION OF SINGLE NUCLEOTIDE POLYMORPHISMS AFFECTING SEMEN QUALITY TRAITS IN AI BULLS OF ANDHRA PRADESH
    (SRI VENKATESWARA VETERINARY UNIVERSITY TIRUPATI - 517 502. (A.P.) INDIA, 2023-01) DEEPTHI, CHANDAKA; VINOO, R(MAJOR); SUDHAKAR, K; NARENDRA NATH, D; ASWANI KUMAR, K
    Bull fertility is an important factor for improving the economic value of the herd as the single bull can be used to inseminate many cows using artificial insemination. The bull fertility is measured in terms of semen quality traits like sperm motility and plasma membrane integrity of semen. The scrotal circumference of the bulls influences the semen quality in terms of sperm concentration and percentage of normal sperms of bulls ejaculate. These traits were influenced by both genetic and non-genetic factors. The genes MAP3K1, SPEF2 and PLCZ1 influencing the semen quality traits like scrotal circumference, sperm motility and plasma membrane integrity of semen were identified based on GWAS through Chilibot and Connected paper web-based bioinformatic tools. The SNPs rs463712269 (MAP3K1) and rs722354121 (SPEF2) were identified by screening these genes for missense mutations using Ensembl database and their RFLP pattern was verified using NEBcutterV2.0 software. For PLCZ1 gene, the perusal of literature revealed the presence of rs208019489 affecting the plasma membrane integrity of semen. A total of five frozen semen straws per bull and the relevant data were collected from 239 bulls of different breeds residing in FSBS of Andhra Pradesh. A suitable DNA isolation protocol viz., modified high salt method was selected through comparison of five different DNA isolation procedures in frozen semen. PCR-RFLP polymorphisms were examined in each group by using CviQI, HpyCH4V, and AvaII restriction enzymes for digestion of PCR products in MAP3K1, SPEF2 and PLCZ1 genes respectively. Association of MAP3K1, SPEF2 and PLCZ1 genotypes on scrotal circumference, sperm motility and plasma membrane integrity respectively were worked out using General linear model of SPSS Statistics base 26. The MAP3K1/CviQ1 PCR-RFLP assay revealed that the T allele frequency was more in Ongole population while in other cattle breeds C allele frequency was more. The highest homozygosity values were observed in Jersey and a reversal of this was observed in Ongole and HF population. Negative FIS values in the studied population are indicative of heterozygous excess due to outcrossing. In Murrah, the T allele frequency was more wiaaaaaaaaath effective number of allele of 1.13 and heterozygosity excess at this locus. Fixation of T allele was observed in both the exotic pure breeds (HF and Jersey) and presence of C allele was almost insignificant in cattle SPEF2/ HpyCH4V assay. The low selective pressure on SPEF2 locus was observed and the negative FIS values were observed in the cattle groups studied. In Murrah, the abundance of heterozygotes was observed indicating the selective advantage of C allele in this species and they deviated from the Hardy Weinberg equilibrium suggesting a high selection pressure on this locus. The GG (0.64) genotype frequency was higher than the CG (0.22) in Ongole cattle in PLCZ1/AvaII assay. Except in HF crossbred none off the other cattle genetic groups were with CC genotype which could be an inadvertent result of crossbreeding in HF crossbred. The HF crossbred and indigenous Ongole cattle (P<0.01) were not in agreement with the Hardy Weinberg equilibrium. In Murrah buffaloes, the near fixation of G allele (0.98) was observed accounting for the selection. The presence of low genetic diversity and heterozygosity excess in the Murrah population at this locus was found. Association of MAP3K1/CviQ1 and SPEF2/HpyCH4V polymorphisms had no significant influence on scrotal circumference and pre-thaw and post-thaw sperm motility respectively in both cattle and buffaloes. The PLCZ1/AvaII genotypes have significant influence on the plasma membrane integrity of semen in Holstein Freisiean, Jersey (P<0.05) and Ongole bulls (P<0.01). The plasma membrane integrity of semen was reported to be high in heterozygotes (CG) of Jersey and Ongole cattle. In Murrah, the genotypes have no significant effect on plasma membrane integrity of semen. The present study, conclude the importance of PLCZ1 gene as a marker for semen quality assessment and selection in bulls, owing to the association of PLCZ1 polymorphisms with plasma membrane integrity of bulls. Identification of few more SNPs in the vicinity of the verified SNPs suggests the importance of investigations aiming at screening for further casual mutation responsible for the variation of these traits with higher number of bulls.
  • ThesisItemOpen Access
    GENETIC POLYMORPHISM IN AGOUTI SIGNALING PROTEIN (ASIP) GENE AMONG SHEEP GENETIC GROUPS OF ANDHRA PRADESH
    (SRI VENKATESWARA VETERINARY UNIVERSITY TIRUPATI - 517 502. (A.P.) INDIA, 2022-09) DIANA, M; MURALIDHAR, M(MAJOR); VINOO, R; KALYANA CHAKRAVARTHY, M
    The sheep genetic resources of Andhra Pradesh shows a very clear distinct coat colour pattern. Coat colour is an important economic trait in domestic sheep which vary greatly due to hereditary and environmental factors. The coat colour phenotype is influenced by a large number of genes involved in various stages of melanogenesis, from the migration and maturation of the melanocytes to the production of melanin. The agouti signaling pathway (ASIP) gene is a crucial gene that plays an important role in coat colour determination in sheep through epistatic interaction with other genes. The present study was conducted to provide insight into role of certain ASIP loci in coat colour patterns in the sheep genetic groups of Andhra Pradesh. Blood samples were collected from six sheep genetic groups of Andhra Pradesh. Modified high salt method was used for the isolation of Genomic DNA. An allele specific PCR assay was designed to study variation in the deletion locus D5 located on exon 2 of the gene. PCR-RFLP assay with PstI restriction enzyme was used to determine the non-synonymous SNP (c.5172T>A) polymorphism. Departures from Hardy-Weinberg equilibrium in each population were analyzed using a chi-square test for both the loci. As the pattern of genotypes are not consistent with the genetic groups, it is difficult to draw a conclusion with respect to D5 allele and its role in coat colour in sheep genetic groups of Andhra Pradesh. In 5172T>A SNP, it is interesting to note that how a black coat colour influencing allele under homozygous condition is producing white coat colour in Nellore Palla. No single genetic group is associated with specific genotype for either of the loci so, a total of nine possible combination of diplotypes were scored. However, no specific diplotype is associated with the genetic group. From this, it is plausibly deduced that the combination of wild type at the deletion locus and T allele at the non-synonymous locus could plausibly be giving rise to the white coat colour in these genetic groups except in Nellore Brown which may be due to interactions with other coat colour loci. In order to get better understanding about genetics of coat colour in the native sheep genetic groups of Andhra Pradesh, studies involving coat colour loci other than ASIP gene and specific coat colour pattern of each individual is necessary.
  • ThesisItemOpen Access
    GENETIC EVALUATION OF PRODUCTIVE AND REPRODUCTIVE TRAITS IN CROSSBRED LARGE WHITE YORKSHIRE PIGS (SVVU-T17)
    (SRI VENKATESWARA VETERINARY UNIVERSITY TIRUPATI - 517 502. (A.P.) INDIA, 2022-07) RAMYA NAIDU, B; PUNYA KUMARI, B(MAJOR); GURU VISHNU, P; SURESH BABU, D
    Data collected on 4011 production records and 343 reproduction records of 75% Large White Yorkshire (SVVU-T17) crossbred pigs born during 2005 to 2020 maintained at All India Coordinated Research Project on Pigs (AICRP), Tirupati, Chittoor district was utilized in the present investigation to study the effect of various genetic and non genetic factors including inbreeding on productive, reproductive and litter traits. Single trait analysis were done by fitting a general linear model (GLM) to study the effect of various non-genetic factors (fixed factors) on each trait. The (co)variance components for different production and reproduction traits were estimated by Restricted Maximum Likelihood Method (REML) using WOMBAT programme of Mayer (2007). The (co)variance components and heritability were estimated using four different models with direct, maternal and permanent environment effects were fitted and best model was selected through log likelihood ratio test (LRT). Estimates of (co) variance between different production and reproduction traits were obtained through bivariate analysis. Estimates of breeding values (EBV) for different production traits were obtained by Best Linear Unbiased Prediction (BLUP) method. The overall least squares mean body weights were 1.09 ± 0.003, 1.54±0.004, 2.78±0.009,4.11±0.013,5.44±0.017,6.38±0.017,7.38±0.02,8.48±0.024,9.85±0.03,14.57±0.06,20.49±0.09,29.13±0.13 and 35.94 ± 0.17 kg at birth (BW0), BW1, BW2, BW3, BW4, BW5, BW6, BW7, BW8, BW12, BW16, BW20 and BW24 weeks of age, respectively. Period, Season of birth and inbreeding had significant influence (P<0.05) on body weights at all ages. Parity had significant influence on body weights at birth (BW0), BW7, BW8 and BW12 weeks of age only. Sex of the piglet had significant influence on body weights at birth (BW0), BW1, BW2, BW3 and BW4 weeks of age only. Body weights of piglets born in rainy and winter seasons recorded significantly higher body weights. The overall least squares means for AFF and FI in 75% crossbred LWY (SVVU-T17) pigs were 352.59 ± 6.42 and 249.14 ±2.15 days, respectively. The effect of period, season and inbreeding were significant on reproductive traits. The overall least squares means for LSAB, LSAW, LWAB and LWAW in 75% crossbred LWY (SVVU-T17) pigs were 7.71 ± 0.10, 7.44 ± 0.10, 8.58 ± 0.13 kg and 55.42 ± 0.91 kg, respectively. The effect of period and parity were significant (P<0.05) on majority of the litter traits. Effect of level of inbreeding on all litter traits was also found to be significant. Inbreeding co-efficient (Fx) values in the population varied from 0 to 25.5 percent with an overall mean of 0.36 percent. The direct heritability estimates (h2) obtained through the best model for body weights at birth (BW0), BW1, BW2, BW3, BW4, BW5, BW6, BW7, BW8, BW12, BW16, BW20 and BW24 weeks of age were 0.54, 0.91, 0.87, 0.86, 0.93, 0.94, 0.81, 0.82, 0.18, 0.16, 0.16, 0.20 and 0.87, respectively. Maternal heritability (m2) values were 0.05, 0.07, 0.12, 0.05, 0.02, 0.04, 0.17, 0.16, 0.16, 0.20 and 0.007 at BW1, BW2, BW3, BW4, BW5, BW6, BW8, BW12, BW16, BW20 and BW24 weeks of age in 75% Crossbred LWY (SVVU-T17) pigs. Heritability estimates from REML for age at first farrowing (AFF), litter size at birth (LSAB), litter weight at birth (LWAB), litter size at weaning (LSAW), litter weight at weaning (LWAW) and farrowing interval (FI) were 0.70, 0.96, 0.95, 0.87, 0.93 and 0.70, respectively. The repeatability estimates for LSAB, LWAB, LSAW, LWAW and FI were 0.97, 0.96, 0.88, 0.94 and 0.80, respectively. The highest heritability (0.96) and repeatability (0.97) estimates were recorded for LSAB. All the estimates of genetic correlations among body weight traits were positive. Estimates of genetic correlations for birth weight with weight at later ages were medium to high (0.40 to 0.98). All the estimates for phenotypic correlations among body weight traits were positive. Birth weight had the highest phenotypic correlation with the other traits (0.03 to 0.98). Phenotypic correlations among litter traits were positive and ranged from 0.11 ± 0.10 to 0.91± 0.01. Phenotypic correlations between AFF and FI was low and positive (0.05±0.01) in direction. The estimated overall average breeding values of sires for BW0, BW1, BW2, BW3, BW4, BW5, BW6, BW7, BW8, BW12, BW16, BW20 and BW24 weeks of age were 1.09, 1.53, 2.77, 4.08, 5.39, 6.27, 7.22, 8.26, 9.53, 13.21, 14.40, 20.92 and 24.48 kg, respectively by BLUP method. Highest range of EBV was observed for 24 weeks body weight. The top ranking sires had higher genetic superiority of 51.63% and 64.48% over the average breeding values at BW1 and BW20 weeks of age, respectively.
  • ThesisItemOpen Access
    GENETIC EVALUATION OF GROWTH TRAITS USING RANDOM REGRESSION MODELS IN JERSEY CROSSBRED CATTLE
    (SRI VENKATESWARA VETERINARY UNIVERSITY TIRUPATI - 517 502. (A.P.) INDIA, 2022-04) ANJALI, V; SAKUNTHALA DEVI, K(MAJOR); SUDHAKAR, K; VENKATA SESHAIAH, CH
    A total of around 34,726 number of body weight records of 7363 animals, belonging to 108 sires and 7363 dams with known history and pedigree having minimum 3 number of records per each animal were considered. The data was recorded on body weight at repeated intervals from birth to 54 months of age i.e. BW0, BW6, BW12, BW18, BW24, BW30, BW36, BW42, BW48 and BW54 and were subjected to random regression analysis for additive genetic, individual permanent environmental, maternal genetic and maternal permanent environmental effects by using different Legendre polynomials like quadratic, cubic and quartic etc. Preliminary analysis revealed that all fixed effects included in the study were having significant (P98% and 1.26% of total genetic variation, whereas 3rd Eigen function was zero. The direct genetic heritability estimates obtained for BW0, BW6, BW12, BW18, BW24, BW30, BW36, BW42, BW48 and 54 months of age were 0.03±0.01, 0.09±0.03, 0.17±0.03, 0.09±0.02, 0.18±0.05, 0.22±0.07, 0.21±0.07, 0.21±0.07, 0.23±0.09 and 0.26±0.10 respectively. The heritability value for individual permanent environmental variance was found to be low (0.01±0.10) at birth and high (0.44±0.13) at 54 months of age. The heritability estimates for maternal effects m2 & c2 were found to be similar and low (0.01 to 0.03) across the ages. The direct genetic correlation of birth weight was found to be negatively correlated with BW6 (-0.71±0.29), BW12 (-0.47±0.26), BW18 (-0.22±0.13) and positively correlated with BW24 (0.02±0.03), BW30 (0.12±0.04), BW36 (0.22±0.04), BW42 (0.29±0.05), BW48 (0.34±0.05) and BW54 (0.39±0.06). The animal permanent environmental correlations between body weight at different ages showed strong positive relationship with a range of 0.18±0.06 (BW0 and BW54) to 1.0±0.0 (BW30 and BW36; BW36 with BW42, BW48 and BW54; BW42 with BW48 and BW54; BW48 and BW54). The estimates of maternal genetic and maternal permanent environmental correlations showed a similar pattern of negative correlation of birth weight with body weight at different ages (-0.69±0.02 to -0.35±0.03) and (-0.76±0.02 to -0.48±0.22). The average breeding value for birth weight was found to be 23.24 kg, which improved to 321.10 kg at 48 months of age. Maximum breeding value (333.49 kg) was recorded at 42 months of age.
  • ThesisItemOpen Access
    GENETIC EVALUATION OF GROWTH TRAITS USING RANDOM REGRESSION MODELS IN JERSEY CROSSBRED CATTLE
    (SRI VENKATESWARA VETERINARY UNIVERSITY TIRUPATI - 517 502. (A.P.) INDIA, 2022-04) ANJALI, V; SAKUNTHALA DEVI, K(MAJOR); SUDHAKAR, K; VENKATA SESHAIAH, CH
    A total of around 34,726 number of body weight records of 7363 animals, belonging to 108 sires and 7363 dams with known history and pedigree having minimum 3 number of records per each animal were considered. The data was recorded on body weight at repeated intervals from birth to 54 months of age i.e. BW0, BW6, BW12, BW18, BW24, BW30, BW36, BW42, BW48 and BW54 and were subjected to random regression analysis for additive genetic, individual permanent environmental, maternal genetic and maternal permanent environmental effects by using different Legendre polynomials like quadratic, cubic and quartic etc. Preliminary analysis revealed that all fixed effects included in the study were having significant (P98% and 1.26% of total genetic variation, whereas 3rd Eigen function was zero. The direct genetic heritability estimates obtained for BW0, BW6, BW12, BW18, BW24, BW30, BW36, BW42, BW48 and 54 months of age were 0.03±0.01, 0.09±0.03, 0.17±0.03, 0.09±0.02, 0.18±0.05, 0.22±0.07, 0.21±0.07, 0.21±0.07, 0.23±0.09 and 0.26±0.10 respectively. The heritability value for individual permanent environmental variance was found to be low (0.01±0.10) at birth and high (0.44±0.13) at 54 months of age. The heritability estimates for maternal effects m2 & c2 were found to be similar and low (0.01 to 0.03) across the ages. The direct genetic correlation of birth weight was found to be negatively correlated with BW6 (-0.71±0.29), BW12 (-0.47±0.26), BW18 (-0.22±0.13) and positively correlated with BW24 (0.02±0.03), BW30 (0.12±0.04), BW36 (0.22±0.04), BW42 (0.29±0.05), BW48 (0.34±0.05) and BW54 (0.39±0.06). The animal permanent environmental correlations between body weight at different ages showed strong positive relationship with a range of 0.18±0.06 (BW0 and BW54) to 1.0±0.0 (BW30 and BW36; BW36 with BW42, BW48 and BW54; BW42 with BW48 and BW54; BW48 and BW54). The estimates of maternal genetic and maternal permanent environmental correlations showed a similar pattern of negative correlation of birth weight with body weight at different ages (-0.69±0.02 to -0.35±0.03) and (-0.76±0.02 to -0.48±0.22). The average breeding value for birth weight was found to be 23.24 kg, which improved to 321.10 kg at 48 months of age. Maximum breeding value (333.49 kg) was recorded at 42 months of age.
  • ThesisItemOpen Access
    GENETIC DIVERSITY IN SYNTHETIC CHICKEN BREEDS RAJASRI AND VANARAJA AND THEIR DIVERGENCE FROM ASEEL USING MITOCHONDRIAL COI GENE
    (SRI VENKATESWARA VETERINARY UNIVERSITY TIRUPATI - 517 502. (A.P.) INDIA, 2022-04) BALA SAI SUBHADRA DEVI, MADDIMSETTI; MURALIDHAR, M(MAJOR); SUDHAKAR, K; IQBAL HYDER
    Rural backyard poultry plays an important role in improving food and nutritional security and reducing livelihood insecurity for the poorest households. Backyard farming's low productivity has led many researchers to develop synthetic colored chicken breeds as an alternative. Rajasri and Vanaraja are two such synthetic chicken breeds developed with a motive of improving productivity of backyard poultry besides maintaining the consumer preference for colored chicken and brown shelled eggs. In the present study, it was aimed to characterize the mitochondrial COI region of the Rajasri, Vanaraja breeds from Andhra Pradesh and study their genetic diversity with respect to Aseel breed and explore the possibility of identifying the breeds using this COI gene. Genomic DNA was isolated using phenol-chloroform method from the already collected blood samples of six unrelated individuals belonging to each of the three genetic groups. A 651 bp of mitochondrial DNA encompassing COI region was amplified using primers available from the published literature. The amplicons were sequenced using Sanger’s method. The sequences were aligned to other Indian native chicken breeds, Red jungle fowls from India, China, Japan, Myanmar, layer birds from Germany, Plymouth rock from USA, leghorns from Japan, Canada. A total of 70 sequences were obtained from the NCBI database. The DNA polymorphism and divergence among the three genetic groups, genetic differentiation estimates were measured using DNASP v6 software. DNA barcode signatures among the three genetic groups, phylogenetic analysis was performed using MEGA X software. The results showed that the DNA polymorphism is relatively low in the three genetic groups. Among the three populations Rajasri is highly differentiated from both Aseel and Vanaraja. The analysis revealed the potentiality of COI gene as a barcode in identifying Rajasri birds through a (m.7488 G>A) substitution. The phylogenetic analysis revealed monophyletic origin of the three genetic groups represented as a single clade and sub clustering of Rajasri birds within the first clade