Thesis

Browse

Search Results

Now showing 1 - 6 of 6

Open 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.
Open Access
IDENTIFICATION OF POLYMORPHISM AND EPIGENETIC MODIFICATION OF PARTIAL PROMOTER OF ACACB GENE VIS-A-VIS EFFECT OF POLYMORPHISM ON EGG PRODUCTION AND QUALITY TRAITS IN LAYERS
(SRI VENKATESWARA VETERINARY UNIVERSITY TIRUPATI - 517 502. (A.P.) INDIA, 2021-03) SHIVAPRASAD, C.H; Vinoo, R (MAJOR); Chatterjee, R.N; Muralidhar, M; Narendranath, D; Aswani kumar, K
Poultry eggs are rich source of inexpensive, high-quality protein, vitamins namely A, B2, B6, B12, D, E and K, minerals like zinc, iron selenium, and copper etc. Egg yolk contains more calories and fat. In the recent past, there is demand for consumption of food sources of poly unsaturated fatty acids like dodecanoic acid, nonadecanoic acid, myristoleic acid, alpha linoleic acid and omega-3 fatty acids. The fatty acid composition depends on type of diet and genetic composition. Among the candidate genes, the acetyl-coenzyme A carboxylase beta (ACACB) is a candidate gene that can influence fatty acid composition. Perusal of literature revealed that the identification of partial promoter of ACACB gene was not done in chicken. Hence the present study is aimed at identification of partial promoter region, genetic polymorphism, gene expression and epigenetic regulation of ACACB gene in chicken. Further, the study also aimed at unraveling the association of the genetic polymorphism with body weight, egg production and egg quality traits in the two-layer lines, IWI and IWK. The study could successfully predict the minimal promoter region which is in the upstream 0.5 kb region. The region included certain transcription factors like CEBP, COUP, HNF4, PPARA, SREBP1, and T3R which are known to be involved in lipid metabolism. The minimal promoter region could potentially translate the gene in chicken embryo fibroblasts. Further, the minimal promoter region is polymorphic with 12 haplotypes and 18 haplogroups based on SSCP analysis. The haplotype h5 is least frequent in both IWI and IWK lines while h11 haplotype is most frequent in IWI line and h4 haplotype is the most frequent one in IWK line. Sequencing of the haplotypes revealed indels and substitutes in these haplotypes. The h8h8 haplogroup is associated with higher body weight at 8th, 16th and 20th week in IWI line. The haplogroup h12h12 is strongly associated with higher egg production in IWI line up to 52 weeks of age. The egg weight didn’t vary significantly within the line in any of the age except h1h2 haplogroup in IWI line at 72nd week, which is associated with higher egg weight. The shell weight is not particularly associated with any of the haplotypes in IWI line, but within IWK line, the h6h6, h9h9 haplogroups showed higher shell weight. The h9h9 and h9h10 haplogroups are associated with higher shell weight in IWK line compared to IWI line. The total egg fat% is significantly higher within IWI line, when they have h10h10 haplogroup. The same haplogroup also showed higher total fat% in IWI line compared to IWK line. There is no significant association is observed between haplogroups and HDL concentration in IWI line. But, in IWK line, the h8h8 haplogroup is associated with high serum HDL cholesterol concentration. Temporal expression pattern of the ACACB gene indicated that the gene expresses in all stages in the skeletal muscle of chicken during pre and post-hatch period. Epigenetic profile of the minimal promoter indicated that there are seven CpG islands in this region. There is negative relationship between highest and lowest expressed birds with the percent methylation in both the genetic groups. The present study suggests that the ACACB gene plays a crucial role in pre and post- hatch period in IWI and IWK lines. Further studies with spatial expression pattern of the gene and experiments aiming at precise functional analysis would provide additional insights into the role of ACACB gene in chicken in providing healthy eggs and meat.
Open Access
CHARACTERIZATION AND EVALUATION OF PHYLOGENETIC STATUS OF KENGURI, MOULI AND YALAGA SHEEP OF KARNATAKA
(SRI VENKATESWARA VETERINARY UNIVERSITY TIRUPATI - 517502. (A.P.) INDIA, 2019-09) SIDDALINGSWAMY HIREMATH; VINOO, R(MAJOR); APPANNAVAR, M.M.; MURALIDHAR, M; VENKATA SESHAIAH, Ch.; RAMANI PUSHPA, R.N.
Karnataka state hosts five well adapted indigenous sheep breeds viz. Bellary, Kenguri, Hassan, Deccani and Mandya. Apart from these recognized breeds, there are two lesser known genetic groups viz., Mouli and Yalaga reared by farmers in North Karnataka in Vijayapura and Bagalkote districts, respectively. The objective of the present research is to document and compare the phenotypic traits of three genetic groups, Kenguri, Mouli and Yalaga sheep of Karnataka and to study the genetic diversity existing in these genetic groups, using mitochondrial and Y-chromosome markers. Data on morphological and morphometric traits were recorded in the three genetic groups from farmer's flocks in their breeding tracts. Data was classified based on their age and sex. It was observed that the Kenguri sheep were predominantly brown with white patch on forehead. Males are horned and ewes are polled in this breed. The animals are usually with black hooves, medium long drooping ears, short tail, straight face/fore-head or nose line in males and females. The Mouli sheep were generally white with brown patches all over the body, long tail, polled in both sexes, long drooping ears and typical convex face or bowed fore head with Roman nose. The Yalaga sheep were white in colour, with males being horned and females were polled. They have long tail, long drooping ears, straight forehead and straight nose line. The morphometric traits namely body length, height at withers, flank width and face length were longer in Mouli sheep compared to Kenguri and Yalaga sheep. Body weight is also larger in Mouli sheep compared to Kenguri and Yalaga sheep. The trend also holds good for age wise analysis among the three breeds. The genetic diversity and divergence among the three breeds were assessed using mitochondrial DNA. Metadata of fourteen Indian, Chinese, Caucasian breeds and wild Mouflon were also used for the analysis. The wild ancestor of sheep i.e. urial mitochondrial D-loop region was used as an outgroup for phylogenetic analysis. Mitochondrial DNA analysis indicated that there is high variation within these genetic groups but low differentiation between the genetic groups. Also there is high rate of gene flow among the three genetic groups, particularly between Mouli and Yalaga breeds. The observation is contrasting to the phenotypic differences between the two breeds. The phylogenetic analysis indicated that three genetic groups were predominantly clustered in clade A except one Kenguri sheep which is clustered in clade B. To understand paternal origin of the three breeds, the 611 bp promoter region of SRY gene was amplified and sequenced in the three genetic groups. Orthologous region for a total of 17 sheep representing domestic and wild sheep were obtained from the NCBI database. The three sheep breeds under study didn’t reveal any variation in the promoter region of the SRY chromosome, suggesting they are likely to have same paternal origin. Phylogenetic analysis of sequences indicated a plausible paternal lineage from European or Armenian Mouflon for the three genetic groups. The molecular clock analysis based on mitochondrial control region indicated that the Karnataka breeds must have diverged in the lineage A about 20000 yrs ago. A similar number of years ago the Kenguri individual in clade B also might have diverged. This estimate is slightly higher than the time of sheep domestication suggesting possibility of multiple domestication events in the Indian subcontinent. The results in the present study indicate that phenotypically the three genetic groups are different. At molecular level the Mouli and Yalaga sheep are not differentiated based on the mitochondrial DNA analysis. The paternal source for the three genetic groups is likely from the European or Armenian Mouflon.
Open Access
GENETIC ANALYSIS OF PRODUCTIVE AND REPRODUCTIVE TRAITS IN FARM BRED NELLORE JODIPI SHEEP
(SRI VENKATESWARA VETERINARY UNIVERSITY TIRUPATI - 517502. (A.P.) INDIA, 2019-07) BHAKTHAVATCHALAM, S; PUNYA KUMARI, B (MAJOR); SUDHAKAR, K; JAGADEESWARA RAO, S; RAMANI PUSHPA, R.N.
The data collected on 5008 production records and 2965 breeding records of Nellore Jodipi sheep maintained at the Network Project on Sheep Improvement, Livestock Research Station Palamaner, Chittoor district was utilized in the present investigation to study the effect of various factors including inbreeding on productive and reproductive traits and also to predict and compare the breeding values by using Least Squares (LS), Best Linear Unbiased Prediction (BLUP) and Restricted Maximum Likelihood (REML) methods. The overall least squares means for BW (Birth Weight), 3M (3 Months), 6M (6 Months), 9M (9 Months) and 12 M (12 Months) body weights were 3.03 ± 0.01, 13.29 ± 0.07, 17.86 ± 0.10, 21.34 ± 0.12, 24.96 ± 0.15 kg, respectively. Period, season, sex and parity had significant influence (P<0.01) on all the growth traits under study. The overall least square means for AGR i.e. from birth to 3, 3 to 6, 6 to 9, 9 to 12 and 3 to 12 months were 114.95 ± 0.76, 50.01 ± 0.65, 38.50 ± 0.64, 38.00 ± 0.72 and 40.19 ± 0.46 gms, respectively. Period and sex had significant influence on AGR for all age intervals. Both pre-weaning AGR and post-weaning AGR’s were significantly (p < 0.01) influenced by season of birth except post-weaning AGR 3-12 months. The overall least squares means for age at first lambing (AFL) in Nellore Jodipi sheep was 794.2 ± 6.9 days. Period of birth of ewe but not season of birth was found to be significant on AFL. The overall least squares means for lambing interval was 371.6 ± 11.9 days. Parity of ewe at lambing was found to be significant. The overall least squares mean lambing percentage (ewe covered) was 63.1 ± 2.30. Contemporary Group (CG) at breeding, but not parity of ewe at lambing had a highly significant influence on lambing percent. The mean generation interval, inbreeding coefficient (F), proportion of population inbred, individual increase in inbreeding, equivalent number of generations (EqGi) and effective population size based on birth year were 3.37y, 0.97 %, 31 %, 0.48 %, 2.54 and 1260.52, respectively. The regression coefficients of most of the traits on inbreeding coefficient (F), were negative and non-significant. Maximum and significant effect (p < 0.01) of ‘F’ was noticed on 9M, with a decrease of 0.075 kg of mean value per every 1 per cent increase in inbreeding. Effect of inbreeding was significant on post-weaning AGR 3-6 months. There was a decrease of 0.411 grams mean value in pre-weaning AGR, for every 1 per cent increase in ‘F’. The regression of age at first lambing on F was positive and significant. There was an increase of 5.565 days in AFL per every 1 per cent increase in F. The regression of lambing interval on F was negative (-1.223 days) and insignificant. The regression of lambing percent on F was positive and non-significant (0.001%). When inbreeding coefficient (F), included as fixed class in the analysis it exhibited highly significant effect on BW (p < 0.01), 3-6 months and 6-9 months post-weaning AGR; while significant (p < 0.05) on 3M, 12M body weights and 3-12 months post-weaning AGR. Effect of level of inbreeding on all reproductive traits was also found to be insignificant. The direct heritability estimates for BW, 3M, 6M, 9M and 12M from the best models in Nellore Jodipi sheep were 0.076, 0.194, 0.208, 0.199 and 0.136, respectively. The maternal heritability (m2), estimated from best models for body weights in which it was important, were 0.046, 0.038, 0.063 and 0.082 at 3M, 6M, 9M and 12M of age, respectively in Nellore Jodipi sheep. The estimates of h2 were moderate for pre-weaning (0.210) and all post weaning AGR (0.158 to 0.263) traits. The maternal heritability (m2), estimated from best models for the AGR traits in which it was important were 0.032, 0.025 and 0.029 for pre-weaning; post weaning 6-9 and 3-12 months AGR, respectively. The heritability estimates obtained for age at first lambing (0.082) and lambing percent (0.013) were low. For lambing interval, the estimated heritability was near to zero (0.0002). Repeatability for repeatable reproductive traits like lambing per cent (per ewe covered) was low (0.059) and for lambing interval, the value was near to zero (0.00018). 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 (0.212 to 0.508). The correlation coefficients for 3M, 6M and 9M, with weights at later ages were medium to high (0.449 to 0.894). All the estimates for phenotypic correlations among body weight traits were positive. Birth weight had the lowest phenotypic correlation with the other traits (0.260 to 0.371), whereas, the remaining weights had moderate correlations (0.577 to 0.873). High estimates greater than 0.7 were observed for WW, 6M and 9M with subsequent ages. All the body weight traits (6M, 9M and 12M) had strong positive relationship with pre weaning AGR with medium to high range of values (0.393 to 0.855). Phenotypic correlations also followed the similar trend as genetic correlations (0.545 to 0.778). Genetic association between birth weight with age at first lambing (AFL) was positive and low in magnitude (0.07). Whereas, all body weight traits with lambing interval (LI) showed negative trend. Lambing interval recorded highest and lowest correlations with birth weight (-0.211) and 3 months body weight, respectively (-0.502). Phenotypic association between birth weight and age at first lambing (AFL) was negative and low in magnitude (-0.036). Highest value was noticed between birth weight with lambing interval (-0.031) and lowest between 3 months with lambing interval (-0.153) on phenotypic scale. The estimated overall average breeding values of sires for BW, 3M, 6M, 9M and 12 M body weights were found to be 3.09, 14.36, 19.04, 22.78, 24.73 kg by LSM; 2.96, 13.20, 18.12, 21.59 and 24.62 kg by BLUP method and 2.96,13.19, 18.11, 21.60 and 24.63 kg by DFREML methods, respectively. BLUP method was adjudged to be the most efficient method followed by LS and DFREML methods, because of its least error variance. LSM was best fitted model over the other two methods of sire evaluation based on coefficient of determination (R2), but the accuracy of BLUP was much closer to LSM than DFREML. The rank correlations among breeding values of sires estimated from different methods of sire evaluation were all high, and highly significant (P<0.01). The values ranged from 0.487 (LSM with DFREML for 9M) to 0.999 (BLUP with DFREML for BW). The rank correlations between BLUP and DFREML were greater than 0.9 for all the traits. BLUP or DFREML could select the same set of sires with almost similar ranking for unbiased estimates of breeding values for production traits. The direct genetic trends for BW, 3M, 6M, 9M and 12M were 0.003, 0.067, 0.084, 0.038 and 0.030, respectively in Nellore Jodipi sheep and the corresponding phenotypic trends were 0.010, 0.044, 0.083, 0.201 and 0.248, respectively.
Open Access
GENETIC ANALYSIS OF EXOTIC AND NATIVE CHICKEN
(SRI VENKATESWARA VETERINARY UNIVERSITY TIRUPATI - 517 502. (A.P.) INDIA, 2010-12) SREENIVAS, DASARI; GNANA PRAKASH, M(MAJOR); SHARMA, R.P; RUDRANATH CHATTERJEE; RAVINDER REDDY, V; MAHENDER, M
ABSTRACT: The present investigation was carried out for estimation of genetic parameters on certain production, immunocompetence and egg quality traits in IWH, IWI and IWK strains and control population of White Leghorns and microsatellite marker based analysis on IWH and IWK strains and native breeds of Aseel and Kadaknath maintained at the Project Directorate on Poultry, Hyderabad. Significant genetic group differences were observed for all the production traits studied. The age at first egg (AFE) and body weights at 40, 52 and 64 weeks of age ranged from 143.49 * 0.56 to 155.63 * 0.57 days, 1290.74 * 7.21 to 1428.36 8.36, 1377.72 8.43 to 148 1.82 * 9.77 and 1455.73 * 9.49 to 1547.15 * 1 1.18 g, respectively. Egg production up to 40, 64 and 72 weeks of age ranged from 94.08 * 0.50 to 106.15 * 0.49, 178.24 * 1.20 to 202.32 k 1.18 and 190.90 + 1.22 to 215.17 1.20 eggs. respectively while egg weight at 28, 40, 52 and 64 weeks of age ranged from 43.81 * 0.15 to 46.77 * 0.15, 49.89 * 0.18 to 53.13 * 0.17, 53.1.3 k 0.16 to 54.65 * 0.15 and 55.47 * 0.15 to 57.59 * 0.14 g, respectively. The AFE was low to moderately heritable while the body weights were moderate to highly heritable. In general, egg production traits were lowly heritable while the egg weights were low to highly heritable. The genetic and phenotypic correlations of AFE were positive with body weights and egg weights but negative with egg production. The genetic and phenotypic correlations of body weight at 52 and 64 weeks of age were negative with egg production and positive with egg weight. The correlations among egg production traits and among egg weights were positive and high while the association between egg production and egg weight traits was moderate to high but negative. Significant differences among genetic groups were observed for antibody titre against SRBC and NDV only. Mean anti SRBC titre, anti NDV titre and response to PHA-P (mrn) ranged from 4.729 * 0.142 to 5.803 * 0.11 8, 10.033 .t 0.056 to 1 1.045 * 0.049 and 0.133 * 0.075 to 0.527 * 0.164, respectively. Heritability estimates of antibody titre against SRBC, NDV and response to PHA-P were low to medium. The anti SRBC titre had positive genetic correlation and negative phenotypic and environmental correlations with AFE. Genetic and phenotypic correlations with body weights and egg production traits were mostly positive. The genetic and phenotypic correlations of antibody titre against NDV with AFE and annual egg production were mostly positive. The correlations of response to PHA-P with other traits varied both in magnitude and direction. Significant genetic group differences were observed for various egg quality traits studied. The egg weight, haugh unit, yolk index, albumen index, yolk weight, albumen weight, shell weight and shell thickness ranged from 53.89 0.43 to 50.01 0.48 g, 65.38 * 0.92 to 80.98 * 1.01, 0.341 * 0.003 to 0.353 * 0.003, 0.056 * 0.002 to 0.087 * 0.002, 14.16 i 0.13 to 15.58k 0.12 g, 30.92 * 0.39 to 33.18k 0.39 g, 4.32 * 0.05 to 5.12 * 0.05 g and 0.336 k 0.003 to 0.376 * 0.003 mrn, respectively. The heritability estimates based on sire, dam and sire + dam components of variance for egg weight, yolk index, albumen index and albumen weight ranged from low to medium while those of haugh unit, yolk weight, shell weight and shell thickness ranged from low to high. The genetic and phenotypic correlations of egg weight with other egg quality traits except shell quality traits were mostly positive and moderate to high. High positive genetic and phenotypic correlations between haugh unit and other traits were observed. Genetic correlation of yolk weight with albumen weight was positive while that with shell quality traits was mostly negative. Shell weight was positively correlated with shell thickness. All the 15 microsatellite loci were polymorphic. The mean number of alleles (Na) varied from 2.0 to 5.0 among the loci and 3.13 * 0.13 to 3.80 k 0.13 among the populations. The effective number of alleles varied from 1.041 to 4.755 across the loci and between 2.33 0.09 and 3.21 k 0.1 1 among the populations. The allele frequency ranged from 0.012 to 0.980 across the loci. The overall mean PIC values ranged from 0.038 to 0.756 across the loci and 0.434 to 0.579 among the populations. The expected and observed heterozygosity estimates (0.634 * 0.020 and 0.723 * 0.031) were highest in Aseel, while lowest in IWH strain (0.500 i 0.022 and 0.471 * 0.034). Overall mean inbreeding coefficients for IWH, IWK, Kadaknath and Aseel were 0.205, 0.1 16, -0.052 and -0.130, respectively. The mean values of Fls, FST and FIT values over all the loci were -0.050 & 0.065,0.05 1 & 0.308 and 0.003 k 0.064, respectively. The genetic distance was least between Kadaknath and Aseel (0.023) and highest between IWH and Aseel (0.160). Kadaknath and Aseel were closer with maximum genetic identity index (0.977) while IWH and Aseel were more wide apart with least identity index (0.852). Phylogenetic analysis grouped IWH and IWK strains in to one cluster and Kadaknath and Aseel breeds in to another cluster. All the loci except MCW 048 deviated significantly from equilibrium frequency in at least one of the populations, while all the loci except MCW 007 and MCW 048 departed from the equilibrium frequency on overall basis.
Open Access
GENETIC EVALUATION OF ONGOLE CATTLE UNDER PROGENY TESTING PROGRAMME
(SRI VENKATESWARA VETERINARY UNIVERSITY TIRUPATI - 517 502. (A.P.) INDIA, 2010-05) SAI REDDY, S; RAMESH GUPTA, B(MAJOR); VINOO, R; SUDHAKAR, K; MAHENDER, M
ABSTRACT : The data on Ongole cattle maintained under the ICAR Network Project on Genetic improvement of Ongole breed through the Associate Herd Testing Programme at Lam farm, Guntur (1935), Cattle Breeding Farm, Chadalawada, Prakasam district (625), Livestock Research Station Mahanandi, Kurnool district (404) and Composite Livestock Farm, Chintaladevi, Nellore district (201), spread over a period of 22 years from 1987 to 2008, were analyzed. Multivariate analysis was undertaken to estimate the genetic divergence between the sets of the bulls under the progeny testing programme. The morphometric differences of the chromosomes between the cows born by embryo transfer technique and artificial insemination were studied. The overall least squares means for body weight, height at withers, chest girth and body length of Ongole cattle from birth to 24 months of age ranged from 26.49 to 245.40 kg, 71.58 to 133.58 cm, 66.35 to 146.53 cm and 62.91 to 127.64 cm, respectively. The effects of farm and period of birth were significant on the body weight, height at withers, chest girth and body length at all the ages studied. Season of birth significantly affected the body weight at birth, 1 and 3 months of age; height at withers at birth, 1 and 6 months age; chest girth at 3 months and body length at 6 months of age. The sex of the calf and set of the bulls significantly influenced the body weights and biometrical measurements, virtually at all the ages. The overall least squares means for 300-days lactation milk yield, total lactation milk yield, lactation length, peak yield, days to reach peak yield, milk yield per day of lactation and milk yield per day of calving interval were 718.53 kg, 720.90 kg, 233.99 days, 3.90 kg, 35.67 days, 3.08 kg and 1.43 kg, respectively and almost all these traits were affected significantly by the farm, period of calving, set of the bulls and order of lactation. However, peak yield alone was affected (P<0.01) by the season of calving and none of the production traits were influenced by the sex of the calf. The overall least squares means of number of inseminations per conception, age at first conception, age at first calving, gestation period, service period, dry period and calving interval were 2.02, 1358.82 days, 1592.22 days, 287.58 days 232.38 days, 282.94 days and 517.61 days, respectively and almost all these characters were affected by the farm, period, set of the bulls and order of lactation, while none of the reproductive traits were influenced by the season. Sex of the calf had significant influence on gestation period and dry period only. The mean breeding efficiency of the Ongole cows varied from 63.66 to 83.75 per cent and the rank correlations of breeding efficiency estimated by three different formulae were positive and significant. The farm and set of the bulls significantly influenced the breeding efficiency. The overall least squares means for life time milk yield, herd life, productive life, milk yield per day of herd life and productive life; wet days and dry days per herd life; wet days and dry days per productive life and gestation period per herd life and productive life were 3805.88 kg, 3773.84 days, 2287.48 days, 1.00 and 1.67 kg; 32.15 and 67.85%; 53.58 and 46.41% and 39.46 and 66.54%, respectively and all these traits were influenced by one or the other of the non-genetic effects studied. However, none of these characters were influenced by the set of the bulls. The estimates of heritability and genetic and phenotypic correlations of body weights and biometrical measurements varied from 0.01 to 0.43, 0.06 to 0.99 and 0.03 0.40 respectively. Similarly, the heritabilities of 300-days lactation milk yield, total lactation milk yield, Lactation length, peak yield, milk yield per day of lactation, milk yield per day of calving interval, gestation period, service period, dry period and calving interval were 0.27, 0.24, 0.21, 0.24, 0.09, 0.22, 0.14, 0.06, 0.06 and 0.06, respectively. The genetic correlations among production and reproduction traits were positive and ranged from 0.04 to 0.99, while the phenotypic correlations among these traits varied from 0.01 to 0.49. The heritability estimates for life time milk yield, herd life, productive life, lactation milk yield per herd life and productive life; wet and dry days per herd life; wet and dry days per productive life and gestation period per herd life and productive life were 0.66, 0.10, 0.17, 0.49 and 0.49; 0.23 and 0.23; 0.30 and 0.30 and 0.08 and 0.08, respectively. The genetic correlations among the various life time production traits ranged between 0.69 and 0.99 whereas the phenotypic correlations ranged from 0.01 to 0.47. The Mahalonobis genetic distances (D2) between all combinations of sets were highly significant. The calving interval, total lactation milk yield and lactation length contributed 40%, 40% and 20% to the total genetic diversity among the sets. Two distinct clusters were formed, the first one consisting of sets 1, 2, 3 and 5, while the second cluster had only 4th set. The diploid chromosome number was found to be 60, XX in both ET born and AI born cows. All autosomes were acrocentric, while the X-chromosome was longest submetacentric. The mean relative length of the autosomes varied from 1.95 to 4.97 and 1.95 to 4.99 per cent in ET and AI born cows respectively. The relative length of chromosome 20 of ET born cows was significantly longer (2.86%) than that of the AI born cows (2.77%). Except this, no other differences either in chromosome number or in chromosome morphology were detected between the ET born and AI born cows, suggesting that ET born cows were as good as the AI born cows with respect to their chromosome profiles. The present study indicated that the overall performance of the animals of Lam farm, with respect to the production, reproduction and life time traits, was the best, followed by Chadalawada, Mahanandi and Chintaladevi farms. The performance of the Ongole cattle during various periods did not exhibit any specific trend while the animals either born or calved during summer exhibited superior performance, when compared to those in rainy and winter seasons. The production and reproduction performance of the cows delivering female calves was better than those giving birth to male calves. The genetic variation among the set of bulls did not show a definite trend although the multivariate analysis revealed two clusters, one consisting of sets 1, 2, 3 and 5 and another set 4, with a considerable inter cluster distance.

Thesis

Browse

Thesis Type

Type

Author

Date

Subject

Search Results