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2007 - 200912010 - 20151
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Subject: Animal Genetics and Breeding × Thesis Type: M.Sc ×
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    ThesisItemOpen 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, K
    ABSTRACT : 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.
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    ThesisItemOpen Access
    MICROSATELLITE MARKER BASED ASSESSMENT OF GENETIC STRUCTURE OF MACHERLA BROWN SHEEP
    (SRI VENKATESWARA VETERINARY UNIVERSITY, TIRUPATI – 517502. (A.P.) INDIA, 2015-12) MOHAN KISHORE, MOLABANTI; Punya kumari, B (Major); Jaya laxmi, P; Suresh, J
    ABSTRACT: Macherla Brown sheep is the native sheep distributed along the banks of river Krishna flowing through Guntur, Krishna, Prakasam and Nalgonda districts of Andhra Pradesh and Telangana states. The home tract is mainly from the Nagarjuna sagar dam areas of Guntur and Nalgonda. Macherla Brown is known for heat tolerance, disease resistance and thrives well in harsh climatic conditions and scarce feeding conditions. The assessment of genetic variation is important to characterize the populations for breed recognition, conservation and also to determine the level of inbreeding in the population. The present study was carried out to assess the genetic structure of Macherla Brown sheep at molecular level to understand the genetic variability and diversity of population and to recognise this high performing local variety of sheep as a breed. Twenty four ovine microsatellite markers recommended by ISAG/FAO for population diversity studies in sheep were used in the present study. Phenol-chloroform method was used for the isolation of DNA from the collected blood samples and the microsatellite markers were amplified by PCR reaction. The amplicons were identified using agarose gel electrophoresis. The genotypes were scored using regression equation of the 100 bp DNA standard. The number, size and frequency of alleles were calculated using POPGENE version 1.3.2 software. A total of 275 alleles were observed for the twenty four marker loci under investigation in the sampled Macherla Brown population. The number of alleles at each locus varied from a minimum of eight (BM6506, HSC, OarCP34) to a maximum of eighteen (MAF214) with a mean of 11.458 alleles. Allele size ranged from a minimum of 69 bp (OarCP20) to a maximum of 313 bp (MAF214), while allele frequency varied between 0.0102 (HSC, INRA63, MAF214, OarP49 and OarVH72) to 0.2551 (HSC). The number of effective alleles across twenty four microsatellite loci studied ranged from 5.8065 (HSC) to 14.1652 (OarFCB48). The mean number of effective alleles was 9.597 ± 2.454. The observed heterozygosity ranged from 0.0612 (BM8125) to 0.2653 (OarCP34) with a mean value of 0.110 ± 0.049 whereas, the expected heterozygosity ranged from 0.8278 (HSC) to 0.9294 (OarFCB48) with a mean value of 0.889 ± 0.029. All the twenty four microsatellite loci (100 percent) were found to be highly polymorphic and the PIC values ranged from 0.8052 (HSC) to 0.9295 (OarFCB48). The mean PIC value for all the twenty four loci was found to be 0.882 ± 0.036. The Chisquare test revealed that all the twenty four loci were showing significant deviation from Hardy-Weinberg Equilibrium. The inbreeding estimates obtained in this study were all positive and ranged from 0.6915 (OarCP34) to 0.9341 (OarFCB48) with the mean FIS value of 0.876 ± 0.057 indicating the high deficiency of heterozygotes.