خيارات البحث
النتائج 1 - 10 من 15
Study of hereditary cerebellar degeneration in cats.
1996
Inada S. | Mochizuki M. | Izumo S. | Kuriyama M. | Sakamoto H. | Kawasaki Y. | Osame M.
Genetic parameters and trends of growth traits in Nelore cattle raised in the Northern region of Brazil
2022
Mariana Rocha Rodrigues | Rafael Espigolan | José Bento Sterman Ferraz | Fernando Oliveira Bussiman | Ricardo Toniolli | Raysildo Barbosa Lôbo | Helcileia Dias Santos | Leandro Lopes Nepomuceno | Jorge Luís Ferreira
The objective of this study was to estimate (co)variances and genetic parameters and to predict genetic trends for weight at 120 (W120), 210 (W210), 365 (W365), and 450 (W450) days of age in Nelore cattle raised in the northern region of Brazil. The database comprised records of 30,387 animals born between 2000 and 2013 in the Brazilian North. Estimates were calculated by the Restricted Maximum Likelihood (REML) method, in single- and multi-trait analyses in an animal model. Heritability as obtained using single- and multi-trait models for W120 (0.22 and 0.31), W210 (0.20 and 0.34), W365 (0.51 and 0.51), and W450 (0.49 and 0.51) indicated moderate to high magnitudes, with the possibility of genetic selection and incorporation into the herd. Genetic correlations between growth traits were favorable, ranging from 0.78 to 0.96. Genetic trends for W120 and W210 varied largely, from -0.31 to 4.68 and -0.53 to 7.62 kg/year, respectively. Smaller fluctuations were observed in genetic trends for W365 and W450, which ranged from -1.08 to 10.90 and -1.29 to 12.51 kg/year, respectively. Selection for W365 and W450 proved to be the criterion of choice for Nelore herds raised in the region; however, it may compromise adult performance because of higher costs and time for production. A thorough analysis of mattings is recommended to allow the selection of earlier-developing animals.
اظهر المزيد [+] اقل [-]Nongenetic effects and genetic parameters of the limb measurements in Iranian Turkoman horses
2018
Shahabodin Gharahveysi | Hadi Ghezelsoflou
From the past to now, body conformation is an instrument for the Iranian horse judging. This research aimed to study and estimate the genetic and nongenetic parameters of limb conformation traits in the Iranian Turkoman horses. Therefore, body conformation traits, specifically limb conformation, of 1273 horses were measured. Among the horses studied, 357 stallions and 916 mares were included. For studying the nongenetic (such as sex, province and birth year) and genetic effects (such as additive genetic effect), the LSMEANS procedure and the restricted maximum likelihood method (REML) were used by SAS and MATVEC software, respectively. Birth year had a significant effect on most of the traits, especially scapula length and arm length (P < 0.05). The lowest and the highest heritability was estimated for femur length (0.11 ± 0.03) and forearm length (0.40 ± 0.09), respectively. Overall, considering the heritability estimations, the expectation is that limb conformation traits will have a good response to the selection and genetic progress. Farmers can choose the best stallions and mares based on the traits mentioned, so that their foals can have good body conformation.
اظهر المزيد [+] اقل [-]Genetic parameters of growth traits and carcass weight of New Zealand white rabbits in a tropical dry forest area
2021
Donicer Eduardo Montes-Vergara | Darwin Yovanny Hernndez-Herrera | Naudin Alejandro Hurtado-Lugo
Objective: The objective of this study was to estimate the heritability (h2 ), repeatability (r), and correlations (r yi yi ) in some traits of zootechnical interest in a population of New Zealand white rabbits of a tropical dry forest area. Materials and Methods: Three mating groups were formed, each one of 1 male and 70 females. The traits evaluated were littersize at birth (LB), born alive (BA), born dead (BD), litter weight born alive (LW), litter weight at weaning (LWW), weaning weight (WW), slaughter weight (SW), and carcass weight (CW). Weaning took place at 42 days, and the fattening phase lasted 60 ± 3 days. A descriptive statistical study was carried out on the study variables. Paternal heritability was esti mated (h2 f ) and maternal (h2 m), repeatability, rabbit index IC, and Pearsons correlations (r yi yi ) between traits. The descriptive statistics showed high variation for the BD traits. Results: The values of the productivity found were similar to those presented in studies around the world. h2 presented magnitudes between low and medium. h2 f ranged between 0.09 and 0.42 and between 0.11 and 0.45 for h2 m. In general, the values of h2 m were higher than the values of h2 f . The r valuesforthe traits LB, BA, LW, LWW, and SW presented low magnitude, while it was medium for WW and CW. From the values of r, IC was calculated for each of the rabbits, allowing their categorization, which will be used in future selection plans. r yi yi among the variables ranged from −0.01 to 0.860. They were generally positive and mostly not significant (p > 0.05); they took a magnitude from low to moderate, except for the correlation between LB and BA. Conclusion: The production of rabbits under tropical conditions is similar to other reports. The genetic parameters evaluated were medium-to-low, indicating a robust non-additive gene and/ or environmental effect. [J Adv Vet Anim Res 2021; 8(3.000): 471-478]
اظهر المزيد [+] اقل [-]Effects of genetic and non-genetic factors on growth traits of high yielding dairy seed calves and genetic parameter estimates
2015
Syed Mohammad Ashiqur Rahman | Mohammad Shamsul Alam Bhuiyan | Abul Kashem Fazlul Haque Bhuiyan
The study was conducted to know the effects of several genetic and non-genetic factors like season, sex, year of birth, genotype of calves and milk yield of dam associated with growth performance of crossbred calves. Data were collected from registered farmers during the period of May, 2011 to April, 2013. Birth weight, three-month weight, six-month weight, weaning weight and heritability estimates of those growth performances were performed using a total of 82 registered calves which had pedigree information having the genotypes of 25% Local - 75% Friesian and 37.5% Local - 62.5% Friesian. The average birth, three-month, six-month and weaning weight of calves were 29.33, 64.32, 99.06 and 151.77 kg, respectively. The effects of non-genetic factors like sex, season of birth and genotype were non-significant (P>0.05) for the traits birth weight, three-month, six-month, weaning weight and average daily gain of calves. However, year of birth was found significant on birth (P<0.01), three-month and six-month (P<0.05) weight; but non-significant (P>0.05) on weaning weight and average daily gain of calves. The heritability estimates were 0.40±0.09, 0.46±0.08, 0.39±0.12 and 0.50±0.12 for the traits birth weight, three-month weight, six-month weight and weaning weight, respectively. Estimated heritabilities of live weights suggest that individual own performance basis selection would be more effective for increasing growth and therefore, should be paid more emphasis in cattle improvement program.
اظهر المزيد [+] اقل [-]Prevalence of perinuclear antineutrophilic cytoplasmic autoantibodies in serum of healthy Soft Coated Wheaten Terriers in the United Kingdom
2012
Wieland, Barbara | Summers, Jennifer F. | Hasler, Barbara | Mancho-Alonso, Carolina | Craig, Amanda | Allenspach, Karin
Objective: To estimate the prevalence of perinuclear antineutrophilic cytoplasmic autoantibodies (pANCA) in the serum of healthy Soft Coated Wheaten Terriers (SCWTs) in the United Kingdom and to identify potential risk factors and heritability patterns associated with a positive result for pANCA. Animals: 188 SCWTs (age range, 18 months to 14.3 years). Procedures: Blood samples were obtained from SCWTs in various locations in England. Serum was tested for pANCA by use of an immunofluorescence assay, and total protein and albumin concentrations were determined. Pedigrees were evaluated to identify close relatives that had protein-losing enteropathy (PLE) or protein-losing nephropathy (PLN). Results: 39 of 188 (20.7%) dogs, including young dogs, had positive results for pANCA. Dogs had significantly higher odds of having positive results for pANCA if they had at least 1 littermate that had PLE or PLN (odds ratio, 12.1) or if they had at least 1 full sibling from another litter known to be affected with PLE or PLN (odds ratio, 4.0). Conclusions and Clinical Relevance: This study revealed a high prevalence of pANCA in the serum of a representative sample of healthy SCWTs in the United Kingdom and a significant association between positive results for pANCA and a diagnosis of PLE or PLN in a sibling.
اظهر المزيد [+] اقل [-]Genetic analyses of the radiographic appearance of the distal sesamoid bones in Hanoverian Warmblood horses
2006
Stock, K.F. | Distl, O.
Objective-To evaluate whether additive genetic correlations existed between certain aspects of the radiographic appearance of the distal sesamoid (navicular) bones (RNB) or between RNB and other types of radiographic changes in the limbs of Hanoverian Warmblood horses. Animals-5,157 horses. Procedures-Quasi-linear and binary traits were defined by the appearance of canales sesamoidales (CSs) and the structure and contour of the forelimb navicular bones (NBs). Prevalences of osseous fragments in the metacarphophalangeal and metatarsophalangeal (fetlock) and tarsocrural joints and deforming arthropathy in tarsal joints were analyzed as binary traits. Genetic parameters were estimated by use of multivariate linear models. Results-Heritability estimates for the RNB traits ranged from 0.10 to 0.34. Additive genetic correlations among those traits were usually close to unity. Extensive radiographic changes in the NBs, including changes in CSs and alterations in structure and contour, had correlations with less distinct radiographic changes. Negative additive genetic correlations were observed between small numbers of short and conical CSs in the central portion of the distal border of the NB and osseous fragments and arthropathy, and between most types of radiographic findings in the NBs and osseous fragments in tarsal joints. Conclusions and Clinical Relevance-The genetic bases for different types of RNB were not identical. The detection of correlations between normal RNB and findings of short and conical CSs versus deformed CSs and structural and contour changes warrants further study. Genetically justified distinction between physiologic and pathologic NB changes will increase the efficiency of selecting against NBs with radiographically apparent alterations.
اظهر المزيد [+] اقل [-]Inheritance of pancreatic acinar atrophy in German Shepherd Dogs
2002
Moeller, E Michael | Steiner, Jörg M. | Clark, Leigh Anne | Murphy, Keith E. | Famula, Thomas R. | Williams, David A. | Stamkovics, Mary E. | Vose, Amy S.
Objective-To assess the heritability of pancreatic acinar atrophy (PAA) in German Shepherd Dogs (GSDs) in the United States. Animals-135 GSDs belonging to 2 multigenerational pedigrees. Procedure-Two multigenerational pedigrees of GSDs with family members with PAA were identified. The clinical history of each GSD enrolled in the study was recorded, and serum samples for canine trypsinlike immunoreactivity (cTLI) analysis were collected from 102 dogs. Dogs with a serum cTLI concentration ≤ 2.0 µg/L were considered to have exocrine pancreatic insufficiency (EPI) and were assumed to have PAA. Results-Pedigree I consisted of 59 dogs and pedigree II of 76 dogs. Serum cTLI concentrations were measured in 48 dogs from pedigree I and 54 dogs from pedigree II. A total of 19 dogs (14.1%) were determined to have EPI, 9 in pedigree I (15.3%) and 10 in pedigree II (13.6%). Of the 19 dogs with EPI, 8 were male and 11 were female. Conclusion and Clinical Relevance-Evaluation of data by complex segregation analysis is strongly suggestive of an autosomal recessive mode of inheritance for EPI in GSDs in the United States.
اظهر المزيد [+] اقل [-]Evaluation of some economic traits in Holstein dairy cattle under Egyptian conditions
2023
Ahmed Easa | Amr M.A. Rashad | Ahmed A. Saleh
The objectives of this study were to estimate heritability and breeding value for some economic traits and the impact of some environmental factors on these traits in Holstein dairy cattle in Egypt. The data of 10034 records for 3295 Holstein cows were studied during the period from 1998 to 2021 in El-Alamia farm which is belonging to Universal Company for Agricultural Development and Soil Reclamation and has a commercial dairy herd located at Nubaria region in the K 90 Alex - Cairo desert road. The traits under study were: Total milk yield (TMY, kg), 305-day milk yield (305-dMY, kg), Lactation length (LL, day), Dry period (DP, day), Days open (DO, day), Calving interval (CI, month) and Gestation length (GL, day). The results showed that all traits under study were significantly influenced by parity. Also, the calving year has a significant effect on the studied traits except for gestation length. In the same trend, the effect of calving season was significant in all traits except lactation length and gestation length. Heritability estimates were 0.265, 0.393, 0.488, 0.238, 0.12, 0.138 and 0.57 for TMY, 305-dMY, LL, DP, DO, CI and GL, respectively. Cow breeding values for TMY, 305-dMY, LL, DP, DO, CI and GL ranged from -957 to 2170.5 kg, from -2432.75 to 2713.75 kg, from -266.25 to 340 days, from -114 to 100.25, from -105.75 to 164 days, from -13.9 to 13.18 months and from -0.33 to 0.45 days, respectively. Dams breeding values ranged from -823.5 to 1364.25 kg, from -1076.75 to 1531.75 kg, from -139.75 to 186.5 days, from -79.75 to 46.5, from -58.25 to 82 days, from -8.23 to 8.63 months and from -0.28 to 0.53 days, respectively. Sires breeding values ranged from -1057.75 to 1082 kg, from -1458 to 1549.25 kg, from -219.25 to 292.75 days, from -79.5 to 85.25 days, from -75.5 to 89 days, from -8.7 to 7.08 months and from -0.58 to 0.60 days, respectively. In conclusion, heritability values for all traits under study were low to moderate except for gestation length was a high value, so the most useful way to improve the traits under the study would be by improving the management level. Also, an estimated cow's breeding value has a wide range than sires' or dams' breeding value revealing a higher genetic variance and a good chance of selecting superior cows.
اظهر المزيد [+] اقل [-]Heritability of susceptibility to scrotal herniation in swine
1990
Vogt, D.W. | Ellersieck, M.R.
Data on 5,711 Duroc-sired, 2,227 Landrace-sired, and 2,494 Yorkshire-sired male pigs born over a 9-year period were used to evaluate the genetic influence on scrotal herniation. Differences in frequency of this defect among boar breeds (Duroc, Landrace, and Yorkshire) were significant (P < 0.01). Differences among sires within the Duroc and Landrace boar groups were significant (P < 0.001 and P < 0.05, respectively), but differences within the Yorkshire group were not significant. Frequency of scrotal hernia among male full siblings of affected males was consistently higher than the overall frequency of the defect among progeny in each of their respective breed of boar groups. Percentage of affected pigs among male full siblings of affected males for Duroc, Landrace, and Yorkshire groups, respectively, was 3.0, 3.0, and 2.7 times greater than the overall percentage affected in their respective breed groups. Heritability of susceptibility to scrotal hernia development was estimated to be 0.29 +/- 0.17, 0.34 +/- 0.23, and 0.34 +/- 0.19 in Duroc, Landrace, and Yorkshire-sired pig groups, respectively.
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