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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Characteristics of progeny test herds and their effects on the genetic evaluation of young sires

Vierhout, Crystal N. 20 March 1998 (has links)
Our purpose was to examine characteristics of progeny test herds and their effects on the genetic evaluation of young sires. Data for a study of response to pedigree selection by stud were evaluated from 6238 Holstein sires in four USDA animal model evaluations from January 1995 to February 1997. When data were restricted to the nine major semen producing organizations, a common intercept and slope for prediction of daughter yield deviation from pedigree merit were appropriate for milk but R2 was low at 0.14. We detected no important differences in response to pedigree selection among progeny testing methods used by major semen producing organizations. Data for a study of specific progeny test herds were 4154 Holstein progeny test herds from two AI studs and 6361 remaining herds from two states. We grouped herds into four categories, 21st Century Genetics and Genex progeny test herds, other Minnesota herds and other New York herds. Herds were described by DHI profile and average cow evaluation data. Cows with extreme yield deviations (± 3 herd standard deviations) were identified, as were daughters of progeny test bulls with extreme daughter performance relative to pedigree merit of the bull. 21st Century Genetics and Genex appear to have chosen the larger, genetically superior and better managed herds from within their regions in which to conduct their progeny testing. We were not able to predict if a bull was going to exceed or fail to meet pedigree prediction by characteristics of the progeny test herds in which he was sampled. / Master of Science
2

A Comparison of Daughters of Sires in Artificial Breeding at Different Levels of Management

Cook, Richard C. 01 May 1960 (has links)
One of t he largest problems facing the successful dairyman of today is selection of proper sires to mate to his high producing cows. Many breeders and dairymen have the impression that proven sires will give the same increase in production regardless of the dam's production or the level of environment present. Even though sires come from high producing herds, some as high as 600 pounds of butterfat, the average production of all cows in the state of Utah remains at a much lower figure. The average for all cows in Utah is about 250 pounds of butterfat and the average in 1958 of cows on Dairy Herd Improvement test was 403 pounds. This difference in level of production may be attributed to either genetic or environmental factors and possibly an interaction of the two. Most workers agree that the heritability estimates for milk production and fat yield are from .2 to .3. This means t hat about 25 per cent of the variance in milk yield is due to inheritance, and the other 75 per cent is due to management or environment. Therefore, there is a need to study daughters of the same sire at various levels of production to determine the amount of increase or decrease found at these levels. This thesis presents a study of daughters of Holstein sires used in artificial breeding. Sires in artificial breeding were used because they have a larger number of daughters, and their daughters come from a wide range of production and management levels.
3

Eating Quality of Beef: Influence of Cooking Method; Sires; Mineral (Fe, Mg, Zn, Na, K, and P), Lipid, and Nitrogen Content

Ream, Elisabeth E. 01 May 1971 (has links)
The influence on eating quality of beef of cooking method, sires, mineral (Fe, Mg, Zn, Na, K, and P), lipid, and nitrogen content was determined by objective measurements, sensory evaluations, cooking losses, and chemical analysis. Two adjacent arm and two adjacent rib roasts from 18 Herford animals were used. The arm and rib (sixth to eighth ribs) roasts were deboned, cut in half, and randomly assigned to the conventional or electronic ovens for dry roasting to the medium-rare stage (145 F, 147 F). Roasts of the ninth to twelfth ribs were dry-roasted in a meat research oven at 325 F to an internal temperature of 155 F. The Warner-Bratzler shear test determined tenderness to be greater in conventional roasts, Press fluid amounts were similar for both ovens. Cooking losses were greatest in the electronic oven. The taste panel judged conventional roasts to have better flavor and to be more tender and juicy. Laboratory analysis of minerals indicated specific ones influenced the tenderness of beef, Lipid content was found to be significantly correlated with juiciness, tenderness, shear force, and percentage drip. The findings showed nitrogen to affect juiciness inversely and the cooking losses positively. High correlations for roasts containing the ninth to twelfth ribs were indicated for flavor, tenderness, and shear force; also tenderness was judged by the taste panel with shear force, and press fluid with cooking loss.
4

Avaliação de estratégias de genotipagem em situações de incerteza de paternidade e seu impacto sobre as avaliações genômicas em bovinos de corte / Evaluation of genotyping strategies in situations of uncertainty paternity and impact on genomic evaluation in beef cattle

Tonussi, Rafael Lara [UNESP] 14 December 2016 (has links)
Submitted by RAFAEL LARA TONUSSI null (rafaeltonussi@yahoo.com.br) on 2017-01-18T17:45:01Z No. of bitstreams: 1 tese_Rafael_Lara_Tonussi.pdf: 1385325 bytes, checksum: ea9dbc49d8fec3ee26a2a139e1dd0baf (MD5) / Rejected by LUIZA DE MENEZES ROMANETTO (luizamenezes@reitoria.unesp.br), reason: Solicitamos que realize uma nova submissão seguindo a orientação abaixo: Incluir o número do processo de financiamento FAPESP nos agradecimentos da dissertação/tese. Corrija esta informação e realize uma nova submissão com o arquivo correto. Agradecemos a compreensão on 2017-01-23T19:14:45Z (GMT) / Submitted by RAFAEL LARA TONUSSI null (rafaeltonussi@yahoo.com.br) on 2017-01-24T10:46:09Z No. of bitstreams: 1 tese_Rafael_Lara_Tonussi.pdf: 1384474 bytes, checksum: 3424ccffa913eaba43458f131eef937b (MD5) / Approved for entry into archive by LUIZA DE MENEZES ROMANETTO (luizamenezes@reitoria.unesp.br) on 2017-01-25T16:33:51Z (GMT) No. of bitstreams: 1 tonussi_rl_dr_jabo.pdf: 1384474 bytes, checksum: 3424ccffa913eaba43458f131eef937b (MD5) / Made available in DSpace on 2017-01-25T16:33:51Z (GMT). No. of bitstreams: 1 tonussi_rl_dr_jabo.pdf: 1384474 bytes, checksum: 3424ccffa913eaba43458f131eef937b (MD5) Previous issue date: 2016-12-14 / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Reprodutores múltiplos (RM) é o sistema de manejo mais comum em produção de bovinos de corte principalmente devido a facilidade e baixo custo de manejo. No entanto, RM não permite a identificação de paternidade, tornando o pedigree incompleto um dos principais obstáculos para avaliações genéticas precisas. Existe um crescente interesse na investigação do uso de dados genômicos em modelos com paternidade incerta, visando aumentar a acurácia e diminuir o viés nas avaliações genéticas. Portanto, o objetivo desse estudo foi investigar a aplicação do BLUP e single step genomic BLUP (ssGBLUP) em diferentes cenários com paternidade incerta utilizando dados simulados e reais em bovinos de corte. Foram simulados genótipos, pedigree e fenótipos para idade ao primeiro parto (IPP) e peso aos 550 dias (P550) utilizando herdabilidades baseadas em dados reais (0,12 para IPP e 0,34 para P550). O genoma foi simulado com um comprimento total de 2.333 cM, com 735.293 marcadores bialélicos e 7.000 QTL distribuídos aleatoriamente ao longo dos 29 cromossomos. Foi assumido que os QTLs explicaram 100% da variância genética. Para QTL, a quantidade de alelos variou aleatoriamente de dois a quatro por loci. Foram estudados cenários com 0%, 25%, 50%, 75% e 100% de RM e foram testados quatro tipos de escalas entre as matrizes G e A22. A acurácia e viés foram calculados para cincos grupos: ALL = todos os animais; BULL = apenas touros; GEN = animais genotipados, FEM = fêmeas e YOUNG = machos jovens. O uso da informação genômica no modelo (ssGBLUP) apresentou acurácia maior (variando de 0,31 a 0,97) do que o BLUP tradicional (variando de 0,05 a 0,97), especialmente no grupo YOUNG. No estudo com dados reais, todos os modelos incluíram grupos de contemporâneos e classe de idade da vaca como efeitos fixos. A acurácia do valor genético (EBV / GEBV) foi calculada em cada cenário para oito grupos de animais: ALL = todos os animais, BULL = apenas touros com dez ou mais progênies; GEN = animais genotipados, GENwithPHEN = animais genotipados com fenótipos, GENwithoutPHEN = animais genotipados sem fenótipos, YOUNG = machos e fêmeas jovens sem fenótipos, YwithoutGEN = animais jovens sem fenótipos e genótipos e YwithGEN = animais jovens sem fenótipos e com genótipos. As acurácias do EBV (método BLUP) variaram de 0,02 a 0,46 para P455 e 0,04 a 0,18 para IPP, enquanto que as acurácias do GEBV (ssGBLUP) variaram de 0,13 a 0,48 para P455 e 0,16 a 0,33 para IPP. Os resultados obtidos com dados simulados e reais mostraram que acurácias do EBV e GEBV diminuíram à medida que as proporções de RM aumentaram. Além disso, o uso da informação genômica na avaliação genética pelo ssGBLUP aumentou a acurácia da avaliação, especialmente para animais com menos informações e para animais jovens. / Multiple service sire (MS) is the most common mating system in extensive beef production systems mainly due the facility and low management cost. However, MS does not allow the paternity identification, which makes the incompleteness of pedigree one of the main obstacles for accurate genetic evaluations. There is a grown interest to investigate the use of genomic data in uncertain paternity models aiming to increase the accuracy and to decrease bias in genetic evaluations. Therefore, the objective of this study was to investigate the application of BLUP and single step genomic BLUP (ssGBLUP) under different scenarios of uncertain paternity, using simulated and real data in beef cattle population. Genotypes, pedigree, and phenotypes for age at first calving (AFC) and weight at 550 days (W550) were simulated using heritabilities based on real data (0.12 for AFC and 0.34 for W550). The simulated genome had a total length of 2,333 cM, with 735,293 biallelic markers and 7,000 QTLs randomly distributed over 29 BTA. It was assumed that QTLs explained 100% of the genetic variance. For QTL, the amount of alleles per loci ranged randomly from two to four. Uncertain paternity scenarios using 0%, 25%, 50%, 75%, and 100% were studied. Four ways of scaling the mean of the genomic matrix (G) to match the mean of the pedigree relationship matrix among genotyped animals (A22) were tested. Accuracy, bias and inflation were investigated for five groups of animals: ALL = all animals; BULL = only bulls; GEN = genotyped animals; FEM = females; YOUNG = young males. The use of genomic information in the model (ssGBLUP) provided more accurated prediction (ranging from 0.31 to 0.97) than traditional BLUP (ranging from 0.05 to 0.97), especially in the YOUNG group. In real data, all models included contemporary groups and age at calving in classes as fixed effects. The accuracy of the estimated breeding value (EBV/GEBV) prediction was calculated in each scenario with eight groups of animals: ALL = all animals in the population, BULL = only bulls with ten or more progenies; GEN = genotyped animals, GENwithPHEN = genotyped animals with phenotypes, GENwithoutPHEN = genotyped animals without phenotypes, YOUNG = male and female young animals without phenotypes, YwithoutGEN = young animals without phenotypes and genotypes, and YwithGEN = young animals without phenotypes and with genotypes. Accuracies of EBV (BLUP method) ranged from 0.02 to 0.46 for W450 and 0.04 to 0.18 for AFC, while the accuracies of GEBV (ssGBLUP) ranged from 0.13 to 0.48 for W450 and 0.16 to 0.33 for AFC. The results obtained in simulated and real data showed that EBV and GEBV accuracy decreased as the proportion of MS increased. Additionally, the use of genomic information in the genetic evaluation by ssGBLUP increases the accuracy of evaluation, especially for animals with few number of information, such as young animals. / FAPESP: 2013/25910-0
5

UAB „Litgenas“ bulių reproduktorių genealogijos ir veislinės vertės dinamika / Dinamics of bulls sires genealogy and value of breed in the company „Litgenas“

Eidintas, Giedrius 19 April 2007 (has links)
Dairy cattle breeding is still taking the first place of it‘s production. Growing requirements in the national and international markets require animals productivity, increase of genetic potential and development of production quality. The growth of animal’s genetic potential promote the use of bull’s sires with high value of breed. There are a lot of the bulls sires witch are improving the breed. So they constitute line of descent or related groups. The company „Litgenas“ during 14 work years has been used 11 line of descent and related groups. There are 4 the main line of descent and related groups: 1. W. A. BURKE LAD 697789 line ( 920 ); 2. R. O. R. A. ELEVATION 1491007 US1491007 related group ( 931 ); 3. O. IVANHOE 1189870 line ( 960 ); 4. P. F. ARLINDA CHIEF TL 1427381 related group ( 982 ). Comparing to the controlled cows’ bands of 2004-2005 years the supply of company coincides with the demand of market. I was using „R“ statistic analysis packet, counting arithmetic avarages of values of bulls breeds and coefficient of variation. Also during the communication with farmers I noticed that the requirements of bulls genealogy schemes which are used by the company „Litgenas“ became much bigger. So due to the information of bulls line of descent which were cumulated by the computation centre “VIC” of Lithuania I made bulls sires genealogy schemes. All farmers, selectioners of company, regions breeding inspectors and inseminators are using this poster. The... [to full text]
6

ANÁLISE DA COMERCIALIZAÇÃO E FATORES DE COMPRA DE REPRODUTORES BOVINOS DE CORTE EM LEILÕES NO RIO GRANDE DO SUL / ANALYSIS OF MERCHANTABILITY AND FACTORS OF PURCHASES FOR BREEDING CATTLE SHOPPING AUCTIONS IN RIO GRANDE DO SUL

Nardino, Tiago Alan Cunha 24 February 2015 (has links)
Fundação de Amparo a Pesquisa no Estado do Rio Grande do Sul / This paper was the objective to identify some deciding factors of purchases of European and synthetic breeding bull at auctions in Rio Grande do Sul and its influence on the purchase price. Were viewed a total of 55 auctions, between television auctions and presential auctions. In total, were collected data of 4,569 Aberdeen Angus, Hereford, Brangus and Braford breeding bull, auctioned in several cities in the state of Rio Grande do Sul. Data were collected in two stages: the first consisted of the collection data catalogs related to phenotypic and genotypic information at auction or websites of the auction companies, the second stage was the collection of information marketing of animals. Data were tabulated in spreadsheets software and then analyzed using a statistical software. Braford bulls had higher value than Aberdeen Angus, Brangus and Hereford breeding cattle. Bulls of two years old were more valued than animals three years old in Aberdeen Angus, Brangus and Hereford breeds, while the opposite occurred to Braford breed. The trade of bulls take effect in the spring have higher sales value compared to trades in the fall. The weight of the bull influence on the best selling price, the same does not occur with scrotal perimeter. The red fur bull has higher value than the black fur, both in Angus as Brangus. / Este trabalho teve por objetivo identificar alguns fatores decisórios no processo de compra de reprodutores das raças europeias e sintéticas em leilões no Rio Grande do Sul e sua influência no preço de venda. Foram acompanhados um total de 55 leilões, sendo alguns televisivos e outros presenciais. Ao total foram coletados dados da oferta de 4.569 reprodutores de bovinos de corte das raças Aberdeen Angus, Hereford, Brangus e Braford, leiloados em diversos municípios do Rio Grande do Sul. Os dados foram obtidos em duas etapas: a primeira constou da coleta de dados dos catálogos referentes a informações fenotípicas e genotípicas distribuídos ao início dos leilões ou através dos sitios das empresas leiloeiras. A segunda foi a coleta de informações da comercialização dos animais. Os dados foram tabulados em planilhas eletrônicas e posteriormente analisados por meio de software estatístico. Touros da raça Braford tiveram maior valor comercial do que os Aberdeen Angus, Brangus e Hereford. Touros de dois anos foram mais valorizados do que os de três anos nas raças Angus, Brangus e Hereford, mas não os Braford. As comercializações efetivadas durante a primavera têm valor de venda superior quando comparada às do outono. O peso do touro influencia no melhor preço de venda, mas não o perímetro escrotal. Os touros de pelagem vermelha têm maior valor comercial do que os de pelagem preta, tanto na raça Aberdeen Angus quanto na Brangus.
7

Voorkoms van stres by huismoeders in diens van 'n kinderhuis

Erasmus, Magdalena 11 1900 (has links)
The research posed two questions, namely (a) how much stress, if any, is experienced by house mothers in a childrens' home, and (b) which factors cause such stress. The methodology employed is descriptive research. It covered the total population of ten house mothers in a childres' home. Measuring instruments employed were; the Heimler scale for Social Functioning, the Glazer Stress Control Life Style Questionnaire, the Stress Questionnaire, and a self-formulated questionnaire. The results are as follows: 70% reported average to high stress, but are inclined to deny stress. 30% reported normal stress levels, Possible causes of stress are the work context of the childrens' home, age, period of service, and personality. / Die studie soek antwoorde op twee vrae, naamlik (a) hoeveel sires, indien enige, beleef huismoeders in 'n kinderhuis, en (b) wat veroorsaak sulke sires? Die metode wat gebruik was, is beskrywende navorsing. Die totale populasie van tien huismoeders in die spesifieke kinderhuis is betrek. Die klein omvang maak hierdie studie nie veralgemeenbaar nie. Die volgende meetinstrumente is benut ; die Heimlerskaal vir Maatskaplike Funksionering, die "Glazer Stress Control Life Style Questionnaire'', die "Stress Questionnaire", en 'n selfgeformuleerde vraelys. Die resultate is soos volg: 70% van die huismoeders in die studie vermeld gemiddelde tot hoe mates van stres, maar is geneig om stres te ontken. Dertig persent van die respondente vermeld normale hoeveelhede stres. Moontlike oorsake van sires is aangetoon as: die werkskonteks binne die kinderhuis, ouderdom, tydperk van diens, en persoonlikheid / Social Work / M.A. (Social Work: Mental Health)
8

Voorkoms van stres by huismoeders in diens van 'n kinderhuis

Erasmus, Magdalena 11 1900 (has links)
The research posed two questions, namely (a) how much stress, if any, is experienced by house mothers in a childrens' home, and (b) which factors cause such stress. The methodology employed is descriptive research. It covered the total population of ten house mothers in a childres' home. Measuring instruments employed were; the Heimler scale for Social Functioning, the Glazer Stress Control Life Style Questionnaire, the Stress Questionnaire, and a self-formulated questionnaire. The results are as follows: 70% reported average to high stress, but are inclined to deny stress. 30% reported normal stress levels, Possible causes of stress are the work context of the childrens' home, age, period of service, and personality. / Die studie soek antwoorde op twee vrae, naamlik (a) hoeveel sires, indien enige, beleef huismoeders in 'n kinderhuis, en (b) wat veroorsaak sulke sires? Die metode wat gebruik was, is beskrywende navorsing. Die totale populasie van tien huismoeders in die spesifieke kinderhuis is betrek. Die klein omvang maak hierdie studie nie veralgemeenbaar nie. Die volgende meetinstrumente is benut ; die Heimlerskaal vir Maatskaplike Funksionering, die "Glazer Stress Control Life Style Questionnaire'', die "Stress Questionnaire", en 'n selfgeformuleerde vraelys. Die resultate is soos volg: 70% van die huismoeders in die studie vermeld gemiddelde tot hoe mates van stres, maar is geneig om stres te ontken. Dertig persent van die respondente vermeld normale hoeveelhede stres. Moontlike oorsake van sires is aangetoon as: die werkskonteks binne die kinderhuis, ouderdom, tydperk van diens, en persoonlikheid / Social Work / M.A. (Social Work: Mental Health)

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