Spelling suggestions: "subject:"cattle deproduction"" "subject:"cattle eproduction""
71 |
Efeitos da sexagem por citometria de fluxo sobre a composição protéica da membrana de espermatozóides bovinosScott, Caroline [UNESP] 17 January 2014 (has links) (PDF)
Made available in DSpace on 2014-08-13T14:50:58Z (GMT). No. of bitstreams: 0
Previous issue date: 2014-01-17 / A sexagem de espermatozoides, para a obtenção de doses de sêmen com alta percentagem de gametas portadores do cromossomo X ou Y, torna ainda mais relevante o papel da inseminação artificial na maximização do progresso genético entre gerações, na produtividade e retorno econômico em algumas atividades pecuárias, na reprodução assistida em mamíferos e no aconselhamento genético da espécie humana. Várias são as técnicas descritas na tentativa de separar os espermatozoides por sexo, porém todas ainda estão em processo de adequação e nenhuma oferece 100% de acuidade. Baseando–se na hipótese que durante o processo de espermatogênese existem proteínas que se expressam diferentemente na membrana de espermatozoides portadores do cromossomo X ou Y, a técnica por separação utilizando anticorpos sexo-específicos vem sendo bastante estudada. Dessa forma este trabalho objetivou em estudar as proteínas de membrana expressas nos espermatozoides sexados e não sexados / The sexing of sperm, to obtain doses of semen with a high percentage of gametes carrying the X or Y chromosome, even more relevant the role of artificial insemination in maximizing the genetic progress between generations, productivity and economic returns in some farming activities; in assisted reproduction in mammals, and in genetic counseling of the human species. Several techniques are described in an attempt to separate the sperm by sex, but all are still in process and no fitness offers 100% accuracy. Based on the hypothesis that during the process of spermatogenesis there are proteins that are differently expressed in the sperm membrane carrying the X or Y chromosome the separation technique using sex-specific antibodies have been extensively studied. Thus this work aimed to study membrane proteins expressed in sexed sperm and not sexed
|
72 |
Efeito das características do pelame e da taxa de sudação sobre parâmetros reprodutivos em vacas da raça Braford /Bertipaglia, Elaine Cristina Abaker. January 2007 (has links)
Resumo: O objetivo deste estudo foi avaliar os efeitos das características do pelame e da taxa de sudação (TS) sobre o desempenho reprodutivo de vacas da raça Braford e estimar as herdabilidades e correlações genéticas destas características. Dados da TS, espessura da capa (E), refletância da superfície da capa (R), comprimento dos pêlos (C), diâmetro dos pêlos (D) e número de pêlos por unidade de área (N) foram observados. Ainda, foram avaliadas as seguintes variáveis da reprodução: intervalo de partos (IEP); dias para o parto (DPP); idade ao primeiro parto (IPP); taxa de detecção de cio (Dcio); taxa de gestação para a primeira inseminação (G1IA) e taxa de gestação para a estação de monta (GEM). Os dados de desempenho reprodutivo referem-se aos partos dos anos de 2003 e 2004. Foram avaliadas as inseminações referentes às gestações da estação de monta do período de outubro de 2003 a janeiro de 2004. Durante este período, foram observadas temperatura máxima do ar (Ta), pressão parcial de vapor (Pv) e carga térmica radiante (CTR). As variáveis contínuas (todas as características do pelame, TS, IEP, DPP e IPP) foram analisadas pelo método dos quadrados mínimos. Os seguintes efeitos fixos foram considerados no modelo de todas as características do pelame: pais; grupos de contemporâneos; mês da observação; genótipo e idade. O pai da vaca foi importante para todas as características do pelame, exceto para N. Grupos de contemporâneos afetou todas as variáveis, o mês afetou a variação do C e da R. O genótipo foi importante para C, D e R e a idade afetou R. Na análise da TS foram considerados: grupos de contemporâneos; pais; genótipo; E; C; D; N; R; hora da observação; idade; Ta; Pv e CTR. Todos os fatores meteorológicos e grupos de contemporâneos foram significativos...(Resumo completo, clicar acesso eletrônico abaixo) / Abstract: This study deals with the effects of hair coat characteristics and sweating rate on reproduction of Braford cows and estimation of heritabilities and genetic correlations of these traits. Data on hair length (L), coat thickness (T), hair diameter (D), number of hairs per unit area (N), coat reflectance (R) and sweating rate (SR) were recorded. In addition, calving interval (CI); days to calving (DC); age at first calving (AFC); Estrous detection rate (EDR); conception rate at first insemination (CR1AI) and conception rate at breeding season (CBS) were evaluated. The continuous data were analyzed by least squares methods; considering the following fixed effects on the model for hair coat traits: sires and contemporary groups; month; genotype and age. The effect of sire was important for all hair coat traits, except for N; contemporary groups affected all hair coat traits; the effect of sampling month was important for L and R; genotype affected L, D and R; age was important only for R. The model of SR considered the following fixed effects: contemporary groups; sires; genotype; T, L, D, N, R; time of day, age, air temperature (Ta), partial vapour pressure (Pv) and radiant heat load (RHL). All the meteorological factors and contemporary groups were significant on SR. Age at calving, genotype, sire, R, T, L, N, D and SR were considered as fixed effects on analyses of CI. For the analyses of DC were considered: R, T, L, N, D, SR, genotype, age and sire. Age, genotype and SR were significant on CI and DC. Age at first calving of heifers born from January to March (AFC1) and from July to October (AFC2) were analyzed. Only sire was significant on AFC1; sire, E and D affected the variation of AFC2. The binary traits EDR; CR1AI and CBS were analyzed by logistic regression models...(Complete abstract, acess undermentioned eletronic address) / Orientador: Roberto Gomes da Silva / Coorientador: César Roberto Esper / Banca: Vera Fernanda Martins H. de Lima / Banca: Danísio Prado Munari / Banca: Josineudson Augusto II de Vasconcelos Silva / Banca: Evaldo Antonio Lencioni Titto / Doutor
|
73 |
Efeitos da sexagem por citometria de fluxo sobre a composição protéica da membrana de espermatozóides bovinos /Scott, Caroline. January 2014 (has links)
Orientador: José Antônio Dell'Aqua / Banca: Fabiana Ferreira de Souza / Banca: Lucilene Delazari dos Anjos / Resumo: A sexagem de espermatozoides, para a obtenção de doses de sêmen com alta percentagem de gametas portadores do cromossomo X ou Y, torna ainda mais relevante o papel da inseminação artificial na maximização do progresso genético entre gerações, na produtividade e retorno econômico em algumas atividades pecuárias, na reprodução assistida em mamíferos e no aconselhamento genético da espécie humana. Várias são as técnicas descritas na tentativa de separar os espermatozoides por sexo, porém todas ainda estão em processo de adequação e nenhuma oferece 100% de acuidade. Baseando-se na hipótese que durante o processo de espermatogênese existem proteínas que se expressam diferentemente na membrana de espermatozoides portadores do cromossomo X ou Y, a técnica por separação utilizando anticorpos sexo-específicos vem sendo bastante estudada. Dessa forma este trabalho objetivou em estudar as proteínas de membrana expressas nos espermatozoides sexados e não sexados / Abstract: The sexing of sperm, to obtain doses of semen with a high percentage of gametes carrying the X or Y chromosome, even more relevant the role of artificial insemination in maximizing the genetic progress between generations, productivity and economic returns in some farming activities; in assisted reproduction in mammals, and in genetic counseling of the human species. Several techniques are described in an attempt to separate the sperm by sex, but all are still in process and no fitness offers 100% accuracy. Based on the hypothesis that during the process of spermatogenesis there are proteins that are differently expressed in the sperm membrane carrying the X or Y chromosome the separation technique using sex-specific antibodies have been extensively studied. Thus this work aimed to study membrane proteins expressed in sexed sperm and not sexed / Mestre
|
74 |
Vliv využití pastvy při odchovu jalovic na jejich užitkovost / Effect of grazing heifers in the rearing of their performanceKUKLOVÁ, Jana January 2009 (has links)
The aim of this work is to evaluate the course of rearing Red Pied heifers reared with use of graze and stable and review effect of graze use on subsequence performance in 1st lactation. In selected breed was monitored process of heifer grow by periodical weighting in three months interval, furthermore was taken for these heifers these reproduction indices: 1st insemination age, insemination index, 1st calve age. Heifers are divided by rearing form (graze, stable) and compared differences in grow intesities and reproduction efficiency between particular groups. Subsequently, for cows on first lactation were monitored and compared these indices: level of milk performance, content of milk elements, degree of physical condition, indices of fertility. Dairy cows are divided into groups according to how they were reared as heifers (graze, stable). When comparing growth of heifers, grazed heifers reaches higher values than group of not grazed heifers. Grazed heifers grows more quickly: at age 3 months was their average weight 93,26 Kg against 88,30 Kg not grazed heifers. At age 6 months was weight of grazed heifers 169,51 kg against 161,80 kg not grazed heifers, At age 9 months was values 236,47 kg for grazed heifers, 228,07 kg for not grazed heifers, at age 12 months 326,62 kg and 299,87 kg, at age 15 months 366,11 kg and 359,98 kg. From reproduction indices have been found statistically significant differences in age at 1st insemination, when the grazed heifers were flushed in average age of 18,43 months against not grazed heifers in age of 17,12 months. In addition, was found statistically significant differences in age at first calving, when the values obtained for the group of grazed heifers was 28.63 months and for not grazed heifers 27,73 months. First calving heifers reared on graze produce in lactation average 7 782,4 Kg of milk, first calving heifers reared in stable produce in lactation average 7 064,40 Kg of milk. Differences was statistically significant. Average duration of lactation at first calving heifers reared on graze was 359,47 days, duration of lactation at first calving heifers reared in stable was 329,01 days. Differences was statistically highly significant. From the linear description is clear that graze has positive effect on heifers muscling and limbs. In overall assessment made grazed heifers higher rating points 81,43 for heifers reared on graze and 81,00 point for heifers reared in stable. These differences could not be statistically demonstrated.
|
75 |
Modelo para predição do estro em vacas leiteiras confinadas / Model for prediction of estrus in confined dairy cowsSantos, Rodrigo Couto 14 November 2007 (has links)
Orientador: Irenilza de Alencar Naas / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agricola / Made available in DSpace on 2018-08-09T21:38:00Z (GMT). No. of bitstreams: 1
Santos_RodrigoCouto_D.pdf: 1767712 bytes, checksum: a3a87a18aca110dc5296d7ef5ded6e08 (MD5)
Previous issue date: 2007 / Resumo: A carência existente no setor da pecuária leiteira brasileira, tanto de aumentar a produtividade, quanto de diminuir os custos de produção, tem induzido os produtores a buscarem novos conhecimentos. Desta forma, as relações entre fatores ambientais e respostas fisiológicas do gado leiteiro são de extrema importância durante o processo produtivo. Assim, informações como a época correta de ocorrência do estro não deve ser analisada como uma variável absoluta, já que fatores ambientais, sistema de criação e tipologia das instalações influenciam nas reações fisiológicas do animal. Se a exposição climática pode influenciar no ciclo estral do bovino leiteiro, então qualquer informação que facilite a identificação correta do cio é de grande valia, pois significa diminuição do trabalho e aumento do número de inseminações com sucesso, possuindo assim, valor econômico significativo. A hipótese verificada nesse trabalho foi que é possível minimizar o erro na estimativa de estro em bovino leiteiro, empregando um modelo multivariável com a utilização de tecnologia da informação. O objetivo geral foi estimar a possibilidade de presença de estro em vacas leiteiras utilizando recursos computacionais. Os objetivos específicos foram o levantamento das situações de campo relacionadas ao manejo e condições ambientais de alojamento que influenciem na detecção de estro, o desenvolvimento de um modelo utilizando a lógica fuzzy, para estimar a presença de cio e seu respectivo teste. Foram utilizadas informações pertinentes a gado holandês alojados em confinamento total com intervalos de idade, peso e produção prédefinidos. Serviram como variáveis de entrada o Índice de Temperatura e Umidade (ITU), período após ultimo cio (PAUC) e número de indícios de estro (NCO). Como variável de saída foi considerada a Taxa de Detecção de Cio (TDC). Após o término deste trabalho, concluiu-se que é possível a construção de um modelo baseado na lógica fuzzy e dados de ambiência, além de informações fornecidas por especialista, que estime a taxa de detecção de cio para diversos cenários. Além disso, sugere-se melhor treinamento da mão-de-obra destinada ao manejo reprodutivo e observação mais atenta dos animais / Abstract: The existing gap in the Brazilian dairy sector for both increase in productivity, and decrease in production costs has induced producers to search for new knowledge. In this way the relation between environmental factors and dairy cattle physiological responses are of extreme importance during the production process. Therefore information such as time of estrus occurrence should not be analyzed as an absolute variable as environmental factors, rearing system and constructions¿ typology influence in the animal¿s physiological response. If the climatic exposition may influence the dairy cows estrus cycle then any information that improve the correct estrus identification is of great value, as it means decrease in losses and increase in success in the process, and meaning significant economical gain. The hypothesis verified in this research was that it is possible to minimize the error in estimating estrus incidence in dairy cows by describing a multivariable model using information technology. This research aimed mainly to estimate the possibility of estrus detection in dairy cows, and the specific objectives were to identify field management conditions and environmental housing scheme that may influence the estrus detection, as well as the development of a model using fuzzy logic for estimating estrus presence, and its respective test. Information pertinent to totally confined Holstein dairy cattle was used such as age interval, weight and pre-defined milk production. Input variables used were the Temperature and Humidity Index (THI), period since last estrus (PSLE) and the number of estrus signals (NES). As output variable there was the estrus detection index (EDI). After this research it was concluded that it was possible the construction of a model based on fuzzy logic and using environmental data, besides the specialist information that helps detecting estrus for several scenarios. Beside that it is suggested better labor training for the workers involved with reproduction management as well as more attention to the animals observation / Doutorado / Construções Rurais e Ambiencia / Mestre em Engenharia Agrícola
|
76 |
Endocrine changes associated with the effect of nutrition on the timing of reconception and puberty in dairy cattleLuna, Gonzalo 26 February 2007 (has links)
Please read the abstract in the section 00front of this document / Dissertation (MSc (Agric))--University of Pretoria, 2007. / Animal and Wildlife Sciences / unrestricted
|
77 |
Desempenho reprodutivo em novilhas Bos indicus e Bos taurus X Bos indicus submetidas a protocolos de sincronização da ovulaçãoRodrigues, Adnan Darin Pereira, 1987- January 2016 (has links)
Orientador: José Luiz Moraes Vasconcelos / Resumo: O objetivo dessa tese foi avaliar o desempenho reprodutivo de novilhas Bos indicus (BI) e Bos taurus x Bos indicus (CR) submetidas a protocolos de sincronização da ovulação. No Capitulo 2, novilhas BI e CR púberes e pré-púberes foram submetidas a estratégia reprodutiva proposta por Rodrigues et al. (2014) e um grupo de novilhas púberes foram sincronizadas com o protocolo de IATF padrão. No Capítulo 3, novilhas BI e CR foram submetidas a estratégia reprodutiva aos 12 meses de idade. No Capítulo 4, foi avaliado o efeito da concentração circulante de P4 no Dia 9 do protocolo de IATF e tratamento com eCG em novilhas BI e CR. No experimento do Capítulo 2 uma maior porcentagem de novilhas BI estavam pré-púberes no início do experimento comparadas as novilhas do grupo CR. A taxa de indução não foi diferente entre novilhas BI e novilhas CR. A raça interferiu na prenhez à IATF na Fazenda 1, mas não interferiu na Fazenda 2. Novilhas que não responderam ao protocolo de indução tiveram menor taxa de prenhez à IATF em relação aos demais grupos experimentais. No experimento do Capítulo 3, a presença de CL no D0 não diferiu entre os grupos genéticos. Animais mais pesados apresentaram maior presença de CL, independentemente de raça. Houve efeito de CL no D0 na taxa de prenhez à IATF. Não foi detectada interação entre presença de CL e raça na prenhez, sendo que novilhas BI tiveram menor P/IA do que as novilhas CR. Houve interação entre peso e CL no D0 na P/IA, sendo que em novilhas com CL no... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Not available / Doutor
|
78 |
Simulation of genetic control of reproduction in beef cowsHepp, Maribeth January 1982 (has links)
A stochastic computer model was constructed to simulate cow reproductive performance. Parameters for single-service conception rate and days from calving to first service (postpartum interval) were developed from the literature. Estimates of the heritability and repeatability (h², t) of each of these traits in four simulated data sets were RUN1 (.20, .20), RUN2 (.15, .20), RUN3 (.10, .10), RUN4 (.05, .10). Binomial conception rate parameters were normalized to simulate assumed normal underlying genetic and environmental distributions. Postpartum interval has a non-normal phenotypic distribution that was produced by combining an assumed normal genetic distribution with a Pearson III gamma distribution of environmental effects. The breeding season was 63 d. Simulation outputs included annual conception rate (BCR), first service conception rate (FSCR), date of first service (FS), number of services (NS), conception-calving date (CD), postpartum interval (PPI), actual weaning weight (ACTWW) and adjusted 205-d weaning weight (ADJWW). Realized heritabilities and repeatabilities for these outputs were estimated from half-sib intraclass correlations based on 5 yr of records on 100 herds of 50 cows each. Realized heritabilities (RUN1-RUN4) for BCR, FSCR, FS, NS, CD, PPI, ACTWW and ADJWW ranged from .165-.028, .187-.055, .023-.010, .227-.071, .071-.032, .158-.022, .148-.176 and .156-.203, respectively. Repeatability estimates (RUN1- RUN4) for BCR, FSCR, FS, NS, CD, PPI, ACTWW and ADJWW ranged from .178-.059, .212-.108, .125-.101, .244-.118, .187-.155, .207-.116, .266-.263 and .280-.286, respectively. / Master of Science
|
79 |
Genetic and phenotypic relationships among fifteen measures of reproduction in dairy cattleMeland, Ole Mervin January 1984 (has links)
Reproductive data from 30 research herds were on 31,132 breeding periods of 11,347 dairy cows. Cows were sired by 1,101 sires and had 66,184 services to 1,320 service sires. Several measures of reproductive pe.rformance were calculated. These included conception rate, number of services, service period length, days open, age at first breeding, calving interval, days between services, and return to estrus lag. First, second and third service period were each analyzed separately, while fourth and later service periods were pooled.
Heritability was estimated using the sire component of variance and the estimate of the total variance derived from MIVQUEO and maximum likelihood analyses. The data set was restricted to daughters of sires used in multiple herds. Heritability estimates were less than .07 for all traits in the heifer service period except age at first breeding (.2 by maximum likelihood and .13 by MIVQUEO). Similarly, with the exception of conception rate, none of the measures of reproduction had heritabilities greater than .05 for all three remaining service period groups. Conception rate measured as a trait of the male (service sire) ranged from .08 to .135 for second and third service periods. Conception rate as female trait (sire) had heritabilities ranging from .09 to .249 for second and third service periods.
Low heritability estimates obtained in this and other studies suggest that large progeny or service sire groups will be necessary to identify the small genetic differences between bulls.
Many genetic and phenotypic correlations were forced positive due to a part-whole relationship or due to the fact they were simply different bounds for the same measure. A few correlations were in the range from .50 to .90, but many were not significantly different from zero due to large approximate standard errors.
Repeatabilities based upon pairwise comparisons were in the range from 0 to .13. Repeatabilities for the reproductive performance of virgin heifers with first parity ranged from .01 to .06 and were generally smaller than later parities. Repeatabilities based upon repeated measures on the same cow ranged from 0 to .12.
Predicted Differences for female (sire) and male (service sire) reproduction were calculated by Best Linear Unbiased Prediction. This analysis included 207 bulls which were in the data both as sire and service sire. Correlations between proofs for male and female reproduction ranged from -.13 to .13. These results suggest limited genetic relationships between male and female fertility. / Ph. D.
|
80 |
The effects of the protein metabolites ammonia and urea on oocyte maturation, fertilization, and early embryo development, using an in vitro systemClark, Tina Marie 11 June 1996 (has links)
Graduation date: 1997
|
Page generated in 0.076 seconds