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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.
51

Comportamento de prog?nies de pinh?o-manso (Jatropha curcas L.) em casa de vegeta??o e no campo quanto ? vari?veis morfoagron?micas / Behaviour progenies of physic-nut (Jatropha curcas L.) in a green house and field regarding morphoagronomic variables

RIBEIRO, Nath?lia Virg?nia da Silva 24 July 2013 (has links)
Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2018-09-25T18:06:32Z No. of bitstreams: 1 2013 - Nath?lia Virg?nia da Silva Ribeiro.pdf: 1961349 bytes, checksum: 43e989102153b88ad17a4eefb1e37f9e (MD5) / Made available in DSpace on 2018-09-25T18:06:32Z (GMT). No. of bitstreams: 1 2013 - Nath?lia Virg?nia da Silva Ribeiro.pdf: 1961349 bytes, checksum: 43e989102153b88ad17a4eefb1e37f9e (MD5) Previous issue date: 2013-07-24 / CAPES / The species Jatropha curcas, popularly known as physic nut, belonging to the family Euphorbiaceae, is currently regarded as one of the greatest potential of oil seeds for biodiesel production in the world. However, the knowledge of available genetic variability and productive behavior of the species are still scarce. This work is part of the Breeding Program of Jatropha curcas developed in UFRRJ, and its objective was know some morphological and productive aspects of 10 progenies of physic nut (Jatropha curcas), grown in greenhouse and camp up to 17 months old, selected from female parents belonging to the Germplasm Collection of physic nut (Jatropha curcas) of the Department of Plant Science at the Institute of Agronomy of UFRRJ. It is expected this study provide important information for the continued Breeding Program of the species in UFRRJ. The experiment was installed in October 2011 in greenhouse, and consisted of 10 progenies of physic nut arranged in experimental design randomized blocks with 3 repetitions, and 15 plants by experimental parcel. After 4 evaluation in greenhouse, the plants were transferred to the camp, here were done 6 evaluation, the last being in April 2013. In the greenhouse it was evaluated aspects related to the germination of the progeny and the behavior of young plants. In the first case, it was estimated germination itself progenies and the index of germination speed (IGS), and at the second, the size of the petiole (SMP), number, width and length of fully developed leaves, respectively, discriminated as NDL, WDL and LDL, insertion angle of the leaf (IALs), length relationship and width of leaf (LWL), height of young plants (HYP), stem diameter (SDI) and branches number (BNU). The obtained data were submitted to analysis of variance, mean test via DMS-t and correlation analysis. The coefficient of genotypic determination (H2), of genotypic variation (CVg) and experimental variation (CVe) were also estimated, and variation index (VIg). The mean germination percentage for Jatropha curcas species was 68,23%, and the mean index germination speed was of 8,60 seeds germinated per day. The progeny that reached higher percentage of gemination and higher germination speed were UFRRJ/PM05 (83,33 and 3,12) and UFRRJ/PM01 (83,33 and 3,38). Whereas the progenies UFRRJ/PM10 and UFRRJ/PM04 were the ones with the lowest percentage of germination and germinated more slowly. In the greenhouse was no statistically significant difference between treatments for the variables SMP, NDL, SDI, HYP, BNU, LDL, WDL. Only for LWL and IALs not statistical difference was detected signficativa. In the camp, it was evaluated variables related to morphological and productive. The morphological variables were: insertion angle of the leaf (IALs), height of young plants (HYP), stem diameter (SDI), of branches number (BNU) and the size of the petiole (SMP). Variables related to aspects of production were: fruit number (FNU), average fruit weight (AFW), fruit length (FRL), fruit width (FRW), weight of fruit of the crop (WFC), weight of dries seeds (WDS), seeds number per fruit (SNF=SNU/FNU), seeds number (SNU), seed length (SEL), seed width (SEW), average seed weight (ASW=GPR/SNU) and grain production (GPR= SNUxASW). All data obtained for each stage of treatment in this study were submitted to analysis of variance, mean test way DMS-t and correlation analyzes. Only for the variables related to morphological aspects considered the effect of season in the ANOVA. Were also estimated the coefficient of genotypic determination (H2), genotypic variation (CVg) and experimental variation (CVe), and the variation index (IVg). All variables (morphological and production) were subjected to regression analysis over the 6 collection periods. Was also estimated genetic the following parameters: genetic variance (?2g), additive variance (?2a), heritability of family means, within family, stratified mass and mass in the experiment. The estimation of genetic parameters was based on the last review performed in the experiment, not considering, therefore, the season effect. From previously mentioned analysis it was observed that all the variables related to morphological aspects showed statistically significant differences between treatments. As for variables related to production only FRW, AFW, SEL and ASW no statistically significant difference. Characters related to leaf morphology showed low coefficients of determination and variation index, while the latter parameters were higher for the variables HYP (83,24 e 0,64) e BNU (80,92 e 0,59), respectively, evaluated in plants in a greenhouse. Progenies with the highest mean branches number were UFRRJ/PM07 (0,49) and UFRRJ/PM08 (0,47). In the camp, the BNU variable had the highest coefficient of genotypic determination (84,16) and variation index (0,54) again. Variables SDI, HYP, IALs and BNU showed a linear behavior over the following months, only exception to IALs variable studied in the progeny UFRRJ/PM 10. Variable SMP proved oscillating in all progenies during the months evaluated. Regarding the variables related to production, the progeny had a different behavior between them. Therefore, the selection of these variables are not indicated when you want to increase grain production in physic nut. Only when considering the quantitative variables is that selection for increased production becomes more effective, for example, the selection of the seeds number. The variable branches number (BNU) was positively correlated with almost all variables in the greenhouse and all related to the production characteristics analyzed in the camp, therefore, this variable can be used in precocious selection for increased production in physic nut. The progenies UFRRJ/PM08 and UFRRJ/PM01 were the most promising in respect of seed production, but, evaluation over the years are still needed, as the plants of the experiment were evaluated in still too early to age, and then, physiological and experimental aspects may be being even more important than genetic factors. / A esp?cie Jatropha curcas, popularmente conhecida como pinh?o manso, pertencente ? fam?lia Euphorbiaceae, ? considerada atualmente como uma das oleaginosas de maior potencial para a produ??o de biodiesel no mundo. No entanto, o conhecimento da variabilidade gen?tica dispon?vel e o comportamento produtivo da esp?cie ainda s?o escassos. O presente trabalho ? parte do Programa de Melhoramento Gen?tico de Jatropha curcas desenvolvido na UFRRJ, e teve como objetivo conhecer alguns aspectos morfol?gicos e produtivos de 10 prog?nies de pinh?o-manso (Jatropha curcas), cultivadas em casa de vegeta??o e campo at? aos 17 meses de idade, selecionadas a partir de genitores femininos pertencentes ? Cole??o de Germoplasma de pinh?o-manso (Jatropha curcas) do Departamento de Fitotecnia do Instituto de Agronomia da UFRRJ. Espera-se com este trabalho fornecer informa??es importantes para a continuidade do Programa de Melhoramento da esp?cie na UFRRJ. O experimento foi instalado em outubro de 2011 em casa de vegeta??o, e foi composto por 10 prog?nies de pinh?o-manso dispostas em delineamento em blocos ao acaso com 3 repeti??es, e 15 plantas por parcela experimental. Ap?s 4 avalia??es em casa de vegeta??o, as plantas foram transferidas para o campo, onde foram realizadas 6 avalia??es, sendo a ultima no m?s de abril de 2013. Em casa de vegeta??o avaliou-se aspectos relacionados ? germina??o das prog?nies e o comportamento das plantas jovens. No primeiro caso, estimou-se a germina??o propriamente dito das prog?nies e o ?ndice de velocidade de germina??o (IVG), e no segundo, o tamanho do pec?olo (TMP), n?mero, largura e comprimento de folhas completamente desenvolvidas, respectivamente, discriminados como NFD, LAF e COF, ?ngulo de inser??o da folha (AIFc), rela??o comprimento e largura de folha (CLF), altura de plantas (APJ), di?metro de caule (DIC) e n?mero de ramos (NDR). Os dados obtidos foram submetidos a an?lises de vari?ncia, teste de m?dia via DMS-t e an?lise de correla??o. Tamb?m foram estimados os coeficientes de determina??o genot?pico (H2), de varia??o genot?pico (CVg) e de varia??o experimental (CVe), e o ?ndice de varia??o (IVg). A porcentagem m?dia de germina??o para a esp?cie Jatropha curcas foi de 68,23%, e o ?ndice m?dio de velocidade de germina??o foi de 8,60 sementes germinadas por dia. As prog?nies que atingiram maiores percentuais de gemina??o e maior velocidade de germina??o foram a UFRRJ/PM05 (83,33 e 3,12) e UFRRJ/PM01 (83,33 e 3,38). Enquanto que as prog?nies UFRRJ/PM10 e UFRRJ/PM04 foram as que apresentaram os percentuais de germina??o mais baixos e germinaram mais lentamente. Em casa de vegeta??o houve diferen?a estat?stica significativa entre os tratamentos para as vari?veis TMP, NFD, DIC, APJ, NDR, COF, LAF. Apenas para CLF e AIFc n?o se detectou diferen?a estat?stica signficativa. No campo, avaliou-se vari?veis ligadas aos aspectos morfol?gicos e produtivos. As vari?veis morfol?gicas analisadas foram: ?ngulo de inser??o da folha (AIFc), altura de plantas (APJ), di?metro de caule (DIC), n?mero de ramos (NDR), tamanho m?dio de entren? (MECc). As vari?veis relacionadas aos aspectos de produ??o foram: n?mero de frutos (NFR), peso m?dio do fruto (PFR), comprimento do fruto (CFR), largura do fruto (LFR), peso de frutos da colheita (PFC), peso de sementes secas (PMSs), n?mero de sementes por fruto (NSF = NSE/NFR), n?mero de sementes (NSE), comprimento da semente (CMS), largura da semente (LSE), peso m?dio de sementes (PMS=PSP/NSE) e produ??o de gr?os (PGP=NSExPMS). Todos os dados obtidos para cada tratamento nesta etapa do trabalho foram submetidos ?s an?lises de vari?ncia, teste de m?dia via DMS-t e an?lises de correla??o. Apenas para as vari?veis ligadas aos aspectos morfol?gicos considerou-se o efeito de ?poca na anova. Foram estimados tamb?m os coeficientes de determina??o genot?pico (H2), de varia??o genot?pico (CVg) e de varia??o experimental (CVe), e o ?ndice de varia??o (IVg). Todas as vari?veis (morfol?gicas e de produ??o) foram submetidas a an?lises de regress?o ao longo das 6 ?pocas de coleta. Estimou-se tamb?m os seguintes par?metros gen?ticos: vari?ncia gen?tica (?2g), vari?ncia aditiva (?2a), herdabilidades entre m?dias de fam?lias, dentro de fam?lia, massal estratificada e massal no experimento. A estimativa dos par?metros gen?ticos foi com base na ?ltima avalia??o realizada no experimento, n?o considerando, portanto, o efeito de ?poca. A partir das an?lises anteriormente citadas observou-se que todas as vari?veis ligadas aos aspectos morfol?gicos apresentaram diferen?a estat?stica significativa entre os tratamentos. Quanto as vari?veis relacionadas ? produ??o apenas LFR, PFR, CMS, e PMS n?o apresentaram diferen?a estat?stica significativa. Caracteres relacionados ? morfologia da folha apresentaram baixos coeficientes de determina??o e ?ndice de varia??o, enquanto que estes mesmos par?metros foram altos para as vari?veis APJ (83,24 e 0,64) e NDR (80,92 e 0,59), respectivamente, avaliados em plantas em casa de vegeta??o. As prog?nies que apresentaram as maiores m?dias do n?mero de ramos foram as UFRRJ/PM07 (0,49) e UFRRJ/PM08 (0,47). No campo, a vari?vel NDR apresentou novamente o maior coeficiente de determina??o genot?pico (84,16) e ?ndice de varia??o (0,54). As vari?veis DIC, APJ, AIFc e NDR apresentaram um comportamento linear ao passar dos meses, exce??o apenas para a vari?vel AIFc estudada na prog?nie UFRRJ/PM 10. A vari?vel MECc mostrou-se oscilante em todas as prog?nies durante os meses avaliados. Em rela??o ?s vari?veis ligadas ? produ??o, as prog?nies tiveram um comportamento diferenciado entre si. Todas as vari?veis ligadas aos aspectos morfol?gicos da semente (largura, comprimento e peso m?dio) apresentaram baix?ssima ou nenhuma variabilidade gen?tica entre as prog?nies estudadas. Portanto, a sele??o sobre estas vari?veis n?o s?o indicadas quando se deseja o aumento da produ??o de gr?os em pinh?o-manso. Apenas quando se considera vari?veis de natureza quantitativa ? que a sele??o para o aumento de produ??o torna-se mais efetiva, como por exemplo, a sele??o sobre o n?mero de sementes. A vari?vel n?mero de ramos (NDR) se correlacionou positivamente com quase todas as vari?veis analisadas em casa de vegeta??o e com todos os caracteres relacionados ? produ??o analisados no campo, assim sendo, essa vari?vel pode ser utilizada em sele??o precoce visando o aumento da produ??o em pinh?o-manso. As prog?nies UFRRJ/PM08 e UFRRJ/PM01 foram as mais promissoras no que se refere a produ??o de sementes, por?m, avalia??es ao longo dos anos ainda s?o necess?rias, visto que as plantas do experimento foram avaliadas em idade ainda muito precoce, e portanto, aspectos fisiol?gicos e experimentais podem estar sendo at? mais importantes do que aspectos gen?ticos.
52

Componentes de variância e valores genéticos para as produções de leite do dia do controle e da lactação na raça holandesa com diferentes modelos estatísticos. / Variance components and breeding value for test day and lactation milk yields in holstein cattle with different statistical models.

Melo, Claudio Manoel Rodrigues de 15 July 2003 (has links)
Foram utilizados 263.390 registros de produção de leite do dia do controle (PDC) de 32.448 primeiras lactações de vacas da raça Holandesa obtidas no período de 1991 a 2001 para estimar componentes de variância e parâmetros genéticos, usando diferentes modelos estatísticos e a metodologia REML. Compararam-se as estimativas de valores genético (EVG) dos modelos de repetibilidade (MR) e de regressão aleatória (MRA) com às do modelo para as produções da lactação (P305). Nos MRA utilizaram-se duas curvas para descrever a trajetória da lactação: a polinomial logarítmica de Ali e Schaeffer (AS) e a exponencial de Wilmink (W), sob duas formas: a padrão e com uma modificação para reduzir a amplitude das covariáveis e contornar problemas de convergência (W Ú ). No ajuste da curva AS considerou-se heterogeneidade de variâncias residuais (VR) entre classes de dias em lactação (cDEL). A estimativa de herdabilidade para as P305 (0,27) foi menor do que àquelas para as PDC obtidas com MR, incluindo ou não a curva AS como sub modelo (0,30 e 0,43, repectivamente). As herdabilidades para as PDC por análises uni-caráter (0,22-0,36) e bi-caráter (0,23-0,33) foram menores no início e fim da lactação. As correlações genéticas entre produções de controles consecutivos foram superiores às estimadas entre controles do ínicio e do fim da lactação. As estimativas de herdabilidade por MRA com as curva AS (0,29-0,42) e W Ú (0,33-0,40) foram semelhantes, mas aquelas estimadas com a curva W (0,25-0,65) foram maiores do que as estimadas com as outras curvas pricipalmente no fim da lactação. Com os MRA as correlações genéticas foram próximas da unidade entre produções de controles consecutivos, mas reduziram com o aumento do intervalo entre controles. As estimativas de VR entre cDEL foram muito semelhantes variando de 4,15 a 5,11 para a curvas AS. Os desvios padrão (DP) para as EVG para produção de leite dos touros foram semelhantes entre os modelos AS, W Ú e MR. Entretando, os DP para as EVG foram maiores nos modelos para PDC do que no modelo a P305. As correlações entre as EVG para touros com o modelo P305 e os demais modelos aumentaram com o aumento no número de filhas e variaram de 0,66 (P305-W) a 0,92 (P305-AS e P305- W Ú ). As estimativas de tendência genética foram maiores para os MRA e menores para o MR se comparadas à estimativa obtida pelo modelo para P305. As estimativas de herdabilidade superiores para as PDC e as altas correlações (0,86-0,99) entre estas e a P305 indicam um potêncial de uso das PDC nas avaliações genéticas. Correlações genéticas heterogêneas (0,64-1,00) entre as PDC, medidas ao longo da lactação, não confimam a suposição de que elas são medidas repetidas do mesmo caráter. O MRA com a curva AS e VR homogênea foi o de melhor ajuste entre os avaliados, mas o modelo W Ú resultou em estimativas de herdabilidade mais estáveis ao longo da lactação. Na comparação dos resultados dos modelos conclui-se que o MRA com a curva AS e homonogeneidade de VR é a melhor alternativa, dentre as estudadas, para avaliação genética para produção de leite de gado Holandês no Brasil. / Covariance components and genetic parameters for milk yield from 263,390 test-day records of 32,448 first lactation Holstein cows were estimated using animal models by REML. Test-day repeatability (RM) and random regression (RR) models were compared to a 305-d lactation model (P305) to estimate breeding values. Random regression involved the five-parameter logarithmic Ali and Schaeffer function (AS) and the three-parameter exponential Wilmink function in standard (W) and modified (W*, to reduce the range of covariates and avoid convergence problems) form to model the shape of the lactation curve. Heterogeneous error variance (EV) for classes of days in milk (cDIM) was considered in adjusting the AS function. Heritability for milk yield by P305 (0.27) was smaller than those estimated for daily milk yield by RM including or not including a logarithmic sub-model (0.30 and 0.43, respectively). Heritability estimates for univariate (0.22-0.36) and bivariate models (0.23-0.33) for test-day milk yields were smallest during early and late lactation. Genetic correlations were higher for daily milk yield between consecutive test-days than between test-days at the beginning and end of lactation. Heritability estimates for AS (0.29-0.42) and W* (0.33-0.40) RR models were similar, but heritability estimates obtained for W (0.25-0.65) were higher than those estimated by other functions, particularly at the end of lactation. Genetic correlations between daily milk yield on consecutive test-days were close to unity, but they decreased with an increase of the interval between test-days. Estimates of EV for cDIM were quite similar, rating from 4.15 to 5.11 for the AS function. Standard deviations (SD) of bulls’s EBVs for milk yield were similar for AS, W* models and RM. However, SD of EBVs for bulls and cows were larger for test-day models than for P305 and for bulls they differed by -33.64 to 321.95 from the P305 depending on progeny number. SD of EBVs for bulls and cows for the W model were the largest ones. Correlation between EBVs among P305 and the other models for bulls increased as progeny number increased and ranged from 0.66 (W-P305) to 0.92 (AS-P305, W*-P305). Genetic trends were larger for RR models and smaller for RM than for P305. Larger heritability estimates for test-day models and large genetic correlations between test-day and lactation milk yields (0.86-0.99) indicated a potential use of test-day records in genetic evaluations. Heterogeneous genetic correlations (0.64-1.00) for test-day milk yields across lactation did not support the assumption that test-day records are repeated measures of the same trait. The AS homogeneous EV model was the most parsimonious and the best fit among those evaluated, but the W* model resulted in more stable heritability estimates for daily milk yield across lactation. RR models provide more information than the RM and describe the shape of the lactation curve from which EBVs for persistency can be derived. These results indicated AS as an alternative model for genetic evaluation for milk yield using test-day records of Holstein cattle in Brazil.
53

Effect of selection at weaning on genetic parameters of weight gain for centralized and on farm test for beef bulls

Mashiloane, Majela Lesley January 2007 (has links)
Thesis (M.Sc.) (Agriculture) --University of Limpopo, 2007 / The objectives of this study were to evaluate the effect of pre-weaning selection on estimates of genetic parameters for post-weaning average daily gain in Phases C (ADG-C) and D (ADG-D) and to estimate genetic relationships between average daily gain in the two phases. Performance records of the South African Angus cattle breed was used in the analysis. (Co)variance components and genetic parameters for weaning (WWT), AGD-C and ADG-D were estimated by REML procedures fitting three different models (Models 1, 2 and 3) that differed in how they integrated sequential selection in the analysis of post-weaning traits. Model 1 was a univariate model of WWT, ADG-C and ADG-D. Model 2 was a two trait model of WWT and either ADG-C or ADG-D. Model 3 was a three trait model of WWT, ADG-C and ADG-D. Estimates of heritability for ADG-C were 0.39±0.08, 0.42±0.06 and 0.44±0.01 from Model 1, 2 and 3 respectively. Corresponding estimates of heritability for ADG-D were 0.18±0.021, 0.19±0.021 and 0.21±0.02 respectively. An estimate of genetic correlation between ADG-C and ADG-D was 0.58± and it suggested that the two traits may not necessarily be under the same genetic control. Rank correlations for all bulls based on ADG-C estimated breeding values (EBV’s) were 0.92, 0.83 and 0.94 for Model 1 vs. Model 2, Model 1 vs. Model 3 and Model 2 vs. Model 3 respectively. Corresponding ADG-D EBV’s rank correlations were 0.88, 0.84 and 0.93. Rank correlations for top and bottom 1%, 5% and 10% were lower than those for all bulls in both ADG-C and ADG-D. Low rank correlations showed that the difference in magnitude of genetic parameters from different models was enough to alter bull rankings based on EBV’s of ADG-C and ADG-D. Hence it was concluded that inclusion of pre-weaning information in genetic analysis for post-weaning average daily gain is necessary to account for selection at weaning. / the THRIP (Technology and Human Resource for Industry Project) and NRF (National Research Foundation).
54

Genetic parameters for productive and reproductive traits of sows in multiplier farms

Kim, Hyung-Joo 12 July 2001 (has links)
No description available.
55

Genetic Regulation of Immune Responses in Holstein Dairy Cows across Canada

Crispi, Kathleen Adele Thompson 05 September 2012 (has links)
Diseases that affect dairy cattle have serious economic and animal welfare implications. The inclusion of immune response (IR) traits in breeding indices has been suggested to improve inherent animal health, and decrease the use of antimicrobials. The objectives of this research were to (1) evaluate cell-mediated (CMIR) and antibody-mediated immune responses (AMIR) on 680 Holstein cows from 58 herds across Canada, (2) estimate genetic parameters of these traits (3) examine the associations with routinely evaluated traits as well as the incidence of mastitis, (4) evaluate the correlation of natural and specific antibody and (5) perform a genome-wide association study (GWAS) to determine genetic markers associated with high or low IR. In collaboration with the Canadian Bovine Mastitis Research Network cows were immunized with both a type 1 and type 2 test antigen to stimulate CMIR and AMIR, respectively. A cutaneous delayed-type hypersensitivity test to the type 1 test antigen was used as an indicator of CMIR, and serum antibody (IgG1 and IgG2) to the type 2 test antigen as an indicator of AMIR. IR phenotypes varied significantly by cow, herd and region in Canada. Heritability estimates were moderate, 0.19 for CMIR and 0.16-0.43 for AMIR depending on time in the immunization protocol and antibody isotype. Beneficial associations between AMIR and some reproductive traits were found. Using estimated breeding values, cows were classified as high, average or low responders. High AMIR cows had significantly lower incidence rates of clinical mastitis compared to average and low cows. No difference was found when cows were classified based on CMIR. Natural antibody was not genetically correlated with specific antibody nor was it associated with mastitis. The GWAS found 198 genetic markers significantly associated with AMIR, with the majority on chromosome 23 where the major histocompatability complex is located. Other significant genes involved in IR include those associated with the complement system, interleukin 17 and tumor necrosis factor. This research confirms the benefit of identifying high IR cows and gives a glimpse of current IR profiles in Canadian Holsteins. This was the first GWAS for IR traits in dairy cattle and suggests it may be possible to include IR traits in genomic selection indices. / This research was financed by grants to B.A. Mallard from National Sciences and Engineering Research Council of Canada, Alberta Milk, Dairy Farmers of New Brunswick, Nova Scotia, Ontario and Prince Edward Island, Novalait Inc., Dairy Farmers of Canada, DairyGen council of Canadian Dairy Network, Agriculture and Agri-Food Canada, Public Health Agency of Canada, Technology PEI Inc., Université de Montréal and University of Prince Edward Island through the Canadian Bovine Mastitis Research Network. Kathleen Adele Thompson Crispi was funded by the Dairy Farmers of Ontario Doctoral Research Assistantship.
56

Direct and correlated responses to selection in large white pigs for growth rate on restricted feeding

Nguyen Hong Nguyen, Nguyen Unknown Date (has links)
Responses in growth rate, food conversion efficiency, carcass composition, residual food intake, meat quality and reproduction traits to selection in pigs for four years, for high or low post-weaning growth rate on a fixed but restricted ration were measured in progeny grown on either restricted, ad libitum individual or ad libitum group feeding regimens. Genetic and phenotypic correlations among the traits were also examined on animals whose full pedigrees comprised a total of 5324 animals. Substantial divergent response was achieved from selection for high vs. low growth rate on restricted feeding, with the genetic means of daily gain diverging by 81.25 g or 2.78 genetic standard deviations (SigmaG). The high and low growth rate lines also differed in ultrasonic backfat and food conversion efficiency by 1.12 SigmaG and 0.84 SigmaG, and by 0.88 SigmaG, 1.10 SigmaG, and 1.14 SigmaG for carcass weight daily gain, carcass fat and lean percentage, respectively. These responses were consistent with the moderately to highly, favourable genetic correlations among and between performance and carcass composition traits. Genetic changes in growth rate, ultrasonic backfat, food conversion ratio, carcass daily gain, carcass fat and lean percentage when measured on ad libitum individual feeding were all economically beneficial. The high growth line had a significantly lower voluntary daily food intake and residual food intake than the contemporaneous low line, indicating a reduced energy requirement for maintenance in the high relative to the low line. Genetic correlations between either growth rate or backfat and carcass traits were favourable but unfavourable between daily food intake and carcass fat or lean percentage, implying that selection strategies which place emphasis on increased leanness and decreased fatness would result in a decline in voluntary food intake of the animals. The descendants of breeding pigs selected for high post-weaning daily gain on restricted feeding showed significantly increased growth rates, slaughter weights and carcase lean percentages and reduced fatness when grown in group housing with ad libitum feeding. This suggests that restricted feeding is an effective performance testing approach for seedstock lines supplying commercial regimens with group housing and ad libitum feeding. Carcase lean pH values measured 24 hours post-mortem (pH24) were not statistically different between the selected lines, suggesting that an increase in basal metabolic rate due to increased rate of lean deposition in the high relative to the low line may have been compensated for by a reduction in heat production from other sources such as physical activity. Such a reduction was evidenced by a lower residual food intake in the high than the low growth lines. This supports the hypothesis that selection for high growth rate on restricted feeding does not have detrimental effects on pork quality. The sows of the high growth line produced more piglets with significantly heavier weights at birth, giving a potential for better post-natal growth and higher yield of pork weaned per sow per year than the low growth sows. Body weights of the high line sows prior to mating were also significantly higher than those of low line sows suggesting earlier age of sexual maturity. A non-significant tendency for high line sows to have a lower voluntary food intake than low line sows pointed to the possibility that their lower maintenance requirement as growers was carried over to the lactational phase of life. It is concluded that selection for high growth rate on a restricted ration of fixed amount will produce pig strains with a high genetic potential for lean growth, reduced energy requirement for maintenance and improved reproductive performance, and which will be suitable for growing under a wide range of commercial feeding environments.
57

Direct and correlated responses to selection in large white pigs for growth rate on restricted feeding

Nguyen Hong Nguyen, Nguyen Unknown Date (has links)
Responses in growth rate, food conversion efficiency, carcass composition, residual food intake, meat quality and reproduction traits to selection in pigs for four years, for high or low post-weaning growth rate on a fixed but restricted ration were measured in progeny grown on either restricted, ad libitum individual or ad libitum group feeding regimens. Genetic and phenotypic correlations among the traits were also examined on animals whose full pedigrees comprised a total of 5324 animals. Substantial divergent response was achieved from selection for high vs. low growth rate on restricted feeding, with the genetic means of daily gain diverging by 81.25 g or 2.78 genetic standard deviations (SigmaG). The high and low growth rate lines also differed in ultrasonic backfat and food conversion efficiency by 1.12 SigmaG and 0.84 SigmaG, and by 0.88 SigmaG, 1.10 SigmaG, and 1.14 SigmaG for carcass weight daily gain, carcass fat and lean percentage, respectively. These responses were consistent with the moderately to highly, favourable genetic correlations among and between performance and carcass composition traits. Genetic changes in growth rate, ultrasonic backfat, food conversion ratio, carcass daily gain, carcass fat and lean percentage when measured on ad libitum individual feeding were all economically beneficial. The high growth line had a significantly lower voluntary daily food intake and residual food intake than the contemporaneous low line, indicating a reduced energy requirement for maintenance in the high relative to the low line. Genetic correlations between either growth rate or backfat and carcass traits were favourable but unfavourable between daily food intake and carcass fat or lean percentage, implying that selection strategies which place emphasis on increased leanness and decreased fatness would result in a decline in voluntary food intake of the animals. The descendants of breeding pigs selected for high post-weaning daily gain on restricted feeding showed significantly increased growth rates, slaughter weights and carcase lean percentages and reduced fatness when grown in group housing with ad libitum feeding. This suggests that restricted feeding is an effective performance testing approach for seedstock lines supplying commercial regimens with group housing and ad libitum feeding. Carcase lean pH values measured 24 hours post-mortem (pH24) were not statistically different between the selected lines, suggesting that an increase in basal metabolic rate due to increased rate of lean deposition in the high relative to the low line may have been compensated for by a reduction in heat production from other sources such as physical activity. Such a reduction was evidenced by a lower residual food intake in the high than the low growth lines. This supports the hypothesis that selection for high growth rate on restricted feeding does not have detrimental effects on pork quality. The sows of the high growth line produced more piglets with significantly heavier weights at birth, giving a potential for better post-natal growth and higher yield of pork weaned per sow per year than the low growth sows. Body weights of the high line sows prior to mating were also significantly higher than those of low line sows suggesting earlier age of sexual maturity. A non-significant tendency for high line sows to have a lower voluntary food intake than low line sows pointed to the possibility that their lower maintenance requirement as growers was carried over to the lactational phase of life. It is concluded that selection for high growth rate on a restricted ration of fixed amount will produce pig strains with a high genetic potential for lean growth, reduced energy requirement for maintenance and improved reproductive performance, and which will be suitable for growing under a wide range of commercial feeding environments.
58

Direct and correlated responses to selection in large white pigs for growth rate on restricted feeding

Nguyen Hong Nguyen, Nguyen Unknown Date (has links)
Responses in growth rate, food conversion efficiency, carcass composition, residual food intake, meat quality and reproduction traits to selection in pigs for four years, for high or low post-weaning growth rate on a fixed but restricted ration were measured in progeny grown on either restricted, ad libitum individual or ad libitum group feeding regimens. Genetic and phenotypic correlations among the traits were also examined on animals whose full pedigrees comprised a total of 5324 animals. Substantial divergent response was achieved from selection for high vs. low growth rate on restricted feeding, with the genetic means of daily gain diverging by 81.25 g or 2.78 genetic standard deviations (SigmaG). The high and low growth rate lines also differed in ultrasonic backfat and food conversion efficiency by 1.12 SigmaG and 0.84 SigmaG, and by 0.88 SigmaG, 1.10 SigmaG, and 1.14 SigmaG for carcass weight daily gain, carcass fat and lean percentage, respectively. These responses were consistent with the moderately to highly, favourable genetic correlations among and between performance and carcass composition traits. Genetic changes in growth rate, ultrasonic backfat, food conversion ratio, carcass daily gain, carcass fat and lean percentage when measured on ad libitum individual feeding were all economically beneficial. The high growth line had a significantly lower voluntary daily food intake and residual food intake than the contemporaneous low line, indicating a reduced energy requirement for maintenance in the high relative to the low line. Genetic correlations between either growth rate or backfat and carcass traits were favourable but unfavourable between daily food intake and carcass fat or lean percentage, implying that selection strategies which place emphasis on increased leanness and decreased fatness would result in a decline in voluntary food intake of the animals. The descendants of breeding pigs selected for high post-weaning daily gain on restricted feeding showed significantly increased growth rates, slaughter weights and carcase lean percentages and reduced fatness when grown in group housing with ad libitum feeding. This suggests that restricted feeding is an effective performance testing approach for seedstock lines supplying commercial regimens with group housing and ad libitum feeding. Carcase lean pH values measured 24 hours post-mortem (pH24) were not statistically different between the selected lines, suggesting that an increase in basal metabolic rate due to increased rate of lean deposition in the high relative to the low line may have been compensated for by a reduction in heat production from other sources such as physical activity. Such a reduction was evidenced by a lower residual food intake in the high than the low growth lines. This supports the hypothesis that selection for high growth rate on restricted feeding does not have detrimental effects on pork quality. The sows of the high growth line produced more piglets with significantly heavier weights at birth, giving a potential for better post-natal growth and higher yield of pork weaned per sow per year than the low growth sows. Body weights of the high line sows prior to mating were also significantly higher than those of low line sows suggesting earlier age of sexual maturity. A non-significant tendency for high line sows to have a lower voluntary food intake than low line sows pointed to the possibility that their lower maintenance requirement as growers was carried over to the lactational phase of life. It is concluded that selection for high growth rate on a restricted ration of fixed amount will produce pig strains with a high genetic potential for lean growth, reduced energy requirement for maintenance and improved reproductive performance, and which will be suitable for growing under a wide range of commercial feeding environments.
59

Milk progesterone as a tool to improve fertility in dairy cows /

Petersson, Karl-Johan, January 2007 (has links) (PDF)
Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2007. / Härtill 4 uppsatser.
60

Estimativas de parâmetros genéticos para caracteres quantitativos em progênies de Eucalyptus urophylla S. T. Blake /

Souza, Cidinei Santos de. January 2010 (has links)
Resumo: O Eucalyptus urophylla destaca-se pelo potencial de utilização de sua madeira, pela sua plasticidade de adaptação a diferentes condições ambientais brasileiras e por ser tolerante ao cancro do eucalipto (Cryphonectria cubensis). A utilização de sementes melhoradas se faz necessária, considerando o iminente déficit florestal que começou no Brasil, a partir de 2004, em função da demanda por madeira ser maior que a sua oferta. Entretanto, o melhoramento dessa espécie, no Brasil, depende da existência de variabilidade genética das populações introduzidas, a qual evita a ocorrência de depressão endogâmica. O presente trabalho visa o estudo genético de uma população base de E. urophylla, originária de Flores e Timor, e instalada em Selvíria-MS. Estudou - se a variabilidade genética dessa população através de análises quantitativas. Dessa forma, os objetivos específicos do estudo foram: a) estimar a variabilidade genética para os principais caracteres silviculturais; b) estimar possíveis ganhos na seleção, utilizando-se da seleção entre e dentro de progênies e do Índice Multi-efeitos, analisando o efeito do desbaste em uma população base de E. urophylla. O experimento foi instalado em 17 de março de 1992, na Fazenda de Ensino, Pesquisa e Extensão da Faculdade de Engenharia, Campus de Ilha Solteira (FE/UNESP), localizada no município de Selvíria - MS. O teste de progênies foi instalado obedecendo a um delineamento experimental em Látice 8x8, quíntuplo, parcialmente balanceado, com 64 progênies provenientes da Estação Experimental do Instituto de Pesquisas e Estudos Florestais (IPEF/ESALQ/USP), localizada no município de Anhembi - S.P. As parcelas contêm oito árvores, no espaçamento de 3,0 x 3,0 metros. Os caracteres quantitativos avaliados e analisados foram: 1- diâmetro à altura do peito (DAP); 2- altura total da planta (H); 3- tipo de ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The Eucalyptus urophylla is detached for its wood potential of utilization for its plasticity of plasticity of adaptation in different Brazilian's environmental conditions and for being tolerant towards the eucalyptus canker (Cryphonectria cubensis). The utilization of improved seeds is needed, considering the imminent woodland's deficit that started in Brazil, in 2004, since the heavy Wood demand was higher than it offers. However the improvements of this specie in Brazil, depends on the existence of genetic variability of the installed populations, which avoids the occurrence of endogamous depression. The present report aims at the genetic study of a base population of E. urophylla, originated from Flores e Timor, and installed in Selvíria-MS. Its genetic variability was studied through quantitative analysis. This way, the specific objectives of this report was: a) Guess the genetic variability for the main silvicultural characters; b) Guess possible earnings in the selection, utilizing this selection among and inside the progenies and inside the progenies and the index of multi-effects, analyzing the skive effect in a base population of E. urophylla. The experiment was installed on March 17th of 1992, on the engineering university's farm of teaching, researches, and extension, campus in Ilha Solteira (FE/UNESP), located in Selvíria - MS. The progenies test was installed obeying an experimental delineation in lattice of 8x8, quintuplet, partially balanced with 64 progenies which came from the experimental station in the woodland's institute of researches and studies, (IPEF/ESALQ/USP), located in of Anhembi - SP. The parcels have 8 trees, in a space of 3,0 x 3,0 meters. The evaluated and analyzed quantitative characters was: 1-Diameter at chest's height (DAP); 2-Total plant's height (H); 3-Kind of bark (CAS); 4- Shape of the shank (FOR); 5- Bifurcation; 6- Survival (SOBR) ... (Complete abstract click electronic access below) / Orientador: Miguel Luiz Menezes Freitas / Coorientador: Mario Luiz Teixeira de Moraes / Banca: Pedro Cesar dos Santos / Banca: Ananda Virgínia de Aguiar / Mestre

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