Estimación de parámetros genéticos para la producción de leche en el día del control empleando un modelo de regresión aleatoria para primeras lactancias en búfalos de la costa norte de Colombia

A total of 5575 monthly test-day yield records from 796 lactations buffaloes first in the north coast of Colombia. The model included random direct additive genetic and permanent environment effects. As fixed effects were included, contemporary groups, and age of cow at calving as covaraible, linear and quadratic effects. Test-day (PLDC) yield was 3.89 ± 1.14 kg. The PLDC ranged from 2.86 kg to 4.26 kg while the highest values towards the middle of lactation. The heritability estimates obtained for PLDC ranged from 0.23 to 0.47. Genetic correlations between PLDC, declining steadily increased the distance between PLDC. Phenotypic variances were higher in the initial PLDC and decreasing towards the end of lactation. The results found in this study indicate that there is a high genetic variability for the PLDC in the population studied using a random regression model.

Linhagem materna: Qual a sua influência em características pré e pós desmama em bovinos da raça Nelore?

The present work had as objective to evaluate the effects of the introduction of the maternal lineage (Lc), representing the mitochondrial inheritance, in the model of genetic evaluation on birth weight (BW), weight for 120 days (W120), weaning weight (WW), weight at 12 month (W12), weight at 18 month (W18), weight gain from weaning to 18 month (WG18), scrotal perimeter (SP) and temperament (TEMP) of a Brazilian Nelore herd. Two models had been used for raise a comparison among of estimates the (co)variances components and genetic parameter, been the first equal one to currently used in the genetic evaluations of this herd, and second included the random effect of maternal lineage. Amongst the analyzed characteristics, the maternal lineage effect was significant (P<0.05) for W18 and SP only it, where this effect was responsible for 3% and 7%, respectively, of phenotypic variance could be explained by Lc effect. For besides characteristics, however not significant, this effect was responsible for 1% and 9% of phenotypic variance.

Genetic parameters for milk yield, age at first calving and interval between first and second calving in milk Murrah buffaloes

In the present study, data of 1,578 first lactation females, calving from 1985 to 2006 were analysed with the purpose of estimating genetic parameters for milk yield (MY), age at first calving (AFC) and interval between first and second calving (IBFSC) in dairy buffaloes of the Murrah breed in Brazil, Heritability estimates for MY, AFC and IBFSC traits were 0.20, 0.07 and 0.14, respectively. Genetic correlations between MY and AFC and IBFSC were -0.12 and 0.07, respectively, while the corresponding phenotypic correlations were -0.15 and 0.30, respectively. Genetic and phenotypic correlations between AFC and IBFSC were 0.35 and 0.37, respectively. Genetic correlation between MY and AFC showed desirable negative association, suggesting that daughters of the bulls with high breeding values for MY could reach physiological mature at a precocious age. Genetic correlation between MY and IBFSC, showed that the selection for milk production could result in the increase of calving intervals.

Buffalo milk production in brazil and colombia: Genotype by environment interaction

The objective of this study was to determine whether there is a genotype by environment interaction (GxE) for dairy buffaloes in Brazil and Colombia. The (co)variance components were estimated by using a bi-trait repeatability animal model with the REML method. Each trait consisted in the milk yield obtained in both countries. Contemporary group (herd, year and season of parity) and age at parity (linear and quadratic covariate) fixed effects, along with the additive genetic, permanent environment, and the residual random effects were included in the model. Genetic, permanent environmental and residual variance and heritabilities were different for both countries. The genetic correlations for milk yield between Brazil and Colombia were low (between 0.10 and 0.13), indicating a GxE interaction between both countries. Knowing that this interaction influences the genetic progress of buffalo populations in Brazil and Colombia, we recommend choosing sires tested in the country they will be used, along with conducting joint genetic evaluations that consider GxE interaction effects.

Test-day model for milk yield of dairy buffaloes in colombia

The test-day model is the preferred method for genetic evaluations in dairy cattle. For this study, 28372 test-day records of 1220 lactations from 1997 to 2009 were used. The (co)variance components for milk in test-day were estimated using a Uni and multiple-traits repeated animal model with the Restricted Maximum Likelihood method (REML). The Contemporary Group (herd, year, and season of parity) and the age of parity (linear and quadratic) fixed effects, and the additive genetic, permanent environmental, and residual random effects were included in the model. The heritabilities ranged between 0.06 and 0.45 during lactation. The genetic correlations were greater than 0.93. In conclusion, the test-day model is appropriate for the genetic evaluation of dairy buffaloes in Colombia.

Estudio de efectos ambientales y genéticos que influyen en la producción de leche y duración de lactación en bovinos de raza guzerat

Objective of present work was study a influence of environmental and genetic effects over characteristics of milk total production (PL) and lactation duration (DL), from 2572 lactations of 477 Guzerat cows, collected since 1957 to 2002, in Rio de Janeiro State. Environmental effects were analyzed by an statistical model that include male randomized effect, fixed effect of contemporary group, and the (co)variables age of cow (lineal and quadratic) and lactation duration. The contemporary group had significant effect just for PL. Bayesian inference was used to obtain estimatives of genetic parameters over an animal model, in which was included as fixed effect the contemporary group and the covariables age of cow (linear and quadratic). The estimates of heritability and repeatability were 0.36 and 0.75 for PL and 0.29 and 0.36 for DL, respectively. The estimated genetic correlation was 0.97. The heritability estimates for PL and DL were moderate, indicating that it is possible answer to the selection of the characteristics under study. The genetic correlation was high and indicates that selection for increase milk production will be accompanied with increase in lactation duration.

Aspectos Históricos e organizacionais da agricultura familiar no desenvolvimento da região Nova Alta Paulista

Nova Alta Paulista region, with strong aptitude for agribusiness, is one of the poorest in the state of São Paulo. However, the development of agribusiness productive chains in the region is very heterogeneous. The study aimed at analyzing how the historical background and organizational arrangements in family farming have contributed to regional development by promoting improvements in social welfare at Nova Alta Paulista region. To this end, we analyzed the case of the Associação Agrícola de Junqueirópolis - AAJ, an organization that has been successful in the search for alternative of agricultural production. Integrated to local and global market, this organization has ensured the maintenance of many farmers and generated positive externalities for the entire region. Thus, this case shows the organizational arrangement based on cooperation can be an alternative for family farmers achieve higher levels of welfare and development.

Grenada country paper

Includes bibliography

Renewable energy sources in Latin America and the Caribbean: situation and policy proposals

Includes bibliography

Multidimensionalidade das unidades territoriais camponesas do município de Teodoro Sampaio

Pós-graduação em Geografia - FCT

Revista de la CEPAL no.60

La evolución de las ideas y las políticas para el desarrollo / Gert Rosenthal. -- Políticas macroeconómicas para el crecimiento / Ricardo Ffrench-Davis. -- Flujos de capitales: lecciones a partir de la experiencia chilena / Eduardo Aninat, Christian Larraín. -- La transformación del desarrollo industrial de América Latina / José Miguel Benavente, Gustavo Crespi, Jorge Katz, Giovanni Stampo. -- Las reformas de las pensiones en América Latina y la posición de los organismos internacionales / Carmelo Mesa-Lago. -- Aportes de la antropología aplicada al desarrollo campesino / John Durston. -- Prospección de la biodiversidad: potencialidades para los países en desarrollo / Julie M. Feinsilver. -- La inversión extranjera y el desarrollo competitivo en América Latina y el Caribe / Alejandro C. Vera-Vassallo. -- La crisis del peso mexicano / Stephany Griffith-Jones.

CEPAL Review no.60

Development thinking and policies: the way ahead / Gert Rosenthal. -- Macroeconomic policies for growth / Ricardo Ffrench-Davis. -- Capital flows: lessons from the Chilean experience / Eduardo Aninat, Christian Lorrain. -- Changes In the industrial development of Latin America / José Miguel Benavente, Gustavo Crespi, Jorge Katz, Giovanni Stumpo. -- Pension system reforms in Latin America: the position of the International organizations / Carmelo Mesa-Lago. -- The contributions of applied anthropology to peasant development / John Durston. -- Biodiversity prospecting: a new panacea for development? / Julie M. Feinsilver. -- Foreign Investment and competitive development In Latin America and the Caribbean / Alejandro C. Vera-Vassallo. -- The Mexican peso crisis / Stephany Grijfìth-Jones.

Revista de la CEPAL no.25

La economía latinoamericana durante 1984: un balance preliminar / Enrique V. Iglesias. -- Las empresas transnacionales y el comercio internacional de América Latina / Eugenio Lahera. -- El papel subsidiario de la inversión externa directa en la industrialización: el sector manufacturero colombiano / Michael Mortimore. -- Políticas de estabilización y ajuste en el Cono Sur, 1974-1983 / Joseph Ramos. -- Desarrollo rural y programación urbana de alimentos / Manuel Figueroa L. -- Sociedades dependientes y crisis en América Latina: los desafíos de la transformación político-social / Germán W. Rama y Enzo Faletto. -- Cultura, discurso (autoexpresióri) y desarrollo social en el Caribe / Jean Casimir. -- Aspectos legales de la deuda pública latinoamericana: la relación con los bancos comerciales / Gonzalo Biggs.