Uso de modelos lineales y no lineales para el estudio de la curva de lactancia en búfalos Murrah y sus cruces en sistemas de cría extensiva en el estado de São Paulo

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Diferentes níveis de torta de nabo forrageiro (Raphanus sativus) como aditivo na silagem de capim elefante

The aim of the study was to evaluate the effects of the inclusion of different levels of turnip cake (TNF) on the chemical composition, digestibility and quality of elephant grass silage. Due to the quality of the oil extracted from the seeds, the turnip is being considered as an important option for the biodiesel industry in Brazil. The turnip cake is obtained from the mechanical pressing of the seeds to produce oil, and it differs from the meal by the content of fat. In the meal the fat is less than 1%, due to the use of solvents for the oil extraction. Experimental silos were used in a completely randomized design, in factorial arrangement 2 x 3 (two types of material and four levels of inclusion). The materials were represented for original material (fresh) and ensiled material, with four levels of inclusion of TNF (0, 3, 6, and 9%). Dry matter (DM), ether extract (EE), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), nitrogen indigestible neutral detergent (NIDN), nitrogen indigestible acid detergent (NIDA), ash (MM), lignin (LIG), buffer power (PT), calcium (Ca), phosphorus (P) and in vitro dry matter digestibility (IVDDM) were determined in all materials. In silage, additionally, were determined pH and amoniacal nitrogen (NH3-N). There were effects of inclusion of TNF and the type of material on the DM, CP, ADF, NIDA, P, and MM contents and on IVDDM. The interaction of the two factors was observed to the contents of CP, NDF, ADF, NIDA, Ca and IVDDM. In silage, the DM levels were lower (P < 0.05) than in original material. The values of DM were increased linearly as increased levels of inclusion of TNF. The fibrous components, including NIDN and NIDA, decreased linearly when the TNF increased. In all treatments, values of pH and N-NH3 considered ideal for good silage were observed. The IVDDM was reduced, linearly, with the addition of increasing levels of TNF. A negative correlation (-0.95) between IVDDM and content of EE may explain the tendency of this variable, due to the EE content increased linearly with the addition of TNF. The addition of TNF as an additive in silage of elephant diminished IVDDM. Considering the changes observed in the chemical composition and digestibility of elephant grass silage with TNF as additive, suggests that this should not be included at levels exceeding 3%. On the other hand, the silages with TNF as additive showed appropriate fermentation characteristics.

Evaluación genética de búfalos de la raza Murrah para la producción de leche en el día de control y a los 305 días de lactancia

There were analyzed 4757 complete lactations of the Murrah breed, daughters of 187 bulls, with the goal of verifying the viability upon employing the test-day (PDLC), on substitution of the milk yield at 305th day of lactation (PL305), in the genetic evaluations. The components of variance for the PDLC1 to PDLC9 and for the PL305 were estimated in uni-traits analysis according to maximum restricted likelihood method. The used model included the genetic direct additive random effects, of residual and permanent environment. There were considered as fixed effects, the contemporary group and the number of milkings and the age of the cow at the moment of parity co-variable (quadratic and linear effect). The contemporary groups were constituted by the herd-year-month of control for the PDLC and by herd-year-epoch of parity for PL305. The estimates of heritability for the PDLC and PL305 were 0.12 to 0.23 and 0.22, respectively. The correlations of order of the predicted genetic values for the 187 bulls, obtained between the PDLC and the PL305, were from moderate to high, varying from 67.74 to 83.12. From the minimum selection of the 10% of the best bulls relating to the predicted genetic value for the PL305, the coincidence among the classification of these animals was over 68%, when evaluated by the PDLC3,PDLC4,PDLC5 and PDLC6. Upon selecting the 5% of the best animals that coincidence presented a lower value.

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.

Multidimensionalidade das unidades territoriais camponesas do município de Teodoro Sampaio

Pós-graduação em Geografia - FCT

Caracterização socio-econômica e tecnológica dos heveicultores vinculados à APROBON no noroeste paulista

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Avaliação dos Projetos Proinf do Território Andradina (SP), a partir da perspectiva de diferentes atores

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação técnica e socioeconômica da cultura da uva para mesa em pequenas propriedades rurais da Regional de Jales (SP)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Avaliação técnica e socioeconômica da produção de cana-de-açúcar na região Oeste de São Paulo

Pós-graduação em Agronomia - FEIS

Análise técnica e econômica da cultura da bananeira maçã (Musa spp.) na região Noroeste do Estado de São Paulo

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)