Santana M.L.,Federal University of Mato Grosso |
Eler J.P.,University of Sao Paulo |
Cardoso F.F.,Embrapa Pecuaria Sul |
Albuquerque L.G.,Sao Paulo State University |
And 2 more authors.
The objectives of the present study were to characterize and define homogenous production environments of composite beef cattle in Brazil in terms of climatic and geographic variables using multivariate exploratory techniques and to use them to assess the presence of G×E for birth weight (BW) and weaning weight (WW). Data from animals born between 1995 and 2008 on 36 farms located in 27 municipalities of the Brazilian states were used. Fifteen years of climate observations (mean minimum and maximum annual temperature and mean annual rainfall) and geographic (latitude, longitude and altitude) data were obtained for each municipality where the farms were located for characterization of the production environments. Hierarchical and nonhierarchical cluster analysis was used to group farms located in regions with similar environmental variables into clusters. Six clusters of farms were formed. The effect of sire-cluster interaction was tested by single-trait analysis using deviance information criterion (DIC). Genetic parameters were estimated by multi-trait analysis considering the same trait to be different in each cluster. According to the values of DIC, the inclusion of sire-cluster effect did not improve the fit of the genetic evaluation model for BW and WW. Estimates of genetic correlations among clusters ranged from -0.02 to 0.92. The low genetic correlation among the most studied regions permits us to suggest that a separate genetic evaluation for some regions should be undertaken. © 2012 Elsevier B.V. Source
Fioreze C.,Instituto Federal Of Educacao |
Ceretta C.A.,Federal University of Santa Maria |
Giacomini S.J.,Federal University of Santa Maria |
Trentin G.,Embrapa Pecuaria Sul |
Lorensini F.,Federal University of Santa Maria
The N release in the soil with organic fertilization is affected by various factors, such as the amount and the caractheristics of the added manure, climatic conditions and soil type. This study aimed to evaluate the effect of soil texture and the N release from two sources of organic fertilizer. Sandy loam soil (238mg clay kg-1), silt clay (470mg kg-1) and veryclay (605mg kg-1) were incubated, to which the poultry litter (47% N-NH4 +) and the pig liquid slurry (14% N-NH4 +) were added or not. The contents of N-NH4 + and N-NO3 - was determined at 0, 7, 14, 28, 56 and 112 days after incubation and calculated the net mineralization and the percentage of available N and net mineral nitrogen in relation to the total and added organic N, respectively. The higher clay caused more gradually nitrification, regardless of the type of organic fertilizer added, which may helps to reduce the polluting potential of N. The net N mineralization was also higher in sandy loam soil. This confirms the recommendation to spread the supply of nitrogen to crops, particularly in sandy soils and slurry rich in Nammonia. The results indicated that the official indices of efficiency of N release (IELN), of 80% for the pig liquid slurry and 50% for the poultry litter, may be overestimated. Therefore, it seems important to consider the N mineral of the soil in the calculation of the efficiency of the release to reduce the depletion of soil organic matter in a medium or long term. Finally, the results point to the need for further studies so that the soil texture classes are considered as a variable to the recommended nitrogen through organic fertilizers. Source
Young J.M.,Queens Medical Research Institute |
Henderson S.,Queens Medical Research Institute |
Souza C.,Embrapa Pecuaria Sul |
Ludlow H.,Oxford Brookes University |
And 4 more authors.
Little is known about the role of activin B during folliculogenesis. This study investigated the expression levels of activin/inhibin subunits (βA, βB, and α), steroid enzyme, and gonadotrophin receptors in theca (TC) and granulosa cells (GC) by QPCR and activin A and B and inhibin A protein levels in follicular fluid (FF) of developing sheep follicles during estrus and anestrus. The effect of activin B on androgen production from primary TC cultures in vitro was also assessed. During folliculogenesis, in anestrus and estrus, FF activin B concentrations and thecal and GC activin bB mRNA levels decreased as follicle diameter increased from 1-3 to >6 mm regardless of estrogenic status. Estrogenic preovulatory follicles had reduced concentrations of FF activins B and A, and TC and GCs expressed higher levels of activin βA mRNA at 3-4 mm, and TCs more inhibin α mRNA at >4 mm stages of development compared with nonestrogenic follicles. Activin B decreased androstenedione production from primary TCs in vitro, an effect blocked by inhibin A. Thus, sheep follicles 1-3 mm in diameter contained high FF levels of activin B, which decreased as the follicle size increased, and, like activin A, suppressed thecal androgen production in vitro, an effect blocked by inhibin. Furthermore, the theca of large estrogenic follicles expressed high levels of inhibin α and activin βA mRNA suggesting local thecal derived inhibin A production. This would inhibit the negative effects of thecal activins B and A ensuring maximum androgen production for enhanced estradiol production by the preovulatory follicle(s). © 2012 Society for Reproduction and Fertility. Source
Silva B.D.M.,University of Brasilia |
Castro E.A.,Embrapa Recursos Geneticos e Biotecnologia |
Souza C.J.H.,Embrapa Pecuaria Sul |
Paiva S.R.,Embrapa Recursos Geneticos e Biotecnologia |
And 7 more authors.
Summary: Brazilian Santa Inês (SI) sheep are very well-adapted to the tropical conditions of Brazil and are an important source of animal protein. A high rate of twin births was reported in some SI flocks. Growth and Differentiation Factor 9 (GDF9) and Bone Morphogenetic Protein 15 (BMP15) are the first two genes expressed by the oocyte to be associated with an increased ovulation rate in sheep. All GDF9 and BMP15 variants characterized, until now, present the same phenotype: the heterozygote ewes have an increased ovulation rate and the mutated homozygotes are sterile. In this study, we have found a new allele of GDF9, named FecGE (Embrapa), which leads to a substitution of a phenylalanine with a cysteine in a conservative position of the mature peptide. Homozygote ewes presenting the FecGE allele have shown an increase in their ovulation rate (82%) and prolificacy (58%). This new phenotype can be very useful in better understanding the genetic control of follicular development; the mechanisms involved in the control of ovulation rate in mammals; and for the improvement of sheep production. © 2010 The Authors, Animal Genetics © 2010 Stichting International Foundation for Animal Genetics. Source
Rodrigues C.S.,Instituto Federal Of Educacao |
do Nascimento Junior D.,Federal University of Vicosa |
Detmann E.,Federal University of Vicosa |
da Silva S.C.,Escola Superior de Agricultura Luiz de Queiroz |
And 2 more authors.
Revista Brasileira de Zootecnia
Morphogenetic and structural characteristics of forage grasses were evaluated in order to group them according to their pattern of development in their respective functional groups. Grasses were planted in plots of 1.0 m2 with 24 plants in a completely randomized block design with three replications. Data were submitted to factor analysis, reducing the variables to four factors: mass development, tiller mortality, developmental stage and leaf longevity. The data were submitted to cluster analysis by Tocher's optimization by adopting the mean Euclidean distance as a basic measure of dissimilarity. Grasses were grouped as follows: Summer - the group I (Xaraés, Massai, Mombaca and Marandu); group II (Molassa and Aruana); and group III (Jaraguagrass). Fall - group I (Mombaca, Massai, Xaraés, Marandu and Molassa); group II - (Jaraguagrass); and group III (Aruana). Possibly, the greater role of the tiller mortality factor in the formation of groups in the fall influenced the reorganization of the groups. The patterns of mass development of the different groups of grasses differ from each other as for the means of utilizing the resources available. There was a change in the scores of all factors with the change of the period from summer to Fall. The functional clustering of grasses demonstrates that gender and/or different species can be placed in the same group. © 2012 Sociedade Brasileira de Zootecnia. Source