Entity

Time filter

Source Type

Porto Velho, Brazil

Pfeifer L.F.M.,Embrapa Rondonia | Siqueira L.G.B.,Embrapa Gado de Leite | Adams G.P.,University of Saskatchewan | Pierson R.A.,University of Saskatchewan | Singh J.,University of Saskatchewan
Animal Reproduction Science | Year: 2012

The objectives of this study were to: (1) evaluate the feasibility of ultrasonic biomicroscopy (UBM) for imaging ovarian follicles in vivo in cows and heifers, (2) compare the transvaginal to the transrectal approach, (3) compare the number of follicles detected by UBM to conventional ultrasonography (US), and (4) identify cumulus-oocyte-complexes (COC) within follicles by UBM. Mature cows (. n=. 5) and peri-pubertal heifers (. n=. 5) were examined once using conventional B-mode US (Aloka 900) with a 7.5. MHz transrectal, and a 5. MHz transvaginal transducers. A second series of examinations was performed using UBM (Visualsonics Vevo 660) equipped with a 30. MHz transrectal and a 40. MHz transvaginal transducer. A three- to four-fold increase in the number of small follicles (<3. mm) was detected using the transvaginal approach with UBM compared to conventional US in both heifers (32.4. ±. 4.24 compared to 7.2. ±. 1.4; P<. 0.0001) and cows (35.0. ±. 13.8 compared to 10.7. ±. 7.5; P=. 0.0013). However, fewer follicles (all sizes combined) were detected using the transrectal approach with UBM compared to conventional US in both heifers (8.6. ±. 5.6 compared to 17.6. ±. 4.9;P=. 0.02) and cows (5.3. ±. 6.1 compared to 20.3. ±. 7; P=. 0.04). In heifers, COC-like structures were identified in 39 of 202 (19.3%) follicles examined. In conclusion, UBM using a transvaginal approach is feasible and may be used for in vivo assessment of early antral follicles as small as 0.4. mm, and COC within follicles. © 2012 Elsevier B.V. Source


Teodoro P.E.,State University of Mato Grosso do Sul | Costa R.D.,Embrapa Agroenergia | Rocha R.B.,Embrapa Rondonia | Laviola B.G.,Embrapa Agroenergia
Pesquisa Agropecuaria Brasileira | Year: 2016

The objective of this work was to identify the most effective method to estimate the coefficient of repeatability in progenies of half-sib families of physic nut (Jatropha curcas), and to predict the minimum number of measurements required for some agronomic traits of this oilseed crop. Eighteen half-sib families, in a randomized complete block design with three replicates, were evaluated from 2009 to 2013. In this period, the following traits were evaluated: plant height, stem diameter, number of branches per plant, crown projection on the line, crown projection on the space between rows, and grain yield. The repeatability coefficient (r) was estimated considering different strategies: analysis of variance; principal component analysis (PCA) based on the correlation matrix (PCCOR); PCA based on the matrix of phenotypic variance and covariance (PCCOV); and structural analysis based on the correlation matrix. The PCCOV strategy provides the most accurate estimates of the repeatability coefficient and of the number of measurements (minimum of four), which are required for an accurate evaluation (minimum 80% accuracy) of the traits, due to the cyclical behavior of the progenies. Source


Akbar H.,Urbana University | Schmitt E.,Embrapa Rondonia | Ballou M.A.,Texas Tech University | Correa M.N.,Federal University of Pelotas | And 2 more authors.
Gene Regulation and Systems Biology | Year: 2013

Polyunsaturated (PUFA) long-chain fatty acids (LCFAs) are more potent in eliciting molecular and tissue functional changes in monogastrics than saturated LCFA. From -21 through 10 days relative to parturition dairy cows were fed no supplemental LCFA (control), saturated LCFA (SFAT; mainly 16:0 and 18:0), or fish oil (FISH; high-PUFA). Twenty-seven genes were measured via quantitative RT-PCR in liver tissue on day -14 and day 10. Expression of nuclear receptor co-activators (CARM1, MED1), LCFA metabolism (ACSL1, SCD, ACOX1), and inflammation (IL6, TBK1, IKBKE) genes was lower with SFAT than control on day -14. Expression of SCD, however, was markedly lower with FISH than control or SFAT on both -14 and 10 days. FISH led to further decreases in expression on day 10 of LCFA metabolism (CD36, PLIN2, ACSL1, ACOX1), intracellular energy (UCP2, STK11, PRKAA1), de novo cholesterol synthesis (SREBF2), inflammation (IL6, TBK1, IKBKE), and nuclear receptor signaling genes (PPARD, MED1, NRIP1). No change in expression was observed for PPARA and RXRA. The increase of DGAT2, PLIN2, ACSL1, and ACOX1 on day 10 versus -14 in cows fed SFAT suggested upregulation of both beta-oxidation and lipid droplet (LD) formation. However, liver triacylglycerol concentration was similar among treatments. The hepatokine FGF21 and the gluconeogenic genes PC and PCK1 increased markedly on day 10 versus -14 only in controls. At the levels supplemented, the change in the profile of metabolic genes after parturition in cows fed saturated fat suggested a greater capacity for uptake of fatty acids and intracellular handling without excessive storage of LD. © the author(s), publisher and licensee Libertas Academica Ltd. Source


Khan M.J.,Urbana University | Khan M.J.,COMSATS Institute of Information Technology | Jacometo C.B.,Federal University of Pelotas | Graugnard D.E.,Urbana University | And 4 more authors.
Gene Regulation and Systems Biology | Year: 2014

Hepatic metabolic gene networks were studied in dairy cattle fed control (CON, 1.34 Mcal/kg) or higher energy (overfed (OVE), 1.62 Mcal/kg) diets during the last 45 days of pregnancy. A total of 57 target genes encompassing PPARα-targets/co-regulators, hepatokines, growth hormone (GH)/insulin-like growth factor 1 (IGF-1) axis, lipogenesis, and lipoprotein metabolism were evaluated on -14, 7, 14, and 30 days around parturition. OVE versus CON cows were in more negative energy balance (NEB) postpartum and had greater serum non-esterifed fatty acids (NEFA), β-hydroxybutyrate (BHBA), and liver triacylglycerol (TAG) concentrations. Milk synthesis rate did not differ. Liver from OVE cows responded to postpartal NEB by up-regulating expression of PPARα-targets in the fatty acid oxidation and ketogenesis pathways, along with gluconeogenic genes. Hepatokines (fbroblast growth factor 21 (FGF21), angiopoietin-like 4 (ANGPTL4)) and apolipoprotein A-V (APOA5) were up-regulated postpartum to a greater extent in OVE than CON. OVE led to greater blood insulin prepartum, lower NEFA:insulin, and greater lipogenic gene expression suggesting insulin sensitivity was not impaired. A lack of change in APOB, MTTP, and PNPLA3 coupled with upregulation of PLIN2 postpartum in cows fed OVE contributed to TAG accumulation. Postpartal responses in NEFA and FGF21 with OVE support a role of this hepatokine in diminishing adipose insulin sensitivity. © the authors, publisher and licensee Libertas Academica Limited. Source


Laviola B.G.,Embrapa Agroenergy | Oliveira A.M.C.E.,Federal University of Vicosa | Bhering L.L.,Federal University of Vicosa | Alves A.A.,Embrapa Agroenergy | And 3 more authors.
Industrial Crops and Products | Year: 2013

The aim of this study was to estimate the repeatability coefficient of grain production in Jatropha, the minimum number of measurements needed to reliably predict the genetic value of selected families, and to determine the cumulative genetic gains when considering the selection of the best families based on different number of measurements. The experiment was conducted with 175 accessions (half-siblings progenies derived from selected plants in the field) that compose part of a germplasm collection. Such bank was established in a randomized block design with two blocks. In each block a given accession was represented in a 5plant/plot scheme (half-siblings). For the analysis, yield data obtained in the years of 2009-2012 were considered. The results of this study indicate that the repeatability coefficient of grain production in Jatropha is low (0.37), but comparable to other perennial species, and that to achieve reliabilities of 70 and 80% in the prediction of breeding values of selected families, 4 and 7 years of evaluation, respectively, are needed. The results of this study also indicate that the efficiency of early selection seems to be small in Jatropha since the coincidence rate of selected genotypes at early age (1 or 2 years of evaluation) and genotypes selected in adult age (4 years assessment) is small (17-23%). Finally, taking into account the repeatability coefficients and coefficients of determination, in a hypothetical period of 21 years (which is equivalent to three selection cycles using seven consecutive measurements - R2=80%), this paper demonstrates that higher cumulative genetic gains can be obtained (159% over 108%) by relaxing the degree of certainty in predicting the best families (R2=65% instead of R2=80%), since it makes possible to perform a greater number of selection cycles in the same period (7 cycles instead of 4). © 2013 Elsevier B.V. Source

Discover hidden collaborations