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São Carlos, Brazil

Espasandin A.C.,Sao Paulo State University | Naya H.,Institute Pasteur Montevideo Mataojo 2020 | Alencar M.M.,Embrapa Southeast Cattle
Livestock Science

The objective of this study was to define production environments by grouping different environmental factors and, consequently, to assess genotype by production environment interactions on weaning weight (WW) in the Angus populations of Brazil and Uruguay. Climatic conditions were represented by monthly temperature means (°C), minimum and maximum temperatures in winter and summer respectively and accumulated rainfall (mm/year). Mode in month of birth and weaning, and calf weight (kg) and age (days) at weaning were used as indicators of management conditions of 33 and 161 herds in 13 and 34 regions in Uruguay and Brazil, respectively. Two approaches were developed: (a) a bi-character analysis of extreme sub-datasets within each environmental factor (bottom and top 33% of regions), (b) three different production environments (including farms from both countries) were defined in a cluster analysis using standardized environmental factors. To identify the variables that influenced the cluster formation, a discriminant analysis was previously carried out. Management (month, age and weight at weaning) and climatic factors (accumulated rainfalls and winter and summer temperatures) were the most important factors in the clustering of farms. Bi or trivariate analyses were performed to estimate heritability and genetic correlations for WW in extreme sub-datasets within environmental factor or between clusters, using MTDFREML software. Heritability estimates of WW in the first approach ranged from 0.27 to 0.54, and genetic correlations between top and bottom sub-datasets within environmental factors, from -0.29 to 0.70. In the cluster approach, heritabilities were 0.58±0.04 for cluster 1, 0.31±0.01 for Cluster 2 and 0.40±0.02 for Cluster 3. Genetic correlations were 0.27±0.08, 0.32±0.09 and 0.33±0.09, between clusters 1 and 2, 1 and 3, and 2 and 3, respectively. Both approaches suggest the existence of genotype x environment interaction for weaning weight in Angus breed of Brazil and Uruguay. © 2012 Elsevier B.V. Source

Sudano M.J.,Sao Paulo State University | Caixeta E.S.,University of Jose do Rosario Vellano | Paschoal D.M.,Sao Paulo State University | Martins A.,Sao Paulo State University | And 3 more authors.
Reproduction, Fertility and Development

In a 2×2 factorial experimental design, embryo development, cryotolerance and global gene expression of Nellore (Bos taurus indicus) and Simmental (Bos taurus taurus) blastocysts produced in vitro (IVP) and in vivo (multiple ovulation derived embryo, MODE) were assessed. Blastocyst production was higher in Nellore than in Simmental (47.7±2.0% vs 27.0±2.0%) cows. The total numbers of ova or embryos recovered (5.5±0.9 vs 3.7±0.8) and transferable embryos (3.8±1.0 vs 2.3±0.8) per cow were not different between breeds. Simmental and MODE (34.6% and 38.5%, n≤75 and 70) blastocysts had higher survival rates after cryopreservation compared with Nellore and IVP (20.2% and 18.1%, n≤89 and 94) embryos, respectively. Differences between transcriptomes were addressed by principal-component analysis, which indicated that gene expression was affected by subspecies (158 genes), origin (532 genes) and interaction between both subspecies and origin (53 genes). Several functional processes and pathways relevant to lipid metabolism and embryo viability involving differentially expressed genes were identified. The lipid metabolism-related genes were upregulated in Simmental (AUH and ELOVL6) and IVP (ACSL3 and ACSL6) blastocysts. The expression profiles of genes related to mitochondrial metabolism (ATP5B), oxidative stress (GPX4), apoptosis (DAD1, DAP, PRDX2), heat shock (HSPA5), pregnancy (IFNT2, PAG2) and cell differentiation (KRT18) varied between experimental groups. © CSIRO 2014. Source

Sudano M.J.,Sao Paulo State University | Landim-Alvarenga F.D.C.,Sao Paulo State University | Sartori R.,University of Sao Paulo | Machado R.,Embrapa Southeast Cattle
Livestock Science

This study assessed the reuse of norgestomet implants in Nelore cows that were superstimulated with eCG. In a crossover design trial, eight cows were randomly divided into two experimental groups and twice superstimulated: Group 1 - half of the cows received a new norgestomet implant and 2mg estradiol benzoate (EB) on Day 0; Group 2 - remaining cows received two once-used norgestomet implants and 2mg EB also on Day 0. On Day 4 all cows received a single dose of 2000IU eCG, and on Day 6 cows were treated with two doses of PGF 2α 12h apart. Ovulation was induced with 12.5mg pLH 12h after implant withdrawal (on Day 7), and fixed-time artificial inseminations were carried out 12 and 24h later. Seven days after pLH injection embryos were recovered and blood samples were taken to determine circulating progesterone. Ultrasound examinations were performed at pLH administration and at embryo recovery. The number of large follicles (≥8mm) was greater (P<0.05) in Group 1 (17.1±1.8) than in Group 2 cows (9.7±1.6). The mean number of corpora lutea was greater (P<0.05) for Group 1 (13.8±1.8) as compared to Group 2 cows (5.4±1.0) and the percentage of large follicles that ovulated following pLH administration also differed (P<0.05) between treatments (80.3% and 53.8% for cows in Groups 1 and 2, respectively). However, no differences (P>0.05) were found between treatments (respectively, for Group 1 and Group 2 cows) in the follicle diameter (10.5±1.6 and 10.2±1.7mm), corpus luteum (CL) diameter (15.7±1.8 and 14.4±1.7mm), CL volume (2232±1356 and 1893±1828mm 3), ova/embryos recovered (6.3±1.1 and 4.0±1.9), transferable embryos (4.0±1.8 and 2.5±1.0) and plasma progesterone concentration (36.1±8.3 and 35.1±6.9ng/mL). In conclusion, the stimulatory effects on the ovaries provided by the use of two once-used implants were less intense than the ones verified after using a new implant. © 2011 Elsevier B.V. Source

Sudano M.J.,Sao Paulo State University | Santos V.G.,University of Campinas | Tata A.,University of Campinas | Ferreira C.R.,University of Campinas | And 5 more authors.
Biology of Reproduction

Lipid droplets, subspecies (Bos taurus indicus vs. Bos taurus taurus), and in vitro culture are known to influence cryopreservation of bovine embryos. Limited information is available regarding differences in membrane lipids in embryo, such as phosphatidylcholines (PC) and sphingomyelins (SM). The objective of the present study was to compare the profiles of several PC and SM species and relate this information to cytoplasmic lipid levels present in Nellore (B. taurus indicus) and Simmental (B. taurus taurus) blastocysts produced in vitro (IVP) or in vivo (ET). Simmental and IVP embryos had more cytoplasmic lipid content than Nellore and ET embryos (n=30). Blastocysts were submitted to matrix-assisted laser desorption/ionization mass spectrometry. Differences in the PC profile were addressed by principal component analysis. The lipid species with PC (32:1) and PC (34:1) had higher ion abundances in Nellore embryos, whereas PC (34:2) was higher in Simmental embryos. IVP embryos had less abundant ions of PC (32:1), PC (34:2), and PC (36:5) compared to ET embryos. Moreover, ion abundance of PC (32:0) was higher in both Nellore and Simmental IVP embryos compared to ET embryos. Therefore, mass spectrometry profiles of PC and SM species significantly differ with regard to unsaturation level and carbon chain composition in bovine blastocysts due to subspecies and in vitro culture conditions. Because PC abundances of Nellore and Simmental embryos were distinct (34:1 vs. 34:2), as were those of IVP and ET embryos (32:0 vs. 36:5), they are potential markers of postcryopreservation embryonic survival. © 2012 by the Society for the Study of Reproduction, Inc. Source

Sudano M.J.,Sao Paulo State University | Paschoal D.M.,Sao Paulo State University | Da Silva Rascado T.,Sao Paulo State University | Crocomo L.F.,Sao Paulo State University | And 4 more authors.

Summary The objective of the present study was to correlate some parameters (cleavage, blastocyst production, quality degree score, total cell number, fresh apoptosis and lipid content) with embryo survival after cryopreservation. A total of 1727 in vitro-produced bovine blastocysts were used to establish the parameters (mean ± standard error of the mean (SEM)) for cleavage (85.6 ± 0.8), blastocyst production (39.9 ± 1.4), quality degree score (1.6 ± 0.1), total cell number (140.1 ± 2.9), fresh apoptosis (20.8 ± 1.1) and lipid content (21.3 ± 0.8 droplets). On the same way 1316 blastocysts were vitrified for the determination of post-cryopreservation embryo survival (49.4 ± 1.9). Fresh apoptosis rate and total lipid droplets value were correlated (P < 0.05) with embryo survival after cryopreservation (r = 0.91 and r = 0.59; respectively). However, cleavage, blastocyst production, quality degree score and total cell number were not correlated (P > 0.05) with embryo cryotolerance (r = 0.23, r = 0.38, r = 0.22 and r = 0.28; respectively). Therefore, the increased lipid content was moderately correlated with apoptosis in vitrified blastocysts. On the other hand, increased apoptosis in fresh blastocysts was strongly correlated with apoptosis in vitrified blastocysts, which indicated that the apoptosis rate in fresh embryos was a better parameter than the lipid content to predict post-vitrification embryo survival. Copyright © 2012 Cambridge University Press. Source

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