Hematological and cerebrospinal fluid changes in cattle naturally and experimentally infected with the bovine herpesvirus 5

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Best site for embryo transfer: the upper or lower half of endometrial cavity?

BACKGROUND: the objective of the present study was to determine the importance of the site of embryo transfer (upper or lower half endometrial cavity) on implantation and clinical pregnancy rates. METHODS: A total of 400 transfers guided by ultrasound were randomly assigned to two groups according to the distance between the uterine fundus and the catheter tip at the time of embryo placement. Group I (n=200) consisted of transfers corresponding to a distance of <50% of the endometrial cavity length (ECL), i.e. transfer in upper half of the cavity; and group II (n=200) consisted of transfers corresponding to a distance of greater than or equal to50%, of the ECL, i.e. transfer in lower half of cavity. The Student's t-test, Mann-Whitney test and Fisher's exact test were used where appropriate. RESULTS: the general characteristics of the study population and the main transfer cycle characteristics had an equal distribution (P>0.05) between groups I and II. No significant difference in implantation or pregnancy rates was observed between groups I and II. CONCLUSION: the implantation or pregnancy rates were similar whether the embryos were deposited in the upper or lower half of the endometrial cavity.

Ultrasound guidance is not necessary during easy embryo transfers

Purpose: To determine whether the use of ultrasound (US) to guide embryo transfer (ET) in a population previously defined as likely to have easy transfer would change the implantation and pregnancy rates in an ICSI program.Methods: A total of 100 patients identified as likely to have easy transfer after mock transfer were divided into two groups: Group I, US-guided ET (N = 50) and Group II, ET without the aid of US (N = 50).Results: Implantation and pregnancy rates were similar (p = 0.51, p = 0.29) for Group I (19.6%,42%) and Group II (16.3%,30%), as also was the abortion rate (p = 0.55) (Group I: 1/21; Group II: 2/15).Conclusion: As long as previous mock transfers are routinely performed during a cycle preceding assisted reproduction and the clinician considers transfer to be easy, ultrasound does not benefit the process of embryo transfer.

Comparison of day 2 embryo quality after conventional ICSI versus intracytoplasmic morphologically selected sperm injection (IMSI) using sibling oocytes

Objective: To evaluate whether intracytoplasmic morphologically selected sperm injection (IMSI) could influence early paternal effects by observing embryo quality at day 2.Study design: The study included 30 couples with at least one of the following criteria: male factor infertility, at least 2 previous failures of implantation or previous miscarriages after IVF/ICSI. Sibling oocytes of each patient were randomly assigned to either the ICSI group or the IMSI group. For IMSI, spermatozoa were selected at 8400x magnification through an inverted microscope equipped with Nomarski differential interference contrast optics, Uplan Apo 100x oil/1.35 objective lens and variable zoom lens. For conventional ICSI, spermatozoa were selected at 400x magnification. An embryo was defined as top quality if there were four identical blastomeres on day 2 with no fragments or multinucleation of blastomeres. Data were analysed using the Wilcoxon and chi-squared tests. The significance level was set at P < 0.05. The variables were analysed in relation to the general population and the subpopulations with or without male factor.Results: A total of 331 MII oocytes (30 oocyte retrievals) were selected and injected by the ICSI (n: 172) or IMSI (n: 159) procedure. For IMSI, only spermatozoa classified as morphologically normal at high magnification were used. No differences (P > 0.05) in fertilisation rate (ICSI: 70.9%; IMSI: 70.4%), early embryo cleavage rate (ICSI: 66.9%; IMSI: 60.4%) or cleavage rate (ICSI: 99.2%; IMSI: 99.1%) were observed. on day 2, as compared to ICSI, IMSI provided a similar proportion of top quality embryos (ICSI: 57.8%; IMSI: 52.2%; P > 0.05). These results were not influenced by the presence or absence of male factor.Conclusion: In terms of embryo quality at day 2, IMSI had the same performance as conventional ICSI. However, we cannot exclude the possibility that IMSI effects occur only as a positive later paternal effect. (C) 2010 Elsevier B.V. All rights reserved.

Single-embryo transfer reduces clinical pregnancy rates and live births in fresh IVF and Intracytoplasmic Sperm Injection (ICSI) cycles: a meta-analysis

Background: It has become an accepted procedure to transfer more than one embryo to the patient to achieve acceptable ongoing pregnancy rates. However, transfers of more than a single embryo increase the probability of establishing a multiple gestation. Single-embryo transfer can minimize twin pregnancies but may also lower live birth rates. This meta-analysis aimed to compare current data on single-embryo versus double-embryo transfer in fresh IVF/ICSI cycles with respect to implantation, ongoing pregnancy and live birth rates.Methods: Search strategies included on-line surveys of databases from 1995 to 2008. Data management and analysis were conducted using the Stats Direct statistical software. The fixed-effect model was used for odds ratio (OR). Fixed-effect effectiveness was evaluated by the Mantel Haenszel method. Seven trials fulfilled the inclusion criteria.Results: When pooling results under the fixed-effect model, the implantation rate was not significantly different between double-embryo transfer (34.5%) and single-embryo transfer group (34.7%) (P = 0.96; OR = 0.99, 95% CI 0.78, 1.25). on the other hand, double-embryo transfer produced a statistically significantly higher ongoing clinical pregnancy rate (44.5%) than single-embryo transfer (28.3%) (P < 0.0001; OR: 2.06, 95% CI = 1.64,2.60). At the same time, pooling results presented a significantly higher live birth rate when double-embryo transfer (42.5%) (P < 0.001; OR: 1.87, 95% CI = 1.44,2.42) was compared with single-embryo transfer (28.4%).Conclusion: Meta-analysis with 95% confidence showed that, despite similar implantation rates, fresh double-embryo transfer had a 1.64 to 2.60 times greater ongoing pregnancy rate and 1.44 to 2.42 times greater live birth rate than single-embryo transfer in a population suitable for ART treatment.

Morbidity-mortality and performance evaluation of Brahman calves from in vitro embryo production

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

Nocardiosis: an overview and additional report of 28 cases in cattle and dogs

A caracterização fenotípica, perfil de sensibilidade aos antimicrobianos e aspectos clínico-epidemiológicos foram avaliados em 28 linhagens de Nocardia isoladas de 19 casos de mastite, oito lesões tegumentares e um caso de pneumonia em cão. Foram utilizados no diagnóstico métodos microbiológicos, bioquímicos, citológicos e microscopia eletrônica de varredura. Nocardia asteroides tipo IV, N. otitidiscaviarum,N. nova (tipo III) e N. farcinica (tipo V) foram isoladas do leite de vacas com mastite, de material de lavado transtraqueal e de lesões cutâneas de cães. Nocardiose mamária bovina foi diagnosticada predominantemente sob a forma clínica, em propriedades com precárias condições de higiene na pré e pós-ordenha, e inadequado procedimento de terapia intramamária. Nocardiose canina foi diagnosticada comumente em animais co-infectados com o vírus da cinomose. Sulfametoxazole/trimetoprim (92,8%), amicacina (92,8%) e ceftiofur (92,8%) foram os antimicrobianos mais efetivos frente às linhagens de Nocardia. Resistência múltipla a três ou mais e cinco ou mais antimicrobianos foram observadas, respectivamente, em dez (35,7%) e três (10,7%) linhagens, notadamente frente à cloxacilina, cefoperazona e ampicilina. A caracterização de espécies (tipo), aspectos clínico-epidemiológicos, diagnóstico, resistência múltipla aos antimicrobianos e reflexos em saúde pública de linhagens de Nocardia isoladas de bovinos e cães no Brasil foram discutidos. Foi destacada a similaridade entre as espécies de Nocardia isoladas de animais e do homem, e a primeira descrição no Brasil de N. otitidiscaviarum na etiologia da mastite bovina.

Genetic characterisation of Giardia duodenalis in dairy cattle in Brazil

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

Effects of GHR gene polymorphisms on growth and carcass traits in Zebu and crossbred beef cattle

The growth hormone receptor (GHR) is the cell surface receptor for growth hormone (GH) and is required for GH to carry out its effects on target tissues. The objectives of the present study were to estimate the allele and genotype frequencies of the GHR/Alu I gene polymorphism located in the regulatory region in beef cattle belonging to different genetic groups and to determine associations between this polymorphism and growth and carcass traits. Genotyping was performed on 384 animals, including 79 Nellore (Zebu), 30 Canchim (5/8 Charolais+3/8 Zebu), 30 Simmental X Nellore crossbred and 245 Angus x Nellore crossbred cattle. Alleles Alu I(+), Alu I(-) and Alu I(N)-null allele-were evidenced for the GHR/Alu I polymorphism and the frequency of the Alu I(N) allele was significantly higher than the frequency of the Alu I(+) and Alu I(-) alleles in all genetic groups. Genotype Alu I(N/N) of the GHRIAlu I predominated in Nellore animals, while the Alu I(N/+) and Alu I(N/-) predominated in the other genetic groups. In the association studies, traits of interest were analyzed using the General Linear Model (GLM) procedure of the SAS program and least squares means of the genotypes were compared by the Tukey test. Significant associations (P < 0.05) were observed between the Alu I(N/N) genotype of the GHRIAlu I polymorphism and lower weight gain and body weight at slaughter, although a confounding between genotypes and genetic groups may have occurred. (c) 2005 Elsevier B.V. All rights reserved.

Effects of polymorphic microsatellites in the regulatory region of IGF1 and GHR on growth and carcass traits in beef cattle

Growth hormone (GH), insulin-like growth factors 1 and 2 (IGF1 and IGF2) and their associated binding proteins and transmembrane receptors (GHR, IGF1R and IGF2R) play an important role in the physiology of mammalian growth. The objectives of the present study were to estimate the allele and genotype frequencies of microsatellite markers located in the 5'-regulatory region of the IGF1 and GHR genes in beef cattle belonging to different genetic groups and to determine effects of these markers on growth and carcass traits in these animals under an intensive production system. For this purpose, genotyping was performed on 384 bulls including 79 Nellore, 30 Canchim (5/8 Charolais + 3/8 Zebu) and 275 crossbred animals originating from crosses of Simmental (1/2 Simmental, n = 30) and Angus (1/2 Angus, n = 245) sires with Nellore females. The effects of substituting L allele for S allele of GHR microsatellite across Nellore, Canchim and 1/2 Angus were significant for weight gain and body weight (P < 0.05). The IGF1 microsatellite allele substitutions of 229 for 225 within Nellore group and of 225 for 229 within 1/2 Angus were not significant for any of the traits.

Association between IGF-I, IGF-IR and GHRH gene polymorphisms and growth and carcass traits in beef cattle

Molecular biology techniques are of help in genetic improvement since they permit the identification, mapping and analysis of polymorphisms of genes encoding proteins that act on metabolic pathways involved in economically interesting traits. The somatotrophic axis, which essentially consists of growth hormone releasing hormone (GHRH), growth hormone (GH), insulin-like growth factors I and II (IGF-I and IGF-II), and their associated binding proteins and receptors (GHRHR, GHR, IGF-IR and IGF-IIR), plays a key role in the metabolism and physiology of mammalian growth. The objectives of the present study were to estimate the allele and genotype frequencies of the IGF-I/SnaBI, IGF-IR/TaqI and GHRH/HaeIII gene polymorphisms in different genetic groups of beef cattle and to determine associations between these polymorphisms and growth and carcass traits. For this purpose, genotyping was performed on 79 Nellore animals, 30 Canchim (5/8 Charolais+3/8 Zebu) animals and 275 crossbred cattle originating from the crosses of Simmental (n=30) and Angus (n=245) sires with Nellore females. In the association studies, traits of interest were analyzed using the GLM procedure of SAS and least square means of the genotypes were compared by the Tukey test. Associations of IGF-I/SnaBI genotypes with body weight and subcutaneous backfat were significant (p < 0.05), and nearly significant for longissimus dorsi area (p=0.06), with the 1313 genotype being favorable compared to the AB genotype. No significant associations were observed between this polymorphism and weight gain or carcass yield (P > 0.05). The IGF-IR/TaqI and GHRH/HaeIII polymorphisms showed no association with production traits. (c) 2004 Elsevier B.V All rights reserved.

Comparison among three approaches for evaluation of sexual precocity in Nellore cattle

Restricted breeding seasons used in beef cattle produce censored data for reproduction traits measured in regard to these seasons. To analyze these data, adequate methods must be used. The objective of this paper was to compare three approaches aiming to evaluate sexual precocity in Nellore cattle. The final data set contained 6699 records of age at first conception (AFC14) (in days) and of heifer pregnancy (HP14) (binary) obtained from females exposed to the bulls for the first time at about 14 months of age. Records of females that did not calve in the following year after being exposed to a sire were considered censored (77.5% of total). The models used to obtain genetic parameters and expected progeny differences (EPDs) were a Weibull mixed and a censored linear model for AFC14 and threshold model for HP14. The mean heritabilities obtained were 0.76 and 0.44, respectively, for survival and censored linear models (for AFC14), and 0.58 for HP14. Ranking and Pearson correlations varied (in absolute values) from 0.54 to 0.99 (considering different percentages of sires selected), indicating moderate changes in the classification. Considering survival analysis as the best selection criterion (that would result in the best response to selection), it was observed that selection for HP14 would lead to a more significant decrease in selection response if compared with selection for AFC14 analysed by censored linear model, from which results were very similar to the survival analysis.