Economic losses due to bovine brucellosis in Brazil

Brucellosis is an important zoonosis of worldwide distribution. Reliable epidemiologic brucellosis data covering approximately 90% of the cattle population in Brazil have been recently published. Therefore, considering the scarcity of information regarding the economic impact of bovine brucellosis in Brazil, the goal of this study was to estimate economic impact of brucellosis on the Brazilian cattle industry. Several parameters including abortion and perinatal mortality rates, temporary infertility, replacement costs, mortality, veterinary costs, milk and meat losses were considered in the model. Bovine brucellosis in Brazil results in an estimated loss of R$420,12 or R$ 226,47 for each individual dairy or beef infected female above 24 months of age, respectively. The total estimated losses in Brazil attributed to bovine brucellosis were estimated to be approximately R$ 892 million (equivalent to about 448 million American dollars). Every 1% increase or decrease in prevalence is expected to increase or decrease the economic burden of brucellosis in approximately 155 million Reais

Sex affects immunolabeling for histone 3 K27me3 in the trophectoderm of the bovine blastocyst but not labeling for histone 3 K18ac.

The mammalian embryo displays sexual dimorphism in the preimplantation period. Moreover, competence of the embryo to develop is dependent on the sire from which the embryo is derived and can be modified by embryokines produced by the endometrium such as colony stimulating factor 2 (CSF2). The preimplantation period is characterized by large changes in epigenetic modifications of DNA and histones. It is possible, therefore, that effects of sex, sire, and embryo regulatory molecules are mediated by changes in epigenetic modifications. Here it was tested whether global levels of two histone modifications in the trophectoderm of the bovine blastocyst were affected by sex, sire, and CSF2. It was found that amounts of immunolabeled H3K27me3 were greater (P = 0.030) for male embryos than female embryos. Additionally, labeling for H3K27me3 and H3K18ac depended upon the bull from which embryos were derived. Although CSF2 reduced the proportion of embryos developing to the blastocyst, there was no effect of CSF2 on labeling for H3K27me3 or H3K18ac. Results indicate that the blastocyst trophoctoderm can be modified epigenetically by embryo sex and paternal inheritance through alterations in histone epigenetic marks

NRAMP1 3′ Untranslated Region Polymorphisms Are Not Associated with Natural Resistance to Brucella abortus in Cattle

The NRAMP1 gene encodes a divalent cation transporter, located in the phagolysosomal membrane of macrophages, that has been associated with resistance to intracellular pathogens. In cattle, natural resistance against brucellosis has been associated with polymorphisms at the 3′ untranslated region (3′UTR) of the NRAMP1 gene, which are detectable by single-strand conformational analysis (SSCA). This study aimed to evaluate the association between NRAMP1 3′UTR polymorphisms and resistance against bovine brucellosis in experimental and natural infections. In experimentally infected pregnant cows, abortion occurred in 42.1% of cows with a resistant genotype (SSCA(r); n = 19) and in 43.1% of those with a susceptible genotype (SSCA(s); n = 23). Furthermore, no association between intensity of pathological changes and genotype was detected. In a farm with a very high prevalence of bovine brucellosis, the percentages of strains of the SSCA(r) genotype were 86 and 84% in serologically positive (n = 64) and negative (n = 36) cows, respectively. Therefore, no association was found between the NRAMP1-resistant allele and the resistant phenotype in either experimental or naturally occurring brucellosis. To further support these results, bacterial intracellular survival was assessed in bovine monocyte-derived macrophages from cattle with either the resistant or susceptible genotype. In agreement with our previous results, no difference was observed in the rates of intracellular survival of B. abortus within macrophages from cattle with susceptible or resistant genotypes. Taken together, these results indicate that these polymorphisms at the NRAMP1 3′UTR do not affect resistance against B. abortus in cattle and that they are therefore not suitable markers of natural resistance against bovine brucellosis

First follicular wave and first postpartum ovulation of primiparous Holstein dairy cows receiving diets with different energetic sources during the transition period

The effects of different energy sources added to the diet on the first postpartum ovarian follicle wave and first postpartum ovulation were evaluated. Forty primiparous Holstein dairy cows were used from 28 days before the expected calving date until 46 days postpartum. Cows were randomly allotted to the following groups: control, Megalac-E calcium salts of soybean fatty acid), toasted soybean and propylene glycol. Ovarian structures were scanned using ultrasound from 10 to 46 days postpartum. Follicles were classified according to the diameter in classes I, II, III, and IV and the luteal tissue volume was registered when present. Blood samples for progesterone dosage were colleted on days 10, 17, 24, 31, 38, and 45 post-partum. Follicular growth from groups of salts of polyunsaturated fatty acids and propylene glycol showed to be the most efficient and were characterized by a reduction in the number of classes I and II follicles and an increase in classes III and IV follicles. The first postpartum ovulation after calving for control, salts of polyunsaturated fatty acids, toasted soybean and propylene glycol animal groups occurred at 29, 23, 30, and 37 days, respectively (P\u3c0,05)

Desenvolvimento folicular no pós-parto de vacas da raça Gir tratadas com acetato de buserelina (GnRH) ou gonadotrofina coriônica humana (hCG) Follicular development in Gir breed cows (Bos indicus) treated with buserelin acetate or human chorionic gonadotrophin during the postpartum period

Foram utilizadas 22 vacas da raça Gir (Bos indicus) em anestro pós-parto, amamentando e mantidas sob regime de pastejo. O padrão de crescimento folicular foi estudado em 15 animais, enquanto os outros sete foram utilizados somente no acompanhamento da resposta aos tratamentos hormonais. Ultra-sonografia em tempo real foi realizada diariamente, do quarto ao qüinquagésimo dia de lactação, por meio de aparelho equipado com probe de 5MHz. Nenhum animal apresentou estro, ovulação ou luteinização folicular durante o período de avaliação. Verificaram-se quatro a oito ondas foliculares surgindo em intervalos de seis a sete dias, cujo diâmetro máximo dos folículos dominantes e subordinados foi de 8,9±0,6 e 6,3±0,7mm, respectivamente. Aos 56 dias pós-parto, as 22 vacas foram divididas em dois grupos: 11 tratadas com 4,2 mig de acetato de buserelina e 11 com 3.000UI de hCG. A ovulação, regressão e luteinização folicular foram verificadas em animais dos dois tratamentos e uma nova onda folicular surgiu dentro de dois a três dias após a terapia hormonal. Corpos lúteos de menor tamanho e concentrações de progesterona abaixo de 1ng/mL indicaram baixa atividade luteal.<br>This experiment was carried out with 22 anestrus Gir cows (Bos indicus), with the postpartum follicular growth studied in 15 of these suckling and kept on pasture, while the seven others were used only for hormonal treatments. Daily real time ultrasonography was done from 4th to the 50th day, using B-mode ultrasound scanner equipped with a linear array 5.0MHz probe. No animal showed estrus, ovulation or follicular luteinization during de experimental period. Four to eight follicular waves emerged each six or seven days and maximum diameter of dominant and subordinate follicles were 8.9±0.6mm and 6.3±0.7mm, respectively. On day 56 of postpartum all cows were separated in two groups: 11 cows were treated either with 4.2 mug of buserelin acetate and 11 with 3,000UI of hCG. Ovulation, follicular regression and luteinization were observed in the two treatments animals, and one new follicular wave emerged within two to three days after the hormonal treatments. Small size corpus luteum and progesterone concentrations under 1ng/mL showed lower luteal activity