To investigate the impacts of uterine type and conceptus genotype on development through late gestation, Meishan and Yorkshire embryos were co-transfe

Three experiments were conducted to examine the in vitro development of preimplantation embryos from the prolific Chinese Meishan pig. Experiment 1 was conducted to assess whether Meishan embryos would develop in vitro and retain their viability, whereas Exp. 2 and 3 examined the developmental pattern of Meishan embryos. In all three experiments, Yorkshire embryos served as a contemporary comparison. Ovulation and embryo recovery rates were not different between Meishan and Yorkshire gilts. Meishan embryos cultured for 96 h were capable of establishing pregnancies. The number of cell nuclei present after 144 h of culture was lower (P < .01) for Meishan than for Yorkshire blastocysts. Meishan preimplantation embryos exhibited a slower (P < .02) in vitro rate of development from the four-cell to the compact morula stage than did Yorkshire embryos. Early blastocysts from Meishan gilts, although morphologically similar in size, contained fewer (P < .06) cells than did their counterpart Yorkshire embryos. These data demonstrate that Meishan embryos develop more slowly and contain fewer cells than do Yorkshire embryos. This differing developmental pattern of Meishan preimplantation embryos, if similar to that previously reported in miniature swine and mice, may relate to increased embryo survival.

The objectives of this research were to determine the effects of beta-mercaptoethanol (beta-ME) and fetal bovine serum (FBS) on in vitro development of bovine embryos derived from oocytes matured and fertilized in vitro and to examine the mechanism through which beta-ME may influence embryo development. A 2 x 2 factorial treatment arrangement was used to evaluate the effect of 0 or 100 microM beta-ME and 0% or 10% FBS on embryos cultured in Medium 199 (M199) in the absence of somatic cells. Embryos were randomly allocated within stage of development (< 8 cells or 8-16 cells) to one of four treatment combinations and were cultured for 6 days. Both beta-ME and FBS promoted increased (p < 0.01) development of embryos to the blastocyst stage, and their effects were greater (p < 0.01) in 8- to 16-cell embryos than in embryos having fewer than 8 cells at the initiation of treatment. The cysteine and cystine content of M199, with and without beta-ME, were determined by HPLC. Medium supplemented with beta-ME contained neither cysteine nor cystine, and it is suggested that these compounds were converted into a mixed disulfide between cysteine and beta-ME. These results indicate that beta-ME is capable of enhancing bovine embryo development in a cell-free, serum-free culture system.

Query (Q) fever is a globally distributed zoonotic disease caused by Coxiella burnetii, a bacterial agent for which ruminants are the most prevalent natural reservoir. Data regarding Q fever infection in camels in Algeria are limited. Therefore, a survey to detect seroprevalence of C. burnetii antibodies was conducted among healthy camel populations in a vast area in southeastern Algeria to determine distribution of the Q fever causative organism and to identify risk factors associated with infection. Between January and March 2016, blood samples were collected from 184 camels and serum samples were subsequently analysed using a commercial Enzyme-Linked Immunosorbent Assay (ELISA) kit. At the time of blood collection, a questionnaire investigating 13 potential predisposing factors associated with C. burnetii seropositivity was completed for every dromedary camel and herd. Results were analysed by a chi-square (χ2) test and multivariate logistic regression. The seroprevalence of C. burnetii at the animal level was 71.2% (95% CI: 65.2–78.3) and 85.3% (95% CI: 72.8–97.8) at the herd level. At the animal level, differences in seroprevalence were observed because of herd size, animal age, animal sex, presence of ticks and contact with other herds. A multivariable logistic regression model identified three main risk factors associated with individual seropositivity: (1) age class > 11 years (OR = 8.81, 95% CI: 2.55–30.41), (2) herd size > 50 head (OR = 4.46, 95% CI: 1.01–19.59) and (3) infestation with ticks (OR 2.2; 95% CI: 1.1–4.5). This study of seroprevalence of C. burnetii infection in camels in Algeria revealed a high seroprevalence of Q fever in camel populations in southeastern Algeria and provided strong evidence that Q fever represents an economic, public health and veterinary concern. Appropriate measures should be taken to prevent the spread of C. burnetii and to reduce the risk of Q fever in farm animals and humans in this agro-ecologically and strategically important region of North Africa.

The aim of this research was to determine the effects of L-cysteine and beta-mercaptoethanol on the in vitro development of bovine embryos that had been produced in vitro. A 2 x 3 factorial arrangement of treatments was used to evaluate the effect of 0.63 or 6.9 microM L-cysteine and 0, 10, or 100 microM beta-mercaptoethanol on the development of bovine embryos in a chemically defined medium. Embryos containing 6 to 8 cells were randomly allocated to one of the six treatment combinations and were cultured for 7 d. Both beta-mercaptoethanol and L-cysteine increased the number of embryos that reached the blastocyst stage of development, although no interaction was observed between the compounds. Embryos that were cultured in the presence of beta-mercaptoethanol had more cells at the blastocyst stage than did embryos cultured in medium without beta-mercaptoethanol. These findings provide evidence that beta-mercaptoethanol and L-cysteine promote increased embryonic development and that beta-mercaptoethanol increases the number of cells in bovine embryos produced in vitro and cultured in a cell-free, protein-free culture system.