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Advanced maternal age is an important predisposing factor on the reduction of reproductive efficiency. The aim of this study was to evaluate the effect of donor's age on several reproductive parameters in a commercial equine embryo transfer program. Donors were classified into 3 age groups: Group 1 = fillies (3 and 4 years old), Group 2 = middle age mares (aged 5–10) and Group 3 = old mares (aged 13–25). Embryo recovery, multiple ovulation and pregnancy rates and interovulatory intervals were compared amongst age groups. Group 1 (171/244, 70.1%) and Group 2 (774/1081, 71.6%) had a higher ( P < 0.005) embryo recovery rate than Group 3 (385/701, 54.9%). Groups 2 and 3 were 2.5 and 3.4 times more likely to have multiple ovulations than Group 1 ( P < 0.05), respectively. The effect of age group on pregnancy rate was not significant ( P > 0.05). The interovulatory intervals length was influenced by individual mare ( P < 0.001), age ( P < 0.04), Day of flushing ( P = 0.009) and by month ( P < 0.012). The overall mean interovulatory interval of Group 1 (16.4 ± 0.17 days) and Group 2 (16.6 ± 0.12 days) was not different ( P > 0.05), but was shorter than the one of Group 3 (17.4 ± 0.15 days; P < 0.04). The embryo recovery rate of flushings from Groups 1 and 2 was influenced by the length of the previous interovulatory interval ( P = 0.03). [ABSTRACT FROM AUTHOR]

In the present study, 2.228 cycles of 180 Polo Argentino donor mares from an embryo transfer program in Argentina were examined to evaluate the effects of: (1) Interval from Prostaglandin F2alpha analog treatment to ovulation (ITO) on embryo recovery rate (ERR); (2) ITO on number of embryos per flushing (EPF); (3) ITO on multiple ovulation (MO) rate; (4) ITO from donor mare on pregnancy rate (PR) in recipient mares. Mares were inseminated with fresh semen from 31 fertile stallions in the induced estrus. Embryo flushing was performed 7-8 days postovulation. Following embryo flushing, donor mares were treated with prostaglandin F2alpha analog (cloprostenol 250 μg). The ERR increased along with the ITO (P = .01), with the lowest ERR (30.7%) for mares with an ITO of <4 days, and the highest (78.3%) in mares with an ITO of 10 days. The ITO from the donor mare in which the embryo was recovered did not have a significant effect on PR: ITO <6, 6 to 10, and >10 days were 74.6, 81.4, and 77.3%, respectively. The number of EPF and MO rate increased gradually along with the ITO (P < .05). In conclusion, the results of this study indicated that the ITO is positively correlated with the embryo recovery and the multiple ovulation rate., (Copyright © 2019 Elsevier Inc. All rights reserved.)

It is scientifically demonstrated that lunar cycles have important effects on several biological events. Controversy exists about the lunar influence on human and animal parturition. In addition, in the horse industry, especially in Polo Horse breeders of Argentina and around the world there is a higher demand for female offspring than for males. The objective of this study was to determine whether there is a significant association between the lunar phase at the time of mating and the sex ratio at birth in horses. The Argentinean Stud Book provided information related to all matings registered for Thoroughbred and Arab horses between 2003 and 2011. Statistical associations were tested between dates of matings at different lunar phases or days and sex ratio at birth. A total of 65.535 gestations were studied. Overall, sex ratio at birth resulted in 33.396 fillies (50.96%) and 32.139 colts (49.04%). The percentages of males and females at birth were not statistically different amongst the different lunar phases or days. We can strongly conclude that managing the breeding dates in relation to lunar cycles in order to manipulate the sex ratio of the offspring is not a viable option in horses.

Because of the importance of food safety for public health, a study was done to determine the microbiologic quality of foods provided to patrons of community dining halls in greater Buenos Aires, Argentina. The study was descriptive and was conducted in three municipalities with intermediate or high poverty indices; a sample of 52 dining halls was selected randomly from those municipalities. Information was collected from April 1994 through April 1995 by means of surveys, direct observations, and microbiologic analyses of the water and food served. Water and food analysis followed the recommendations of the Argentine Food Code and the International Commission on Microbiologic Specifications for Foods, respectively. The results were interpreted according to the values for cooked foods agreed upon by the Working Group on Food Monitoring. The microbiologic analysis revealed that 28 (54%) of the dining halls had food or water of inadequate quality and 11 (21%) had inadequacies in both. Bacillus cereus was the most commonly found pathogenic bacterium in the food samples analyzed. The factors that were significantly associated with unsatisfactory microbiologic conditions in the food and water were lack of disinfection of the water (P = 0.009), lack of hygiene in the environment (P = 0.03), the presence of rodents and insects (P = 0.05), the supply system for raw materials (P = 0.01), and a relatively small number of users, i.e., fewer than 100 (P = 0.0008). It was concluded that water disinfection and general clean-up of the dining halls were measures that could be put in place by providing education in the areas of hygiene and food handling to supervisors and employees. The results obtained also indicate the need to include a food safety evaluation among the general evaluation criteria for food assistance programs.

The relationship between the number of Escherichia coli, terrestrial and marine heterotrophic bacteria, with certain physical and chemical parameters in Bahia Blanca estuary waters, were investigated by means of a statistical analysis of multiple linear regression. The samples were taken during a period of 16 months. Although distance from the sewage outlet seems to be the factor having the greatest effect on the number of alien bacteria, the models obtained for E. coli are inappropriate to predict bacterial behaviour in this particular natural habitat, while for heterotrophic bacteria descriptive models were selected. The results of this study suggest that many factors affect bacterial population densities in this estuarine ecosystem. This should be taken into account trying to solve the problem in order to avoid progressive degradation.