Despite an increase in domestic milk production, the dairy industry in the Dominican Republic (D. R.) has not been able to adequately meet the demand of the ever-growing Dominican population, prompting the government and milk processing plants to sponsor programs which will increase the national production of milk and eventually lead to milk self-sufficiency. One obstacle to this goal is a very low reproductive rate in cows and heifers due in part to the tropical setting. Year-round heat stress may result in abnormal follicular dynamics and decreased oocyte and sperm quality causing reproductive efficiency to decline drastically. The specific purpose of this project was to examine and characterize the reproductive practices and outcomes of the Dominican dairy industry by region and to attempt to identify factors that influence dairy reproductive efficiency. During the course of the study, 43 farms were visited over a 10-week period and evaluated. Farms were chosen throughout 4 of the 5 regions of the country and were selected based on their size (preferably 40 adult cows or more), availability of data, and demonstrated motivation by the owner in improving the herd. Individual herd evaluation was broken into four major components: owner interview, farm evaluation, collection of individual cow reproductive data, and adult cow evaluation. Once observations had been made and catalogued, all data were summarized on the herd level and analyzed descriptively. In addition to descriptive analysis, multiple regression techniques were used to select independent variables which explain most of the variance for each of four reproductive outcomes: days to first service, services per pregnancy, projected calving interval, and service rate. In general, reproductive management practices varied depending on region and farm size. Average lameness within the herd was the most important factor in explaining the variability within services per pregnancy and projected calving interval. As average herd lameness increases by 1 point (based on a 1 to 4 scale), services per pregnancy and projected calving interval increase by 0.65 services per pregnancy and 61.1 days respectively according to the model formulated. Increase in the number of employees involved in estrus detection resulted in higher days to first service. The Santo Domingo region had lower days to first service possibly due to widespread reproductive hormone use within the region. The percentage of Holsteins within the herd was associated with increased services per pregnancy and projected calving interval. Increases in service rate were most closely associated with the type of record category used, indicating that a larger sample population with thorough insemination records may be needed to adequately assess this outcome. In part, reproductive efficiency in the Dominican Republic can be potentially improved by enhancing methods for estrus detection. Mechanical aids to estrus detection (tailhead chalk, K-mar® patches, etc.) may help increase estrus detection efficiency in herds currently only relying on visual observation. Assigning 1-2 people primarily to estrus detection and increasing the frequency of hormone usage may also improve estrus detection efficiency. The main emphasis for Dominican dairy producers, however, should be on preventing new lameness and culling chronically lame cows once it is economically feasible to do so. Reducing the incidence of lameness could, in itself, dramatically improve reproductive efficiency in the Dominican Republic. / Master of Science

[Truncated abstract] Veterinarians have considerable potential for exposure to several known reproductive hazards such as radiation, anaesthetic gases, pesticides, long working hours and occupational stress. Reproductive effects are a concern to female veterinarians, especially now that about 65% of graduates from Australian veterinary science schools are female. In the last two decades, there have been reports on the possible associations between occupational exposures and adverse reproductive outcomes in female veterinarians, but most of them have been equivocal and the whole area remains controversial. More evidence is needed before firm conclusions can be drawn. The Health Risks of Australian Veterinarians project (HRAV) was conducted as a questionnaire-based survey of all graduates from Australian veterinary schools during the 40-year period 1960-2000. Of 5,748 eligible veterinarians who were sent the questionnaires (73% of the whole cohort), 2,800 replied including 1,197 females (42.8%). Among women veterinarians eligible to participate, 59% participated . . . Identification of these associations may provide the opportunity for preventing harmful exposures and thus reduce the risk of any adverse reproductive outcomes not only for veterinarians, but also for other groups exposed to these risks such as veterinary nurses, animal laboratory technicians, anaesthetists, dentists, dental assistants, and other similar professional groups. The author of this thesis, having completely addressed the research objectives of her doctoral candidacy, has set out and acted on a future research agenda designed to explore the association between perceived occupational stress and pregnancy outcomes and infertility in Australian female veterinarians.