Extração de dna de amostras de sêmen bovino e revisão sobre fertilidade bovina

Abstract

The fertility of cattle is an important factor for the livestock market. Several management strategies are used targeting a improvement in reproductive capacity of animals, since the occurrence of limiting fertility causes economic losses to producers. The causes are varied limitation, any interference such as poor nutrition; inadequate management, genetic factors, climate change, hormonal disorders and diseases. One of the most common problems that are limiting bovine fertility disorders are caused by micro-organisms which affect animal fertility through diseases such as leptospirosis, or contaminations and infections of the genital organs and semen. But even with these losses to livestock breeding index caused by microorganisms, it is known that animals have about ten times more cells than microbial cells in their own bodies. These micro-organisms known as microbiota are important because they provide some collaboration in key processes of the animal. Therefore, it should be borne in mind that there may be an acceptable level of presence of micro-organisms, not causing such a strong negative impact on the point of compromise reproductive efficiency of animals. When researching the global literature one realizes that there is no data that relate micro-organisms with the influence of time and experiences of the animal. For this reason it is interesting to conduct studies leading to the characterization of this "microbiota" and compare the influence of time and experience in the animal copulations this microbiota can cause changes that would entail negative impacts leading to limitation of animal fertility. Therefore this study aims to characterize the present microbiota in bovine semen, Steers (less than 2 years virgins) and adults (approximately four years and experienced). We use eight Hereford bulls for sampling. We performed the extraction of DNA from these samples using two protocols of two extraction kits. To evaluate the results of extraction performed revealing 0.8% agarose gels, we noted inconsistencies in all gels in the extraction, which prevented us from proceeding with the next steps of the work. We conclude that the methodologies for extracting DNA tested were not effective due to lack of reproducibility, further experiments should be conducted to better extraction and further work.