GENETIC IMPROVEMENT OF DAIRY CATTLE: STUDY OF TECHNIQUES AND IMPACTS OF GENETIC IMPROVEMENT ON MILK PRODUCTIVITY AND QUALITY

Abstract

Genetic improvement of dairy cattle plays an essential role in modern livestock farming, aiming to increase both productivity and milk quality. Thus, the following question arises: how can increased production be reconciled with the maintenance of milk's nutritional and sensory characteristics, animal welfare, and economic sustainability? This research addressed the relevance of this topic in a scenario of growing demand for high-quality dairy products and the need for more efficient production practices. With the main objective of analyzing genetic improvement techniques and their impacts on milk productivity and quality, the study explored three specific fronts: identifying the main genetic improvement techniques currently used, assessing the impacts of these techniques on herd productivity, and analyzing how they influence milk quality. The methodology adopted consisted of a bibliographic review based on renowned sources such as PubMed, Scielo, and Lilacs, complemented by books and other relevant documents. The analysis included studies on techniques such as conventional genetic selection, artificial insemination, embryo transfer, crossbreeding and emerging technologies such as gene editing by CRISPR/Cas9. The results demonstrated that the use of these techniques provides significant genetic gains, such as increased average milk production per animal, improved feed efficiency and greater resistance to diseases. However, it was observed that productivity and quality do not always go hand in hand. In some cases, the search for high levels of production resulted in the loss of nutritional characteristics, such as reduced fat and protein content in milk. To balance these aspects, the importance of adopting integrated approaches is highlighted, which combine increased productivity with the preservation of the sensory and nutritional qualities of milk, respecting animal welfare and the principles of sustainability.