Applied Animal Genetics SAQ's Q & A PDF

How does understanding DNA contribute to genetic improvement in animals? ANSWER: Understanding DNA allows identification of animals with high genetic merit, enabling farmers to select for desirable traits. What physical trait is characteristic of Aberdeen Angus cattle and how is it determined gene...

How does understanding DNA contribute to genetic improvement in animals? ANSWER: Understanding DNA allows identification of animals with high genetic merit, enabling farmers to select for desirable traits. What physical trait is characteristic of Aberdeen Angus cattle and how is it determined genetically? ANSWER: Aberdeen Angus cattle are naturally polled, determined by a dominant gene that prevents horn development. Explain the concept of performance testing in cattle evaluation. ANSWER: Performance testing involves comparing a bull\'s weight gain and feed conversion ratio with others under similar conditions. What is the difference between performance testing and progeny testing? ANSWER: Performance testing evaluates a bull\'s direct performance, while progeny testing assesses the performance of its offspring. Define line breeding and its significance in animal genetics. ANSWER: Line breeding is a form of selective breeding that focuses on specific bloodlines to enhance desirable traits. Why is progeny testing considered more reliable than performance testing? ANSWER: Progeny testing evaluates the genetic potential of breeding animals based on their offspring, offering a clearer indication of hereditary traits compared to performance testing, which relies on the individual\'s performance alone. Discuss how selective breeding can impact the genetic diversity of a population. ANSWER: Selective breeding can diminish genetic diversity by favoring specific traits and narrowing the gene pool. Why is it important for farmers to monitor feed conversion ratios in bulls? ANSWER: Monitoring feed conversion ratios helps determine the efficiency of feed use, impacting overall farm profitability. What is natural selection and how does it influence breeding practices? ANSWER: Natural selection refers to the process where organisms best adapted to their environment survive and reproduce, influencing breeding by favoring traits that enhance survival and fitness. What is a deleterious gene and how does it affect animal fitness? ANSWER: A deleterious gene is one that negatively impacts an organism\'s fitness, making it less likely to survive and reproduce, such as the Brachyspina gene in Holsteins affecting embryonic development. Describe the process of cloning and its significance in agricultural biotechnology. ANSWER: Cloning involves creating genetically identical individuals, which is significant in agriculture as it enables the propagation of desirable traits in plants and animals uniformly. What was the significance of Dolly the sheep in the context of cloning? ANSWER: Dolly was the first cloned animal from a somatic cell, demonstrating the possibility of creating genetically identical animals and raising ethical and scientific discussions in biotechnology. What is genetic modification and its application in livestock? ANSWER: Genetic modification involves inserting new genes into an organism\'s genome, and in livestock, it has enabled the production of pharmaceuticals, like Atryn, from genetically modified goats.