Author
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Snowder, Gary |
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Submitted to: Symposium Proceedings
Publication Type: Proceedings Publication Acceptance Date: 11/20/2007 Publication Date: 11/28/2007 Citation: Snowder, G.D. 2007. Genetic resistance to disease in cattle. In: Proceedings 2007 Academy of Veterinary Consultants meeting, August 3-4, 2007, Kansas City, Missouri, #2 p. 65-73. Interpretive Summary: Genetic resistance to disease in cattle is a popular topic of scientific discussion and research. Justifications for genetic selection for disease resistance include the need for additional approaches to counter antibiotic and therapeutic resistance by pathogens, consumer demand for zero drug residues in meat, known genetic variation for disease susceptibility, and lack of adequate vaccines for some diseases. The challenges of successfully developing genetically-resistant animals are numerous. Foremost, microbes often mutate and can use such mutations to overcome genetic improvements to disease resistance in host animals. Secondly, selection traits for disease resistance are often difficult and expensive to measure. For some diseases, there is a lack of a proper trait to select for resistance. Also, the immune system is a highly complex system. Selection related to the immune system may result in altering the homeostasis of the immune system such that the animal is susceptible to another pathogen. The genetic relationships between production and disease resistance are often antagonistic, so selection for disease resistance may be at the cost of some production traits. However, recent research indicates in feedlot cattle these genetic relationships are not undesirable. Although successes in genetic resistance to disease in livestock and poultry have been minor, the stage is being set for advancing this field of science with many new scientific developments including genome mapping of livestock and their pathogens, and advances in immunogenetics and proteinomics. Technical Abstract: Genetic resistance to disease in cattle is a popular topic of scientific discussion and research. Justifications for genetic selection for disease resistance include the need for additional approaches to counter antibiotic and therapeutic resistance by pathogens, consumer demand for zero drug residues in meat, known genetic variation for disease susceptibility, and lack of adequate vaccines for some diseases. The challenges of successfully developing genetically-resistant animals are numerous. Foremost, microbes often mutate and can use such mutations to overcome genetic improvements to disease resistance in host animals. Secondly, selection traits for disease resistance are often difficult and expensive to measure. For some diseases, there is a lack of a proper trait to select for resistance. Also, the immune system is a highly complex system. Selection related to the immune system may result in altering the homeostasis of the immune system such that the animal is susceptible to another pathogen. The genetic relationships between production and disease resistance are often antagonistic, so selection for disease resistance may be at the cost of some production traits. However, recent research indicates in feedlot cattle these genetic relationships are not undesirable. Although successes in genetic resistance to disease in livestock and poultry have been minor, the stage is being set for advancing this field of science with many new scientific developments including genome mapping of livestock and their pathogens, and advances in immunogenetics and proteinomics. |
