UniFatecie | Introdução ao Melhoramento Genético | Turma III | Med. Veterinária | Prof. Toid

UniFatecie | Introduction to Genetic Improvement | Class III | Veterinary Medicine | Prof. Toid .pdf for advance study (https://url.gratis/ZZIF4) ➡️ Genetic Improvement Genetic improvement is a science that aims to increase the frequency of desirable alleles in a population. ➡️ Basic Techniques Genetic improvement increases the productive efficiency of living beings using artificial selection and crossbreeding (hybridization) techniques between living beings of the same species and breed. Selection is the decision-making process that determines which animals in one generation will become parents of the next, and how many offspring they will be allowed to produce. Mating (crossbreeding), on the other hand, is a broad term that, for domestic animals bred for commercial purposes, is important when it results in the conception, gestation, and birth of offspring. Selection, in general, aims to improve and/or establish some important trait. This means that its purpose is to increase the frequency of favorable alleles in the population. Crossbreeding is undoubtedly a way to achieve genetic improvement and increases in production and productivity. However, this does not eliminate the need for selection as a method and for genetic improvement to be carried out simultaneously. Crossbreeding without selection results in advantages that are easily overcome by selection in purebreds, while the combination of the two leads to a positive synergy. ➡️ History The wheel and the plow, for example, were only invented in societies that domesticated draft animals. In early colonial Brazil, cattle provided fundamental support for sugarcane production, not only as work animals but also for providing meat, fat, milk, and leather. Still in the 16th century, pig and sheep farming grew in importance. The former excelled in producing meat for salting, as well as leather and fresh meat; while sheep produced the wool needed for warm clothing. If in the past, changes occurred slowly, today they occur rapidly, largely due to globalization. Therefore, it is important to emphasize that, in recent years, the genetic improvement of beef cattle has become increasingly important. This has resulted not only in an increase in the number of programs that develop genetic evaluations for various herds, but also in the greater appreciation of animals with estimates of expected progeny differences (EPDs). ➡️ Quantitative Traits So-called quantitative traits are generally influenced by many genes at multiple loci, unlike so-called qualitative traits, which are influenced by a few genes. ➡️ Economically important traits in beef cattle are generally quantitative in nature and have the following attributes: i) they are influenced by many genes; most of which individually have a small effect; ii) additive, dominance, and epistatic effects, although of varying importance depending on the trait, are always present; and iii) gene expression is greatly influenced by the environment. ➡️ Examples of quantitative traits: Weight Body measurements Fertility measurement Coat color Etc. ➡️ Some Important Concepts Inbreeding: Inbreeding is a mating system in which individuals more closely related to each other than the population average are used as parents for the next generation. By mating closely related individuals (a higher percentage of identical alleles by offspring), the likelihood of previously hidden deleterious traits increases. Heterosis: Heterosis can be defined as the deviation of offspring performance from the average of the parents' genetic groups. Heterosis is a genetic phenomenon that occurs when genetically distant animals are crossed. UniFatecie | Introduction to Genetic Improvement | Class III | Veterinary Medicine | Prof. Toid Instagram: https://goo.gl/Vq2q5K I2NTfWKdXkAsnCyybLqr #UniFatecie #VeterinaryMedicine #ProfessorToid #Biology #Paranavaí #2020 #Students #University