Genetics and Breeding Terms: A Comprehensive Glossary, Quizzes of Agricultural engineering

Download Genetics and Breeding Terms: A Comprehensive Glossary and more Quizzes Agricultural engineering in PDF only on Docsity! TERM 1 correlated response to selection DEFINITION 1 genetic change in one or more traits reulting from selection for another TERM 2 pleiotropy DEFINITION 2 the phenomenon of a single gene affecting more than one trait TERM 3 genetic correlation DEFINITION 3 a measure of the strength of the relationship between breeding values for one trait and breeding values for anothermeasure of pleiotropy TERM 4 phenotypic correlation DEFINITION 4 a measure of the strength of relationship between performance in one trait and performance in another trait TERM 5 environmental correlation DEFINITION 5 a measure of the strength of the relationship between environmental effects on one trait and environmental effects on another trait TERM 6 compensatory gain DEFINITION 6 a relative increase in the growth rate of thin animals after they are placed on adequate feedthey tend to compensate for being underweight TERM 7 direct response to selection DEFINITION 7 genetic change in a trait resulting from selection for that trait TERM 8 indirect selection DEFINITION 8 selection for one trait as a means of improving a genetically correlated trait TERM 9 direct selection DEFINITION 9 selection for a trait as a meas of improving that same trait TERM 10 indicator traits DEFINITION 10 a trait that may or may not be important in itself but is selected for as a way of improving some other genetically correlated trait TERM 21 effective proportion saved DEFINITION 21 in selection a value that when substituted for actual proportion saved, reflects correct selection intensity TERM 22 Repeated backcrossing DEFINITION 22 or introgressiona mating system used to incorporate an allele or alleles existing in one population into another populationan initial cross is followed by successive generations of backcrossing combined with selection for the desired alleles TERM 23 backcrossing DEFINITION 23 the mating of a hybrid to a purebred of the parent breed or line TERM 24 grading up DEFINITION 24 or topcrossinga mating system designed to create a purebred population by mating successive generations of nonpurebred females to purebred siresa mating system designed to convert a population from one breed to another by mating successive generations of females descended from the first breed to sires of the second breed TERM 25 random mating DEFINITION 25 a mating system in which mates are chosen at random TERM 26 assortative mating DEFINITION 26 the mating of either similar individuals or dissimilar individuals TERM 27 corrective mating DEFINITION 27 a mating designed to correct in their progeny faults of one or both parents TERM 28 complementary DEFINITION 28 an improvement in the overall performance of offspring resulting from the mating of individuals with diferent but complementary breeding values TERM 29 crossbreeding DEFINITION 29 breeding of sire of one breed or combination of breeds to dam of another TERM 30 linecrossing DEFINITION 30 the mating of sires of one line or line combination to dams of another line or line crossing TERM 31 breed complementarity DEFINITION 31 an improvement in the overall performance of crossbred offspring resulting from crossing breeds of different but complementary biological types TERM 32 maternal breed DEFINITION 32 a breed that excels in maternal traits TERM 33 maternal trait DEFINITION 33 a trait especially important in breeding femalsexamples: fertility milk production etc TERM 34 paternal breed DEFINITION 34 a breed that excels in paternal traits TERM 35 paternal trait DEFINITION 35 a trait especially important in market offpsringrate of feed efficiency, meat quality, carcass yield TERM 46 path method DEFINITION 46 a method for calculating inbreeding ad relationship coefficients that simulates the paths taken by identical genes as they flow from ancestors to descendents TERM 47 tabular method DEFINITION 47 a method for calculating inbreeding and relationship coefficients involving construction and updating go a table relating all members of a population TERM 48 base population DEFINITION 48 the population of animals whose parents are either unknown or ignored for the purposes of inbreeding and relationship calculationtypically the individuals appearing at the back of the pedigrees of the original animals in the herd or flock TERM 49 linebreeding DEFINITION 49 the mating of individuals within a particular linea mating system designed to maintain a substantial degree of relationsihp to a highly regarded ancestor or group of ancestors without causing high levels of inbreeding TERM 50 purebreeding DEFINITION 50 straight breedingthe mating of purebreds of the same breed TERM 51 outbreeding DEFINITION 51 outcrossingthe mating of unrelated individuals TERM 52 paternal hybrid vigor DEFINITION 52 hybrid vigor for the direct component of a trait TERM 53 maternal hybrid vigor DEFINITION 53 hybrid vigor for the maternal component of a trait TERM 54 paternal hybrid vigor DEFINITION 54 hybrid vigor for the paternal component of a trait TERM 55 f1 hybrid vigor DEFINITION 55 the amount of hybrid vigor attainable in first cross individuals- maximum hybrid vigor TERM 56 retained hybrid vigor DEFINITION 56 retained heterosishybrid vigor remaining in later generations of hybrids- generations subsequent to the first cross generationretained hybrid vigor is commonly expressed as a proportion of f1 vigor TERM 57 recombination loss DEFINITION 57 a combination value caused by the gradual breaking up of favorable epistatic blocks of linked loci in advanced generations of certain hybrids TERM 58 bc1 DEFINITION 58 backcross 1referring to the first generation of crosses between hybrids and purebreds of a parent breed or line TERM 59 degree of backcrossing DEFINITION 59 the proportional amount of backcrossing involved in a matingthe proportion of an offspring's loci t which both genes of a pair trace to the same acestral breed or line TERM 60 backcrossing DEFINITION 60 he mating of an individual to any other individual with which it has one or more ancestral breeds or lines in common