ANS 217Poultry Genetics

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Information about ANS 217Poultry Genetics

Published on August 2, 2007

Author: Freedom


Slide1:  Poultry Genetics Scanes, et al, Ch. 4 Slide2:  Genetics as the study of heredity had its practical origin. Slide3:  Augustinian Monastery in Brno, Czech Rep Gregor Johann _______ In _____ began experiments, paper presented to the Brünn Society for National History in 1865, proceedings published in _______. The formal start of the ___________ Historical Genetics Facts:  Historical Genetics Facts Mendel’s results not accepted for 40 years 1900’s, findings were rediscovered Mendel’s research validated in animals by Wm. Bateson = Slide5:  Where is this ________ found ? Genetics Terms:  Genetics Terms Gene, unit of __________ Composition - chemical polymer Units consists of Nitrogen Base, sugar, and phosphoric acid -- nucleotides Location of the gene __________ __________ ___________ Chromosomes:  Chromosomes How many chromosomes are present in an animal’s cell ? 1,10, 50.... Does the animal’s __________ relate to the number of _____________ it contains? Slide8:  Examples of Animal Chromosome Numbers Organism Chromosome No. Fruit Fly 8 Mouse 40 Dog ____ Chicken ___ Jap. Quail ____ Turkey ___ Duck ____ Slide9:  Chromosomes Karyotype 2N=38 Organized in ____s Birds are genetically ______ = ___ copies of each chromosome, and each gene except ____ chromosomes (__ andamp; __) non-identical Gene Terminology:  Gene Terminology _____, gene site Alleles, forms of a gene that can occupy a locus Homozygous versus Heterozygous (AA vs Aa) Allelic Interactions (in the _____________) Complete Dominance, one allele suppresses expression of the other Rose comb andgt; Single comb ______-dominance, both alleles are expressed in the same bird Example ?? Incomplete Dominance, one allele cannot totally suppresses the expression of the other Creeper; Dead at 72 hoi; shortened legs; normal sized legs Blue Anadalusian, feather color, White, Blue, Black Karyotype and ______ Determination:  Karyotype and ______ Determination Karyotype 2N=38 Paired set of unequal chromosomes Slide12:  Terms __________, chromosome not associated with sex determination. Sex-linked gene, a gene located on the sex chromosome. ________gametic Sex, that sex which produces two types of gametes (relating to sex chromos.) _______, each ova contains a Z or W chromosome Homogametic Sex, that sex which produces only one type of gamete (relating to sex chromos.) male, all the sperm contain a Z chromosome Slide13:  Sex Determination Which parent determines the sex of its offspring in birds? Female (WZ) Gametes M a le ‘Punnett Square’ W Z Z Z Breeding Systems:  Breeding Systems Single Locus Traits, Discrete, _________ Examples:feather color, naked neck, feathered shanks.. Other traits controlled by several gene loci (n = 10, 20, 30 +), __________ Breeding strategy (method of gene manipulation) differs according to the type of economic trait Economic Traits of Importance to the Poultry Industry:  Economic Traits of Importance to the Poultry Industry Plumage color, color vs no color - white Skin color, white vs yellow Egg Production, no., size, quality, FCR/dz Livability Hatchability, fertility, saleable no. Growth, gain/day, FCR, yield, abd. Fat Disease Resistance, genetic vs vaccines Breeding Systems - Quantitative Traits:  Breeding Systems - Quantitative Traits Manipulation involves measuring the trait and then selecting from within the flock -- gain in the next generation is only a percentage -- quantitative traits Heritability, % of the variation in the trait due to the genes. Commercial Poultry Breeding Involves Matings of Different Birds :  Commercial Poultry Breeding Involves Matings of Different Birds Genetic Engineering since 1900’s Multi-way crosses 2 or 3 different lines of birds Each line has its own characteristics Two-way cross, Line A male x Line B female Three-way cross, Line A x B male x Line C female Resultant chick exhibits ‘hybrid vigor’ = performs better than its parents ! Slide18:  Example of a Breeding Program - Broiler Type Chickens Three-way outbred cross to maximize maternal and paternal heterosis -- Hen performance andamp; Male Growth Lines 4, 66, 978 (Gr. Grand. Parents, GGP; Foundation Line 4 Male x Line 66 Female = 664 Female (Parent) Line 978 Male (Parent) Products marketed - 664 Female and 978 Male (Day-old parent stock chixs) Terminal Cross: 664-978 male and female chixs Slide19:  GGP, Foundation Animals n= 80-120 M; 480- 720 F Multiplier Flocks n= 500M; 5000F ea Production Flocks = x 3 (pure lines) = no. flocks varies per line 66 F x 4 M 978 pure line emphasize growth, eggs Slide20:  Production Flocks responsible for producing the 664 F and 978 M that are marketed as day-old parent chicks Line 66 F x Line 4 M Line 978 664 M and 664 F 978 M andamp; F Sell Only: 664 F andamp; 978 M, alternate sex? Slide21:  Line 66 F x Line 4 M Line 978 (k-) x (KK) (kk) 664 M and 664 F 978 M andamp; F ( all Kk andamp; K-) (all kk) 664 F x 978 M k- (F) Kk (M) Mutations and Lethal Genes in Poultry:  Mutations and Lethal Genes in Poultry Mutation, change in the DNA - spontaneous or environmentally induced Mutation, aka. ‘Sport’ Beneficial or Deleterious Deleterious - Harmful, lethal,…. Costly ($$) Lethal, congenital conditions that result in death of the bird at hatch or later in life andgt; 30 lethals identified in chickens. in Turkeys ? Ducks ? Quail ? Pheasants ? Genetic load - number of deleterious genes present in a population = challenge to bird improvement Slide23:  Bio Security What is it ? Do you Need it ? Types of Pathogens to be Concerned about. Keep Out Restricted Area No Admittance

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