ANSC 107 I II III IV V I II III IV V VI VII 1nd Edition Lecture 14 Outline of previous lecture Health and Welfare Disease Immune System Operational Health Programs Prevention Outline of current lecture Productive performance Growth Milk production Efficiency of production Records Improvement Traits Learning objectives To be able to identify and explain the key points of breeding evaluations to become familiar with different identification systems be able to read and understand an EPD These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute Important traits Producers should only select for those traits that have economic value o Define economic value yield quality carcass weight Phenotype genotype environment o Phenotype physical appearance genetics Sometimes breeders get onto tangents of extremes Productive performance Has highest economic importance of all traits o Calving season 90 days o Out of season breeding o Twins or triplets in sheep and goats o pigs weaned litter o calf lamb or goat crop weaned pigs and sheep ovulation rate higher heritability Productive performance Calve every 365 days H2 low 0 2 Difficult to select for reproduction o Improve the environment We can select for birth weight scrotal circumference and use breeding soundness exams o Scrotal size matters More fertility more offspring Larger more sperm Growth Birth weight avoid dystocia Weaning weight affected by mother milk production Yearling weight affected by mother milk production Weighing animals should be done Milking and mothering ability 205 days adjusted weight post weaning ADG 140 days of feed h2 0 25 365 day adjusted 160 days x ADG 205 days adjusted h2 0 45 feed efficiency Milk production Cow records Sire selection measure daughters performance Slow 5 years Boar selection 12 teats Ram or Billy observed teats o Replacement females should be checked for abnormalities Calf lamb pig performance o Role of milk early in life Ruminants milk is critical first 60 days of life Influenced by environment Feed resources Want optimum not maximum o Optimize buy Holstein and feed her o Maximum milk production o Make the animal fit the environment Efficiency of production Depends on the environment o Breed differences Difficult to measure Need individual data Longevity how long she stays productive Replacement rate Longer life greater return Athletic ability horses Objective timed event Subjective western pleasure Intelligence horses and dogs Heritably through training Value added product Identification systems Branding hot or freeze damages hide Ear tagging can fall out Ear notching in pigs Tattoo permanent Microchip Retinal scanning RFID products Radio frequency ear tag o Rumitag Stays in ruminant Determines if animal is sick Sends data Records that should be kept Beef o Birth date o Sire o Dam o Birth weight o Weaning weight o o Sheep o o o o o o o o o swine o o o o o o o o Gain test weight yearling weight Yearling scrotal measurement Birthdate Sire Dam Birth weight Birth type sheep and goat 60 90 day weight gain test weight fleece weight gain yearling scrotal measurement birth date sire dam NBA Weaning weight Days to 260 lbs Feed gain Ultrasound data Horses o Birth date o Sire o Dam o Growth o Time distance speed index Increase heritability more progress Carcass Merit Highest heritability Quality and yield grades Muscling h2 4 Fat Improvement in growth Objective can measure Heritably is moderate to high Select for WW YW cattle Days to 260 pigs Feedlot cattle select for YW why o Retained ownership through feedlot Improvement in carcass merit Easy to measure but animal bust be dead Use ultrasound o Can measure size of rib eye marbling etc High heritable REA h2 6 7 Improvement in reproductive efficiency Not highly heritable and very influenced by environment cows and mares ewes and does many sows point of diminishing returns Improvement in conformation traits Hard to change because so subjective Structure and balance hard to measure Structure is easier to measure they are or aren t plus heritable Level rump set to shoulder We can evaluate breeding stock Visually o Select on phenotypic values good when h2 is high growth rate o Subjective opinions o Sell on visual appraisal purebreds o Can cull on structural problems Individual performance records o Objective measureable o Gives us more information o BW YW WW mature wt birth date makes more efficient Performance of close relatives Especially useful in selecting young animals no offspring yet Not always beneficial random genetics Only meaningful if performance records are kept Progeny o Tells us about the ability of the sire and dam from actual offspring o Best evaluation system when there are enough offspring 40 individuals Traits o Carcass traits o Sex limited traits o low heritably traits problem longer generation interval advantage accuracy collateral relatives o brothers 50 o sisters 50 o cousins 12 5 o aunts 25 o uncles 25 o helps with low heritability traits Expected progeny differences Use of estimate how future progeny of the subject animals will compare to progeny of other animals within the breed o Estimate future compare and within breed Based on any combination of individual pedigree sire and dam and progeny performance information More accurate than anything previously available because they account for o Genetic value of cow the bull was bred to o Environmental differences affecting contemporary group o Genetic trend EPD s are reported in pounds for birth weight weaning weight yearling weight maternal weaning weight and maternal milk Scrotal circumference is reported in centimeter For each EPD an accuracy value will be reported o How many cows to breed to o i e EPD for yearling weight is 20 accuracy would be 40 lbs 20 3 lbs Used to determine which bulls to use in breeding program and accuracy values are used to determine how many cows to breed to the bull Trait definitions Birth weight indicator of calving ease larger birth weights generally indicated more calving difficulty Weaning weight reflects pre weaning growth as influenced by the dams milk production Yearling weight differences in 365 days adjusted weights The best estimate of growth because less material influence in this weight Would most closely predict feedlot performance Scrotal circumference the best estimate of fertility Related to the bulls semen quality and age of puberty in daughters