Lecture 14Outline of previous lectureI. Health and WelfareII. DiseaseIII. Immune SystemIV. Operational Health ProgramsV. PreventionOutline of current lectureI. Productive performanceII. GrowthIII. Milk productionIV. Efficiency of productionV. RecordsVI. ImprovementVII. TraitsLearning objectivesTo be able to identify and explain the key points of breeding evaluationsto become familiar with different identification systemsbe able to read and understand an EPDImportant traitsProducers should only select for those traits that have economic valueDefine economic value-yield, quality, carcass weightPhenotype=genotype+ environmentPhenotype-physical appearance/geneticsSometimes breeders get onto tangents of extremesProductive performanceHas highest economic importance of all traitsCalving season -90 daysOut of season breedingTwins or triplets in sheep and goats# pigs weaned/litter% calf, lamb, or goat crop weanedpigs and sheep-ovulation rate=higher heritabilityProductive performanceCalve every 365 daysH2=low 0.2Difficult to select for reproductionImprove the environmentWe can select for birth weight, scrotal circumference and use breeding soundness exams.Scrotal size mattersMore fertility=more offspringLarger=more spermGrowthBirth weight-avoid dystociaWeaning weight –affected by mother/milk productionYearling weight- affected by mother/milk productionWeighing animals should be doneMilking and mothering ability205 days adjusted weightpost weaning ADG140 days of feed (h2=0.25)365 day adjusted=(160 days x ADG) +205 days adjusted (h2=0.45)feed efficiencyMilk productionCow recordsSire selection-measure daughters performanceSlow-5 yearsBoar selection-12 teatsRam or Billy-observed teatsReplacement females should be checked for abnormalitiesCalf, lamb, pig-performanceRole of milk early in lifeRuminants-milk is critical first 60 days of lifeInfluenced by environmentFeed resourcesWant optimum not maximumOptimize-buy Holstein and feed herMaximum-milk production**Make the animal fit the environment**Efficiency of productionDepends on the environmentBreed differencesDifficult to measureNeed individual dataLongevity-how long she stays productiveReplacement rateLonger life=greater return $Athletic ability (horses)Objective-timed eventSubjective-western pleasureIntelligence (horses)-and dogsHeritably through trainingValue added productIdentification systemsBranding (hot or freeze)-damages hideEar tagging-can fall outEar notching-in pigsTattoo-permanentMicrochipRetinal scanningRFID productsRadio frequency ear tagRumitagStays in ruminantDetermines if animal is sickSends dataRecords that should be keptBeefBirth dateSireDamBirth weightWeaning weightGain test weight yearling weightYearling scrotal measurementSheepBirthdateSireDamBirth weightBirth type-sheep and goat60,90 day weightgain test weightfleece weight/gainyearling scrotal measurementswinebirth datesiredamNBAWeaning weightDays to 260 lbs.Feed/gainUltrasound dataHorsesBirth dateSireDamGrowthTime/distance (speed index)Increase heritability=more progressCarcass Merit-Highest heritabilityQuality and yield gradesMuscling (h2=4)FatImprovement in growthObjective-can measureHeritably is moderate to highSelect for WW, YW (cattle)Days to 260 (pigs)Feedlot cattle select for YW why?Retained ownership through feedlotImprovement in carcass meritEasy to measure, but animal bust be deadUse ultrasoundCan measure size of rib eye, marbling…etc.High heritable REA=h2.6-.7Improvement in reproductive efficiencyNot highly heritable and very influenced by environment+,- cows and mares+,++,- ewes and doesmany “-“ sowspoint of diminishing returnsImprovement in conformation traitsHard to change because so subjectiveStructure and balance hard to measureStructure is easier to measure-they are or aren’t plus heritableLevel rump set to shoulderWe can evaluate breeding stockVisuallySelect on phenotypic values-good when h2 is high-growth rateSubjective (opinions)Sell on visual appraisal- purebredsCan cull on structural problemsIndividual performance recordsObjective (measureable)Gives us more information(BW,YW,WW,mature wt, birth date) =makes more efficientPerformance of close relativesEspecially useful in selecting young animals-no offspring yetNot always beneficial-random ½ geneticsOnly meaningful if performance records are keptProgenyTells us about the ability of the sire and dam from actual offspringBest evaluation system when there are enough offspring (40 individuals)TraitsCarcass traitsSex limited traitslow heritably traitsproblem-longer generation intervaladvantage-accuracycollateral relativesbrothers-50%sisters-50%cousins-12.5%aunts-25%uncles 25%helps with low heritability traitsExpected progeny differencesUse of estimate how future progeny of the subject animals will compare to progeny of other animals within the breedEstimate, future, compare, and within breedBased on any combination of individual pedigree (sire and dam) and progeny performance information. More accurate than anything previously available because they account for:Genetic value of cow the bull was bred toEnvironmental differences affecting contemporary groupGenetic trendEPD’s are reported in pounds for birth weight, weaning weight, yearling weight, maternal weaning weight, and maternal milk. Scrotal circumference is reported in centimeterFor each EPD, an accuracy value will be reportedHow many cows to breed toi.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 bullTrait definitionsBirth weight-indicator of calving ease, larger birth weights generally indicated more calving difficultyWeaning 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 daughtersMaternal weaning weight-reflects what the sire is expected to transmit to his daughters for a combination of growth genetics through weaning and genetics for milking ability. It is an estimate of daughters progeny weaning weightMaterial milk- milking ability of a sires daughters expressed in pounds of calf weaned. Expresses differences in weaning weight that is dues to milking