s. mazza 1* n. guzzo1,2 & r. mantovani 1 -...

Geneticcorrelationsbetweenmorphologicalfactorsandtestdaymilkin

Valdostana RedPiedbreedS.Mazza 1*, N.Guzzo1,2 &R.Mantovani 1

1 DepartmentofAgronomyFoodNaturalresourcesAnimalsEnvironment,UniversityofPadova,Legnaro (PD),Italy2DepartmentofComparativeBiomedicineandFoodScience

*[email protected]

VALDOSTANABREED

• Dual purpose breed• Good longevity and fertility• Resistance to common diseases• Good adaptability to different climates

AOSTA RED PIED

Registered Cows 12,834

Average Milk Yield 4,000 kg

-Fat 3.56%

-Protein 3.24%

ADG 1 kg/d

Dressing Percentage 63%

SEUROP Score R(+)/U(-)

EAAP2014,Copenhagen(Denmark)– 27/08/2014– SerenaMazza

AOSTA RED PIED

Measured by linear type traits


SELECTIONINDEX


MORPHOLOGICALTRAITS


Theinfluenceoftypeonherdlifecanbeseveraly overstimated whentheestimationisbasedonalargenumberoftypetraits

TO AVOID THIS…

‘’ONLYALIMITEDNUMBEROFTYPETRAITSSHOULDBEUSEDINTHEINDIRECTESTIMATION’’

(Visscher,1994)

FACTORANALYSISTomaintainthevariabilitycontributedbyeachtrait,atthesametimetoreducethenumberofvariablestobemanaged

(Foraboscoetal.,2005)

FACTORANALYSIS

Factor1 Factor2 Factor3Frontfleshiness 0.85Back,LoinsandRump 0.88Thigh,Buttockssideview 0.88Thigh,Buttocksrearview 0.89Foreudderattach 0.68Rearudderattach 0.80Udderwidth 0.79Udderdepth 0.74SuspensoryligamentTeatplacementrearview 0.38TeatplacementsideviewTeatlength ‐0.48

Coefficient≥|35|


FACTORANALYSIS


Nowadays lactationmodel

REPEATABILITYMODELS

• Subsequentcontrolsinthesamelactation

• Geneticevaluationsbasedontest‐day(insteadoflactation)datacanaccountforenvironmentalinfluencesmoreaccurately

TESTDAYMODEL

Toestimategeneticparametersandcorrelationsbetweenmilkyieldrelatedtraitsand

morphologicalfactorsregardingspecificregionofthebodyofanimalsbelongingtothesmall

autochthonouspopulationofValdostana RedPieddualpurposebreed


AIMOFTHESTUDY

MORPHOLOGICALDATASET TESTDAYMILKDATASET

33,206records 33,206animals 61,378animals inpedigree

169,008testday 16,605animals 41,991animals inpedigree

FINALDATASET202,214 records36,019animals

(13,792animals withboth MORPHandTD)61,912animals inpedigree

FACTOR1 fleshiness traitsFACTOR2 dimensional udder traitsFACTOR3 udder conformation traits

FATcontent (kg)PROTEINcontent (kg)MILK(kg)


MATERIALS&METHODS

Morphological Model:yijkl =µ+HYCi+ACj+DIMk+al+eijkl

Where:yijkl =lineartypetraitµ =overallmeanHYCi = fixedeffectoftheherd‐year‐classifier

(7,475levelsforARP)ACk = fixedeffectofageatcalving

(5classes: from22to29mo,30‐34mo,35‐36mo,37‐41mo and≥42mo)DIMj = fixedeffectofdaysinmilk

(7classes:10‐30d,from31to180daftercalvingusing30‐dintervalsand≥181dforthelastclass)

al = randomadditivegeneticeffectofcoweijkl = randomresidualterm


MATERIALS&METHODS


Repeatability TestDay Model:yijklmno =µ+HTD(nl)i+Gestj+ lxAC(nl)k*+ lxMP(nl)l*+PEwm+PEbn+ao+eijklmno

Where:yijklmno =milk‐relatedtraitµ =overallmeanHTD(nl)i =fixedeffectoftheherd‐testday withinlactation

(46,722levels)Gestj =fixedeffectofdaysofgestation

(16classes:from1to210dofgestationusing15‐dintervalsand≥211dforthelastclass)AC(nl)k =fixedeffectofageatcalvingwithinlactation(42classes)MP(nl)l =fixedeffectofmonthofparitywithinlactation(36classes)PEwm =randompermanentenvironmenteffectwithinlactationPebn =randompermanentenvironmenteffectbetweenlactationao =randomadditivegeneticeffectofcoweijklmno =randomresidualterm

*ascovariates;Shapeofthelactationcurvedescribedby

4th orderLegendrepolynomials(Strabel andMisztal, 1999):

l1=1,l2=x,l3=(3x2‐1)/2,l4=(5x3‐3x)/2;xlactationdaysonastandardscale

of5‐305DIM

MATERIALS&METHODS

FACTOR TRAITS σ2a σ2r h2(SE)

1‐ Frontfleshiness‐ Back,Loins& Rump‐ Thigh,Buttockssideview‐ Thigh,Buttocksrearview

0.250 0.550 0.31(0.02)

2‐ Foreudderattach‐ Rearudderattach‐ Udderwidth

0.130 0.650 0.17(0.01)

3‐ Udderdepth‐ Teatplacementrearview‐ Teatlength

0.163 0.667 0.20(0.01)


RESULTS_1Heritability estimates

TRAIT σ2pe σ2a σ2r h2(SE)

MILK(kg) 0.004 0.002 0.006 0.20(0.02)

FAT(kg) 0.003 0.001 0.002 0.13(0.02)

PROTEIN(kg) 3.554 1.311 1.740 0.17(0.02)


RESULTS_2Heritability estimates


Factor 1Fleshiness

Factor 2Udder size

Factor 3Udder conformation

Factor1 ‐0.38 0.21

Factor2 ‐0.09 ‐0.12

Factor3 0.06 0.08

RESULTS_3Genetic (above)andphenotypic (below)

correlations between factors

0.03≤SE≥0.06

MILK(kg) FAT(kg) PROTEIN (kg)

MILK(kg) 0.79 0.87

FAT(kg) 0.79 0.86

PROTEIN(kg) 0.91 0.77


RESULTS_4Genetic(above)andphenotypic(below)correlationsbetweenmilkyieldtraits

0.01≤SE≥0.02

MILK(SE) FAT(SE) PROTEIN (SE)

Factor 1Fleshiness

‐0.53(0.11)

‐0.44(0.13)

‐0.41(0.11)

Factor 2Udder size

0.89(0.03)

0.83(0.04)

0.86(0.09)

Factor 3Udder

conformation

‐0.34(0.09)

‐0.23(0.10)

‐0.31(0.09)


RESULTS_5Bivariategeneticcorrelationsbetweenfactorsandmilkyield

MilkyieldrelatedtraitsfortheValdostana RedPiedbreedshowedlowbutnormalheritabilityvalues(from13%to20%)

• Positiveandhighgeneticcorrelations(≥83%)betweenF2andmilkrelatedtraits

• MediumnegativegeneticcorrelationsofF1andF3withallthemilkrelatedtraits


Fleshinessfactor(F1)isthemostheritabletrait(31%)

NegativegeneticcorrelationsofUddersizefactor(F2)withbothFleshinessfactor(F1)andUdderconformationfactor(F3)

CONCLUSIONS

National Association of Breeders of Valdostana cattle

Regional Association of Valdostana breed

s. mazza 1* n. guzzo1,2 & r. mantovani 1 -...

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