Estimation and decomposition of genetic trends in a two way cross

using Hungarian pig breeds

Nagy, Farkas, Kövér, Czakó and Gorjanc

ASD, 20th Int. Symposium 2012, Kranjka Gora Slovenia

Introduction

• Genetic evaluation– Based on BLUP in most

domesticated species– First application in pig:

Hudson and Kennedy (1985)

– In Hungary its application is compalsory from 2008

• Purebred and crossbred data

Material

• Field test data of Pietrain (5717), Duroc (4868) and their cross (4728)

• Data from 1998 to 2010 from 68 herds• Pedigree was available from 1983 (60926)• Traits

– Lean meat percentage (LMP)– Age (AGE)– Average daily gain (ADG)

Method• Bivariate animal models• Fixed effects

– Year month– Sex– Genotype– Herd

• Random effects– Animal– Litter

Methods

•Genetic trend decomposition – Gorjanc, G., Potočnik K., García-Cortés L. A.,

Jakobsen, J., Dürr, J. 2011. Partitioning of International Genetic Trends by origin in Brown Swiss Bulls. Interbull Bulletin, 44, 81-86.)

•Softwares– PEST, VCE, R-Project

Descriptive statistics (Pietrain)

Variable Mean SD Min Max

LMP 61.7 2.10 52.7 68

ADG 527 60.5 283 774

Age 176 23.2 120 295LMP, lean meat percentage %; ADG, average daily gain; AGE, age

Descriptive statistics (Duroc)

Variable Mean SD Min Max

LMP 58.2 1.87 50.0 66.8

ADG 557 56.6 318 756

Age 175 21.7 120 285LMP, lean meat percentage %; ADG, average daily gain; AGE, age

Descriptive statistics (Cross)

Variable Mean SD Min Max

LMP 59.7 2.02 52.5 66

ADG 566 67.9 317 764

Age 175 21.6 120 282LMP, lean meat percentage %; ADG, average daily gain; AGE, age

LMP: variance component ratios

0

0.1

0.2

0.3

0.4

0.5

0.6

h2c2e2h2c2e2

ADG

ADG

ADG

LMP

LMP

LMP

Genetic trends for ADG and LMP were 0.4 g/day and -0.004 %,

Partitioning of the genetic trend by

genotype for average daily gain (g/day)

(10, Duroc;12, Pietrain; 34, Pietrain ×

Duroc)

Partitioning of the genetic trend by genotype for lean meat percentage (%)(10, Duroc;12, Pietrain; 34, Pietrain × Duroc)

Conclusions• Observed progress in both traits was low

• As selection is now based on BLUP increased genetic trends are expected in the future

• Application of trend decomposition is advocated for the different crosses