Estimation and decomposition of genetic trends in a two way cross using Hungarian pig breeds

(1)

Estimation an d d ecomposition of g enetic trends in a two way cross

using Hungarian pig breeds

Nagy , F arka s, Kövér , Czakó and Gorjanc

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

(2)

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

(3)

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)

(4)

M ethod

• Bivariate animal models

• Fixed effects

– Year month – Sex

– Genotype – Herd

• Random effects

– Animal – Litter

(5)

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

(6)

Descriptive statistics (Pietrain)

Variable Mean SD Min Max

LMP 61.7 2.10 52.7 68

ADG 527 60.5 283 774

Age 176 23.2 120 295

LMP, lean meat percentage %; ADG, average daily gain; AGE, age

(7)

Descriptive statistics (Duroc)

LMP 58.2 1.87 50.0 66.8

ADG 557 56.6 318 756

Age 175 21.7 120 285

(8)

Descriptive statistics (Cross)

LMP 59.7 2.02 52.5 66

ADG 566 67.9 317 764

Age 175 21.6 120 282

(9)

LMP: variance component ratios

0 0.1 0.2 0.3 0.4 0.5 0.6

h2 c2 e2 h2 c2

A e2

D G

A D G

L M P

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

(10)

Partitioning of the genetic trend by genotype for average

daily gain (g/day) (10, Duroc;12, Pietrain; 34, Pietrain ×

Duroc)

(11)

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

(12)

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