Status as of:  2012-12-05

Form GE

DESCRIPTION OF NATIONAL GENETIC EVALUATION SYSTEMS

Country (or countries)	Korea	
Main trait group1	Somatic cell score	
Breed(s)	HOLstein	
Trait definition(s) and unit(s) of measurement2
Attach an appendix if needed	Somatic cell score (SCS) is defined as the trait and is calculated from somatic cell count (SCC) using :
SCS = log2(SCC/100,000) + 3	
Method of measuring and collecting data	All production data collected by official milk recording agencies using ICAR certified milk recording methods	
Time period for data inclusion	All lactation records from 2000 onwards are used	
Age groups (e.g. parities) included	First five lactations	
Other criteria (data edits) for inclusion of records	Allowed ranges of age of calving for first five lactations are   18- 42,   30-54,   42- 66,   54-78 and 66-90 months, respectively.	
Criteria for extension of records		
Sire categories	All categories of bulls are evaluated jointly.	
Environmental effects3, pre-adjustments 	- Test day SCS data are pre-adjusted with Wilmink function :
SCS = a0 + a1*DIM + a2*e (-0.05*DIM)
- Lactation curve effects nested within parity (5) x calving age (5) x calving season (4) x calving year classes (3) (300 lactation curves in total)
- Average residual SCS + 3 between test days and predicted values are applied for multiple lactation model	
Method (model) of genetic evaluation3	ST-ML-BLUP-AM	
Environmental effects3 in the genetic evaluation model	Fixed effects : herd-year-season effects and calving age classes for each  lactation. Random effects: animal additive genetic effect for each of the first five lactations.	
Adjustment for heterogeneous variance in evaluation model	Not implemented yet	
Use of genetic groups and relationships	Genetic group are defined for unknown parents of animal base on sex, year of birth and country of origin of the animal. At least ten generations of pedigree are traced back from the cows in multiple lactation data.	
Blending of foreign/Interbull information in evaluation	No	
Genetic parameters in the evaluation	See appendix SM	
System validation	Check on data quality (raw data, pedigree information, etc.)
Check on results : genetic trends, change in EBV between evaluations, stability of EBV over time, 
Interbull validation methods I (SCS) and III  (SCS)	
Expression of genetic evaluations
If standardised (e.g. RBV), give standardisation formula in the appendix	EBV = (EBV1st*0.30) + (EBV2nd*0.32) + (EBV3rd*0.33) + (EBV4th*0.025) + (EBV5th*0.025);	
Definition of genetic reference base
Next base change	EBV: stepwise 5-year cow base including all cows born in 2005
EBV: April 2015 with the base population including all cows born in 2010. 	
Calculation of reliability	Using multiple trait effective daughter contribution method	
Criteria for official publication of evaluations	Bulls: daughters are distributed in at least 10 herds, and at least 50% reliability for protein yield	
Number of evaluations / publications per year	3 / April, August,  December	
Use in total merit index4	KTPI = (0.5*(PTAF/SDPTAF) + 1.5*(PTAP/SDPTAP) + 1*(PTAT/SDPTAT) + 1*(UDC/SDUDC))*50 + 576;
PTAT: final linear score , UDC : udder conformation 	
Anticipated changes in the near future		
Key reference on methodology applied	Liu, Z., Reinhardt, F., Bünger, A., Dopp, L., and Reents, R. 2001. Application of a random regression model to genetic evaluations of test day yields and somatic cell scores in dairy cattle. Interbull Bulletin : 27:159-166.
Liu, Z., Reinhardt, F., Bünger, A., and Reents, R. 2004. Derivation and calculation of approximate reliabilities and daughter yield-deviations of random regression test-day model for genetic evaluation of dairy cattle. J Dairy Sci. 87:1896-1907. 	
Key organisation: name, address, phone, fax, e-mail, web site	National Institute of Animal Science(NIAS), RDA
Animal Genetic & Breeding Division
#9, Eoryong-ri, Seonghwan-eup, Cheonan-si, Chungnam 331-801, Korea
Phone : 82-41-580-3362, Fax : 82-41-580-3369
e-mail : ckh1219@korea.kr  web site : http:// www. nias.go.kr	
1) Either: Production (e.g. milk, fat, protein), Conformation, Health (e.g. mastitis resistance, milk somatic cell, resistance to diseases other than mastitis), Longevity, Calving (e.g. stillbirth, calving ease), Female fertility (e.g. non-return rate, interval between reproductive events, number of AI’s, heat strength), Workability (e.g. milking speed, temperament), Beef production, Efficiency (e.g. body weight, energy balance, body conditioning score), or Other traits.
2) Indicate frequencies per category if the trait is categorical and specify transformation of data if practiced.
3) Use abbreviations for most common effects (see document with list of abbreviations at http://www-interbull.slu.se/service_documentation/General/list_of_abbreviations.rtf) and indicate random (R) or fixed (F).
4) Please give economic weights and indicate how they are expressed (preferably in genetic standard deviation units).

 

Form GE	Appendix SM

Parameters for national genetic evaluations for udder health traits as provided to Interbull

Country (or countries):	Korea	
Main trait group:	Health	
Breed(s):	Holstein	

Trait	h2a	genetic
variancea	official proof
standardisation formulab	
Milk Somatic Cell:
	0.16	0.108		
Clinical Mastitis:
				
a	If repeated records are treated as separate traits, provide heritability estimates and genetic variances separately for each trait, as well as for all traits pooled, i.e. for the trait submitted to Interbull.
b	Expressed as follows:
StandEval=((eval-a)/b)*c+d where a=mean of the base adjustment, b=standard deviation of the base, c=standard deviation of expression (include sign if scale is reversed), and d=base of expression.

Table 1: Genetic parameters for somatic cell scores with heritabilities on diagonal, genetic correlations above diagonal and phenotypic correlations below diagonal
Trait	Lactation	Genetic
variance	Lactation	
			1	2	3	4	5	Combined	
Somatic
cell
score	1	.090	.09	.80	.78	.77	.67		
	2	.082	.34	.10	.98	.99	.89		
	3	.089	.26	.47	.10	.98	.88		
	4	.092	.23	.37	.48	.10	.93		
	5	.081	.22	.30	.40	.50	.10		
	Combined	.108						.16