Status as of: 2020-10-01

Form GE

DESCRIPTION OF NATIONAL GENETIC EVALUATION SYSTEMS

Country (or countries)	ZAF	
Main trait group1
NOTE! Only one trait group per form!	
Udder Health	
Breed(s)	Holstein	
Trait definition(s) and unit(s) of measurement2
Attach an appendix if needed	Somatic Cell Score = ln(SCC) where SCC is somatic cell count (1000s/ml).	
Method of measuring and collecting data	Milk recording. Collected by owner sampling. Based on single samples (am/pm).	
Time period for data inclusion	Test-days since 1996, pedigree information traced back as far as possible.	
Age groups (e.g. parities) included	First 3 parities.	
Other criteria (data edits) for inclusion of records	Test-day records included from the 3rd test onwards. All test-day records of the first 3 lactations between 5 and 305 days in milk from cows participating in performance testing. First test should be within 70 days in milk, no period longer than 100 days and only one period longer than 70 days in a lactation are permitted.  Age at calving restrictions per lactation : 1st lactation 20--42 months, 2nd lactation 30-54 months, 3rd lactation 40-67 months	
Criteria for extension of records (if applicable)	N.a.	
Sire categories	All domestic and foreign AI sires with daughter information, as well as natural service herd sires included. All domestic and foreign AI sires with daughter information, as well as natural service herd sires included.	
Environmental effects3, pre-adjustments 	None	
Method (model) of genetic evaluation3	FR -  TD - BLUP – AM	
Environmental effects3 in the genetic evaluation model	Fixed : Herd x test-date x nr of milkings, regressions on DIM within season x ageclass (Wilmink curve), length of previous calving interval class, herd x calving year x month
Random : PE	
Adjustment for heterogeneous variance in evaluation model	Adjusting for heterogeneous variance due to DIM 	
Use of genetic groups and relationships	Unknown parents are grouped together according to country, birth year and selection path (4 paths).	
Blending of foreign/Interbull information in evaluation	MACE EBVs are blended with national EBVs until reliability based on SA daughters are 80%.	
Genetic parameters in the evaluation	Use Appendix GE for heritability/genetic variance estimates; for multiple-trait genetic evaluations, provide genetic correlation estimates between traits separately.
Use also appendices PR, CO, BCO, SM, LO, CA, as applicable, if you participate in the international genetic evaluations of Interbull	
System validation	Data checks and validations on quality before genetic evaluation based on outlier detection, duplicates and pedigree checks. Trend validation based on Interbull Methods I and II, correlations between successive runs.	
Expression of genetic evaluations
If standardised (e.g. RBV), give standardisation formula in the appendix	(0.42*EBVLac1 + 0.34*EBVLac2 + 0.24*EBVLac3) * 100	
Definition of genetic reference base
Next base change	Cows born in 2015

2025 to 2020	
Calculation of reliability	PEVs	
Criteria for official publication of evaluations	Cows should be measured. Sires should have 20 daughters in 10 herds.	
Number of evaluations / publications per year	Three evaluations : March, June and Oct	
Use in total merit index4	HSI = 0.17 BF(kg) + 0.21 Prot(kg) + 0.08 Efficiency + 0.08 Conformation – 0.01 ANG + 0.11 Udder + 0.06 F&L + 0.10 Herd Life – 0.05 SCS – 0.13 ICP	
Anticipated changes in the near future	None	
Key reference on methodology applied	Reents et al. 1995. JDS 78: 2858 – 2870.
Reents et al. 1998. Interbull Meeting, New Zealand. 49-54.
Mrode et al., 2002. Anim. Sci. 74: 189-197.
Lidauer et al., 2015. Technical Reference Guides for Mix99.	
Key organisation: name, address, phone, fax, e-mail, web site	SA Stud Book and Livestock Improvement Association
PO Box 270, Bloemfontein, South Africa, 9300
Tel : +27-51-4100900 Fax : +27-51-4473964
Japie@studbook.co.za     Bernice@studbook.co.za
http://www.studbook.co.za	
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 used in genetic evaluation

Country (or countries):	South Africa	
Main trait group:	Udder Health	
Breed (repeat as necessary):	Holstein	

Trait	Definition	ITBa	h2b	genetic
varianceb	official proof
standardisation formulac	
Milk Somatic Cell 	Ln(SCC)	X	0.058	0.079	(0.42*EBVLac1 + 0.34*EBVLac2 + 0.24*EBVLac3) * 100	
						
SCS Lac 1	Ln(SCC) lac 1		0.052	0.069		
SCS Lac 2	Ln(SCC) lac 2		0.071	0.095		
SCS Lac 3	Ln(SCC) lac 3		0.051	0.075		

a	Indicate, with X, traits that are submitted to Interbull for international genetic evaluations.
b	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.
c	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.

Direct Ratios

	SCS Lac 1	SCS Lac 2	SCS Lac 3	
SCS Lac 1	0.052 	0.746 	0.793 	
SCS Lac 2		0.071 	0.997 	
SCS Lac 3			0.051 	

Permanent Environment

	SCS Lac 1	SCS Lac 2	SCS Lac 3	
SCS Lac 1	0.297	0.370	0.256	
SCS Lac 2		0.299	0.495	
SCS Lac 3			0.348