Status as of: 2016-04-08

DESCRIPTION OF NATIONAL GENETIC EVALUATION SYSTEMS

DESCRIPTION OF NATIONAL GENETIC EVALUATION SYSTEMS

Country (or countries)	ITALY	
Main trait group1
NOTE! Only one trait group per form!	LONGEVITY	
Breed(s)	HOLSTEIN	
Trait definition(s) and unit(s) of measurement2
Attach an appendix if needed	Risk of involuntary culling during a cow’s lifetime	
Method of measuring and collecting data	The productive life span is calculated from the data from the milk recording system: the number of days between the first calving and the last test date.	
Time period for data inclusion	All lactations from the official milk recording are used when the cow, having an official pedigree registration, was in lactation at 1st of January or started after 1st of January 1980. The minimum age at first calving should be at least 18 months. Bulls should have at least 20 daughters and/or granddaughters in 10 herds in the analysis.	
Age groups (e.g. parities) included	All lactations.	
Other criteria (data edits) for inclusion of records		
Criteria for extension of records (if applicable)		
Sire categories	All	
Environmental effects3, pre-adjustments 		
Method (model) of genetic evaluation3	Direct longevity is estimated directly from the data with a single trait sire-maternal grandsire model using survival analysis, applying a proportional hazard function following a Weibull distribution. 
rho       = 2.00
gamma = 2.20 (re-estimated at each run)
Culled cows are made uncensored but culled cows from herds with shrinkage > 50% in one year are made censored. Cows that do change herds are considered right censored.	
Environmental effects3 in the genetic evaluation model	Herd-Year-Season: Four seasons are distinguished per year. This random class effect is time-dependent and changes when a cow is transferred, and on January 1, April 1, July 1 and October 1 of each year. It is assumed that the dispersion follows the gamma distribution;

Year-Season: Fixed effect of time-dependent class that changes at January 1, April 1, July 1 and October 1 of each year;

Parity-Lactation Stage: Fixed class effect which is time-dependent and changing as of calving, 90 days after calving 180 days after calving, 270 days after calving, and 365 days after calving;

Herd-Size-Change: Fixed and time-dependent class effect, calculated by comparing the average number of cows present in a certain year with the average number of cows in the same herd one year earlier. Five classes are distinguished: shrinkage over 50%, shrinkage between 50 and 15%, neither shrinkage nor growth over 15%,  growth over 15%, herds that were terminated ( = shrinkage > 50 %, records are made censored) and data from herds in the current year;

Age: At first calving, expressed in months (time independent);

Lactation Value: Lactation value (LV) is a management index that compares phenotypic performances (305 days) of cows within a herd year for production of milk, fat and protein percent. It is time dependent related to each lactation in each year. Milk, fat and protein defined in deviation classes from the herd-year average. There are five classes according to standard deviations.

Sire-mgs effect: Half of the additive genetic effect or half of the breeding value of the sire, as a time-dependent random class effect with a coefficient of 0.5 with its value as maternal grand sire;	
Adjustment for heterogeneous variance in evaluation model	No	
Use of genetic groups and relationships	No phantom groups
A sire-maternal grandsire model is applied where sire and maternal grandsire of the sire and maternal grandsire of the cow are used in the evaluation.	
Blending of foreign/Interbull information in evaluation	None 	
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  as applicable, if you participate in the international genetic evaluations of Interbull	
System validation	Interbull Method 2 genetic trend validation, residual and Mendelian sampling checks (to be performed).	
Expression of genetic evaluations
If standardised (e.g. RBV), give standardisation formula in the appendix	RTA (mean TA of base animals is 100 with a SD of 5) based on relative culling rate.
Higher breeding values means better longevity.
	
Definition of genetic reference base

Next base change	Rolling base cows born 2008-2010;
AI bulls born between 1989 and 1998 with reliability of at least 50 percent. 
Planned for April 2017	
Calculation of reliability	reliability = nd/(nd + ( 4 –h2)/ h2)
where nd = number of culled daughters + 0.5 * number of culled granddaughters and h2 = heritability on original scale.
Sires with no culled daughters have a reliability estimated from their male parents.	
Criteria for official publication of evaluations	A bull should have at least a 50% reliability 	
Number of evaluations / publications per year	Quartely on the first thursday of February, May, August and Novembre.	
Use in total merit index4	8% in PFT	
Anticipated changes in the near future		
Key reference on methodology applied	M.P. Schneider, F. Canavesi and A.B. Samorè. 2000. Genetic evaluation for functional longevity in Italian Holsteins. Book of Abstract of the 51th Annual Meeting of the EAAP. page 34. The Hague, The Netherlands.	
Key organization: name, address, phone, fax, e-mail, web site	ANAFI
Via Bergamo, 292
26100 CREMONA
ITALY
Phone:  +39-0372-4741
Fax:      +39-0372-474203
e-mail: ricercasvil@anafi.it
web site: www.anafi.it      	
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).

 

Parameters for national genetic evaluations for longevity traits as provided to Interbull

Country (or countries):	ITALY	
Main trait group:	Longevity	
Breed(s):	HOLSTEIN	

Trait	h2	genetic
variance	official proof
standardisation formulaa	
Direct longevity:
	0,097	0,10	SE = (-(Eval- 1.09 )/.13)*5 +100	
Combined longevity:
				
a	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.