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Index PF –Production and Functionality for Polish Holsteins was changed
The Polish total merit index called PF “Production and Functionality” was introduced in June 2007 to rank the Holstein bulls both HO and RW. After 7 years of running this TMI the Breeding Committee of the Polish Federation of Cattle Breeders and Dairy Farmers decided to change the formula of PF. In the new PF index weights for particular traits was changed and the breeding value for longevity was added. Now PF takes into account five groups of traits.
Currently, a new index is estimated for all domestic and foreign Holstein bulls, with daughters evaluated in Poland for all index components. For bulls without daughters evaluated in Poland PF index is calculated based on EBVs estimated by INTERBULL Center.
Three times per year, according to INTERBULL number routine evaluations, the Polish breeding values are officially published on the National Research Institute of Animal Breeding website: www.izzo.krakow.pl.
The new PF index is also apply for Holsteins cows, being from April 2014 the only selection criterion.
The new formula of PF is as follows:
PF = 0.4 * PI_ PROD + 0.25 * PI_POKR + 0.15 * PI_PŁOD + 0.1 * WH _KSOM+0.1*WH_DŁUG
- PI_PROD - Production Index
- PI_POKR - Conformation index
- PI_PŁOD - Fertility index
- WH_KSOM - Breeding Value for Somatic Cell Score
- WH_DLUG - Breeding Value for Longevity
Production Index - PI_PROD
Breeding value for yield of fat + 2 x breeding value for yield of protein
Conformation Index – PI_POKR
0.1 x Body Frame Index + 0.1 x Dairy Strength Index + 0.3 x Feet and Legs Index + 0.5 x Udder Index
The relative weight of conformation traits:
Body Frame Index:
1. Rump angle 40%
2. Stature 25%
3. Rump width 15%
4. Chest Width 15%
Dairy Strength Index:
1. Angularity (Dairy Character) 50%
2. Chest Width 25%
3. Body Depth 15%
4. Stature 10%
Feet and Legs Index:
1. Foot Angle 45%
2. Rear Legs, Rear View 35%
3. Rear Legs, Side View 20%
Udder Index:
1. Udder Depth 35%
2. Fore Udder Attachment 18%
3. Rear Udder Height 15%
4. Central Ligament 10%
5. Rear Udder Width 10%
6. Rear Teat Position 6%
7. Front Teat Placement 3%
8. Teat Length 3%
Fertility Index – PI_PŁOD
0.70 × NPj +0.10 × NPk + 0.10 × PP + 0.10 × OMC
where:
NPj – NRR at 56 days of heifers
NPk – NRR at 56 days of cows
PP – days to first service
OMC – days open period
WH_KSOM – Breeding Value for Somatic Cell Score (SCS)
Breeding value for Somatic cell score is estimated on the basis of SCC in trial milking.
WH_DŁUG - Breeding Value for Longevity (Survival)
In case of Holsteins bulls the breeding value is estimated for direct longevity using of “survival analysis”.
The breeding value for cow’s longevity is estimated on the basis of EBVs of sires and maternal grand-sires by the following formula:
BVcow_LONGEVITY= 100 + 0.5(EBVsire -100) + 0.25(EBVmgs -100)
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