Sire summaries provide extensive genetic information on the top Total Performance Index (TPI) bulls in the Holstein breed. The sire summaries also include information on other available sires and older sires that were previously marketed through artificial insemination (A.I.) organizations.
Several indexes are used in sire summaries to prioritize different traits, including:
- Total Performance Index (TPI): TPI is a balanced breeding objective that gives emphasis to multiple traits, including production, udder health, early breeding, mobility, calving ability, and body size. The key features of the TPI formula are:
- 47% emphasis on production (Fat and Protein & part of PTAT)
- 20% emphasis on udder health (SCS, UDC & part of PTAT)
- 19% emphasis on early breeding (DPR, PL & DF)
- 8% emphasis on mobility (Feet & Leg composite & part of PTAT )
- 3% emphasis on calving ability (Daughter Calving Ease & Stillbirth )
- 3% emphasis on body size (part of PTAT )
- TPI was recently changed from Type and Production Index to Total Performance Index to better reflect the balanced breeding objective.
- Net Merit (NM$): Net Merit is an economic index that is based on Milk, Fat, and Protein (MFP$) and subtracts feed costs, mastitis, and milk quality costs associated with somatic cell score and adds the value based on productive life.
- Cheese Merit (CM$): Cheese Merit is an index of milk, fat, and protein based on cheese yield prices.
- Fluid Merit (FM$): Fluid Merit is an index of milk and fat.
- Udder Composite (UDC): The Udder Composite index combines linear descriptive type information on several related traits into one number value. The traits included in the udder composite are udder depth, front teat placement, udder cleft, rear udder height, rear udder width, fore udder attachment, and rear teat placement. The desirability values for each trait are weighted according to their economic value and added together to arrive at the index value.
- The Udder Composite is computed as the total of the STAs of the seven udder traits times their respective relative herd life weight.
- Udder Depth .35
- Fore Udder Attachment .16
- Rear Udder Height .16
- Rear Udder Width .12
- Udder Cleft .09
- Front Teat Placement .05
- Rear Teat Placement .07
- The Udder Composite is computed as the total of the STAs of the seven udder traits times their respective relative herd life weight.
- Feet and Legs Composite (FLC): The Feet and Legs composite index combines linear descriptive type information on several related traits into one number value. The traits included in the feet and legs composite are rear legs-side view, foot angle, rear legs-rear view, and feet and legs score.
- Body Size (BD): The Body Size composite index combines linear descriptive type information on several related traits into one number value. The traits included in the body size composite are stature, body depth, strength, and thurl width.
- Dairy Capacity (D): The Dairy Capacity composite index combines linear descriptive type information on several related traits into one number value. The traits included in the dairy capacity composite are dairy form and strength.
- Cow Total Performance Index (CTPI): CTPI is the index for cows, which includes the same factors for calculation as TPI.
- Pedigree Total Performance Index (PTPI): PTPI is the index for young stock, which estimates the ability of the young animal to transmit superior traits. PTPI is calculated by combining the Parent Averages for Protein, Fat, Type, Udder Composite and Feet and Legs Composite in a 3: 1: 1: 1 .65: .35 ratio.
These indexes help breeders select sires that will improve specific traits in their herds. For example, a breeder aiming to improve a cow’s udder should use a bull with a high udder composite.
Contact us for detailed consultation – 6000Rs for general and specific advice valid for one month (including advise on concentrate feed and TMR).
