By: Chuck Sattler, vice president of genetic programs, Select Sires Inc.
The state of the industry
Today’s dairy herds are optimizing the value of calves and breeding more dairy cows to beef sires. This breeding strategy is happening around the globe and there looks to be a permanent shift in dairy herd management. With this strategy, we are seeing a steady decline in heifer inventories. Smaller heifer inventories means reduced culling and reduced turnover rates in the milking herd. This, in turn, means we will be milking more and more older cows.
This is a good thing. Recent studies1 show the economic optimal culling rate is between 25 and 30 percent. This is lower than the industry average, so less culling makes economic sense for most dairy farms. As always, the more we can shift
culling from involuntary to voluntary helps increase herd profits. For example, there’s a better return on investment with older cows because they are more productive than two-year-olds. Some other benefits of reduced culling include reduced
heifer raising expenses and more opportunity to diversify income with beef x dairy calves.
Tighter management of dairy heifer inventories is a chance to review dairy sire selection strategies. With the need to reduce culling, it makes sense to focus sire selection on making improvement in the areas that most frequently cause cows to leave
the herd. These reasons will vary from herd to herd but most usually boil down to four key reasons – failure to get pregnant, mastitis, low production or lameness.
An evolving genetic strategy
Direct selection for improvement in these areas is almost always more effective than indirect selection. Since the mid-1990s we’ve used Productive Life (PL) PTAs for selecting animals that best avoided culling. When evaluations
for Daughter Pregnancy Rate (DPR) were introduced, this provided the opportunity to directly select for improved cow fertility rather than indirectly improving it by selecting for PL. Gradually, we saw most industry indexes add emphasis to
DPR and remove some emphasis on PL.
Industry Index Comparison
| | TPI® | NM$ | CM$ | DWP$® | HHP$ |
| Milk | 0% | 1% | -2% | 1% | 0% |
| CFP | 44% | 48% | 48% | 34% | 37% |
| Mastitis, SCS | 5% | 3% | 4% | 13% | 19% |
| Fertility | 13% | 6% | 5% | 12% | 11% |
| Other Cow Health | 9% | 21% | 20% | 21% | 17% |
| Calving Ability | 2% | 3% | 3% | 2% | 1% |
| Calf Health | 0% | 1% | 1% | 7% | 0% |
| Conformation | 25% | 4% | 4% | 0% | 8% |
| Size/RFI | -2% | -13% | -13% | -10% | -7% |
A similar scenario exists today with effective genetic evaluations for mastitis resistance. Mastitis is a major reason cows leave the herd and shifting emphasis away from PL and directly selecting for mastitis resistance makes sense. PL PTAs are
a valuable breeding tool but directly selecting for things like cow fertility and mastitis resistance, that are measured earlier in a cow’s lifetime, will speed up the genetic progress in these important traits.
This is the major reason behind Select Sires’ new Herd Health Profit Dollars™ index (HHP$™). HHP$ places strong emphasis on health traits, particularly mastitis resistance, using health trait PTAs from the Council of Dairy Cattle
Breeding (CDCB). Mastitis resistance and Somatic Cell Score (SCS) PTAs receive a relative emphasis of 19 percent in the HHP$ formula compared to only 5 percent in both TPI® and Net Merit (NM$).
Another distinguishing feature of HHP$ is that it places some emphasis on udders. HHP$ rewards animals with shallower udders and uses an intermediate optimum approach for teat size and rear teat placement.
HHP$ includes the latest genetic information from CDCB on feed efficiency. However, it uses a slightly different approach from other industry indexes. HHP$ includes negative weights for stature and Residual Feed Intake (RFI) PTAs to genetically
improve feed efficiency. It does not reward animals that are low for strength or high for dairy form.
Average of Top-100 Holstein A.I. Sires Ranked by Various Indexes
| | CFP | Mastitis Resistance | SCS | DPR | PL | RFI | ST | STR | DF | Udder Depth | R Teat Place | Teat Length |
| HHP$ | 154 | +2.2 | 2.71 | +0.5 | +6.1 | -26 | +0.32 | +0.06 | 0.76 | 0.72 | 0.42 | -0.34 |
| NM$ | 161 | +1.3 | 2.77 | 0.0 | +6.0 | -27 | -0.41 | -0.80 | 1.12 | 0.19 | 0.61 | -0.65 |
| TPI | 163 | +1.3 | 2.79 | +0.1 | +5.5 | -4 | +0.41 | -0.11 | 1.30 | 0.72 | 0.88 | -0.54 |
Building a sustainable future
To be profitable and sustainable, dairies must leverage genetics. Breeding for cows that are productive
and trouble-free into their third lactation and beyond can improve profitability. However, it’s important to note that avoiding mastitis and maintaining low cell counts is a major challenge in these second and later lactation cows.
HHP$ prioritizes selection for mastitis resistance and offers a solution to help improve this reality. This index directly selects for key reasons cows leave the herd to create older cows.
The HHP$ index is the result of significant research, planning and direction from Select Sires’ farmer-owner sire committees. As dairies consider their future and potential to pass their farm onto the next generation, genetic standing can be a determining factor. By emphasizing health and wellness genetics, herds can secure better profit margins-regardless of the milk market. HHP$ is not just another selection index, it is an innovative tool that can bring immense value to the dairy and sustain the operation for years to come.