HealthMark™: A New Tool to Identify Health Trait Specialists
In today’s commercial dairy environments, health and fertility traits are becoming more and more
important. Recent results of a dairy producer survey conducted by USDA’s National Animal Health
Monitoring Service indicate that the primary reasons for cows to be removed from herds are
mastitis problems and reproductive problems. These two reasons account for 53.4 percent of all cows
leaving the herd. The survey also shows that low production is less and less of a reason why cows
leave the herd.
Dairy producers know that keeping cows healthy and in the herd is crucial to improving the bottom
line. That is why we see more producers considering genetic values for Somatic Cell Score (SCS),
Daughter Pregnancy Rate (DPR) and Productive Life (PL) in choosing their A.I. sires.
Somatic Cell Score
SCS genetic evaluations are computed based on the somatic cell count data that comes from routine
monthly DHIA tests. SCS measurements provide an indicator of clinical and sub-clinical mastitis
in bulls’ daughters. The correlation between SCS and clinical mastitis is between 60 and 70 percent.
Predicted transmitting abilities (PTA) for SCS generally range from 2.50 to 3.50. Higher values
indicate bulls with daughters that tend to have higher somatic cell counts. Therefore, bulls with
lower SCS PTA’s are preferred. SCS is a trait that is influenced more by management and less by
genetics. For this reason, SCS PTA’s tend to have lower reliabilities than the customary
production and type evaluations. New graduates will enter the lineup with reliabilities for SCS
PTA at about 70 percent and these will remain pretty steady until the second-crop daughters arrive.
Daughter Pregnancy Rate
DPR genetic evaluations use breeding dates and freshening dates reported in DHI records to
calculate the number of days open in each lactation for cows as an indicator of fertility. USDA
uses this data to rank bulls based on how quickly their daughters breed back. By looking at days
open, the DPR PTA’s take into account how quickly after calving cows come back into heat and also
their conception rate when bred.
DPR values range from +3.0 to –3.0 with higher values preferred. They represent the percentage of
eligible cows that become pregnant during each 21-day cycle. Each point of DPR corresponds to
four days open. Higher values for DPR PTA are preferred.
The genetic control of fertility is notoriously low but with DPR we are able to gather several
observations for each cow during her lifetime. Holstein sires will enter the marketing lineup
with DPR reliability of 50-55 percent and then gradually climb to about 60 percent reliability over the next
several proof runs.
Productive Life
PL genetic evaluations rank sires based on the longevity of their daughters. They use the calving
dates and days in milk from lactation records gathered by DHIA to indicate how long cows remain
in the herd. Each cow gets credited with the number of months she is lactating. The number of
months she is dry are not counted.
PL PTA’s generally range from –7.0 to +7.0 and represent the number of months of additional
lifetime that can be expected from a bull’s daughters. PL is influenced more by management than
by genetics. It also is observed only once during an animal’s lifetime so there are fewer data
points to use to predict an animal’s genetic merit. Reliability for PTA PL will start around 55 percent
on new graduates and will gradually increase as productive life data comes in.
DNA Markers Can Help
One thing health and fertility traits have in common is that the genetic evaluations have low
reliabilities until bulls reach their second-crop proofs. This makes sire selection decisions
based on these traits difficult, especially since most sires being considered have first-crop
proofs. This situation provides an excellent opportunity for DNA markers to improve the
reliability of the available genetic information.
In October 2006, Merial introduced an updated IGENITY™ profile that includes new DNA markers for
Productive Life and Dairy Form, both leading indicators of cow longevity. These markers were the
result of a cooperative effort to validate potential genetic markers utilizing results of bulls
progeny tested through the Program for Genetic Advancement™ (PGA™). The research identified several markers with a strong
association with PL. The level of association and their relative impact on PL are listed in Table
1.
Bulls at Select Sires have been tested with these new genetic markers to provide extra
information about their ability to transmit positive health traits. Comparing the PL PTA
of the lineup sires that have high IGENITY PL scores to those with low scores provides
additional evidence about the value of these PL markers. Table 2 indicates that lineup
bulls with high IGENITY scores for PL, on average, transmit additional productive life
to their daughters compared to sires with low IGENITY PL scores.
HealthMark – A Designation of Balanced Health and Fertility
To help dairy producers zero in on sires that transmit a balance of health and fertility traits,
Select Sires has developed HealthMark. DNA marker results combined with genetic evaluation data
for SCS, DPR and PL are used to identify HealthMark sires. This designation:
- Includes sires below (better than) breed average for PTA SCS.
- Includes sires above breed average for PTA DPR.
- Includes sires above breed average for PL based on PL performance information and their
IGENITY PL score.
HealthMark Sires Stand the Test of Time
To illustrate the advantage of HealthMark sires, geneticists at Select Sires took the current
criteria and applied it to the November 2002 national lineup. A comparison was made of their
genetic evaluations at that time as well as their November 2006 evaluations, which had much higher
reliability. Table 3 shows that the HealthMark designation effectively identifies outstanding
health and fertility bulls even though their early genetic evaluations have low reliability.
HealthMark is a unique and powerful tool to identify positive health trait bulls sooner than ever
before, allowing producers to meet their breeding goals faster.
Choosing the Best HealthMark Sires for Your Herd
Recognizing that different operating environments call for different management and breeding
strategies, we understand that you need to know more about HealthMark sires to find the ones that
are right for your dairy. That’s why you’ll find details about Select’s HealthMark sires below.
Your professional Select Mating Service™ (SMS™) evaluator and sales representative can work with you to
health and fertility bulls even though their early genetic evaluations have low reliability.
identify sires that will fit best in your program.
Backed by research and designed for use in the real world, HealthMark sires can put you a notch
ahead in improving the health, fertility and profitability of your herd.
Select Sires HealthMark Sires – April 2008
| Name |
NM$ |
Milk |
PTAT |
PL |
SCS |
DPR |
7HO6168 AMATEUR TV TL    |
352 |
709 |
1.35 |
2.1 |
2.97 |
1.8 |
| 7HO6417 O MAN TR TV TL TD |
781 |
1089 |
0.81 |
6.7 |
2.68 |
2.2 |
| 7HO6782 ZENITH TV TL |
404 |
258 |
1.92 |
2.9 |
2.56 |
1.5 |
| 7HO6834 DALE TR TV TL |
318 |
973 |
2.03 |
3.9 |
2.65 |
0.4 |
| 7HO6838 MATCHES TR TV TL TD |
436 |
1703 |
1.7 |
1.9 |
2.69 |
0.1 |
| 7HO7004 DAMION TR TV TL TD |
102 |
-111 |
3.72 |
1.0 |
2.99 |
0.4 |
| 7HO7043 DISON TV TL |
379 |
1555 |
1.42 |
3.4 |
2.73 |
0.3 |
| 7HO7145 CASIMIR TR TV TL TD |
456 |
1676 |
1.1 |
4.1 |
2.79 |
0.5 |
| 7HO7264 MAN TR TV TL TD |
476 |
1301 |
1.45 |
2.8 |
2.53 |
0.4 |
7HO7287 JINX TR CV TL TD  |
444 |
520 |
1.2 |
5.0 |
2.84 |
2.2 |
| 7HO7313 NATHAN TR TV TL TD |
412 |
745 |
1.8 |
2.1 |
2.91 |
0.8 |
| 7HO7383 ZEUS TV TL |
334 |
214 |
2.01 |
4.9 |
2.77 |
2.6 |
| 7HO7463 PONTIAC TR TV TL TD |
356 |
890 |
2.4 |
3.2 |
2.76 |
0.9 |
| 7HO7466 MOSCOW TV TL |
459 |
1751 |
2.09 |
5.0 |
2.56 |
0.1 |
| 7HO7566 DEX TR TV TL TD |
267 |
149 |
2.31 |
1.6 |
2.91 |
0.3 |
| 7HO7615 COLBY TR TV TL TD |
383 |
485 |
2.4 |
5.1 |
2.86 |
2.1 |
| 7HO7683 ANANDO B/R TV TL TD |
356 |
1186 |
1.36 |
2.1 |
2.58 |
0.1 |
| 7HO7725 ALLOCATE TR TV TL TD |
471 |
1334 |
0.52 |
2.9 |
2.98 |
-0.8 |
| 7HO7735 CADET TR TV TL TD |
307 |
1257 |
2.38 |
2.3 |
2.82 |
0.4 |
| 7HO7737 MENDEV TR TV TL TD |
388 |
1482 |
2.09 |
3.3 |
2.61 |
0.4 |
| 7HO7853 MICHAEL TR TV TL TD |
492 |
273 |
2.01 |
4.0 |
2.88 |
2.6 |
| 7HO7872 ADVENT-RED TV TL TD |
63 |
-954 |
3.46 |
1.4 |
2.96 |
1.9 |
| 7HO8032 PATZ TR TV TL TD |
512 |
526 |
1.11 |
4.3 |
2.86 |
1.2 |
| 7HO8039 APACHE TR TV TL TD |
241 |
955 |
2.65 |
2.4 |
2.79 |
-0.2 |
| 7HO8227 LOGAN IRON TV TL TD |
367 |
117 |
2.38 |
3.2 |
2.54 |
1.2 |
| 9HO2575 BRET CV TM TL |
457 |
555 |
1.64 |
4.7 |
2.46 |
3.1 |
| 9HO2673 TOUCH TR TV TL |
227 |
195 |
1.78 |
2.7 |
2.68 |
1.7 |
 = New Active Sire for April 2008
= HerdLife Builder™
= Eligible for semen export to Canada
= Superior Settler Designation
= gender SELECTed™ Sire
|
| Name |
NM$ |
Milk |
PTAT |
PL |
SCS |
DPR |
| 7JE590 ACTION |
339 |
395 |
2.6 |
4.8 |
2.86 |
0.9 |
| 7JE712 AWARD |
190 |
88 |
1.5 |
2.7 |
2.85 |
1.3 |
| 7JE715 FINALIST |
274 |
883 |
2 |
2.3 |
2.89 |
0.0 |
| 7JE739 MVF |
334 |
1217 |
1.4 |
1.9 |
2.99 |
0.3 |
= New Active Sire for April 2008
= HerdLife Builder™
= Eligible for semen export to Canada
= Superior Settler Designation
= gender SELECTed™ Sire
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Select Sires Inc., 11740 U.S. 42 North, Plain City, Ohio 43064 / Phone: (614) 873-4683 Fax: (614) 873-5751
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