Mention polled to dairy cattle breeders and you can get differing reactions – ‘Yes, it’s the future’, ‘No, it’s just a fad and it will die out’ or Maybe? The majority are on the fence waiting to see if breeding for polled does catch on.
Let’s work through the factors breeders face when considering the incorporation of polled into their breeding programs.
Let’s start off with who should decide whether polled sires should be used in a herd.
There are many groups with many opinions. They range from breeding companies that do not have polled genetics in their product line-up to breeding companies that have invested in developing polled sires and females. As well the question is raised by consumers. They want to know if the animals in the herds that their milk comes from suffered if they are born horned and then are dehorned.
The Bulllvine is of the opinion that it is the breeders that should decide. They are the ones who make the investment of time, energy and resources.
Significant Catch-Up by Polled
Until about five years ago the vast majority of dairy cattle breeders paid no attention to polled. Globally few breeders breed for polled, and they regarded it to be the primary trait. They paid limited attention to selection for type and minor attention for production. Then things changed.
Table 1 – Average Genomic Index (Dec ’15) for Top 10 North American Holstein Bulls
|Birth Year||Index||Polled (P)||Horned (H)||Difference (P-H)|
|Average Change Per Year||Ratio (P/H)|
Note: Data Source – CDN files. All values listed are on Dec ’15 base. 2015 sires
are for those born and tested to Nov ’15 and will not have semen distributed.
Pro$ values not available for bulls born in 2011.
Table 1 shows that in 2011 polled Holstein bulls trailed their horned contemporaries by 555 LPI points. However, in 2015, that difference is now reduced to 271 LPI points. In large part that reduction has come about because bull breeders have bred their very best females to the top polled sires or the best polled females have been bred to elite indexing sires. Furthermore, the number of polled bulls with high indexes has increased significantly.
Other take-home messages from Table 1 include:
- Top horned bulls improved by 91 LPI points per year from 2011 to 2015 while top polled bulls improved by 162 LPI points per year. The rate for polled is 178% of that for horned.
- Top polled bulls started at a low Pro$ level in 2012 and have increased by 256 Pro$ points per year. The rate of improvement for Pro$ for polled bulls was 165% of that for horned bulls.
- Within another 3-5 years, top polled sires will be almost on par with their horned contemporaries.
Why have some breeders bought into polled?
The list is likely long but include:
- Dislike the task of dehorning
- Want to eliminate calf stress
- Concern about the industry’s image in the consumers’ eyes
- Already have high genetic levels in their herd for economically important traits
- Want to increase their breeding stock marketing opportunities
Why are many breeders choosing to wait to use polled?
Those reasons given include:
- Genetic levels of polled animals are inferior to horned
- Do not see polled ever being mainstream
- Staff at dehorning time dehorn everything – polled or not.
- Cannot see a financial benefit for polled
What about Current genetic levels?
Table 2 – Average Dec ’15 Index for Top Ten Daughter Proven Holstein Sires
Table 3 – Average Dec ’15 Index for Top 10 Genomic Holstein Bulls Born in 2014
|Country||Index||Polled (P)||Horned (H)||Difference (P-H)||Ratio (P/H)|
Tables 2 and 3 contain some interesting facts:
- Daughter proven polled sires are significantly behind horned in the USA and Canada for all of TPI, LPI, NM$ and Pro$ (Table 2).
- For genomic evaluated bulls born in 2014 (Table 3) the TPI and LPI averages for top sires, horned and polled, are considerably closer than for daughter proven sires (Table 2). Polled are 90% of horned.
- Polled will be while a catching horned for NM$ and Pro$ as the top genomic sires are only 67% and 80% respectively of their horned year mates.
What would make it easier to universally adopt polled?
In an ideal world the following could help:
- If there were 3-5 very high (2600+ gTPI, 3300+ gLPI, 800+ NM$ or 2400+ Pro$) indexing PP sires
- If there were high indexing PP sires that also have low (< 7%) future inbreeding coefficients
- If gene editing was a reality and polled could be a reality for any or all embryos
For which breeders can polled be a fit?
Breeders with a program that:
- Group houses pre-weaned calves
- Entirely selects sires using genomic indexes
- Continually evaluates and adopts the next innovative step
- Supports the expansion of dairy’s market share of the food dollar
The Bullvine Bottom Line
The decision whether to use polled sires cannot be set in stone. Considerable progress has been made in the genetic level of polled Holsteins. Within five years polled will be equal genetically to horned for the majority of economically important traits. Since quick ways to change the gene from horned to polled in an embryo are still likely some time off, the decision on the value of having polled animals still rests in breeder’s hands.