This article addresses recent animal genetic improvement for purebred Canadian Holsteins. To do that The Bullvine studied the sires used to produce females registered at Holstein Canada for the years 2021, 2022 and 2023. Thus, covering inseminations from early 2020 to early 2023.
Overview of the Study Results
Studying all the sires that produced female registrations would be a time-consuming task. Therefore, the study was limited to the thirty sires per year with the most female registrations. The following is a summary of the overall details found for the top ninety places for the three-year time period.
- Many sires were in the top thirty for female registrations for more than one year. This resulted in only 53 individual sires (24 daughter-proven and 29 genomic) producing 238,306 female registrations (2021-2023) of which 36.4% of the females were sired by genomic sires. A relatively large number of genomic sires being on the most used sire lists was not expected as the recommendation to breeders is not to over-use genomic sires in order to spread risk. Nevertheless, Canadian Holstein breeders obviously have faith in genomic indexing. Three genomic sires with the most registered daughters attained 5th place (3147gLPI, A2A2) in 2021, 3rd place(3346gLPI, Pp) in 2022 and 5th place (3675gLPI, A2A2) in 2023.
- All 53 sires were Beta Casein evaluated and, on a proportional female registration basis, 45% were sired by A2A2 sires, 45% by A1A2 sires and 10% by A1A1 sires. The 29 genomic sires were 63% A2A2, 28% A1A2 and 9% Breeders are rapidly taking up using Beta Casein test results when selecting sires. In all years, the proven sires with the most registered daughters were all A2A2.
- 19% of the female registrations were sired by BB kappa casein sires*, 4% by PP polled (/POS) sires, 11% by Pp polled (/POC) sires, 3.4% by red (/RW) sires and 4.4% by red carrier (/RDC) sires. This study of the most used sires may underrepresent the usage of polled and red Holstein sires in Canada. [* All the sires did not have a kappa casein profile in the national database so beyond the BB category a percentage could not be determined.]
- Significant improvement occurred on a weighted average LPI per registration over the three-year time period for both proven and genomic sires in the study group. The percentile ranks for the LPI’s of the study group sires were – proven sires were 70%RK LPI in 2021, 81%RK LPI in 2022 and 88%RK LPI in 2023 while genomic sires were 76%RK LPI in 2021, 90%RK LPI in 2022 and 97%RK LPI in 2023. The increases were due to an increased emphasis being placed in sire selection on health, fertility and functional traits.
Analysis of Sires Used
Daughter Proven Sires were used for their specific attributes in genetic improvement. The 24 sires averaged +9 CONF with high mammary system and stature indexes, averaged 95+% index accuracy and their daughters often had showring appeal. All were well-known proven sires for their owners. However over 40% of the time these sires had one or more deficiencies in fertility, milking speed, mastitis resistance, milk volume, or %Fat. Any of these deficiencies can negatively impact the HL index for a sire. As well for 30% of these sires, their high positive indexes for type (CONF based of first lactations only) and stature were not uniformly good predictors of longevity. As well the Feet and Leg indexes of these proven sires did not show a consistent pattern in predicting longevity, yet hoof health, depth of heel and rear legs rear view were useful predictors of higher HL indexes.
Genomic Sires were used to address future Holstein breed needs. These 29 sires had a different genetic index profile pattern than did the proven sires. They were not as highly indexed for CONF or stature, but their indexes were superior to the proven sires for %Fat, milk solids yield, Herd Life, Mastitis Resistance, Teat Length (they added length), Milking Speed, Daughter Calving Ability, Feed Efficiency and Beta Casein profile. The current genomic sires will greatly assist breeders with their plans for healthy, efficient and functional animals. A review of the most used genomic sires indicates that 90% of them had been selected by breeders based on their genetic merit rather than on their pedigree popularity.
Predictions for Breed Outcomes and Further Research Needed
Outcomes that Canadian Holstein breeders can expect by using breed leading sires over the next decade will include.
- There will be increased fat and protein yields, increased %Fat and a prevalence of A2A2
- There will be increased animal functionality and efficiency for many traits including foot health, locomotion, parlor traits, feed conversion and reduced labor per animal. Cows will be of moderate stature.
- There will be increased animal longevity to an average of four lactations or 4,500 kgs of fat and protein per lifetime.
- There will be increased animal health and welfare (including polled). Resulting in a positive impact on margins and consumer confidence.
- Animals will be monitored, recorded and managed 24/7. The data in national databases will be paramount for benchmarking, evaluating and creating the future for farm, animal and industry success.
Further Genetic Research is needed in the following areas.
- Feet: The jury is out on the most desired foot. Much more in-depth research is needed.
- Transition / Fertility: The genetic factors associated with the time from pre-calving until when a successful pregnancy post calving is achieved need to be studied and then indexed genetically.
- Body Size: The optimum body measurements are currently a topic being discussed. Objective study is needed for the best definitions for how body parts affect profitability.
- Calf and Heifer Performance: There is much that has yet to be determined on calf and heifer performance and genetic traits as they affect an animal’s lifetime productivity and profitability.
- Revised Total Merit Indexes: Most of tomorrow’s dairy farmers will select sires that produce productive, efficient, functional, fertile, trouble-free daughters. There are economically important traits not yet included in national or stakeholder total merit indexes.
The Bullvine Bottom Line
Canadian Holstein Breeders are constructively using genetic information in selecting sires. Given that 90% of a herd’s genetic improvement comes from sires, breeders need to have an open and proactive approach to the genetic merit of the sires they purchase and use. Returning a profit will always be important when selecting sires. Select the best and ignore the rest.
Notes: 1) The Bullvine thanks Holstein Canada for providing the list of sires with the most registered daughters, and 2) The Dec ’23 Lactanet genetic indexes were used for the calculations.
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