northeastern Ohio | kipps - 6/11/2022 18:57
By breeding the whole herd to a single bull?
I'm running a 30-cow non-registered Jersey dairy, using exclusively sexed-Jersey semen and cheap Angus semen from Select Sires. I'm using as much sexed as possible, with the goal of tripling the herd size within five years. My choice of bulls is based primarily on Fat Percentage, Net Merit, and a negative selection for stature. Jersey Udder Index, a2a2 status, and general fertility factor in as well. My typical method is to find a really promising young-sire bull, and use him exclusively until someone better comes along, or until his daughters are big enough to breed. At that point, I switch to the next hot new upcoming bull. I've done a decent job of picking which bulls will stay in the catalog as proven sires. I'm currently using Stoney(14Je769), and am looking at Bulwurx-P(14Je1810) to replace Stoney in a few months. I'm paying no attention to individual cow traits, strengths, and weaknesses in this breeding program. My theory is if I'm choosing good bulls, it will all come out in the wash anyway.
How much would I have to gain by keeping several bulls in stock, and intentionally 'mating' the cows? Should I keep doing what I'm doing, or do I need to do something different?
Full disclosure: 99% of the bulls I use are young sires. The reason: there are not enough proven polled Jerseys. When I started using polled in 2007, I think there were only 6 polled bulls in active AI out of 600 total AI bulls in the USA. Today, there are currently 65 polled Jerseys available in the USA. So the polled trait has made tremendous gains! However, only 18 of them have daughters on test (proven). So that means 47 polled with only genomic data.
Now to your question: I think you can have tremendous success using a single bull across the whole herd, but I would use a proven sire (90+% reliability).
Genomic bulls are now up to 75% reliability in the Jersey breed. That is not too bad, but still leaves a lot of wiggle room for numbers to go up or down by a significant amount when the daughters start milking. That is why I would recommend using multiple bulls when they only have genomic data.
Mating individual cows can work. But as others have mentioned, it increases the diversity of your herd and you will have a less uniform herd. This can be good and bad. With only 30 cows, your semen inventory is going to be higher with this strategy and each bull will be used over a longer period of time on a wider range of cows/heifers. As new data comes in and daughters start milking, you may find that some of your old inventory is no longer meeting your goals. My personal preference is to use up all semen by the time the next round of proofs come out (4 months).
My strategy:
I use Bullseye https://infojersey.usjersey.com/publictools/BullseyeV2/ to pick 10 bulls based on what my herd needs in terms of genetic change. I start by de-selecting "not polled" on the Bullseye filter. Then I go to work on the other traits. For example: in reviewing my records, I see that my herd's average foot angle score has been on the decline for the past 3 years. So this time I pick the top 20 bulls based on foot angle score. I then whittle the list down to 10 by picking another trait that my herd needs improvement (JUI).
Now that I have 10 bulls, I go to JerseyMate: https://www.usjersey.com/AJCA-NAJ-JMS/AJCA/GeneticsCenter/JerseyMate... I run those bulls and JerseyMate then whittles it down to 5. In looking at the report, I can see which bulls are recommended for the most corrective matings in my herd. I then choose the top 2.
With 2 or 3 bulls in the semen tank, I alternate every 3 weeks. In other words, I will use a single bull across the entire herd for 3 weeks on anything that needs bred. No individual matings for me although it is possible with JerseyMate.
I have 8 Bulwurx-P daughters, but none are milking age yet. Just a heads up: Need to be aware that Bulwurx-P is a JNS carrier. I dropped him from my potential sire list because of that. I replaced him with SKALSKI-P (14JE1929) .
Edited by Jay NE Ohio 6/12/2022 08:11
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How badly am I shooting myself in the foot...
