Three different approaches: Traditional cow line selection for longevity, to gain the ease of high production that comes from matured cows that stay “fit”. That is exemplified by the new Radix P bull, with three tremendous cows behind him (and five milking maternal sisters from five different matings, standing in the barn alongside his momma, who continues to add to her lifetime production totals).
Compare that to what was prevalent in AI even before Genomics started—the cow who is “all done” with a single large first lactation, in which she milks 365 days without carrying calf to build up her index, and then becomes a permanent embryo donor to fill the bull stud contracts. That is the ad above left.
OR there are
still breeders trying to bridge both sides of the debate, breeding up from
developed cow lines, using the highest-TPI-ranked of the Genomic sires that
survive to early-age progeny evaluation, not always getting them to milk a full
2x first lactation (health traits reducing persistency), resorting to 3x to get
a couple bigger records and raise type scores before turning them into embryo
That is the ad above right.
If you needed to buy a bull, which herd would you prefer to visit first?