Ever since the first estrus-synchronization protocol was developed, researchers and dairy producers have debated the merits of “cherry picking,” or artificially inseminating (A.I.) cows that come into heat before the protocol is completed. The answer has shifted back and forth over the years, but the latest advice is to adapt your strategy as dictated by herd performance, says the Dairy Cattle Reproduction Council (DCRC).
For herds that struggle with estrus detection — whether due to facility limitations, personnel limitations, poor estrus expression, poor conception rates for cows bred at detected estrus or because the dairy prefers not to observe for estrus daily — 100 percent A.I. protocols are probably the best way to go, notes the Texas AgriLife Extension dairy team.
However, for herds with adequate estrus detection accuracy, the number of pregnancies per A.I. of cows inseminated at estrus, in general, is similar to or greater than the number of cows inseminated at a fixed time.
If you choose to breed off of heats rather than follow a synch program schedule, it is critical to keep management records up-to-date and/or mark the cow to alert others that she has already been bred, say DCRC experts. This will help avoid an ill-timed hormone dose that may abort a pregnancy and undo efforts to improve reproductive performance.