A.I. & BREEDING

Long-term trends suggest the dairy industry has a mixed record when it comes to maintaining the health of our cows. On the one hand, we have seen a substantial decline in somatic cell counts.

After nearly a decade of being widely available to dairy producers, sexed semen is now commonly used across the country.

What is interesting about sexed semen, however, is the various ways and reasons it is being used, and it isn’t just about making more heifers. When deployed as part of a greater genetic strategy, sexed semen will open up new opportunities and change the way you manage your herd.

While certainly not a new concept, inbreeding has become a hot topic in recent years. Producer concern is on the rise over whether genomics is creating too much inbreeding in the dairy cattle population. The worry is that there will soon be limited options to which a herd can be bred to avoid negative effects of inbreeding.

While mating an animal to her father or brother is certainly not desirable, we need to ask what the real goal is in terms of inbreeding. Should we aim for 0 percent inbreeding or, rather, manage it to maximize profit?

When we talk about how to evaluate reproductive performance in a dairy herd, numerous terms come up in the discussion. Some of these terms are related to averages, and others are related to rates (or risks).

Average days open, average days in milk at first breeding, average interbreeding interval, percentage of the herd pregnant, average calving interval and conception rate (or pregnancies per A.I.) are some examples of the first category, while heat detection rate (or insemination risk or service rate) and pregnancy rate (or pregnancy risk) are examples of the second category.

It’s time; it’s time for an intervention – no, not with that crazy nephew that makes a few too many visits to Colorado – a genetic intervention.

What could be wrong, you ask? The dairy cow has made tremendous strides in the last 75 years due to the great work of producers, the A.I. industry and dairy geneticists. Cows produce more milk than ever before. Great job. So what’s the problem? What’s the message?

Heat detection is often cited as the most costly component and, undoubtedly, the major limiting factor to the success of A.I. programs on many dairy farms.

Incorrect detection of estrus is related to loss of income due to extended calving intervals, milk loss, increased veterinary cost, increased heifer-rearing cost and slowed genetic progress. To achieve excellent heat detection, many factors have to be taken into account.