Fertility: Your Number One Trait

In any breeding program, improving fertility is key to keeping it profitable. How is this achieved? What strategies give you the best results? This article discusses some of the basics and how to make improvements.

• Measure and manage your fertility.
• Culling empty or less reproductive females gives immediate management benefits.
• Culling empty females does not create genetic gain in your herd or flock.
• Genetic gain is created by buying in superior fertile genetics. It is a hard to measure trait with low heritability, so it takes a long time to make progress.

Why Fertility Comes First

Improving fertility is a long term goal. It has low heritability, and therefore will take time to make significant genetic progress. However, this should not be a deterrent to making it your number one trait for improvement. Low fertility in a breeding business is simply not sustainable. Agricultural enterprises have to be dynamic, adapt to changing markets and environments, and having low fertility is like driving around with the handbrake on. Low fertility means you have less selection pressure to drive improvement in other traits, and fewer animals for sale to generate revenue.

The benefit of improving your fertility is not only the immediate result of having more animals to sell. Selection of replacement females is an important part of shaping your future flock or herd. With a highly fertile herd, you need fewer replacements and you have a bigger pool of females to choose from. Fleece traits, growth traits, structure issues, yield, temperament, and muscling can all be measured and selected for in the replacements. Improvement in all these other traits can be made faster, because you can eliminate more of the undesirable traits in your current flock or herd.

Measuring What Matters

The first step to managing any situation is to measure it. We say it time and time again: you can't manage it if you don't measure it.

So for fertility, how do we practically measure it? The simplest form of fertility measurement is pregnancy testing. It's easy to do, and there should not be a breeding flock or herd that does not pregnancy test. Both sheep and cattle breeding businesses get immediate management benefits from pregnancy testing. Elimination of empty and non-breeding animals has an immediate benefit of not consuming resources maintaining unproductive animals. Gone are the days where you could knock a reasonably priced fleece off a ewe and still make some money out of her.

The other simple half of fertility measurement is wet/dry udder checks. This piece of information validates the pregnancy test and is easy enough to do and practical.

How do we use these two pieces of information? Ideally, you should get rid of anything identified as empty or dry. What you do with these animals will depend on your own circumstances, but at least segregate them from breeding or lactating animals so they don't compete for valuable resources to simply exist.

Management Gain Versus Genetic Gain

Does this culling lead to long term genetic gain, though? Unfortunately, not. The biggest impact of this culling practice is making your current herd or flock as efficient as possible, and stopping infertile animals consuming resources for no return. Elimination of non-breeders can dramatically affect your current herd or flock, and will flow onto next year's results, because freemartins and other non-fertile animals are gone. Does this pass onto the next generation, though? Fertility has low heritability, and getting rid of infertile animals does not create genetic gain, because they were not going to pass on the undesirable genetics anyway, they are infertile.

Don't let this stop you from measuring and managing fertility in your herd or flock, because the management benefits are immediate and will have a big impact on your bottom line. Measuring fertility gives you options. Bad season, price spike or plunge, need to get rid of a few animals: then pick on the lower performing animals.

The type of recording involved is fairly basic and can be achieved with small expense. A software package such as KoolCollect, combined with a stick reader and RFID tags, is affordable and practical. Don't be fooled into thinking you need expensive drafting equipment or scales, keep it simple to start with and build on it. You need to capture data first before you can justify expensive drafters.

For sheep, these are the perennial single bearers. For cattle, these are the ones that have missed a beat in years gone by or calve later in the year. To do this, you need to have on tap your information on every individual animal. You need to be able to re-sort and re-organise your flock or herd on screen, from the best performers to the worst. Use this information to assist with your culling or selling decisions. Turn every threat into an opportunity to improve your flock or herd. Traditionally, when faced with those difficult decisions, it's the skinny and old that go. The fat barren females get to hang around.

Heritability Versus Repeatability

Another point to make is that although heritability might be low, around 30% for females, repeatability is high. So a ewe that has had one set of twins is quite likely to keep having twins, so she should be kept. A barren maiden is quite likely to be a poor reproducer for the rest of her life. Retaining proven twin-bearing ewes will enable you to rebuild your flock faster, rather than hanging onto a heap of fat single-bearing ewes.

Making Genetic Progress

So how do you improve fertility genetically, so that you are more likely to breed a highly fertile animal? Well, the simple answer is to buy highly fertile rams and bulls. Use seedstock and stud breeders who measure a whole heap of difficult-to-measure traits and have reported fertility EBVs and ASBVs. It's not easy, but it can be done. Infusing your herd or flock with higher fertility genetics is the best way to improve your own genetics.

Fertility facilitates faster improvements in all other traits, because you can eliminate more of the undesirable traits in your current flock or herd. You have more replacements to choose from and can apply greater selection pressure. These other traits generally have much higher heritability than fertility, so you can make good genetic gain through culling on these. To really move ahead, use the same philosophy: buy in desirable genetics, good rams or bulls, to create genetic gain, and eliminate the undesirable to improve your current flock or herd.

So start measuring your individual animal performance today to lift the production of your herd or flock. Make sure fertility is your number one trait to improve, and it is not a handbrake on your breeding business.