Sire Reference Schemes

Table of Contents

1. What are Sire Reference Schemes?
2. Do You Want to Participate?
3. For more information...

What are Sire Reference Schemes?

In the past couple of years sheep producers in Canada have started to become interested in sire reference schemes. There is an Ontario Suffolk Sire Reference Association, an Alberta Suffolk sire reference group, a Rideau sire reference group is just beginning and there has been talk of possible Texel and Charollais sire reference groups.

A sire reference scheme is a group of breeders who get together and agree on using the same sire or sires to breed a portion of their flock. This usually translates to using semen from the reference sire to breed a minimum number of ewes per year. The breeders generally have similar goals and want to improve similar traits in their sheep. Most of the sire reference groups in Canada are for terminal sire breeds of sheep. The goals are to improve gain and lean meat yield in their animals. Annually, the members meet and nominate potential rams from their flocks to be used as the next reference sire and agree on the ram(s) that will be best suited to improve the genetics in their flocks.

This sounds great and in some cases works just like that. But reality for many groups trying to work together is that there are differences of opinion. Opinions vary concerning things such as: What trait should be changed? By how much? What is most important? And what other traits must be considered in their reference animal?

Cooperation in business is a challenge and it is easier to cooperate if the terms are strictly defined. In most schemes there is a simple definition such as: “A member will use semen from one of the designated reference sires to breed a minimum of 15 ewes”. This makes it easier for more people to participate. If you agree with the basic philosophy of increasing gain and lean yield, you can benefit from belonging. If you don’t particularly like the chosen reference sire in one year for some reason (maybe there is a particular conformation trait that you don’t like or do like) you can use the sire on the minimum number of ewes and simply market the offspring. You may still get some progeny that combine the best traits from your flock and better gain and lean yield from the reference sire.

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Do You Want to Participate?

The advantage to joining a reference group is being able to compare animals from different flocks on an equal basis. Across flock genetic evaluation numbers (Estimated Progeny Differences or EPDs) are only valid between flocks if the genetic links between flocks are strong. With little artificial insemination done in sheep, the genetic links between many flocks are weak. Good reliable genetic links between flocks create the genetic advantages that would be gained if all of the flocks were managed on the same farm in the same environment. In simple terms, a larger flock provides a larger pool from which to select rams. If only the top 2 percent of rams were potential flock sires that would mean there would be only 2 to choose from out of 100 rams but 200 to choose from out of 1000 rams. Obviously you have a much better chance of finding an exceptional animal when choosing out of 200.

The terminal sire reference schemes rely on realtime ultrasound measurements to provide some objective measurement of lean yield. Simply looking at the live animals can be misleading. Generally, you can see the difference between two animals that are exceptionally good and exceptionally poor. But to objectively evaluate whether a 3 or 4 month old animal that weighs 40 kg has more muscle than a 36kg animal that is 10 days younger is difficult. The animals may look very similar but one animal may have more muscle and one more fat.

Purebred breeders should consider joining a sire reference scheme if there is one available for your breed. It is difficult to judge how much benefit you may obtain from this for your operation. A sire reference scheme: increases the accuracy of across flock evaluations for the flocks involved in the scheme, provides the genetic advantages of a much larger flock and provides the opportunity to nominate animals as a reference ram which may provide benefits of semen sales in the long-term. At the very least, by trying the scheme, you are assessing all of your options for improving your flock and producing the best possible animal.

For a smaller flock, there are major advantages to having access to a larger gene pool. It is more difficult to make genetic improvement on your own because of the problems in deciding whether a potential ram will improve the traits that you want in your flock. In a sire reference scheme the reference sire will be directly comparable to the ewes in your flock. Also, the reference sire changes every year providing much needed new genetics to avoid inbreeding.

In a larger flock it is easy to ‘try’ the sire reference program without impacting your flock or existing selection program. The reference program may also supply new genetics that will assist in avoiding inbreeding. Pooling your flock with others will provide an advantage to you when comparing your animals to others enroled in the scheme and in selection intensity for traits used in the scheme.

As we move to a global marketplace, consumer demand is becoming more important. The consumer will reward industries that are able to change or adjust their products quickly. Sire reference schemes will be able to make changes to their product faster than an individual flock because of the larger animal numbers that are comparable for selection and the ability to use an individual animal to breed ewes in many different flocks. The current marketplace demand is for lower fat products. Terminal sire reference schemes are using the selection tools necessary for the sheep industry to compete with other meat products by producing a lean product that yields well for the processing sector.

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