Sire Reference Schemes
Table of Contents
- What are Sire Reference Schemes?
- Do You Want to Participate?
- 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.
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.
