Line Breeding vs In Breeding
One of the most interesting parts of being in the livestock business for me is the opportunity to create a next generation by merging two sets of
genetics. It is what attracts me and keeps me in seed stock production. One of the keys, and in my mind the most important key, to producing top
quality breeding stock is your breeding program. Some folks assume that if they will just purchase the last 'Champion' they will have a generation of
champions in the next generation. Advertisements are full of such promises as they parade their newly purchased sire that is a son of the last national
champion. This approach really works pretty well for those who in commercial production or for those who enjoy following the leader. If, on the other
hand, you want to be in the winner's circle, you need another strategy.
You need to think of the genetic makeup of an animal as having a narrow span of genetics or a wide span of genetics. The wider the span the more
heterosis (hybrid vigor) the animal will have. One of the maximum amounts of heterosis you can obtain in goat production is a cross between a Boer
and an Angora. These two breeds have very different genetic makeup and result in a very high amount of heterosis. The same is true in cattle when you
cross a Brahma with a European breed such as Hereford or Angus. Heterosis can be a great thing when used in commercial production as animals will
gain faster and have more resistance to disease etc. Taken to an excess, however, heterosis results in mongrels, where all the gains are lost in a pool
of inferior genetics. In the case of line breeding the opposite goal is desired.
Line breeding is a breeding plan that focuses on families and narrowing the range of genetic variability. Thinking of this from a statistical view, the goal
is to narrow the span and steepen the arch of the bell shaped curve in line breeding. Put another way, the goal is to reduce variability in the offspring
and make them alike phenotypically (what they look like) as well as genotypically (similar genetic makeup). Perhaps one of the best ways for me to
explain this is to tell you about one of my mentors, Warren Kuhl, who was the shepherd at Brigham Young University for several years. I will provide a
condensed version of his breeding plan.
When Warren was hired, he inherited a flock of Suffolk sheep that were good, but not the greatest flock in the nation by any means. He also was gifted
a group of Rambouillet ewes from Canada that were very small and of poor quality. Warren picked a few ewes from each flock and sold the rest. He
then got in his pickup truck and went across the country looking at Suffolks and Rambouillet flocks. When he found a group where both the ewes and
the rams not only looked alike, but looked like he wanted his sheep to look, he either purchased or leased a ram from those flocks. Then he bred the
ram to his ewes. He then took the best daughters from those matings and bred them back to their father (which is what I call inbreeding). He also took
the best sons and mated them to the best daughters, brother and sister matings. From both matings, he got a few unacceptable offspring that he sent
to slaughter; he also got a group of individuals that were neither really good nor unacceptable, just middle of the road quality. He also got a few
individuals that were superior. He kept both of those groups and sold most of the sires. He then went in search of another sire that had more of the
traits that he desired in his flock that needed to be added. He introduced that sire and mated him to the females that he had retained from his earlier
matings. This process continued until he had produced both a sire that he thought was near his ideal and several daughters that likewise met his
criteria. It should be obvious at this point that a meticulous set of records is mandatory in this process in order to keep track of traits, genetics and
various matings. In a few generations, he had 2 or 3 families that he could mate back and forth and rarely did he bring in another outside sire and even
more rarely did he ever bring in another female. His flock was basically closed. As he continued to mate the families, the offspring became more and
more alike and when the flocks were dispersed some 25 years later, they were recognized as two of the leading flocks in the nation if not the world.
Probably more champions had come from those two flocks than any other flock.
Does every story of line breeding and in breeding end up this good? No, several mistakes along the way often derail the program and divert it back into
another mode. Those mistakes include:
" Failure to recognize the role of the female in the success of the program.
" Inability to recognize the traits needed to escalate and improve the family.
" Inability or unwillingness to pay the price to find or obtain the right sire.
" Lack of confidence to cull the flock of undesirable females and sires.
" Lack of confidence to not have a group of 'winners' while you are assembling the families.
" Temptation to sell the best offspring rather than retain them for inclusion in the breeding program.
" Lack of adequate records on which you can make informed matings and selections.
" Inadequate feeding and health program to maximize potential of all offspring.
The list goes on, but some key points that you need to remember are:
1. There is a payoff down the road.
2. The payoff will be significant if you pay the price up front.
3. It can be more costly up front, but will be much cheaper in the end as you will have rare need of new sires and genetics.
Inbreeding is often referred to as line breeding that did not work. While this may be true, inbreeding (mating sons and daughters back to parents) is a
highly leveraged approach. In my opinion, it works best up front while the genetic pool is broad, but can result in numerous rejects as you are
concentrating both the undesirable traits as well as the desirable. You will then get problems that you did not know you had such as bad mouths,
eyelid problems and a host of other physical deformities. You can however, get a superior individual in the same manner. I often tell buyers who
purchase a sire from us and have a variety of does from other sources that they should look at the offspring from the first mating and if they are good,
then mate them right back to that sire again. That will line up the genetic pool and narrow the range of genetics faster than any other mating. Yes, you
will get a few that need to be shipped to slaughter, but you will also get a good group of uniform offspring that you can then move on to another sire,
hopefully a line bred sire that compliments that group you have and you are well on your way to a quality breeding program!
The importance of establishing a picture in your mind of the goat or sheep you want to raise is critical to the breeding process. If you cannot establish
that picture, you will find that you will continually be chasing an unknown destination to which you will never arrive. There is a place for the quick
maturing thick made goats that the South Africans sent to this country. There is also a place for the slower maturing larger framed goats that have
been developed in this country. There are goats in between those two extremes as well. Again, quality breeders will select a particular type and stick
with it, whether it wins or stands dead last in the class. It is also important that you keep an open mind, and look objectively at the various styles of
goats, that you may want to select a trait from. Fat can be a very deceptive factor in making a objective evaluation. The most attractive goats and
sheep are those that are in great show shape and fitted for the show ring, these are often improved upon by photography and they look even better in
advertising photos. Often the sires and dams to these great show animals are back home in working condition and they would not be given a second
look if you were to see them. Often the great sires go unnoticed.
It is important to note that the previous discussion pertains to Fullblood and Purebred breeding schemes. The selection and breeding of Commercial
goats is another discussion that we will cover in a future edition.
Boyer Land and Livestock
Tom, Carrie & Maren Boyer