1968-Voice Of The Tennessee Walking Horse 1968 January Voice RS | Page 14

BREED THE BEST YOU’VE GOT
TO THE BEST YOU CAN FIND
Slogans are used to a great extent to attract atten­
tion to a particular theme or idea, especially “ aQve*'
tising and promotion. In this fifth annual e 1 1011
the VOICE Stallion Directory we decided to adopt a
slogan for all Walking Horse breeders in hopes that
it would help everybody with their breeding.^ Bree
the best you’ve got to the best you can find" did not
originate'with us. It is, in fact, a quotation from an
article about Mr. Ogden Phipps, owner of such famous
Thoroughbred race horses as BUCKPASSER, BOLD
LAD and SUCCESSOR. It is a statement made by his
trainer, Mr. Eddie Xeloy, when he was questioned
about the long-time success of the Phipps- owned hor­
ses. We felt that there was merit in this approach and
decided to pursue the thought throughout our 1968
Stallion issue. So . . . with this in mind, let’s talk
about breeding.
SYSTEMS OF MATING
by
J. C. Dollahon, Ph.D.
Wisconsin State University, River Falls, Wise.
The following article is used wtih the permission of Dr. M. E. Ensmingcr,
Director of the AgrServices Foundation, ft was reprinted from the "Stud
Manager's Handbook.' Yol. 3. published by Agriservices Foundation. Clovis.
California.
The author is Dean of ihe Coliege of Agriculture. Wisconsin State University.
He has been a breeder of Quarter Horses for many years and was a staff
member of the Department of Husbandry at Mississippi Slate University for
three years. lie- moved to Wisconsin State University in 1960 and became
Dean of the College of Agriculture in 196-i. Dr. Dollahon has been an accredi­
t'd American Quarter Horse .Judge for many years and is well qualified to
. •.•sent an article of this nature.
In addition to some of the basic tools available to
me animal breeder in the form of selection methods
or tools, a number of mating systems exist which may
be of value in the improvement of farm animals. Some
of the mating systems that can be employed would in­
clude: inbreeding, crossbreeding, outcrossing, and
grading up.
"Inbreeding" may be described as a system of mat­
ing where progeny are produced by parents more
closely related than the average of the population
from which they came. Inbreeding may be divided in­
to two categories according to the closeness of the
relationship of the animals mated. These categories
would be '"close inbreeding” which may be defined
as the production of progeny from closely related in­
dividuals such as the mating of a sire to his daugh­
ters, son to dam and brother to sister, which would
include the mating of litter mates. The second cate­
gory of inbreeding is usually referred to as "line
breeding.” This is a mild form of inbreeding in which
an attempt is made to concentrate the genetic ma­
terial of some outstanding ancestor. When following
a linebreeding program, the breeder attempts to main­
tain a high degree of relationship between each par­
ent and the common ancestor but otherwise not re­
lated to each other. Quite often a linebreeding pro­
gram is initiated by the mating of half-sibs. The rela­
tives have a common ancestor, generally the sire
so their progeny in return have as a common ances­
tor their double grandparent.
The basic genetic effect of inbreeding is that
creasing the chance that an animal will inhere itv
same genes from both of its parents. This tvn the
mating system, if practiced, increases the amoL°/ a
homozygosity. The trend toward genetic homozv„ °f
ity facilitates the 'fixing of traits,’ whether desw??~
or undesirable.
rable
Rapid inbreeding for several generations mav K
expected to cause some loss in size, vigor and fern
ity. Many breeders avoid this system of mating 8ino
it may result in a loss of vigor. The success of an i 6
breeding program depends upon (1) the genetic merB
of the foundation animals, (2) rate or intensity of in
breeding, and (3) efficiencies and possibility 0f selec
tion. While the results of inbreeding may not always
be desirable, it is highly effective as an animal breed­
ing tool and has been used with a high degree of sue
cess by many animal breeders in most phases of
livestock production.
A precise criteria for evaluating the advisability
and extent of an inbreeding program before its adop­
tion does not exist. Based on the genetic merit of the
available breeding stock, the breeder must make the
decision to embark or undertake such a program.
Only those breeders with superior animals should con­
sider such a program.
"Outcrossing” may be defined as the mating of in­
dividuals within the same breed which do not show a
high degree of relationship within their pedigrees.
This system of mating generally implies that a certain
amount of inbreeding has been practiced, or quite
often the female population shows a degree of relation­
ship. Outcrossing is one of the more prevalent sys­
tems used in many livestock breeding programs.
Breeders employ it with the intent of introducing su­
perior germ plasm into their breeding herd from un­
related sources. Outcrossing, unlike inbreeding, in­
creases genetic heterozygosity in a herd and is an
effective means of decreasing inbreeding or homozy­
gosity. The outcross is generally made in hopes of
producing a 'nick’ in herds where the females are
similar from both the genotypic and phenotypic stand­
point. The 'nick’ is considered by many as the genetic
equivalent of heterosis or hybrid vigor expressed in
the crossbred. If a herd has been inbred for a period
of time, an outcross will often increase growth rate,
vigor and reproductive efficiency.
"Crossbreeding” is the mating of two animals of
two different breeds. In a broad sense, crossbreeding
also includes the mating of purebred sires of one
breed and high grade females of a second breed.
Crossbreeding has been practiced with varying de­
grees of success in most classes of farm animals.
The major reasons for establishing a crossbreeding
program would include: (1) to produce the foundation
stock for a new breed; (2) to combine the desired
characteristics of two or more breeds; (3) to capitalize
on heterosis or hybrid vigor; and (4) incidental in
changing from one breed to another.
Probably the greatest amount of progress using
systems of crossbreeding has been within the swine
industry. Using either the two breed criss-cross oi
the three or more breed rotational crossbreeding Pro^
grams, a tremendous number of market bogs have
been produced.
The major disadvantages of crossbreeding systems,
depending upon the classes of livestock involved.
(Continued on page ’ 18 )
14
Voice of the Tennessee Walking
Horse