This document discusses outbreeding, which involves breeding animals that are unrelated or distantly related to exploit heterosis and complementarity. The key advantages are that it increases genetic variation and masks recessive traits, allowing for introduction of new, high-yielding genes. However, it also introduces new genes that could potentially be damaging. Factors to consider for outbreeding include breeding objectives, which animals to select, and the type of mating. Forms include outcrossing, grading up, linecrossing, crossbreeding (two-breed, rotational, terminal), and interspecies breeding.

1. OUTBREEDING
By:
Arjane Mae Maestrado, Ph.D.
Junemae Libuangan. RA

2. CONTENTS
A. WHAT IS OUTBREEDING
◦ PURPOSE
◦ ADVANTAGES
◦ DISADVANTAGES
◦ FACTORS TO CONSIDER
◦ DIFFERENCE BET INBREEDING AND
OUTBREEDING
◦ FORMS AND EXAMPLES

3. OUTBREEDING
 Breeding of animals of same breed but not
related through blood
 Between unrelated or distantly related
individuals of a species.

4. PURPOSE
 Exploit the genetic phenomenon of
HETEROSIS and COMPLIMENTARITY
 Heterosis- where performance of the offsprings
are better or worse than the mean of the two
parents.

5. PURPOSE
 Complimentarity- the phenomenon under which the
progeny inherits advantageous traits from the both
parents
SIRI COW (the pest
resistant, highly adapted
to the terrain)
JERSEY BULL (known
for milk production
better than Siri and high
fat content)
JERSEY-SIRI XBRED (milk yield better
than Siri, resistance and adaptability
better than pure jersey)
X

6. ADVANTAGE/S
 Populations usually show more variation
than inbreeding ones and have a greater potential
for adapting to environmental changes.
 Increases the number of heterozygous individuals,
so disadvantageous recessive characteristics tend to
be masked by dominant alleles.
 New and high yielding genes can be introduced into
the population through out breeding.
 They produce some valuable traits

7. DISADVANTAGE/S
 Introduction of new genes into population
 Animal Discomfort
 accidentally reproduce traits that are damaging to
the health of the animal
 Ex. Cows can only produce large amount of milk if
they have large udders. Usually, a product of
selective breeding may find it heavy because they
have large udders. (Occupytheory.org)

8. FACTORS TO CONSIDER
 Breeding objective
 What and who do we measure
 Number and which animals to select as
parents
 Mating

9. DIFFERENCE BET INBREEDING
AND OUTBREEDING

10. FORMS OF OUTBREEDING
 Outcrossing- the mating of an individual to
another in the same breed that is not related
to it; produces a higher level of
heterozygosity
 Grading up- the mating of purebred sires to
nondescript or grade females and their
female offspring generation after generation
 Linecrossing- the crossing of rather distinct
lines (that may or may not be inbred) of the
same breed

11. FORMS OF OUTBREEDING
 Crossbreeding
─ the mating of animals of different established
breeds
─ utilizes these breed differences in a strategic
manner to improve the efficiency of meat, wool,
and milk production over pure breeding
─ produce a uniform product
 Two Breed Cross
 Rotational Cross
 Terminal Cross

12.  Species cross- the crossing of animals of
different species