Outbreeding

Animal Reproduction System

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