ANIMAL BREEDING

Is the process of selective mating of animals with desirable genetic traits to maintain or enhance these traits in future generation.

BREEDIs a specific group of domestic

animals having homogeneous appearance (phenotype), homogeneous behavior, and/or other characteristics that distinguish it from other organisms of the same species.

SYSTEMS OF MATING

The way animal populations are being structured in relation to reproductive/sexual behavior.

PEN MATINGa cohort of females is brought into the

male's pen and he services them all while they are in the pen. This is the least labor-intensive mating system because the animals are just left to mate at will.

HAND MATING mating in which the female is detected to

be estrus and is then handheld while she is mated or is let into a paddock or pen with a male, where she is the only female.

MONOGAMYone male and one female have an exclusive mating relationship, serially or for a life-time.

PROMISCUITYany male mates with any female in a population or social group.

POLYGAMYone or more males have a relationship with one or more females.

POLYGYNYone male has a relationship with two or more females.

POLYANDRYone female has a relationship with two or more males.

POLYGYNANDRYtwo or more males have a relationship with two or more females (almost promiscuity).

SYSTEMS OF BREEDING

PURE BREEDINGis the mating of males and females livestock animals of the same breed or type.

TYPES OF PURE BREEDING1.Out-breeding – mating of animals of the

same breed but which have no closer relationship than at least 4 to 6 generation.

2.Inbreeding – mating of closely related animals. For example, sire to daughter, son to dam, and bother to sister.

3.Line breeding – a system of breeding in which the degree of relationship is less intense than in inbreeding. It is usually directed towards keeping the offspring related to some highly priced ancestor.

CROSSBREEDINGIs the mating of males and females livestock

animals of different breed compositions or types.

Crossbreeding offers two distinct advantages:1.Heterosis – is the

superiority of the crossbreed offspring. Mathematically, heterosis is the difference in performance between the crossbred and the average performance of its purebred parents.

2. Breed Complementarity – all breeds have strengths and weaknesses. No breed excels in all relevant traits. Thus, production can be optimized when mating systems place breeds in roles that maximize their strengths and minimize their weaknesses.

POLYPAY SHEEP

SUFFOLK SHEEP

TYPES OF CROSSBREEDING1.Terminal Crossing – all the crossbred offspring

are sold and replacement of females must be purchased or produced in the group by mating the proportion of the group to the males of the same breed.

2.Rotational Crossing – involves alternating the use of males of two, three or more breeds. Females are mated to males of the breed which are least related.

3.Roto-terminal Crossing – involves both terminal crossing and rotational crossing.

4. Grading Up – denotes the repeated crossing of females’ and their females progeny to males of a single breed.5. Single Crossing – a first generation breeds between two selected and usually inbred lines.6. Back Crossing – breeding of animals with one of its parents or individual genetically similar to its parent, in order to achieve offspring with a genetic identity which is closer to that of the parent.