Animal Breeding PDF

ANIMAL BREEDING Based on DR MARIO S. SUBA’s Book “Principles of Animal Breeding” Animal Breeding  is the science that deals with the application of the various animal genetic principles purposely to improve or enhance the performance of livestock and poultry species.  art and science of...

ANIMAL BREEDING Based on DR MARIO S. SUBA’s Book “Principles of Animal Breeding” Animal Breeding  is the science that deals with the application of the various animal genetic principles purposely to improve or enhance the performance of livestock and poultry species.  art and science of the genetic improvement of animals  Genetics is the science that deals with heredity and variation.  Mating Mating Scheme  Natural  Artificial Mating Systems  Inbreeding – a form of non-random mating of closely related animals by ancestry  Linebreeding – a form of inbreeding which is done to concentrate the characteristics of a superior ancestor  Backcross – a crossbred mated back to one of the two parents  Crossbreeding or outcrossing – refers to mating between animals of different established breeds Types of Crossing Systematic Crossing  hybrid vigor – average superiority of offspring over the parents  breed complementation – combining the good characteristics of the breeds Two Way Cross Straightbred Parents Sire Line ♂ x Dam Line♀ A (100%) B (100%) AB (50% A: 50%B) Bloodline composition Three Way Cross Sire Line ♂ x Dam Line♀ A (100%) B (100%) AB (50% A: 50%B) Dam Line ♀ x C (100%) Sire Line ♂ (AB)C (50% C: 25%B: 25%A) Four Way Cross or Double Cross Sire Line ♂ x Dam Line♀ Sire Line ♂ x Dam Line♀ A (100%) B (100%) C (100%) D (100%) AB (50% A: 50%B) x CD (50% C: 50%D) (AB)(CD) (25%A:25%B:25%C:25%D) Rotational Cross - use of two or more breeds in regular sequences (subscripts indicate that there is no backcross) Sire Line ♂ x Dam Line♀ A (100%) B (100%) AB (50% A: 50%B) Dam Line♀ x A2 Sire Line ♂ (100%) (AB)A Dam Line♀ (75%A: 25%B) x B2 Sire Line ♂ (100%) [(AB) A]B (37.5%A: 62.5%B) Crossing to Produce Synthetics or Composites - resulting into a new breed - examples: Costwold, Seghers Nieuw Dalland in swine Other types of outcrossing  Upgrading – a mating system where an inferior breed in mated to a superior breed to improve characteristics of the lesser breed (usually the mating of exotic breed to a native breed)  Topcrossing – mating of males and females which are considered top in their performance pedigrees SELECTION Selection – process of choosing animals with desirable traits that are to be maintained and reproduced in a herd or flock Basis of Selection for Breeders  Individuality – animal’s own performance record  Pedigree – records of ancestors  Progeny Test – on basis of performance of offsprings  Collateral Relatives – based on performance of relatives (cousins, aunts and uncles) Methods of Selection  Tandem – only one trait at a time is being considered  Independent Culling Level – 2 or more traits at a time is measured; if one trait did not pass the standard it will not be selected  Selection Index - Combining all traits included in the selection program into an index; usually gives best results; each trait is given weight in the selection - e.g. backfat thickness, ADG and FCR in swine  Average daily gain (ADG) – daily growth rate ADG = total gain in weight Total days of fattening  Feed Conversion Efficiency (FCR) – measures the amount of feed needed to produce a kg gain in weight FCR = total feed consumed Total gain in weight  Backfat – average acceptable backfat thickness for a 90 kg gilt is 2 cm