Animal Selection

module 8

selection

• Process of deciding which animals will remain in the herd to become parents of the next generation

• Ensures the choice of the best animals for reproduction

• Most of the productive and reproductive traits are greatly influenced by the kind of breeding stocks in the herd

General recommendations in selecting breeding animal

• Select a breed or breed combination or strain that is most common in the country

• Start preferably with crossbred or upgraded animals

• Consider the market outlet and consumers’ preference

Pointers in selecting pigs for breeding

• Select pigs based on reliable production records

• Start evaluating or selecting potential breeding animals when they are 2-3 months old

2-3 months old

when do we start evaluating or selecting potential breeding animals?

bases of selection

• Physical selection

• Performance

physical selection

strong legs, long body, good body conformation

performance

mothering ability, Average Daily Gain, backfat thickness

selecting boars

• Selected based on economically important traits

• Masculine, with well developed testicles of about the same size

• Must possess strong constitution and high libido, but controlled temperament

• With strong pasterns esp. on hindlimbs, strong back and long bodies

• Boars with no physical deformities and hereditary defects such as hernia (umbilical and scrotal), cryptorchidism, blind or inverted teats

performance basis

• with good muscle development in ham, loin and shoulder

• Backfat thickness should not exceed 2 cm at 90 kg

• LW Select boars that show an ADG of not less than 800 g and(28 90 kg LW) a feed conversion efficiency of not more than 2.5

• Must be at least 90 kg and not more than 160 days old during selection

2 cm

Backfat thickness should not exceed ___ at 90 kg LW

800 g

Select boars that show an ADG of not less than _____ and (28-90 kg LW) a feed conversion efficiency of not more than 2.5

2.5

Select boars that show an ADG of not less than 800 g and(28 90 kg LW) a feed conversion efficiency of not more than ___

90 kg

Must be at least _____ and not more than 160 days old during selection

160 days old

Must be at least 90 kg and not more than _____ during selection

Selecting replacement gilts

• With good temperament and smooth in general appearance

• With at least 6 pairs of well developed teats

• with a relatively long body to accommodate the suckling pigs while nursing

• Must have strong limbs and pasterns

• with strong, straight or slightly arched but not too broad back; low, sagging back is a defect

• With backfat of about 2 cm at 90 kg

6 pairs

gilts should have ____ of well developed teats

culling

• Removal of undesirable animals in terms of economically important traits and overall performance

• Must be based on reproductive performance and physical appearance of the animals

culling parameters (boars)

• Boars with difficulty in mounting for no apparent reason

• Boars with poor semen quality

• Boars that are highly temperamental, vicious and difficult to handle

• Boars that can no longer breed or produce viable semen

culling parameters (gilts/sows)

• Gilts that do not come into heat after 10 months of age

• Sows that have not been bred 30 days after weaning their litter

• Sows with poor maternal instinct and mothering ability

• Sows which fail to wean at least 8 healthy pigs

• Sows with poor performance in terms of litter size for 2 consecutive farrowing

culling parameters (boars and sows)

• Boars and sows that are found positive of infectious diseases like Brucellosis, Leptospirosis , and pseudorabies

• Boars and sows with unsound characteristics—hernia, blind or inverted teats

cattle selection

• For a single trait, selection may be done on the basis of any of the ffg.

  • The animals own phenotypic merit (external features)

• Pedigree information and collateral relatives

• Progeny tests

selection of parents of the next generation (general)

• Comparable production records

• physical characteristics conformation, structural soundness, health and freedom from hereditary defects

• Weaning weights of calves of the respective dams

• Weaning weights and yearling weights for bulls and heifers

• Weight and size of the breeding stock at two years of age

Selecting cows and heifers for breeding

• Milking ability and femininity

• Age

• Breeding ability and ancestry

• Types and conformation

13 yrs

Beef cows remain productive for ____ if they start calving at 3 years of age

rectangular

An ideal beef cow has a _____ frame

selecting a bull

• Physical appearance

• Sex character

• Purchase price

cattle culling parameters

• A cow that calves every one and a half to two years

• A cow that produces a little amount of milk and raise a small calf despite good feeding and management

• Small, weak and unhealthy animals

• Heifers in the herd that do not settle despite 3-4 repeated matings with a proven bull

• Heifers that do not come into heat in spite of proper age, good size, healthy condition, vigor and strength

• Heifers that fail to meet the standards set for the breeding herd

• Bulls and cows which have undesirable hereditary defects such as inverted teats, hernia and cryptorchidism