ASC32 MIDTERMS

• The Pig Production Cycle

  1. Dry Period

  2. Pregnancy Period

  3. Lactation Period

  4. Rearing Period of Weaners

  5. Growing and Finishing of Fatteners

  6. Rearing of Replacement Stock
• Dry Period


  Period between weaning and the next service. After weaning, a sow is expected to come into heat within 3 to 7 days.
• Pregnancy Period


  Also referred to as conception period which starts from fertile service and ends in farrowing. A sow is pregnant for about 114 days or 3 months + 3 weeks + 3 days.
• Estrus cycle of a pig

  1. Has an average duration of 3 weeks (21 days). If a sow fails to conceive after service, she is expected to repeat, or to come into heat 3 weeks after the unsuccessful service.

  2. It is also possible that a sow repeats (much) later than 21 days after the service. In that case, the sow has been pregnant, but for some reason, the pregnancy stopped at a certain point. Such a sow will also come into heat again.

  3. False pregnancy (pseudo pregnancy) occurs rarely on sows which have been bred.
• Lactation Period


  Also called the suckling period, lasts or as long as the farmer allows it. The normal lactation period is between 28 to 42 days in the tropics.
• Rearing Period of Weaners

  After a 28 to 42 days suckling period, the piglets can be separated from the sow and further reared. This rearing period will take another 30 to 40 days. At the end, they will be ready for sale, fattening or rearing as replacement breeders. Their weights by then will be 15-20 kgs.
• Growing and Finishing of Fatteners

  After rearing, the pigs are now ready for fattening. The time needed to reach market weight is variable and depends on the quality of the pig and feeds, market demands and some other factors. Usually, growing and finishing take 3-5 months.
• Rearing of Replacement Stock


  Some farmers rear their own replacement breeders from piglets they have produced on their own far. Replacement breeders are reared to an age of about 8 months. Then they can be served and added to the breeding herd. This rearing period takes 5-6 months depending on the breed.
• Summary of Production Cycle/Period

  • Dry Period: 3-7 days
  • Pregnancy Period: 114 days
  • Lactation Period: 28-42 days
  • Rearing period of weaners: 30-50 days
  • Growing and finishing of fatteners: 90-150 days
  • Rearing period of replacement stocks: 150-180 days
• Farrowing interval

  From one farrowing to the next, a sow needs 145-163 days.
• The performance of a pig is influenced by its environment and its genetic potential. On the average, 70% of the performance of the animal can be attributed to the environment—nutrition and feeding, housing, health, etc. and the 30% of its genetic potential.
• There is no best breed of pig. Each breed has its own good and bad characteristics. A farmer can choose the proper breed to use depending on the type of production that he wants to attain and his view on what is an ideal pig.
• Characteristics used to differentiate pig breeds

  • Color
  • Color combinations
  • Size of ears
  • Position of ears
  • Length and shape of the snout
  • Body length
  • Weight at maturity
  • Backline
• Landrace


  • White-meat type, large hanging ears, small head, long and narrow neck and body, long deep side but low in the back, square-shaped ham, highly prolific, superior in feed efficiency and daily gain, lacks hardiness and has weak feet, pastern and legs
• Large White


  • White-meat type, medium erect ears, curved back and body inclining forward, slightly dished face, fast growing, good feed converter, highly prolific, excellent milkers with superior mothering ability, carcass suited for bacon production, can adapt well in confinement but not in rugged conditions
• Hampshire


  • Black-meat type with white belted body, smaller in size with strong, short legs and erect ears, prolific, shows good mothering ability, acceptable average daily gain, high lean meat percentage but lacks body thickness, adapted to rugged conditions
• Berkshire


  • Black dual purpose type with six white points, wide, dish-shaped face, short snout and medium size erect ears, medium size with long body inclined forward, excellent carcass quality but not highly prolific, poor in feed efficiency and average weight gain
• Duroc


  • Meat type, red (gold to yellow) with small, forward 2/3 erect and 1/3 hanging ears, good body constitution, strong legs, good mothering ability, fast grower, good milker and prolific, adapts well to rugged conditions
• Pietrain


  • Very meaty type with spotted black and white color, well-shaped hams, loin and shoulders, erect ears, high lean meat percentage but poor body constitution, not good feed efficiency, slow grower, highly susceptible to stress, only worthwhile in crosses but not as purebreeds
• Common uses of pig breeds

  • Landrace and Large White as sow line
  • Duroc, Pietrain and Large White as boar line
  • Landrace and Large White (F1) and Duroc for fattener production
• There is no best breed of pig. Each breed has its own positive and negative traits. The weakness of a breed may become the strong point of the other and vice-versa.
• Heritability of economically important traits in swine

  • Litter size at birth: 15% (low)
  • Post-weaning rate of growth: 29% (medium)
  • Feed efficiency: 30% (medium)
  • Litter size at weaning: 12% (low)
  • Litter weight at weaning: 12% (low)
  • Length of body: 59% (high)
  • Length of legs: 65% (high)
  • Number of vertebrae: 15% (low)
  • Number of nipples: 40% (high)
  • Carcass length: 58% (high)
  • Loin eye areas: 48% (high)
  • Ham weight (% in carcass weight): 58% (high)
  • Shoulder weight (% in carcass weight): 47% (high)
  • Fat cuts (% in carcass weight): 63% (high)
  • Lean cut (% in carcass weight): 31% (high)
• Breeding systems


  • Inbreeding
  • Outbreeding (Purebreeding, Crossbreeding, Upgrading)
• Inbreeding


  Breeding of closely-related animals to purify the blood line. Can decrease vigor and production performance due to bringing together recessive genes with undesirable effects. However, if strict selection is practiced, it may be useful for eliminating defects and bringing out desired characters in a pure form.
• Types of inbreeding


  • Closebreeding (mating of closely related individuals)
  • Linebreeding (mating of less closely related individuals)
• Effects of inbreeding


  • Reduction in the strength and vigor of offspring
  • Decrease in the number of pigs born and weaned
  • Decrease in the weight of piglets at birth and weaning
  • Sterility and abortions
  • Retardation of physiologic maturity
  • Occurrence of abnormalities (hernia, cryptorchidism)
• Outbreeding - Purebreeding


  Mating of animals of the same breed to maintain the production supply of the breed and avoid the effects of inbreeding
• Outbreeding - Crossbreeding


  Breeding of two animals from different breeds to combine desirable traits and obtain hybrid vigor (superiority of crossbreds over parental breeds)
• Types of crossbreeding


  • Two-way cross
  • Three-way cross
  • Four-way cross
• Outbreeding - Upgrading


  A system of breeding where a purebred sire of superior quality is mated with grade females to gradually improve the quality of the herd
• Crossbred animals


  • Grow faster than the purebreed parents
• Crossbreeding


  Beneficial, produces good stock but is expensive
• Advantages of crossbreeding


  • Increased vigor and growth rate of litters
  • Larger litters
  • Increased production efficiency to about 5% to 10%
  • Increased disease resistance
• Types of crossbreeding


  • Two-way cross-mating with 2 different breeds
  • Three-way cross-mating with 3 different breeds
  • Four-way cross-mating with 4 different breeds
• Upgrading


  A system of breeding wherein an inferior breed is improvised by continued crossing, commonly used among native breeds
• Upgrading procedure


  1. Selected female pigs are bred to purebred boards of any preferred breed

  2. The female progenies are bred to boars of the same breed

  3. This procedure is repeated until the resulting offsprings approach the characteristics of the purebred
• Judging of pigs is a way to recognize and evaluate economic features which can be seen on the external parts of the pig</b>
• Standards used in judging pigs

  • Meat quality
  • Color
  • Strong legs
  • Length of body
• Double selection


  Selecting animals at 2-3 months and again when the selected 2-3 month weaners reach 6 months old
• Requirements of a good parent stock

  • Good production of the sow (>18 piglets weaned per year, >6 litters)
  • Long life
  • Good ADG of the offspring (>650 grams)
  • Good FCR of the offspring (<3.0)
  • Good carcass quality of the offspring