GB/T 22284-2025Large white breeding pig (English PDF)

1 Scope

This document specifies the place of origin and characteristics, the body type and appearance, the adult body weight and body measurements, the performance and the basic requirements for breeding use of Large White breeding pigs, and describes the measurement methods.

This document applies to the evaluation of Large White breeding pigs.

4 Place of origin and characteristics

The Large White pig, also known as the Large Yorkshire, originated in Yorkshire and the neighbouring areas of northern England. It is now widely distributed throughout the world and is characterised by high fertility, fast growth and strong adaptability.

5 Body type and appearance

The coat of the Large White pig is white all over, occasionally with a few dark spots. The body is rectangular and large in frame. The head is of medium size, with a straight or slightly dished face and erect ears. The back, loin and underline are level, the legs and feet are strong, the shoulders are wide, the back is broad and the hindquarters are full. Photographs of Large White breeding pigs are given in Annex A.

6 Adult body weight and body measurements

An adult boar of 23 to 25 months of age shall weigh not less than 277.0 kg, with a body length of not less than 157.0 cm, a height at the withers of not less than 90.0 cm and a chest girth of not less than 152.0 cm.

An adult sow in her third parity and two months in pig shall weigh not less than 215.0 kg, with a body length of not less than 145.0 cm, a height at the withers of not less than 77.0 cm and a chest girth of not less than 135.0 cm.

7 Performance

7.1 Reproductive performance. A boar shall be not less than 225 days old and weigh not less than 140.0 kg when first mated. A sow shall be 210 days to 250 days old and weigh not less than 130.0 kg when first mated. The total number of piglets born shall be not less than 10 for a gilt and not less than 11 for a sow that has farrowed before; individual birth weight shall be not less than 1.0 kg; and litter weight at 21 days shall be not less than 50.0 kg for a gilt and not less than 55.0 kg for a sow that has farrowed before.

7.2 Growth and development. The age at 100 kg live weight shall be not more than 174.0 days, with a live backfat thickness at 100 kg of not more than 15.0 mm, a loin eye area of not less than 32.00 square centimetres and a feed conversion ratio of not more than 2.70. The age at 120 kg live weight shall be not more than 194.0 days, with a live backfat thickness at 120 kg of not more than 17.0 mm and a loin eye area of not less than 35.00 square centimetres.

7.3 Carcass traits. At slaughter at 100 kg live weight, the dressing percentage shall be not less than 70.0 per cent, the carcass length not less than 93.0 cm, the average backfat thickness not more than 18.0 mm, the lean meat percentage of the carcass not less than 62.0 per cent, the loin eye area not less than 35.00 square centimetres and the ham and rump proportion not less than 32.0 per cent. At slaughter at 120 kg live weight, the dressing percentage shall be not less than 73.0 per cent, the carcass length not less than 96.0 cm, the average backfat thickness not more than 23.0 mm, the lean meat percentage of the carcass not less than 60.0 per cent, the loin eye area not less than 40.00 square centimetres and the ham and rump proportion not less than 30.0 per cent.

7.4 Meat quality. At slaughter between 100 kg and 120 kg live weight, the meat colour expressed as an L value shall be 37 to 52, the pH at 1 hour 5.9 to 6.5, the pH at 24 hours 5.6 to 6.0, the drip loss 1.5 per cent to 5.0 per cent, and the intramuscular fat content not less than 1.40 per cent.

8 Measurement methods

8.1 Adult body weight, body measurements and reproductive performance are measured in accordance with NY/T 820.

8.2 Growth and development performance is measured in accordance with NY/T 822.

8.3 Carcass traits are measured in accordance with NY/T 825.

8.4 Meat quality is measured in accordance with NY/T 821.

9 Basic requirements for breeding use

The basic requirements for breeding use are as follows: a) the body type and appearance conform to the characteristics of the breed, and the number of functional teats is not less than 14; b) there is no genetic defect or blemish, and the animal is in good health; c) the ear tag of the individual intended for breeding is legible, its origin is clear, and its pedigree records are accurate and complete; d) performance testing records for the individual or for both parents are available, with the main breeding performance indicators complete.