GB/T 2773-2025Ningxiang pig (English PDF)

1 Scope

This document specifies the origin and characteristics of the breed, the body type and appearance, the adult body weight and body measurements, the performance and the basic requirements for breeding use of the Ningxiang pig, and describes the measurement methods.

This document applies to the identification of the Ningxiang pig breed.

2 Normative references

NY/T 820 Technical specification for swine registration; NY/T 821 Technical regulations for the determination of pork quality; NY/T 822 Regulations for the testing of the performance of breeding pigs; NY/T 825 Technical specification for the determination of carcass traits in lean-type pigs.

4 Origin and characteristics of the breed

The Ningxiang pig originates in Ningxiang, Changsha, Hunan province; its central area of production is Ningxiang, and it is found mainly in Changsha, Zhuzhou, Xiangtan, Loudi and Shaoyang.

The breed adapts well, matures early and fattens readily, lays down fat strongly, tolerates coarse feed, and gives meat that is fine-grained, tender and juicy.

5 Body type and appearance

The coat of the Ningxiang pig is mainly black on the back and white on the belly; some individuals carry large black patches or small scattered flecks on the back, the neck and shoulder are white, and there is a black halo where black and white meet.

The body is of medium size, short, squat, round and barrel-shaped. Three head types are recognised, called the lion head, the fu character head and the capon head. Both ears hang down, the neck is thick and short and carries a dewlap. The back line is mostly hollow, the belly is large and hangs down but does not trail on the ground. The four legs are thick and short and the pasterns often sink. There are six to eight pairs of teats, evenly arranged. The rump slopes slightly and the tail is set low. Photographs of the breed are given in Annex A.

6 Adult body weight and body measurements

An adult boar of 23 to 25 months weighs 115.66 kg +/- 13.21 kg, with a body length of 133.5 cm +/- 10.7 cm, a height at the withers of 79.8 cm +/- 15.5 cm and a chest girth of 129.9 cm +/- 10.1 cm.

An adult sow in her third parity and two months in pig weighs 142.73 kg +/- 11.37 kg, with a body length of 137.6 cm +/- 7.5 cm, a height at the withers of 65.4 cm +/- 3.2 cm and a chest girth of 132.3 cm +/- 7.6 cm.

7.1 Reproductive performance

Boars reach sexual maturity at 90 d to 120 d, are suitable for service at 180 d to 240 d and at a body weight of 55 kg to 70 kg. Sows come into first oestrus at 90 d to 120 d, are suitable for service at 180 d to 240 d and at a body weight of 50 kg to 70 kg.

The litter and weaning traits of sows shall meet Table 1, in which the figures are means plus or minus the standard deviation and the weaning age is 35 d. In the first parity the total number born is 8.9 +/- 1.9, the number born alive 8.5 +/- 1.9, the birth weight of the litter 7.39 kg +/- 1.90 kg and the weaning weight of the litter 48.19 kg +/- 14.23 kg. In the second parity the figures are 10.2 +/- 1.6 born in total, 9.9 +/- 1.6 born alive, a birth litter weight of 8.97 kg +/- 1.69 kg and a weaning litter weight of 68.04 kg +/- 16.92 kg. In the third and later parities they are 10.7 +/- 1.7 born in total, 10.4 +/- 1.6 born alive, a birth litter weight of 10.48 kg +/- 2.73 kg and a weaning litter weight of 65.74 kg +/- 19.59 kg.

7.2 Growth and development

A boar weighs 0.94 kg +/- 0.16 kg at birth and 7.90 kg +/- 0.38 kg at weaning at 35 d; a gilt weighs 0.90 kg +/- 0.13 kg at birth and 8.12 kg +/- 1.33 kg at weaning at 35 d.

On a diet with a digestible energy of 12.6 MJ/kg to 13.3 MJ/kg and a crude protein content of 14.0 % to 15.3 %, boars and gilts weigh respectively 13.02 kg +/- 1.96 kg and 13.77 kg +/- 2.44 kg at 2 months and 35.21 kg +/- 6.42 kg and 35.61 kg +/- 6.88 kg at 4 months, and gilts weigh 63.36 kg +/- 8.66 kg at 6 months.

7.3 Fattening performance

Between 18 kg and 85 kg, on a diet with a digestible energy of 13.0 MJ/kg to 13.3 MJ/kg and a crude protein content of 13.5 % to 14.4 %, fattening pigs have a mean daily gain of 430.03 g +/- 52.36 g, a feed conversion ratio of 4.55 +/- 0.23 and a live backfat thickness of 35.4 mm +/- 4.7 mm.

7.4 Carcass traits

Slaughtered at a live weight of 87.00 kg +/- 6.60 kg, the pig gives a dressing percentage of 71.7 % +/- 1.7 %, a carcass weight of 62.43 kg +/- 4.98 kg, a carcass length of 83.7 cm +/- 3.9 cm, a lean meat percentage of 37.4 % +/- 2.2 %, a loin eye area of 19.54 square centimetres +/- 5.65 square centimetres and a mean backfat thickness of 42.9 mm +/- 5.8 mm.

7.5 Meat quality

Slaughtered at a live weight of 87.00 kg +/- 6.60 kg, the pig gives a meat colour value 1 of 40.1 +/- 3.2 and a meat colour value 2 of 42.3 +/- 3.7, a marbling score of 3.0 +/- 0.8, a pH at 1 h of 6.37 +/- 0.38 and a pH at 24 h of 6.17 +/- 0.34, a drip loss at 48 h of 2.76 % +/- 1.51 % and an intramuscular fat content of 3.72 % +/- 1.20 %.

8 Measurement methods

Adult body weight and body measurements, reproductive performance and growth and development traits are measured in accordance with NY/T 820. Fattening performance is measured in accordance with NY/T 822. Carcass traits are measured in accordance with NY/T 825. 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 growth and development are normal; b) there is no hereditary defect or blemish and the state of health is good; c) the identification of the animal is clear, its origin is known and its pedigree records are accurate and complete; d) the animal or both its parents have undergone performance testing and the records of the main economic traits are complete.