GB/T 44964-2024Technical specification for performance testing of egg-type chicken (English PDF)

1 Scope

This document specifies the basic conditions, the test items and the numbers to be tested for the performance testing of egg-type chickens, and describes the test methods and the verification method.

This document applies to the performance testing of breeder egg-type chickens and of commercial egg-type chickens.

3 Terms and definitions

The terms and definitions given in NY/T 823 and the following apply to this document.

3.1 egg-type chicken: chickens kept for the production of eggs for food, and their parent stock. Note: this includes bred varieties, the successive generations of a cross, and local breeds.

4 Basic conditions

4.1 Test farm. 4.1.1 Hygiene. 4.1.1.1 The quality of environmental hygiene shall comply with NY/T 388. 4.1.1.2 The treatment of sewage and waste shall comply with HJ/T 81.

4.1.2 Test house. 4.1.2.1 It shall be a closed poultry house. 4.1.2.2 It shall be fitted with control systems for temperature, humidity, ventilation and lighting; intelligent control of the house environment is preferred. 4.1.2.3 It shall have cages and equipment suitable for the performance testing of egg-type chickens.

4.1.3 The layout and the facilities of the hatchery shall meet the requirements of GB/T 40454.

4.2 Laboratory. The environmental conditions shall comply with GB/T 27404, and the instruments and equipment shall be able to meet the requirements of egg quality determination.

4.3 Personnel. Personnel shall have received professional training, shall have the corresponding skills and shall be able to undertake the testing work.

4.4 Samples. 4.4.1 The samples shall come from a flock that is managed to standard and is in good health, and the basic information shall be available, such as the place of production, the breed category, the age of the breeder flock in weeks and the immunization status. 4.4.2 The collection and the management of the hatching eggs shall meet the requirements of GB/T 40454, and the time from laying to setting should not exceed 7 d.

5 Test items

5.1 Breeder egg-type chickens. 5.1.1 Body type and appearance. 5.1.1.1 This shall include the colour of the down, the beak, the shank and the skin of the day-old chick, and the feathering rate type. 5.1.1.2 This shall include the body type of the adult bird and the characteristics of the plumage, the comb, the beak, the shank and the skin.

5.1.2 Body weight. Birth weight, body weight at 6 weeks of age, at 18 weeks of age, at the onset of lay, at 43 weeks of age and at 72 weeks of age shall be measured.

5.1.3 Body measurements at 43 weeks of age. Body slanting length, keel length, shank length and shank circumference shall be measured.

5.1.4 Laying performance. Age at the onset of lay, eggs per hen housed, eggs per hen-day, qualified hatching eggs per hen housed and qualified hatching eggs per hen-day shall be measured.

5.1.5 Quality of hatching eggs at 43 weeks of age. Egg weight, shell colour, egg shape index, shell thickness, shell strength and Haugh unit shall be measured.

5.1.6 Hatching performance of the hatching eggs at 43 weeks of age. Fertility, hatchability of fertile eggs, hatchability of set eggs and rate of healthy chicks shall be measured.

5.1.7 Viability. The survival rate during the brooding and rearing period and the survival rate during the laying period shall be measured.

5.1.8 Feed consumption. The feed consumed during the brooding and rearing period and the feed consumed during the laying period shall be measured.

5.2 Commercial egg-type chickens. 5.2.1 Body type and appearance, as for the breeder birds, covering the day-old chick and the adult bird. 5.2.2 Body weight: birth weight and body weight at 6 weeks, 18 weeks, the onset of lay, 43 weeks and 72 weeks of age. 5.2.3 Body measurements at 43 weeks of age: body slanting length, keel length, shank length and shank circumference. 5.2.4 Laying performance: age at the onset of lay, eggs per hen housed and eggs per hen-day. 5.2.5 Egg weight: egg weight at the onset of lay, at 43 weeks of age and at 72 weeks of age.

5.2.6 Egg quality at 43 weeks of age. Egg weight, shell colour, egg shape index, shell thickness, shell strength, Haugh unit, yolk ratio, yolk colour and the rate of blood and meat spots shall be measured.

5.2.7 Viability. The survival rate during the brooding and rearing period and the survival rate during the laying period shall be measured. 5.2.8 Feed consumption. The feed consumed during the brooding and rearing period and during the laying period shall be measured. 5.2.9 Feed conversion. The feed-to-egg ratio and the feed consumed per egg shall be measured.

6 Number of birds tested

6.1 Size of the flock tested for breeder egg-type chickens. The minimum size of the flock used for the performance testing of breeder egg-type chickens shall comply with Table 1. Table 1 gives, for hatching eggs set, chicks housed and laying hens housed, the minimum numbers required both for a breed or line, separately for males and females, and for the parent generation of a cross, separately for the sire line and the dam line. A note to the table requires the number of replicate groups of chicks housed and of laying hens housed to be not fewer than three.

6.2 Size of the flock tested for commercial egg-type chickens. The minimum size of the flock shall comply with Table 2, which requires 1 200 hatching eggs set, 360 chicks housed and 300 laying hens housed, again with not fewer than three replicate groups.

6.3 Sampling numbers for the test items. The minimum sampling numbers for body type and appearance, body measurements, body weight and egg quality shall comply with Table 3, and the numbers for the other test items shall comply with Table 1 and Table 2. Table 3 requires 100 males and 100 females for body type and appearance, 30 males and 30 females for body weight, 15 males and 15 females for body measurements, and 30 eggs for egg quality.

7 Test methods

7.1.1 Body type and appearance. By visual inspection. Day-old chicks should be examined within 24 h of hatching and adult birds at 43 weeks of age, males and females being described separately.

7.1.2.1 Birth weight. Within 24 h after hatching, chicks are weighed individually, in grams (g); the calculated result is rounded in accordance with GB/T 8170 and reported to one decimal place.

7.1.2.2 Body weight at 6 weeks, 18 weeks, the onset of lay, 43 weeks and 72 weeks of age. At each of those ages the birds are weighed individually on an empty stomach, in grams (g), and the result is reported as a whole number, the rounding rule being that of 7.1.2.1.

7.1.3.1 Body slanting length. Measured along the body surface with a tape from the front upper joint of the clavicle to the ischial tuberosity on the same side, in centimetres (cm), to one decimal place.

7.1.3.2 Keel length. Measured along the body surface with a tape from the front end of the keel to the end of the keel, in centimetres (cm), to one decimal place.

7.1.3.3 Shank length. The straight-line distance from the upper joint of the metatarsus of the bird to the point between the third and fourth toes, measured with a vernier caliper, in centimetres (cm), to one decimal place.

7.1.3.4 Shank circumference. The circumference at the middle of the shank of the bird, measured with a tape, in centimetres (cm), to one decimal place.

7.1.4.1 Age at the onset of lay. Counted as the age in days (d) at which the daily laying rate of the flock first reaches 50 % or more.

7.1.4.2 Eggs per hen housed. The average number of eggs laid per hen housed during the statistical period, calculated by Formula (1) and reported to one decimal place. In the formula, HHE is the number of eggs per hen housed, in eggs per bird; Ai is the number of eggs laid on day i, in eggs; d is the number of days in the statistical period, in days (d); n is the number of hens housed, in birds.

7.1.4.3 Eggs per hen-day. The average number of eggs laid by the hens actually kept during the statistical period, calculated by Formula (2) and Formula (3) and reported to one decimal place. In the formulae, HDE is the number of eggs per hen-day, in eggs per bird; Ai is the number of eggs laid on day i, in eggs; Bi is the number of hens kept on day i, in birds; d is the number of days in the statistical period, in days (d); and the remaining symbol is the average daily number of hens kept during the statistical period, in birds.

7.1.4.4 Qualified hatching eggs per hen housed. The average number of qualified hatching eggs laid per breeder hen housed during the statistical period, calculated by Formula (4) and reported to one decimal place. In the formula, HHSE is the number of qualified hatching eggs per hen housed, in eggs per bird; Ci is the number of qualified eggs laid on day i, in eggs; d is the number of days in the statistical period, in days (d); n is the number of hens housed, in birds. Note: qualified hatching eggs are the eggs that remain after misshapen eggs (too long or too round), over-large and over-small eggs, glassy-shelled eggs, soft-shelled eggs, sandy-shelled eggs, cracked eggs and other eggs that cannot be set have been discarded.

7.1.4.5 Qualified hatching eggs per hen-day. The average number of qualified hatching eggs laid by the breeder hens actually kept during the statistical period, calculated by Formula (5) and reported to one decimal place. In the formula, HDSE is the number of qualified hatching eggs per hen-day, in eggs per bird; Ci is the number of qualified eggs laid on day i, in eggs; d is the number of days in the statistical period, in days (d); and the remaining symbol is the average daily number of birds kept during the statistical period, in birds.

7.1.5.1 Egg weight. Hatching eggs are taken at the end of the 43rd week and weighed one by one, and the mean is calculated, in grams (g), to one decimal place.

7.1.5.2 Shell colour. The shell colour is judged by eye and expressed as white, light brown (pink), brown or green; alternatively the data are measured directly with shell colour measuring equipment.

7.1.5.3 Egg shape index. The long axis and the short axis are measured with egg shape index measuring equipment and the result is read directly; alternatively the long axis and the short axis of the egg are measured with a vernier caliper and the result is calculated by Formula (6) and reported to two decimal places. In the formula, ESI is the egg shape index; l1 is the length of the long axis of the egg, in millimetres (mm); l2 is the length of the short axis of the egg, in millimetres (mm).

7.1.5.4 Shell thickness. The egg is broken open and the contents removed; the inner face of the shell is rinsed with clean water and blotted dry with filter paper; the shell membrane is removed; and the thickness at the blunt end, at the middle and at the sharp end is measured separately with shell thickness measuring equipment and averaged, in millimetres (mm), to two decimal places.

7.1.5.5 Shell strength. The egg is placed upright with the blunt end upwards and measured with shell strength testing equipment, in kilograms per square centimetre; the result is reported to three decimal places.

7.1.5.6 Haugh unit. Eggs laid within the previous 24 h should be collected and weighed, then broken onto a flat plate; the height of the thick albumen is measured with albumen height measuring equipment at the midpoint between the edge of the yolk and the edge of the thick albumen, avoiding the chalazae, at three points forming an equilateral triangle, and the mean is taken. The Haugh unit is calculated by Formula (7) and reported to one decimal place; alternatively the data are measured directly with Haugh unit measuring equipment. In the formula, HU is the value of the Haugh unit; H is the height of the thick albumen, in millimetres (mm); W is the egg weight, in grams (g).

7.1.6.1 Fertility of hatching eggs. The eggs are candled 5 d to 7 d after being set and the number of fertile eggs is counted; the result is calculated by Formula (8) and reported to one decimal place. In the formula, F is the fertility of the hatching eggs, in percent; e1 is the number of fertile eggs, in eggs; e2 is the number of eggs set, in eggs. Note: eggs showing a blood ring or a blood line are counted as fertile eggs; eggs with broken yolks are not included in the count.

7.1.6.2 Hatchability of fertile eggs. Hatching eggs are collected and incubated until the chicks hatch, and the number of chicks hatched is counted; the result is calculated by Formula (9) and reported to one decimal place. In the formula, HF is the hatchability of fertile eggs, in percent; e1 is the number of fertile eggs, in eggs; n1 is the number of chicks hatched, in birds.

7.1.6.3 Hatchability of set eggs. Hatching eggs are collected and incubated until the chicks hatch, and the number of chicks hatched is counted; the result is calculated by Formula (10) and reported to one decimal place. In the formula, HS is the hatchability of set eggs, in percent; e2 is the number of eggs set, in eggs; n1 is the number of chicks hatched, in birds.

7.1.6.4 Rate of healthy chicks. Hatching eggs are collected and incubated until the chicks hatch, and the number of chicks hatched and the number of healthy chicks are counted; the result is calculated by Formula (11) and reported to one decimal place. In the formula, HCP is the rate of healthy chicks, in percent; n1 is the number of chicks hatched, in birds; n2 is the number of healthy chicks, in birds. Note: a healthy chick is one that hatches on time, has normal down, a well healed navel and a lively appearance, and is free from deformity.

7.1.7.1 Survival rate during the brooding and rearing period. The number of birds alive at the end of the statistical period is counted and the result is calculated by Formula (12) and reported to one decimal place. In the formula, LG is the survival rate for the statistical period, in percent; n3 is the number of birds alive at the end of the statistical period, in birds; n4 is the number of birds at the beginning of the statistical period, in birds. Note: the brooding and rearing period runs from 0 weeks of age to the end of 18 weeks of age; the laying period runs from the beginning of 19 weeks of age to the end of the statistical period, the statistical period being set according to the requirements of the breed.

7.1.7.2 Survival rate during the laying period. Determined in accordance with 7.1.7.1.

7.1.8.1 Feed consumed during the brooding and rearing period. The average mass of feed consumed per bird during the statistical period, calculated by Formula (13) and reported to one decimal place. In the formula, FCB is the value of the average feed consumption per bird, in kilograms (kg); Di is the value of the feed intake on day i, in kilograms (kg); d is the number of days in the statistical period, in days (d); and the remaining symbol is the average daily number of birds kept during the statistical period, in birds. Note: the brooding and rearing period runs from 0 weeks of age to the end of 18 weeks of age; the laying period runs from the beginning of 19 weeks of age to the end of the statistical period, the statistical period being set according to the requirements of the breed.

7.1.8.2 Feed consumed during the laying period. The text of the standard reads that the survival rate during the laying period is determined in accordance with 7.1.8.1.

7.2.1 Body type and appearance of commercial birds. Determined in accordance with 7.1.1, only the hens being described. 7.2.2 Body weight is determined in accordance with 7.1.2. 7.2.3 Body measurements at 43 weeks of age are determined in accordance with 7.1.3. 7.2.4 Laying performance: the age at the onset of lay is determined in accordance with 7.1.4.1, the eggs per hen housed in accordance with 7.1.4.2 and the eggs per hen-day in accordance with 7.1.4.3.

7.2.5 Egg weight. The eggs are weighed at the age at the onset of lay, at 43 weeks of age and at 72 weeks of age, in grams (g), to one decimal place, the rounding rule being that of 7.1.2.1.

7.2.6 Egg quality at 43 weeks of age. Egg weight is determined in accordance with 7.1.5.1, shell colour in accordance with 7.1.5.2, egg shape index in accordance with 7.1.5.3, shell thickness in accordance with 7.1.5.4, shell strength in accordance with 7.1.5.5 and the Haugh unit in accordance with 7.1.5.6.

7.2.6.1 Yolk ratio. The egg is weighed, the albumen and the yolk are separated and the yolk is weighed, in grams (g); the result is calculated by Formula (14) and reported to one decimal place. In the formula, YP is the yolk ratio, in percent; W13 is the yolk weight, in grams (g); W14 is the egg weight, in grams (g).

7.2.6.2 Yolk colour. The yolks are graded by comparison against the 15 yolk colour grades of the yolk colour fan, the number in each grade is counted and the mean is calculated; alternatively the yolk colour grade of each egg is measured with egg quality measuring equipment, the number in each grade is counted and the mean is calculated.

7.2.6.3 Rate of blood and meat spots. The eggs tested are examined by candling under strong light or by breaking them open, and the number of eggs containing blood spots and meat spots is counted; the result is calculated by Formula (15) and reported to one decimal place. In the formula, EBM is the rate of blood and meat spots, in percent; e1 is the number of eggs with blood spots and meat spots, in eggs; e2 is the total number of eggs tested, in eggs.

7.2.7 Viability. The survival rate during the brooding and rearing period and the survival rate during the laying period are determined in accordance with 7.1.7.1. 7.2.8 Feed consumption. The feed consumed during the brooding and rearing period and during the laying period is determined in accordance with 7.1.8.1.

7.2.9.1 Feed-to-egg ratio. The mass of feed actually consumed to produce one unit of mass of eggs, calculated by Formula (16) and reported to two decimal places. In the formula, FCR is the feed-to-egg ratio, expressed as X to 1; Ei is the feed intake on day i, in kilograms (kg), to three decimal places; Ci is the mass of the eggs laid on day i, in kilograms (kg), to three decimal places; d is the number of days in the statistical period, in days (d). Note: for the feed-to-egg ratio of the laying period the statistical period runs from the beginning of 19 weeks of age to the end of the statistical period; for the whole-life feed-to-egg ratio it runs from hatching to the end of the statistical period.

7.2.9.2 Feed consumed per egg. The mass of feed actually consumed to produce one egg, calculated by Formula (17) and reported as a whole number. In the formula, FEC is the feed consumed per egg, in grams (g); Ei is the feed intake on day i, in grams (g); Ci is the number of eggs laid on day i, in eggs; d is the number of days in the statistical period, in days (d). Note: for the feed consumed per egg in the laying period the statistical period runs from the beginning of 19 weeks of age to the end of the statistical period; for the whole-life figure it runs from hatching to the end of the statistical period.

8 Verification method

During the testing process, records shall be kept in a standard and detailed way in accordance with the requirements of the relevant forms: the record of body type and appearance, the record of body weight, the record of body measurements, the record of laying performance, the record of hatching egg quality, the record of the hatching performance of the hatching eggs, the record of viability and the record of feed consumption and feed conversion. The relevant record forms are given in Annex A.

All records shall be properly kept, and the period for which they are archived shall be not less than 6 years.