1. Weight increase
In order to reach or exceed the standard of 100 ~ 150g at the age of 4 weeks, it is necessary to adjust the lighting time to make the feed completely ingested. At the age of 6 weeks, the body weight should reach more than1000g, or even1200g. You can carefully try to get your weight back to the standard at 7~ 15 weeks and make your weight grow steadily. It is possible to gradually bring the body weight back to the standard or 50 ~100g higher than the standard in 13~ 15 weeks. 16~26 weeks, no matter what the weight is at this time, the weekly weight gain must be kept up to standard, because the testicles begin to grow rapidly at this time.
2. Bone development and tibia length
Appropriate bone size and tibia length are very important for breeding cocks, and will also affect the physical condition of breeding cocks during laying period. About 85% bones develop in the first eight weeks, and 95% bones develop in the first twelve weeks. Don't miss the best stage of bone development in breeders, because the longer the tibia, the higher the fertilization rate.
3. Testicular development
The size and weight of cock testicles are directly related to the quantity and quality of sperm and semen. The development of cock testis is closely related to the weight gain and feeding management in the growing period. The size of cock testicles is related to functional maintenance, weight control and physical condition during laying period. The development of cock testis can be divided into the following stages:
① At the age of 2~ 15 weeks, the weight of testis increased little, but the number of spermatogonia increased rapidly. Spermatogonial cells not only provide nutrition for the future growth and development of sperm, but also have a great relationship with the ability of testis to produce sperm. 1 1~ 12 weeks later, the testis suddenly increased after development, and then stopped developing. During this period, we should try our best to avoid all kinds of stresses that hinder the growth and development of breeder cocks, otherwise it will affect the development of testicles.
② After15 weeks, the weight of testicles of breeder cocks began to increase rapidly, and the weight of testicles increased more obviously after 3 weeks of light stimulation, reaching 22 grams. During this period, the overweight breeding stock is underweight, reduced or brought back to the standard, which has a great influence on the development of testis.
③ At the age of 25 ~ 35 weeks, the testicular weight and semen volume are the highest. 35-week-old mature breeder, the testicles weigh about 45g, the vas deferens are well developed, the testicle blood vessels are well distributed and the color is healthy. It is easy to lose weight during this period, so we should pay attention to observing and touching chickens, keep proper weight gain and avoid various pressures.
④ After 35 weeks, the testis began to atrophy naturally, the distribution of blood vessels decreased obviously, the testis became pale, and the color and size of vas deferens became worse. The quantity and quality of semen also decreased gradually, and the fertilization rate also decreased gradually. Roosters can keep good weight, weight gain and physical condition, which can delay the decline of fertilization rate after the peak.
Second, the management measures
An increase in weight
Before entering the chicken, the male and female are raised separately, and the rooster stall is placed in front of the henhouse. If possible, it is best to keep cocks in 1 henhouse alone. Breeding chickens should be kept in small captivity, and the number of chickens in each circle should be less than 500. It is best to feed them accurately by hand. Use feeders with the same laying cycle, and the height of feeders should be appropriate. After 18 weeks, the material level of each breeder cock is 20 cm. Breeding chickens are best laid flat on the ground, but the density should not exceed 3.5 chickens /m2.
2. Early management
First of all, high-quality granular crushed materials should be selected, and the crude protein content should reach 21%; Secondly, the daily food restriction should start at the latest at the age of 15, so as to lengthen the bone growth time and make the tibia fully grow, especially when lying flat. If you don't feed them within the time limit, the breeder will not grow hair or bones, but only meat. In addition, it is necessary to control the weight to reach the standard or slightly exceed the standard, and ensure that the weekly weight gain at each stage reaches the standard and the growth curve is smooth.
3. Timely grouping
The uniformity of excellent breeding animals should be above 90%, and they should be sexually mature when grouped. Breeding animals with bad beaks, underweight, small and fat bones, blindness, toe problems and poor body shape should be eliminated. Generally, before the age of 22 days, the feeding intensity is not strong, and the uniformity of the flock is good. If there are no problems such as improper material level, uneven feeding and cross-feeding in the future, there is no need to group.
4. The broken beak should be neat
Generally, when the beak is broken, 1/3 of the upper beak is cut vertically, and the upper and lower beaks must be aligned, otherwise it will affect mating and waste feed. Skilled workers should be selected to operate the broken beak, and special personnel should be appointed to check the broken beak.
5. Appropriate density
Density and feeding area will directly affect the quality, uniformity and fertilization rate of roosters. Excessive density will lead to insufficient feeding area and low fertilization rate. The breeding density is generally 3~3.5 birds /m2, and the material levels are 5cm, 10cm, 1 1~ 15 weeks and 16~64 weeks respectively. The main reason for the poor development of breeder cocks is that the density is too high, resulting in wet padding, low uniformity and poor testicular development.
6. Mixed sex
① Selection of rooster before mating. If the weight is within the average weight range (150g), the oversized and oversized cocks will be eliminated; Chest muscles are plump, tibia length is up to standard, toes are straight, crown, face and flesh are red, back is straight, beak is neat, eyes are bright, etc. Don't mix immature cocks, because immature cocks are suppressed by precocious hens, which will cause lifelong stunting. You should choose one by one when you are in a mixed group.
② mixing time. One week after adding light, the hens are mixed and grouped, usually at the age of 23~24 weeks (mixed and grouped after the hens are sexually mature). If the uniformity is not good, it can be mixed in stages, 5% in 23 weeks, 2% in 24 weeks and the rest in 25 weeks.
(3) Weigh twice a week after mixing, and adjust the feed amount in time according to the weight (the range is 100 ~ 160g/ day). You should not only read the instructions, but also touch your chest muscles to determine the amount of materials. As soon as the chest muscles are soft, they need to be fed.
④ Proportion control between men and women. When you first mix, 8.5% breeders are enough, and bad cocks should be eliminated in time. Finally, 6.5% breeders are enough.
7. Laying period management
① The rooster feeding system should have the advantages of simplicity, accurate feeding quantity, uniform distribution, suitable height, no damage to cockscomb, and separate feeding of males and females.
(2) The height of the shelf plate should be appropriate. Scaffolding height more than 45 cm, after 45 weeks must have a ladder; If the height of scaffolding is more than 60 cm, it is necessary to always build a ladder, otherwise the breeder will not want to mate off the ground after going up, which will seriously affect the fertilization rate. On the other hand, the shelf board is too low, the height of the laying box is not enough, chickens are piled below, and the padding is easy to get moldy, which affects workers to take eggs.
③ Pay attention to the daily inspection of breeders.
One is to check whether male hens steal feed from each other.
A good feeding system is the key to prevent material theft. Check the anti-habitat fence frequently to prevent the male hens from stealing feed from each other. Check whether the cock's nose mark is normal every week, and make up the nose mark in time if it is not found.
The second is to check the plumpness of the breeder cock when weighing.
Plumpness score of breeder chickens: 15 cocks are selected every week and divided into 5 grades, 1 grade = too thin and too weak; Level 2 = thin but healthy work; Grade 3 = perfect, with part of keel exposed; Grade 4 = slightly overweight; Level 5 = full breasts. According to the plumpness of breeder cock, add and subtract materials in time.
The third is to avoid weightlessness of breeders.
The influence of weightlessness on breeder chickens: at the beginning of weightlessness, the quality and quantity of sperm are affected; When there is slight weightlessness, sperm quality decreases; If you lose more than100g within 5 weeks, the quality and quantity of sperm will decrease. If you lose more than 500 grams in 5 weeks, sperm production will stop, sometimes even irreversible. After 30 weeks, the most dangerous situation is that the cock loses weight. If the cock is found to lose weight, it can be fed 4 ~ 5g every day, and it can be reduced by 4 ~ 5g after being overweight. In general, the feed amount is 130 ~ 135g. If the hen steals cock feed, the feed amount can reach 160 g at most.
The fourth is to observe the cock's face.
Observe the change of cock's face every week after mixing. If it turns white, it proves that the nutrient intake is insufficient and the secretion of sex hormones begins to decline. At the same time, check the changes of chest muscles, such as muscle softening or emaciation, which proves that nutrition intake is insufficient. The fifth is to check the color of anus and blood spots on tibia. The cock with high fertilization rate has a wide, open and ruddy anus, and its tibia is covered with blood spots.
(4) eliminate the farmers in time. Breeding chickens with poor vitality, hiding under the feed line, poor chest muscle fullness, immature sexual development, overweight, pale color around anus, pale face, bad legs and toes, excessive mating and other bad cocks will be eliminated in time.
8. Rooster replacement
The advantages of breeding chicken replacement are: enhancing the mating vitality of new and old chickens, increasing sperm quality and improving fertilization rate. It is generally recommended to exchange cocks between henhouses. If 25%~30% breeder cocks are exchanged between henhouses, the fertilization rate can be increased by 4%~5% within 4~8 weeks. Changing breeders between chicken houses can also reduce the disease problems caused by the entry of foreign cocks. Before the fertilization rate decreased (40 weeks old), when the breeders were evenly distributed in the henhouse, the males and hens were evenly mixed, and the breeders were in good health, the effect of internal chicken exchange was better.