Body Weight Control of Broiler Breeders

 

Key Points of Whole Body Weight control of Broiler Breeders

In the breeding process of broiler breeders, in order to give full play to its excellent genetic potential and obtain the best economic benefits, it is necessary to provide a good house environment, with special attention to the whole-process weight control and uniformity management of breeders. Below, the author talks about some of his own views based on breeding experience for reference by peers.

 

1. Weight control during the brooding period (0-28 days old)

According to the physiological characteristics of chicks, do a good job in the control of the environmental conditions of the early chicken house and the management of the chicken flock to ensure that the bones, immune system, cardiovascular function, and feather growth are well developed in the early stage. Because one of the key factors in weight control is to give chicks a good start, especially the first 72 hours of a chicken's life is important, not only to determine the ability to resist disease attack, but this initial stage determines the development of the chicken skeleton. 

7-14 days of age should meet or exceed the weight standard. In the brooding period, high-energy (12.1 MJ/kg) and high-protein (19%-19.5%) full-price compound feed should be provided. 

The accumulated feed of hens should reach 850-900 grams per chicken at the end of 4 weeks, and the accumulated energy should be 10.5 MJ.

 

Matters needing attention

At any stage of early growth, if the body weight is not up to the standard or the appetite is lost, corresponding measures should be taken immediately. Taking measures as soon as possible can avoid the adverse consequences caused by poor uniformity and hindered development of important physiological organs in the later stage of brooding. 

The 4-week-old body weight of the hens is between 380-450 grams. If the body weight is too large at the end of the 4th week, the body shape of the adult chicken is too large, and higher feed amount and nutrition are required.

If the body weight is too small, the body shape of the adult chicken is too small, which affects the qualified rate of hatching eggs. 

The roosters should be fed ad libitum for the first 4 weeks, and the body weight should be monitored every day from the 4th week. Once it reaches 690 grams, it will be restricted immediately. It is not advisable to raise the frame by pulling, because the change of feed amount is too large and the stress on the rooster is too great, which directly leads to the rapid decline of the fertilization rate in the later stage of laying eggs. For hens, when the feeding time is less than 4 hours, switch to the 4/3 method.

 

2. Weight control during the breeding period (29-154 days old)

 

2.1 Early stage of breeding (29--70 days old)

This stage is the stage in which the growth rate of broiler breeders is relatively fast. It is best to use the method of restricting feeding intensity to control the rapid weight growth, so it is also called the stage of reducing maintenance needs. 

The average weekly feeding is 2--3 grams. This stage is only for the purpose of bone growth, maintenance needs, feather growth and weight gain. The feeding range is small to ensure an average weight gain of about 95 grams. 

If the uniformity of the flock is unsatisfactory at the end of the 4th week, the breeders should be raised in three pens according to their body weight, and different amounts of feed should be given to different pens. 

OBJECTIVE: To control the uniformity by staging, so as to achieve the same weight standard in 10-12 weeks. The feeding program can only be used as a reference when determining the feeding amount. 

The feeding amount should be calculated according to the difference between the actual body weight and the body weight standard, as well as the current feeding amount.

 

29-70 days of age is a critical period for the development of rooster muscles, tendons and ligaments. At this stage, the rooster's legs develop rapidly. Any deviation from the growth curve standard can have a negative impact on the rooster's survival rate and production performance after adulthood. At the age of 8 weeks, 85% of the skeleton development is basically completed, so this stage must reach or even exceed the early weight standard. Otherwise, the mature size of the rooster will be smaller than the optimal size.

 

2.2 Mid-term breeding (78-98 days old)

At this stage, chickens are very sensitive to changes in light time and intensity, and are prone to leg disease and coccidiosis, requiring complete shading and rearing, and timely correction of any accidental light leakage. 

The growth and development at this stage does not change significantly with the change of the feeding amount. The breeder should be grown according to the body weight standard to ensure that the weekly weight gain of the breeder meets the standard. Increase the amount of feed by 3-5 grams per week to ensure a weekly weight gain of 95 grams.

 

2.3 Late growth period (105-154 days old)

This stage is the energy reserve stage of broiler breeders, and the total body weight is increased by more than 1500 grams to meet the development of reproductive organs. 

At this stage, because the reproductive system is in a vigorous period, to prepare for light stimulation, the feeding range also needs to be increased, with an average of 6-8 grams per week. 

If the amount of feeding is too small, it will inhibit the development of the reproductive system and directly lead to hypoplasia of the ovaries and fallopian tubes. For roosters, it affects testicular development and ultimately sperm production in the later stages of laying eggs.

 

In order to ensure the weekly weight gain of breeders at this stage, it is recommended to increase the feed amount by 10%-15% from the age of 105 days. Regardless of the size of the body weight, the feed should be increased proportionally.

The increase in body weight of breeders stimulates physiological changes and reaches sexual maturity. 

The gradual increase in weight gain will ensure a smooth physiological transition to sexual maturity and full sexual maturity at around 210 days of age. 

Insufficient body weight gain and poor ovarian development can have the following effects: 

• delayed onset of lay 
• low egg weight in the early laying period
• increased proportion of defective and deformed eggs
• decreased fertilization rate
• increased brooding tendency
• poor uniformity

 

If the actual body weight at this stage exceeds the standard, resulting in poor sexual maturity and body weight uniformity, it will cause the ovaries and fallopian tubes to pack too much fat and affect the fertilization rate, premature birth, and the proportion of unqualified eggs will increase. The amount of feed and the fertilization rate decreased.

 

The breeding of roosters is equally important to the feeding of hens of the same breed, and the requirements for hens are basically applicable to roosters. 

If the 105-day-old is underweight or overweight, the weight standard should be re-established to ensure that the weekly weight gain of the flock before sexual maturity and the same increase in body weight as the standard curve.

 

2.4 Before and after the mixed group of male and female

Problems that are easy to occur before and after mixing: due to stress such as changing feeding equipment, mixing, adding light, etc., the rooster is prone to unsatisfactory weekly weight gain, which seriously affects the performance of the breeding rooster.

 Measures to be taken: Consciously add 3-5 grams of stress feed before and after mixing the group, take a random weight measurement at least twice a week, and closely monitor the weight change. Strengthen the management of rooster buckets to prevent male and female from stealing feed from each other. 

The mixing time is generally 21-23 weeks, and the mixing time is late, which can control the weight more effectively. 

After mixing the group, pay attention to observe the feeding behavior to ensure the correct and effective implementation of male and female feeding.

 

2.5 Control of feeding amount

During the brooding period, when formulating the weekly feed amount, the principle of forward-looking and backward-looking and step-by-step should be followed, and the comprehensive decision should be made according to the quality of the feed, the environmental conditions of the chicken house, and the increase in the weight of the chickens. 

In the early stage, the weekly increase in feed amount should be small, and in the later stage, with the rapid growth and development of the breeder, the feed amount will be gradually increased. 

Regularly measuring the body weight every week, and frequently touching and evaluating the chickens, can enable managers to adjust the feed amount in time, and have a more comprehensive grasp of the basic development status of the chicken flock. It is also the main basis for checking whether the feeding amount is accurate.

 

3. Weight control during the laying period (155-462 days old)

 

3.1 The expected production period is light stimulation to 5% egg production rate (155-182 days old)

This stage is the stage of rapid growth of sexual maturation and non-reproductive organs. The increase in light time is generally based on the growth and development of chickens at 22 weeks. 

The following factors need to be considered in the determination of the light program for the expected date of delivery: 

• whether the body weight at 22 weeks reaches the standard body weight, 
• whether the nutrient storage meets the standard, more than 80% of the chickens with a V-shaped chest muscle cross section
• the number of chickens with 1 to 2 main wing feathers remaining

 

After 23 weeks, do not add too hastily, but add a small amount and several times. Overfeeding at this stage will directly lead to abnormal uterine structure, excess body weight, poor egg quality, and low hatchability of breeding hens. Before the egg production rate reaches 5%, feed 2-3 times a week, no more than 3 grams each time. After the egg production rate reaches 5%, feed every day until the egg production peak is reached.

 

3.2 The early stage of egg laying is 5% egg laying - peak egg laying (183-210 days old)

This stage is the stage of rising egg production, and both body weight and egg weight are increasing. Therefore, chickens with 10% egg production rate should be regarded as 20%-25% chicken feeding, otherwise the hens use their own body fat reserves to supplement the feed. Insufficient nutrients, chickens show a slow rise in egg production.

 Breeders should gain continuous weight gain from the start of production to the peak of egg production, and maintain a certain weight gain (about 15-20 grams per week) throughout the egg-laying period after the peak of egg production. 

Feeding principle: hens need to increase feed first, that is, the increase in feed must precede the increase in egg production rate. 

The main reason for this need is that the egg production rate of many individual hens is higher than the average egg production rate of the flock.

 

The chickens in the rising stage of egg production should implement dynamic management, draw the egg weight curve according to the daily egg weight and add a trend line to understand the growth trend of egg weight and guide feeding.

 

3.3 Peak egg production period (211-280 days old)

This stage is the peak egg production period, and it is necessary to maintain the balance of physical energy and energy intake. 

To ensure that chickens can take in sufficient nutrients every day, high yields have a material basis. Factors that affect the maintenance of physical fitness include body weight, egg production, egg weight, and ambient temperature.

 

3.4 Late peak period (281-462 days old)

In order to maintain the persistence of high-yield breeding hens and maximize the yield of qualified eggs, it is necessary to reduce feed after the peak. 

If a breeder eats more than it needs, it can continue to gain weight through fat deposition. Fat deposition rate is a key factor affecting the decline of egg production rate and fertilization rate after the peak period. Therefore, the feeding amount should be adjusted according to changes in body weight and egg production rate to adjust the rate of fat deposition. 

The exact timing of breeder feed reduction should depend on the growth history of the flock and the condition of the flock. For flocks with high egg production rate, the first feed reduction should not be earlier than 34 weeks, and the feed reduction should be carried out gradually.

 

After the peak of egg production, the feeding amount is reduced in a planned way, so that the weekly weight gain of the flock is kept at 15-20 grams, which can maintain a good egg production rate, fertilization rate, hatching rate and egg weight. 

The amount of feed should be determined weekly on the basis of analyzing data such as body weight, egg weight, feed consumption time, number of eggs produced per day and the condition of the flock, and should be adjusted in time according to changes in the ambient temperature of the chicken house. 

The total amount of material reduction is about 8% - 12% of the peak material amount. The principle of material reduction: first fast and then slow, reduce the material by 0.5-1 grams per week.

 

4. Weight control of roosters during laying period

Breeding male breeding management and weight control should be adjusted according to the growth and development of male reproductive organs-testis, which can be divided into the following periods: 

• 0-12 weeks testis basically do not grow (initial phase)
• 12-27 weeks testis growth and rapid development period (growth period)
• 27-35 weeks testicular development peak maintenance period
• 35-50 weeks testicular atrophy, testicular atrophy period after 50 weeks

The good or bad management of the male rooster determines the rate of testicular atrophy.

 

The most critical factor in the laying period is to continue to control the body weight of the males to ensure that the males have good physiological conditions for mating. Feed the rooster while the hen is cutting. 

General principles of feeding

The feeding range is determined according to the actual weekly weight gain. After the peak, it is appropriate to control the weekly weight gain at 15-20 grams, control the number and weight of the males, maintain a high fertilization rate, and make the actual weight of the males consistent with the weight standard. 

Use well-maintained equipment to implement strict male and female feeding. Weigh males at least once a week for average male body weight and weekly gain. 

In addition, males should be culled based on male physical characteristics, feather condition, and male alertness and activity in order to maintain an optimal male-female ratio and prevent males from over-mating. After the peak, if the male and female feeding is well implemented, generally 1 gram of feed is added every 4 weeks.

 

Conclusion

In a word, in the whole production cycle of broiler breeders, as grass-roots managers, we should always evaluate and observe the behavior of chickens, analyze and summarize more, take corresponding measures in time for the abnormal situation of the chickens, and try our best to achieve the best quality of breeders. 

Optimum production performance is obtained when the actual body weight curve matches the standard curve.

See also:

Feed of Commercial Broiler Chicken

Economic Benefits of Chicken Farming