Methods to delay the start of egg-laying in laying hens

Abstract

To provide a method that allows for delaying the start of egg-laying in laying hens and achieving good egg-laying results after the delay. [Solution] A method for delaying the start of egg-laying in laying hens, comprising maintaining the weight of adult hens after 120 days of age at 120% or less of the standard weight of the adult hens at 120 days of age for a predetermined period, and adjusting the lighting time and illuminance.

Description

Technical Field

[0001] The present invention relates to a method for delaying the onset of egg laying in laying hens and a method for raising laying hens.

Background Art

[0002] Normally, laying hens are raised with the period from hatching to about 120 days of age when they reach sexual maturity as the rearing period, and then moved to a laying hen house. The feed is switched from rearing feed to laying hen feed with high nutritional components, and the lighting time is gradually increased to promote egg laying, thereby starting egg laying. Egg laying can be observed from about 130 days of age, and the egg laying rate reaches 90% from 165 to 175 days of age. Thereafter, egg laying with an egg laying rate of 90% or more continues until about 400 days of age.

[0003] However, there may be cases where there is no laying hen house for introducing laying hens due to the occurrence of notifiable infectious diseases such as avian influenza or natural disasters such as earthquakes and floods.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] When it is impossible to move to a laying hen house, it is required to delay the onset of egg laying for a predetermined period. Conventionally, it has been proposed to regulate (improve or decrease) the egg laying performance of chickens by regulating the blood melatonin concentration during the rearing period, the egg laying start period or the egg laying period using melatonin (Patent Document 1), but it does not regulate the egg laying start period. Therefore, an object of the present invention is to provide a method capable of delaying the onset of egg laying in laying hens and obtaining good egg laying performance after the delay.

Means for Solving the Problems

[0006] The inventors of this invention have conducted extensive research to solve the above problems and have found that by maintaining the weight of adult chickens below a certain level for a predetermined period and by adjusting the lighting time and intensity, it is possible to suppress the start of egg-laying even as the chickens get older, and that good egg-laying results can be obtained even if egg-laying is started after a delay. As a result, the inventors have completed the present invention.

[0007] In other words, the present invention solves the above problem by delaying the start of egg-laying in laying hens, which includes maintaining the weight of adult hens after 120 days of age at a weight within 120% of the standard weight of the adult hens at 120 days of age for a predetermined period, and adjusting the lighting time and illuminance. Furthermore, the present invention solves the above problems by a method for raising laying hens, which includes maintaining the weight of adult hens after 120 days of age at a weight within 120% of the standard weight of the adult hens at 120 days of age for a predetermined period, adjusting the lighting time and illuminance, gradually increasing the lighting time after the predetermined period, and / or feeding adult hens feed containing 4.0 to 4.5% by mass of calcium. [Effects of the Invention]

[0008] According to the method of the present invention, the start of egg-laying by laying hens can be delayed for a predetermined delay period, and good egg-laying results can be obtained even when egg-laying is started after the delay. [Modes for carrying out the invention]

[0009] The present invention provides a method for delaying the start of egg-laying in laying hens, which includes maintaining the weight of adult hens after 120 days of age at a weight within 120% of the standard weight of the adult hens at 120 days of age for a predetermined period, and adjusting the lighting time and illuminance. Furthermore, the method for raising laying hens of the present invention includes maintaining the weight of adult hens after 120 days of age at a weight within 120% of the standard weight of the adult hens at 120 days of age for a predetermined period, adjusting the lighting time and illuminance, gradually increasing the lighting time after the predetermined period, and / or feeding adult hens feed containing 4.0 to 4.5% by mass of calcium. In this specification, laying hens are chickens raised in chicken coops for egg production. Examples of chicken breeds include Julia Light (white), Julia (white), Boris Brown (red), and DeKalb White (white). Chicken coops are not particularly limited and include open-type coops, semi-windowless coops, and windowless coops, but the present invention is suitable for laying hens raised in windowless coops because the lighting can be controlled.

[0010] In this specification, the start of egg-laying in laying hens means that egg-laying is observed when the egg-laying rate is 1% or higher. Laying hens usually reach sexual maturity and become egg-laying adults around 120 days of age, and egg-laying is observed from around 130 days of age. However, in this invention, even after 120 days of age, by maintaining the weight of the adult hens at 120% or less of their standard weight at 120 days of age for a predetermined period, the egg-laying rate of the adult hens can be suppressed to less than 1%, preferably less than 0.5%, during that predetermined period.

[0011] In this specification, the standard weight at 120 days of age refers to the standard average weight of a chicken at 120 days of age. The standard weight at 120 days of age can be determined by referring to the standard weights listed in the manuals distributed by each breeding company. For example, the standard weight at 120 days of age for Julia Light (white) is 1215g, for Julia (white) it is 1230g, for Boris Brown (red) it is 1490g, and for DeKalb White (white) it is 1287g.

[0012] In this invention, the weight of adult chickens after 120 days of age is maintained at a weight within 120% of the standard weight of the adult chicken at 120 days of age, but preferably within 115% of the standard weight of the adult chicken at 120 days of age. The lower limit is not particularly limited, but from the viewpoint of maintaining physical strength in preparation for the start of egg-laying, it is preferably 108% or more of the standard weight of the adult chicken at 120 days of age, and more preferably 110% or more of the standard weight of the adult chicken at 120 days of age.

[0013] The period for maintaining the adult chicken's weight (delay period) is preferably at least 200 days old, and more preferably at least 230 days old, from the viewpoint of the need to delay the start of egg-laying. From the viewpoint of economic loss, the maximum delay period is preferably up to 350 days old, and more preferably up to 270 days old.

[0014] In this invention, it is preferable to feed adult chickens 120 days old or older with feed for large chicks during the delay period, from the viewpoint of delaying the start of egg-laying and suppressing weight gain. Feed for large chicks is typically given to growing chickens from about 70 to 120 days old, with a crude protein content of 13.0% to 16.0% by mass and a metabolizable energy content of about 2600 kcal / kg to 2900 kcal / kg. The feed ingredients (basic feed) used for adult chicks are not particularly limited and include, for example, grains such as corn, milo, wheat, barley, oats, rye, brown rice, buckwheat, millet, foxtail millet, and barnyard millet; bran products such as rice bran, corn bran, and corn germ; vegetable oils such as soybean meal, kinako (roasted soybean flour), flaxseed meal, palm kernel meal, sesame oil, sunflower oil, and rapeseed meal; animal feed ingredients such as fish meal, fish soluble, meat meal, meat and bone meal, blood meal, skim milk powder, casein, and dried whey; vegetable or animal fats such as soybean oil, peanut oil, coconut oil, palm oil, tallow, and lard; and inorganic salts, amino acids, minerals, and vitamins. The feed can be in the form of mash, pellets, crumble, flakes, etc.

[0015] From the viewpoint of delaying the start of egg-laying, it is preferable to feed the adult chicks such that the average daily feed amount during the delay period is preferably 38-50g / chick / day, more preferably 40-48g / chick / day. A possible method of feeding the adult chicks is to repeat a cycle of feeding 55-65g / chick / day for 7 consecutive days, followed by a 3-4 day fast.

[0016] During the delay period, it is preferable to reduce the lighting time compared to the growing period up to 120 days, or to keep it constant. The lighting time during the delay period is preferably less than 12 hours per day, more preferably 9 to 11 hours. The illuminance is preferably 3 to 5, more preferably 3 to 4 lux.

[0017] After a predetermined period, egg-laying begins due to weight gain. In this invention, by gradually increasing the lighting time after a predetermined period and / or by feeding adult chicken feed containing 4.0 to 4.5% by mass of calcium, good egg-laying results can be obtained even if egg-laying is started later.

[0018] It is preferable to gradually increase the lighting time after a predetermined period up to a maximum of 14 hours per day, as this stimulates spawning. Preferably, the lighting time is gradually increased from 9 hours at the end of the delay period to 14 hours. It is preferable to increase the lighting time to 14 hours over a short period of time. For example, extend it by 1 hour every 7 days. The illuminance is preferably 6 to 10 lux.

[0019] Adult chicken feed is for the egg-laying period and has a crude protein content of 14.0% to 19.0% by mass and a metabolizable energy content of approximately 2650 kcal / kg to 2900 kcal / kg. In this invention, the calcium content in the adult chicken feed given after a predetermined period is 4.0 to 4.5% by mass. By feeding adult chicken feed with a high calcium concentration after a predetermined period, the rise in egg production rate can be accelerated, egg weight can be increased, and a high egg production rate of 96% or more can be sustained. The calcium content in the adult chicken feed is preferably 4.15 to 4.45% by mass. Examples of calcium sources include carbonate, sulfuric acid, phosphoric acid, hydrogen phosphate, salts with citric acid and gluconic acid, oyster shells, seashells, and shell fossils. These can be used individually or in combination of two or more. The feed ingredients (basic feed) and feed form used for adult chicken feed are the same as those for adult chick feed described above. The feeding method is not particularly limited and can include continuous feeding or restricted feeding, but continuous feeding is preferred. It is preferable to feed the feed for adult chickens containing 4.0 to 4.5% by mass of calcium for at least 90 days from the start of egg laying during the period when the egg laying rate is 90% or more.

Example

[0020] Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto.

[0021] 1. Overview of the test Number of introduced chickens; 123,570 chickens in the control group and 123,565 chickens in the test group Chicken breed; Dekalb White

[0022] 1) Feed and feeding method Control group; Raised in a growing chicken house until 119 days old. During the growing period, feeding feed (crumbles), chick feed, medium chick feed, and large chick feed were used and fed. From 120 days old, they were moved to an adult chicken house and fed adult chicken feed daily. Test group; Raised in a growing chicken house based on the same feed and feeding method as the control group until 119 days old. After 120 days old, they were continuously raised in the growing chicken house. For the first 7 days, large chick feed was fed at 55 - 65 g / chicken / day daily, and then a cycle of fasting for 3 - 4 days was repeated. The average feed intake per day was adjusted to 40 - 48 g / chicken / day. At 270 days old, they were moved to an adult chicken house and fed adult chicken feed with a higher calcium content than the control group daily. Also, the previous feed was fed for a longer period of about 190 days.

[0023] Table 1 shows the nutrient component contents and feeding periods of the feed during the growing period, and Table 2 shows the nutrient component contents and feeding periods of the feed during the adult chicken period. The feeding system of the control group is the standard.

[0024]

Table 1

[0025]

Table 2

[0026] 2) Lighting time during the rearing and maturing stages The light sources used were incandescent bulbs and LEDs, with one bulb installed for every 200-250 chickens during both the rearing and maturing stages. 600 bulbs were installed per maturity chicken house, with two rearing houses equivalent to one maturity chicken house, and the rearing houses had 300 bulbs per house, half the number of bulbs in the maturity chicken houses. For both groups, the lighting time was 24 hours from birth to 3 days old, and then shortened as the cubs got older, with the shortest time being 9 hours. However, the test group also took more days to reach the 9-hour lighting period, and the duration of 9-hour lighting was 148 days, which was longer than the 13 days for the control group. After moving to the chicken coop, the control group took 54 days to reach 14 hours of lighting time, increasing it by 30 minutes every 4-7 days. The test group, on the other hand, increased the lighting time by 1 hour every 7 days, reaching 14 hours in a shorter period of 29 days.

[0027] The illumination level was kept high at 20 lux from hatching to 3 days old, and then decreased to 3-5 lux as the chicks got older, with the same treatment applied to both groups. After moving to the adult chicken house, the illumination level was increased to 6-10 lux and maintained at a constant level, with the same treatment applied to both groups. Table 3 shows the lighting times during the rearing and maturing stages of chickens.

[0028] [Table 3]

[0029] 2.Results 1) Per capita food intake and survival rate during the rearing period Table 4 shows the results of comparing the amount of food consumed per bird during the rearing period with the survival rate. The food intake was standard, and there was no difference in survival rates between the two groups.

[0030] [Table 4]

[0031] 2) Weight changes from birth to 270 days old Table 5 shows the results of comparing the weight changes from birth to 270 days of age. In the control group, weight increased, reaching a mature weight of 1700-1800g / bird at 220 days of age. In contrast, the test group weighed less than 1400g / bird. Since the standard weight of a DeKalb White at 120 days of age is 1287g, the weight of the test group from 120 days to 270 days of age was maintained within approximately 109% of the standard weight at 120 days of age.

[0032] [Table 5]

[0033] 3) Egg production performance of the control group for 200 days after moving to the adult chicken house, and for 200 days after reaching a 90% egg-laying rate. Table 6 shows the egg-laying performance of the control group for 200 days after moving to the adult chicken house, and for 200 days after reaching a 90% egg-laying rate. The control group began laying eggs at approximately 140 days of age, and the egg-laying rate reached 90% at 171 days of age. It took approximately 50 days after moving to the adult chicken house for the eggs to reach this stage. Furthermore, the individual egg weight reached 60g / egg at 250 days of age, approximately 130 days after moving to the adult chicken house. Subsequently, the survival rate remained high, and the egg-laying rate, egg weight, feed conversion ratio, and daily egg yield all showed good results.

[0034] [Table 6]

[0035] 4) Egg production performance for the test group for 200 days after moving to the adult chicken house, and for 200 days after reaching a 90% egg-laying rate. Table 7 shows the egg-laying performance of the test group for 200 days after moving to the adult chicken house, and for 200 days after reaching a 90% egg-laying rate. The test group began laying eggs at 272 days old, and reached a 90% egg-laying rate at 291 days old. It took approximately 20 days after moving to the adult chicken house, about 30 days earlier than the control group. Individual egg weight reached 60g / egg at 290 days old, about 10 days after moving to the adult chicken house, significantly earlier than the control group. As a result, the daily egg yield was superior to the control group during the egg-laying period. Similarly, the test group showed good results in terms of survival rate, egg-laying rate, egg weight, feed conversion ratio, and daily egg yield.

[0036] [Table 7]

[0037] 5) Spawning performance for 200 days after reaching a 90% spawning rate Table 8 shows the spawning performance for 200 days after reaching a 90% spawning rate. The number of days required to reach a 90% egg-laying rate from the start of egg-laying was 21 days shorter for the test group. In a comparison of egg-laying performance over 200 days after reaching a 90% egg-laying rate, the test group's feed consumption was 2.1g / bird / day higher than the control group, possibly due to their earlier increase in maturity weight. However, their egg-laying rate was 4.5% higher, their average egg weight was 6.6g / egg heavier, resulting in a higher daily egg yield of 9.0g / bird / day and a feed conversion ratio that was 0.25 better.

[0038] [Table 8]

Claims

1. A method for delaying the start of egg-laying in laying hens, comprising maintaining the weight of adult hens after 120 days of age at 120% or less of the standard weight of the adult hens at 120 days of age for a predetermined period, and adjusting the lighting time and illuminance.

2. A method for delaying the start of egg-laying in an egg-laying hen according to claim 1, wherein the hen maintains a weight of 108% or more but not exceeding 120% of the standard weight at 120 days of age.

3. A method for delaying the start of egg-laying in an egg-laying hen according to claim 1 or 2, wherein the period for maintaining body weight is at least 200 days of age.

4. A method for raising laying hens, comprising: maintaining the weight of adult hens after 120 days of age at a weight within 120% of the standard weight of the adult hens at 120 days of age for a predetermined period, adjusting the lighting time and intensity; gradually increasing the lighting time after the predetermined period; and / or feeding adult hens feed containing 4.0 to 4.5% by mass of calcium.

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