JPH0367553A - Breeding of chicken for laying white york egg - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for raising hens for producing white yolk eggs that yield white egg yolks with a Rocher color fan number of 1 or less.

[Conventional technology]

Generally, commercially available chicken eggs have yellow to orange yolks.

The degree of egg yolk color from yellow to orange is generally evaluated and ranked using the Roche Color Fan manufactured by Roche as a criterion value.

Roche Color Fans are divided into ranks from 1 to 15, and the lower the number, the lighter the egg color, and the higher the number, the darker the yellow to orange color. U-fan is often egg yellow and has a number of 9 to 11.

Furthermore, in recent years, chicken eggs with white yolks have been increasingly required for applications such as confectionery.

By the way, the yellow color of egg yolk is caused by the transfer of xanthophylls contained in feed into the egg yolk.
The yellow of commercially available chicken eggs has a Roche color fan number of 9 to 9.
11, xanthophylls are 10 to 30 ■/k
The animals were fed feed containing g.g.

Therefore, conventionally, in order to obtain chicken eggs with pale yellow and white yolk, the xanthophyll content must be 1 mg/kg in chickens during the laying period.
This was done by feeding the following feed for 3 to 4 weeks.

[Problem to be solved by the invention]

However, in the above method, the color of the egg yolk is only about 1 to 2 in terms of Roche color fan number, and it is difficult to obtain egg yolks with a Rocher color fan number of 1 or less. Further, there was a problem in that it took a long period of 3 to 4 weeks to obtain white yolk chicken eggs.

An object of the present invention is to solve the above-mentioned problems and provide a method for breeding hens for producing white yolk eggs, which can produce white egg yolks with a Roche color fan number of 1 or less in a short period of time.

[Means to solve the problem]

In order to achieve the above object, the present inventors have conducted intensive research on factors that affect the color of egg yolk. As a result, they found that not only the xanthophylls in the feed, but also the xanthophylls contained in the body fat of the chickens themselves, greatly influenced the color of egg yolks. Therefore, in the conventional method of feeding feed with xanthophylls of 1 mg/kg or less during the egg-laying season, the Roche color fan number is 1. .0
It turned out that it was not possible to obtain less than white egg yolk.

The present invention was made as a result of the above research, and aims to minimize the amount of xanthophyll accumulated at the beginning of spawning,
By feeding feed containing xanthophylls of 1 mg/kg or less, it is possible to obtain white egg yolks with a Roche color fan number of 1.0 or less.

That is, the method of raising hens for laying eggs with white yolks according to the present invention is characterized by feeding feed with a xanthophyll content of 1 mg/kg or less from the late stage of breeding, and continuing to feed the feed with this feed even after the start of egg laying. There is.

In addition, the other method of raising hens for producing white yolk eggs is as follows.
The method is characterized in that chickens in the laying period are starved to reduce their body weight by at least about 15%, and then fed again with feed having a xanthophyll content of 1 mg/kg or less.

The latter stage of growth generally corresponds to the period of 130 to 140 days of age, and during this period, the amount of body fat accumulated is low, and therefore the amount of xanthophyll accumulated in the body is also small, and the amount of xanthophyll does not increase thereafter, so the amount of accumulated xanthophyll is small. In this state, eggs enter the spawning period, and the conversion to white egg yolk occurs quickly.

The method of fasting chickens during the laying period to reduce their body weight by at least 15% and then refeeding them with feed is generally used for forced molting, and it It is used as a rejuvenation method.

In this method, when the body weight decreases by 15% or more due to fasting, the amount of xanthophylls becomes extremely small because most of the body fat decreases. Feathers are then shed by refeeding, and egg laying, which had stopped, begins as the weight regains weight.

Note that the body weight to be reduced is required to be 15% or more, but is preferably in the range of 20 to 25%.

Therefore, spawning begins with a small amount of accumulated xanthophyll.

The feed used for feeding laying hens in the present invention has a xanthophyll content of 1 mg/kg or less.

The feed ingredients may be any known feed for livestock, containing proteins, energy sources, calcium sources, phosphorus sources, vitamins, minerals, etc., and are formulated to satisfy NCR requirements.

Protein sources include fish meal, soybean meal, rapeseed meal, feather meal, and meat bone flour, and to compensate for amino acid imbalance, DL-methionine, L-)liptophan,
Amino acids such as L-lysine and L-threonine may also be added.

Energy sources include hydrocarbons such as corn, milo, and wheat flour, and fats such as feed oil, soybean oil, and powdered oil. In addition, it is necessary to contain phosphorus sources, vitamins, minerals, etc. in the same way as known feeds, and it goes without saying that the above feed ingredients must be blended so that the xanthophyll content is 1 mg/kg or less. The content of ingredients is crude protein! Approximately 12-25%, crude fat approximately 3-10%, calcium approximately 2.5-4.5%, M
E2,700 to 3,300 Kcal/kg may be sufficient. Examples are shown in Table 1.

The feed shown in Table 1 was fed at a concentration of 1 mg/kg or less, and this feed was continued to be fed even after the start of egg laying.

The egg yolk Roche color fan number associated with this feeding is shown below.

Days after the start of spawning 1 day 5 days 10 days 15 days 20 days [Example] Example 1 Table 1 Example 2 Xanthophyll content shown in
During the fasting period, the body weight was measured, and when the body weight decreased by about 15% of the weight before the start of the fasting, the xanthophyll content shown in Table 1 was determined to be 1 mg/day. kg of feed was re-fed. Salary amount is 1
Started with 20g per day and increased by 20g each day.

At this time, the egg-laying hens immediately stopped laying eggs after they started fasting, and when they were re-fed, they molted.

After refeeding, the animals started laying eggs when their body weights returned to about 90% of their pre-fasting weights.

The egg yolk Roche color fan number associated with this salary is shown below.

Age 1 day 5 days 10 days 15 days 20 days after the start of spawning The yolk of the eggs that started spawning becomes white from the beginning, and the degree of yolk is rapidly increasing.

Conventional Example 1 A 400-day-old egg-laying chicken was fed a feed having a xanthophyll content of 1 mg/kg or less shown in Table 1 above and allowed to freely consume it.

The egg yolk Roche color fan number associated with this salary is shown below.

The egg yolks of eggs laid on days 0, 5, 10, 15, and 20 after feeding gradually became closer to white, but even after 20 days after feeding, Roche still remained strong - fan number 1.
．． It was 5.

In the above examples and conventional examples, 30 chickens were used, and the egg yolk was measured on 10 eggs.

In addition, the white eggs obtained in Example 2 15 days after the start of spawning,
The results of measuring the cholesterol content of normal eggs obtained using a normal commercial feed (17HCP 17% ME 2850 kcal type, Itochu Feed Co., Ltd., nutritional ingredients are the same as white ready-to-use feed) are shown below.

〔Effect of the invention〕

Since the present invention is constructed as follows, it is possible to efficiently obtain chicken eggs with white yolks in a short period of time, and also to obtain egg yolks with lower Roche color fan numbers.

Claims (2)

[Claims] (1) From the late stage of growth, the xanthophyll content is 1 mg/kg.
A method for raising hens for producing white yolk eggs, which is characterized by feeding the following feed and continuing to feed this feed even after the start of egg laying: (2) Fasting chickens during the egg-laying period to reduce their weight to at least about 1.5 kg.
A method for raising hens for laying eggs with white yolks, characterized by refeeding feed with a xanthophyll content of 1 mg/kg or less after reducing the content by 1 mg/kg