FIELD OF THE INVENTION

The present invention is in the general field of poultry farming. More particularly, the invention relates to a method of feeding female birds with a feed formulation which enhances egg mass.

Poultry diets of this invention are typically diets which include canthaxanthin in an amount such that the average egg mass is increased compared to animals treated without canthaxanthin.

This invention also relates to improved poultry farming. Thus, it relates to methods which provide improved egg production. These methods comprise obtaining an increase in yield of marketable eggs from laying hens. The increase is provided by feeding hens a diet of this invention.

BACKGROUND

The demand for poultry eggs, especially chicken eggs expanded considerably over the last decade. The poultry industry has grown from a home industry to a large scale manufacturing industry in which tens of thousands of eggs are produced daily at single farms or egg laying installations. Some eggs are produced for eating and some eggs are produced for hatching. One problem with such large scale egg producing is keeping the percent of salable eggs for food consumption on a high level during the increased pressure on farming conditions.

Therefore, the desirability of an easy-to-implement means of increasing egg production in poultry requires no citation.

It has now been found, quite unexpectedly, that the egg quality, in particular the egg mass, can be increased by administering to the animals an effective amount of canthaxanthin.

The major use of canthaxanthin in poultry diets has been to enhance yolk or meet colour as this greatly influences consumer purchasing behaviour. In addition, other functionalities such as antioxidant effect, enhanced reproduction and immune-modulation are attributed to canthaxanthin. The fact, that egg production can be incrementally increased by supplementing the diet with canthaxanthin is a completely unanticipated result in laying hen egg production. This supplementation is economical and easy to administer. We presently have no explanation for the mechanism underlying this increase in egg production. These results revealed that canthaxanthin can enhance the productivity of egg farms in addition to yolk coloration, antioxidant effect, enhanced reproduction and immune-modulation.

No prior reference suggests that the administration of canthaxanthin would be expected to have any effect on egg mass in poultry. DETAILED DESCRIPTION OF THE INVENTION

As used throughout the specification and claims, the following definitions apply:

"Poultry" is meant to include turkeys, ducks and chickens (limited to layers).

Canthaxanthin may be obtained from any source, and a composition thereof may be prepared using convenient technology. In a first aspect, the invention is related to the use of canthaxanthin as nutrients to increase egg mass.

In a second aspect, a feed for laying hens is provided which comprises from about 1 to 50 ppm canthaxanthin, preferably 2 to 10 ppm to increase egg mass.

The method for improving egg mass in poultry comprises administering to the animal in need of such treatment an amount of about 1 ppm to 50 ppm of canthaxanthin, preferably 2 to 10 ppm, for example, 2; 2,5; 3; 3,5; 4; 4,5; 5; 5,5; 6; 6.5; 7; 7,5; 8 ppm.

The diet of poultry is advantageously supplemented with canthaxanthin in physiologically effective amounts. The canthaxanthin used in the examples reported below is is available under the Trademark CAROPHYLL ^® Red. Canthaxanthin is suitably administered together with the feed. The term feed as used herein comprises both solid and liquid feed as well as drinking fluids such as drinking water.

Particularly, inventive ingredient can be added as a formulated powder to a premix containing minerals, vitamins, amino acids and trace elements which is added to regular animal feed and thorough mixing to achieve even distribution therein. In the manufacture of poultry feed in accordance with the invention, from about 1 ppm to 50 ppm, preferably 2 - 10 ppm of canthaxanthin is added to regular poultry food. Alternatively, a food premix may be prepared on the basis of regular food components by adding this active ingredient to such feed components in higher concentration. According to the present invention it is further advantageous if the composition also contains one or more of the following ingredients: Vitamin A, Vitamin E, Biotin, copper (e.g. as CuS0 ₄ ), zinc (e.g. as ZnS0 ₄ ), cobalt (e.g. as CoS0 ₄ ), selenium (e.g. as Na ₂ Se0 ₃ ), iodine (e.g. as Kl), manganese (e.g. as MnS0 ₄ ) and/or calcium (e.g. as CaS0 ₄ ). The following non-limiting Examples are presented to better illustrate the invention.

Example 1 : Effect of Canthaxanthin on the productivity of layer hens (1 ^st trial)

Experimental Design

In this study female layer chickens were used, all 35 weeks of age, and of Isa Brown lineage. The birds were housed together in their respective treatment groups as follows: Treatments

1 control, control + 2ppm , control + 4ppm, control + 8ppm Canthaxanthin Replicates

3 hens/replicate and 4 replicates/ treatment = 12 hens/treatment

Period of Experimentation

3 weeks of carotenoids administration. The laying rate was calculated weekly. The weighing of the eggs was carried out using a precision weighing scale (0.001 g).

Feeding

The diet given to the birds was a standard feed for layer hens (Mash fed ad libitum) with the addition of the product that was tested. The feed met all nutritional requirements in relation to the developmental stage of the birds and the recommendations in the layers' guide (Table 1 ).

TABLE 1 . Composition of feed used during the experiment

Vitamin and mineral premix supplies the following per kilogram of diet: vitamin A, 1000000 IU; vitamin D3, 300000 IU; vitamin E 3000 IU; vitamin K3 250 mg; vitamin B1 200 mg; vitamin B2 600 mg; vitamin B5 900 mg; vitamin B6 400 mg; folic acid 80mg; vitamin B12 2000 mg; niacin 3000 mg; biotin 13 mg; vitamin C 10000 mg; choline 25950 mg; iron 5000 mg; cupper 1000 mg; zinc 7000 mg; manganese 12000 mg; iodine 124 mg; cobalt 100 mg; selenium 19,8 mg,

TABLE 2. Treatments used in the experiment on layer hens for a period of three weeks.

Treatments Carophyll Red

(ppm)

1 0

2 2

3 4 Results

The results are shown in Figure 1 . The data show a good response for canthaxanthin. In particular the results show significantly more egg mass per cage over the 4 weeks period (p=0,0058). This leads to a 3% increase of egg mass per ppm canthaxanthin. Example 2: Effect of Canthaxanthin on the productivity of layer hens (2 ^nd trial)

Experimental Design

In this study female layer chickens were used, all 38 weeks of age, and of Isa Brown lineage. The birds were housed together in their respective treatment groups as follows:

Treatments

1 control, control + 2,5ppm , control + 5ppm Canthaxanthin Replicates

3 hens/replicate and 4 replicates/ treatment = 12 hens/treatment Period of Experimentation

3 weeks of carotenoids administration. The laying rate was calculated weekly. The weighing of the eggs was carried out using a precision weighing scale (0.001 g).

Feeding

The diet given to the birds was a standard feed for layer hens (Mash fed ad libitum) with the addition of the product that was tested. The feed met all nutritional requirements in relation to the developmental stage of the birds and the recommendations in the layers' guide (Table 1 ). TABLE 1 . Composition of feed used during the experiment

Ingredient Percentage

Rice 21 ,8

Wheat 40,0

Oat 7,5

Soybean meal 50% 14,0

Vegetable Oil 2, 5 Ingredient Percentage

CaC03 7,8

DCP 1 ,3

(1 )

Vit & Mineral Premix 1 ,0

DL-Methionine -

NaCI 0,1

Fish Meal 4,0

Vitamin and mineral premix supplies the following per kilogram of diet: vitamin A, 1000000 IU; vitamin D3, 300000 IU; vitamin E 3000 IU; vitamin K3 250 mg; vitamin B1 200 mg; vitamin B2 600 mg; vitamin B5 900 mg; vitamin B6 400 mg; folic acid 80mg; vitamin B12 2000 mg; niacin 3000 mg; biotin 13 mg; vitamin C 10000 mg; choline 25950 mg; iron 5000 mg; cupper 1000 mg; zinc 7000 mg; manganese 12000 mg; iodine 124 mg; cobalt 100 mg; selenium 19,8 mg,

TABLE 2. Treatments used in the experiment on layer hens for a period of three weeks.

Results

The results are shown in Figure 2. The data show a good response for canthaxanthin. In particular it shows significantly more egg mass per cage over the 4 weeks period (p=0,0015). This leads to a 1 ,5% increase of egg mass per ppm canthaxanthin.

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