WO2020104654A1

WO2020104654A1 - Method for reducing the incidence of ascites

Info

Publication number: WO2020104654A1
Application number: PCT/EP2019/082227
Authority: WO
Inventors: Theodorus Antonius Theresia Gerardus VAN KEMPEN; Rosa Franco ROSSELLÓ
Original assignee: Nutreco Ip Assets B.V.
Priority date: 2018-11-23
Filing date: 2019-11-22
Publication date: 2020-05-28

Abstract

The present invention is in the field of improvement of performance and/or prevention of metabolic syndromes, particularly in poultry, even more particularly in broilers. Particularly, the present invention is in the field of prevention or reduction of the incidence of ascites, as well as the incidence of Right Ventricular Hypertrophy, and improving performance of poultry, particularly under conditions in which oxygen supply is suboptimal or compromised.

Description

Title: Method for reducing the incidence of ascites

FIELD OF THE INVENTION

The present invention is in the field of improvement of performance and/or prevention of metabolic syndromes, particularly in poultry, preferably in broilers. Particularly, the present invention is in the field of prevention or reduction of the incidence of ascites.

BACKGROUND OF THE INVENTION

One of the major causes of death of poultry, in particular broilers, raised under reduced oxygen pressure, such as occurring in high-altitude production systems, is the syndrome called“ascites”.

Ascites is an accumulation of non-inflammatory transudate in one or more of the peritoneal cavities or potential spaces. The fluid, which accumulates most frequently in the two ventral hepatic, peritoneal, or pericardial spaces, may contain yellow protein clots. Ascites may result from increased vascular hydraulic pressure, vascular damage, increased tissue oncotic pressure, or decreased vascular oncotic (usually colloidal) pressure, but is most commonly associated with venous hypertension in response to increased pulmonary resistance.

The primary cause of ascites in broilers is right ventricular failure (RVF) as a result of increased pulmonary (lung) arterial pressure. Increased pulmonary arterial pressure can be produced in birds by lack of oxygen, e.g., in conditions of reduced oxygen pressure. When the oxygen supply is insufficient, the heart must circulate blood more rapidly to provide the same amount of oxygen to the body. Bird lungs are rigid and fixed in the thoracic cavity. The capillaries can expand very little to accommodate increased blood flow. The lack of oxygen also causes a marked increase in the number of red blood cells (or haematocrit value) that makes the blood more viscid and difficult to pump through the lung, causing pulmonary hypertension. The right side of the heart enlarges in response to the increased workload, and, if the heart has to continue working harder than normal, the result is right ventricular valve insufficiency, volume overload, right ventricular dilatation and RVF. As a result, venous blood pressure increases, and fluid leaks out of the veins and accumulates in peritoneal cavities, resulting in ascites.

The causes of insufficient oxygen supply and subsequent development of ascites in broilers are complex. Predisposing factors that increase the amount of oxygen required, reduce oxygen-carrying capacity of the blood, increase blood volume or interfere with blood flow through the lung may result in flock outbreaks of ascites.

An object of the present invention is therefore to provide an agent which enables a reduction of the incidence of ascites in poultry, in particular in poultry raised at a high growth rate, and thereby reduces mortality/morbidity.

A further object of the present invention is to provide a new treatment of poultry which enables to improve the conversion rate of the feed used to raise the poultry, i.e. which enables to reduce the amount of feed required to produce a certain amount of poultry meat.

SUMMARY OF THE INVENTION

In certain aspects, the present invention relates to use of eucalyptol for reducing the incidence of ascites, for improving ascites score, for reducing the Right Ventricular Hypertrophy Index, and for decreasing blood parameters related to hypoxaemia, in poultry.

The blood parameters may be selected from the group consisting of haematocrit values, haemaglobin levels, and number of red blood cells in blood.

In further aspects, the present invention pertains to the use of eucalyptol for increasing body weight of poultry, and for decreasing Feed Conversion Ratio in poultry. In an embodiment, feed efficiency is improved.

In yet another aspect, the present invention provides the use of eucalyptol for reducing the number of chickens with poor feathering in a flock.

In an embodiment, the eucalyptol is provided in the form of a composition in which it is embedded in a matrix.

In a suitable embodiment, the poultry may be a chicken, preferably a broiler or layer.

GENERAL DEFINITIONS

In the following description and examples, a number of terms are used. In order to provide a clear and consistent understanding of the specification and claims, including the scope to be given to such terms, the following definitions are provided. Unless otherwise defined herein, all technical and scientific terms used have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The disclosures of all publications, patent applications, patents and other references are incorporated herein in their entirety by reference.

Eucalyptol or 1 ,8-cineole is a monocyclic monoterpene ether (oxide). It is a colorless, flammable liquid with a fresh camphor-like odor. It occurs in nature; it is the main component of eucalyptus oil obtained by steam distillation of the leaves of the blue gum tree (Eucalyptus globulus) and other Eucalyptus species. In smaller quantities it also occurs in the essential oil of the camphor tree, mint, thyme, basil, sage and other aromatic herbs. Pure eucalyptol can be obtained from eucalyptus oil by fractional distillation. In the context of the present invention, the term“eucalyptol” may include its natural analogue 1 ,4-cineole.

As used herein,“feed conversion ratio (FCR)” or“feed conversion rate” is a ratio or rate measuring of the efficiency with which the bodies of livestock convert animal feed into the desired output. For broilers, for example, the output is the flesh, i.e., the body mass gained by the animal, represented either in the final mass of the animal or the mass of the dressed output. FCR is the mass of the input divided by the output (thus mass of feed per mass of meat). Conversely, feed efficiency, which is the output divided by the input (i.e. the inverse of FCR), may be used to express the efficiency with which the bodies of livestock convert animal feed into the desired output.

The haematocrit value, also known by several other names, is the volume percentage (vol%) of red blood cells in blood.

Flaemoglobin is the iron-containing oxygen-transport metalloprotein in the red blood cells of all vertebrates. Haemoglobin in the blood carries oxygen from the lungs to the rest of the body (i.e. the tissues). There it releases the oxygen to permit aerobic respiration to provide energy to power the functions of the organism in the process called metabolism.

The term “ascites score” as used herein refers to a score assembled using the following criteria: 0 = no visible injury; 1 = flaccid heart with or without hydropericardium. No presence of fluid in the abdominal cavity; 2 = flaccid heart with little presence of fluid in the abdominal cavity; 3 = severe widespread damage, i.e., marked accumulation of fluid in one or more celomic cavities (other than the pericardium) and liver injuries.

Right ventricular hypertrophy (RVH) is a form of ventricular hypertrophy affecting the right ventricle. Blood travels through the right ventricle to the lungs via the pulmonary arteries. If heart output exceeds the capacity of the pulmonary circulation, meaning blood does not flow well from the heart to the lungs, extra stress can be placed on the right ventricle. This can lead to right ventricular hypertrophy.

The term“Right Ventricular Hypertrophy Index” as used herein refers to the weight of the right ventricle divided by the total weight of the heart.

The term “poultry" as used herein refers to domesticated birds kept by humans for their eggs, their meat, their organs, or their feathers. These birds are most typically members of the superorder Galloanserae (fowl), especially the order Galliformes (which includes chickens, quails, and turkeys). Poultry also includes other birds that are killed for their meat, such as the young of pigeons (known as squabs). Non-limiting examples of poultry include chickens, ducks, geese, turkeys, quails, guinea fowls, squabs, emus, ostriches, partridges, pigeons, pheasants, and the like.

The term“broiler” as used herein refers to any chicken, such as of the species Gallus gallus domesticus, which is bred and raised specifically for meat production. As used herein, the term“test animal” refers to an animal that received eucalyptol as part of its diet. In contrast, a“control animal” refers to an animal of the same species that did not receive eucalyptol as part of its diet. Suitably, both the test animals and control animals were fed the same diet, albeit with the exception of the presence of eucalyptol, and were kept under similar climatic conditions.

The term“diet” as used herein refers to the sum of food and beverages or drinks or drinking water consumed by an animal.

The term“chickens with poor feathering” as used herein refers to chickens that have slight feather loss (moderate wear, damaged feathers or 2 or more adjacent feathers missing up to bare skin visible < 5cm (2 inches) maximum dimension; score 1 ) or moderate/severe feather loss (bare skin visible more than or equal to 5 cm (2 inches) maximum dimension; score 2) as measured by method of feather scoring developed by the University of Bristol, Soil Association and RSPCA (http://www.featherwel.ora/iniuriouspeckinq/howtofeatherscore).

The terms“comprising” or“to comprise” and their conjugations, as used herein, refer to a situation wherein said terms are used in their non-limiting sense to mean that items following the word are included, but items not specifically mentioned are not excluded. It also encompasses the more limiting verb“to consist essentially of” and“to consist of”.

Reference to an element by the indefinite article "a" or "an" does not exclude the possibility that more than one of the elements is present, unless the context clearly requires that there be one and only one of the elements. The indefinite article "a" or "an" thus usually means "at least one".

DETAILED DESCRIPTION

It was surprisingly found that treatment of broilers with eucalyptol improved the performance parameters body weight and feed conversion ratio. Moreover, treatment with eucalyptol lowered blood parameters critical to ascites, and improved ascites score and RVHI. Finally, treatment with eucalyptol lowered the percentage of birds without feathers.

Thus, in an aspect the present disclosure teaches the use of eucalyptol for increasing body weight or body weight gain in poultry, in particular chickens, even more particular in broilers. The body weight or body weight gain of a test animal (i.e., an animal receiving eucalyptol in the diet) may be increased relative to the body weight or body weight gain of a control animal (i.e., an animal of the same species not receiving eucalyptol in the diet). The body weight gain of poultry may be determined using any standard methodology known to the skilled person. For example, the poultry (both the control and the test animals) may be weighed weekly to keep track of the body weight gain. The body weight gain may be increased when the body weight gain of the test animals throughout the test period is higher than the body weight gain of the control animals. The test period may be the period from hatch up to the time of slaughter. For example, the test period may be from day 0 (day of hatch) up to about the age of 25, 30, 35, 40, 45, 46, 50, 55, 60, 65, 70, or more days, depending upon the desired time of slaughter.

In another aspect, the present disclosure teaches the use of eucalyptol for decreasing feed conversion ratio (FCR) in poultry, in particular chickens, even more particular in broilers or layers. Similarly, the present disclosure teaches the use of eucalyptol for increasing feed efficiency in poultry, in particular chickens, even more particular in broilers. The FCR may be decreased in a test animal relative to the feed conversion ratio observed in a control animal. The FCR may be determined using any standard methodology known to the skilled person. For example, feed intake (in, e.g., grams) may be recorded over a period, e.g., a week, as well as body weight gain (or mass gain) (in, e.g., grams) over the same period, and FCR can be calculated by dividing the total feed intake over that period by the body weight gain over that period.

In another aspect, the present disclosure teaches the use of eucalyptol for increasing feed efficiency in poultry, such as poultry held under hypoxaemic conditions, in particular chickens, even more particular in broilers. The skilled person is capable of converting FCR into feed efficiency.

In another aspect, the present disclosure provides use of eucalyptol in reducing the incidence of ascites in poultry, in particular chickens, even more particular in broilers.

In yet another aspect, the present disclosure teaches use of eucalyptol in improving ascites score in poultry.

In yet another aspect, the present disclosure teaches use of eucalyptol in reducing Right Ventricular Hypertrophy, and/or the Right Ventricular Hypertrophy Index (RVHI), in poultry, in particular chickens, even more particular in broilers.

In yet another aspect, the present disclosure teaches use of eucalyptol in decreasing blood parameters related to hypoxaemia in poultry. In particular, such blood parameters may be selected from the group consisting of haematocrit values, haemaglobin levels, and number of red blood cells in blood.

In an aspect, the present disclosure teaches the use of eucalyptol for reducing the number of chickens, such as broilers or layers, with poor feathering in a flock. Feathers on chickens provide protection from injury and insulation for the body. Too much feather loss makes it more likely that injuries will occur to exposed skin resulting in infections or bruising of the tissues. In addition, excessive feather loss can result in higher energy utilization requirements for maintaining body temperature. As a result, birds with excessive feather loss often require more feed to produce the energy necessary to compensate for the heat lost. This condition can also adversely affect feed conversion and result in greater feed costs. Preventing excessive feather loss can, therefore, have an important impact on flock health and profitability.

In a preferred embodiment, the poultry are chickens, such as broilers or layers, even more preferable chickens farmed for meat, i.e., broilers. In an even more preferred embodiment, the poultry, e.g., broilers or layers, are kept under conditions of reduced atmospheric partial oxygen pressure, e.g. such as occurring at high altitude areas. Effective oxygen pressure is affected by many parameters, including, without limitation, altitude, humidity, temperature, ventilation rate within a facility, the use of fossil fuel heating systems within the facility, fermentation within the litter, etcetera.

In the context of the present invention, the“atmospheric partial oxygen pressure” (or partial oxygen pressure” or“partial pressure of oxygen”) under a particular condition may be considered reduced when the partial pressure of oxygen in the atmosphere under such condition is at least 1 %, such as at least 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 12%, 14%, 16%, 18%, or at least 20%, reduced compared to the partial pressure of oxygen in the atmosphere at sea level. It is generally assumed that the partial pressure of oxygen in the atmosphere at sea level is 160 mm Hg (or 0.21 atm). For example, at an altitude of 500 m, the partial pressure of oxygen in the atmosphere is about 94% compared to the partial pressure of oxygen in the atmosphere at sea level, i.e., the partial oxygen pressure in the atmosphere is reduced with 6%.

The term“altitude” is commonly used to mean the height above sea level. The term “high altitude” is relative. The high altitude areas are characterized mainly by low atmospheric pressure resulting from two competing forces, namely gravity which causes the air to be as close as possible to the ground, and the heat content of air which causes the molecules to bounce off each other and expand. In this case, the number of oxygen molecules per breath is reduced, but to a varying extent depending on the magnitude of elevation and other circumstances. Birds reared in high-altitude areas often encounter a number of production, health, and mortality problems. These may not be solely attributed to the oxygen uptake per se, but may also be attributed to other climatic conditions linked with high altitudes, such as low temperature and concomitant decreased ventilation rates, use of heating systems, litter fermentation, and humidity.

The eucalyptol may be administered to said poultry in any way known to the skilled person. The eucalyptol is preferably administered orally. The eucalyptol may be incorporated in starter, grower and/or finisher diets. The diets may be in the form of mash, pellets, crumbles or any other form known to the skilled person. Alternatively, the eucalyptol may be incorporated into the drinking water.

Eucalyptol may be incorporated into the diets or drinking water in any amount that is effective to achieve the desired effects taught herein. For example, the amount of eucalyptol incorporated to diets may be in the range of between 0.1 and 1000 ppm, such as between 1 and 800 ppm, between 4 and 700 ppm, between 10 and 500 ppm, between 20 and 400 ppm, between 30 and 350 ppm, between 50 and 300 ppm, between 75 and 250 ppm, between 85 and 200 ppm, or between 100 and 125 ppm. In general, inclusion rates of eucalyptol in drinking water may be 40-50% of the inclusion rates of eucalyptol in feed. As such, the amount of eucalyptol incorporated to drinking water may be, for example, in the range of between 0.4 and 500 ppm, such as between 2 and 400 ppm, between 4 and 250 ppm, between 80 and 200 ppm, between 20 and 150 ppm, between 30 and 125 ppm, between 35 and 100 ppm, or between 40 and 60 ppm.

To prevent volatilization and/or oxidation of eucalyptol, it may be advantageous to incorporate it into a matrix. In an embodiment, the composition as taught herein is prepared by embedding the eucalyptol in a matrix of, for example, a vegetable oil, e.g., a partially or fully hydrogenated vegetable oil. The vegetable oil may be any vegetable oil, but is preferably selected from the group consisting of non-hydrogenated, partially hydrogenated or fully hydrogenated sunflower oil, palm oil, soybean oil, rapeseed oil, cottonseed oil, and castor oil, or any mixtures thereof. In an embodiment, said matrix comprises or consists of sunflower oil, e.g., hydrogenated sunflower oil.

Embedding the eucalyptol in a matrix can be done by any technique known to a person skilled in the art. A non-limiting but highly suitable exemplary technique is spray chilling, also referred to as spray cooling, spray congealing, or prilling. Spray chilling is a lipid based system where the active ingredient (e.g., eucalyptol) is mixed into a molten matrix (e.g., molten hydrogenated vegetable oil, e.g., molten hydrogenated sunflower oil), which mixture is subsequently fed through a nozzle, e.g., an atomizer nozzle, to produce droplets of the mixture. The droplets are allowed to solidify, e.g., by contacting them with cooled air at a temperature below the melting point of the matrix resulting in the formation of particles.

The present invention is further illustrated, but not limited, by the following examples. From the above discussion and these examples, one skilled in the art can ascertain the essential characteristics of the present invention, and without departing from the teaching and scope thereof, can make various changes and modifications of the invention to adapt it to various usages and conditions. Thus, various modifications of the invention in addition to those shown and described herein will be apparent to those skilled in the art from the foregoing description. Such modifications are also intended to fall within the scope of the appended claims.

EXAMPLES

Example 1 Experimental design

Male, one-day-old Ross 308 broiler chickens were randomly assigned to floor pens, with approximately 50 birds per pen, in a completely randomized block design according to the pen location in the house and 2 dietary treatments. The dietary treatment was replicated 11 times (except the control treatment with 12 replicas). At placement, birds were weighed and introduced to the experimental unit (pen). The trial took place in Mexico at an altitude of 1940 meters. Diets

The study lasted 42 days. A three-part feeding program was applied: starter (placement to 10^th day of age), grower (1 1 to 28 days) and finisher diet (29 to 42 days). Standard diets commonly used in Mexico were formulated to reach current requirement estimates for AMEn, digestible amino acids, vitamins and minerals. Main ingredients were soybean meal and corn.

Treatments

Treatments were distributed among pens randomly.

Table 1. Number of control and test groups

Eucalyptol was blended homogeneously into the feed.

Results

Table 2. Average body weight (g) at 42 days

Average body weight at 42 days of age was significantly increased relative to the control.

Table 3. Average Feed Conversion Ratio (g/g) at 42 days

Feed Conversion Ratio was significantly improved compared to the control.

Table 4. Average results related to Right Ventricular Hypertrophy Index (RVHI) and Ascites score at 42 days of age.

RVHI and ascites score were lower for the eucalyptol treated broilers relative to broilers receiving the control diet. Table 5. Average results of blood parameters (haematocrit (%), haemoglobin (g/dl), and red blood cells (millions/mI) at 42 days of age.

Haematocrit values, haemoglobin levels, and red blood cell count were significantly decreased in eucalyptol-treated broilers as compared to broilers receiving control diet.

Table 6. Results on the percentage of birds without feathers at day 46.

The number of birds without feathers was lower in the eucalyptol-treated group as compared to the control group.

Thus, treatment of broilers with 100 ppm eucalyptol improved the performance parameters, body weight, and feed conversion ratio. Moreover, treatment with eucalyptol lowered blood parameters critical to ascites, and improved ascites score and RVHI. Finally, treatment with eucalyptol lowered the percentage of birds without feathers.

Claims

1. Eucalyptol for use in reducing the incidence of ascites in poultry.

2. Eucalyptol for use in improving ascites score in poultry.

3. Eucalyptol for use in reducing the Right Ventricular Hypertrophy Index in poultry.

4. Eucalyptol for use in decreasing blood parameters related to hypoxaemia in poultry.

5. Eucalyptol for use according to claim 4, wherein the blood parameters are selected from the group consisting of haematocrit values, haemaglobin levels, and number of red blood cells in blood.

6. Use of eucalyptol for increasing body weight of poultry.

7. Use of eucalyptol for decreasing Feed Conversion Ratio in poultry.

8. Use according to claim 7, wherein feed efficiency is improved.

9. Eucalyptol for use according to any of claims 1-5 or use according to any of claims 6-

8 or 10-1 1 , wherein the poultry is a chicken, preferably a broiler.

10. Use of eucalyptol for reducing the number of chickens with poor feathering in a flock.

1 1. Eucalyptol for use according to any of claims 1-5 or use according to any of claims 6- 8, wherein eucalyptol is embedded in a matrix.