GB1570432A - Ironcontaining feeding supplement for piglets - Google Patents

Abstract

A method is described for stimulating the appetite of sucking pigs and for guaranteeing that the sucking pigs are provided with sufficient liquid, by offering the animals an approximately isotonic aqueous solution ad libitum starting when the sucking pigs are one day old up to week six. This aqueous solution has a pH of 2.0 to 4.0 and contains an iron/glutamic acid compound at a concentration of not more than 2% Fe. The solution is palatable to the animals, and their stimulated appetite results in a considerably better weight gain in comparison with sucking pigs who have not been given this solution ad libitum. Moreover, a dilutable aqueous iron salt solution is described for carrying out the appetite-stimulating method, which contains ferric glutamate at a concentration of 20 mg of divalent iron per ml and has a pH of 2 to 2.5.

Description

(54) IRON-CONTAINING FEEDING SUPPLEMENT FOR PIGLETS (71) We, RUMEN CHEMIE AG, a Swiss Body Corporation of Glarus, Switzerland, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention relates to a special organic iron compound, which when administered as an aqueous, peroral iron salt solution to piglets ensures that said piglets have an optimal haemoglobin percentage, i.e. it prevents anaemia during the first 4 to 6 weeks of the piglets life.The administration of this iron preparation is suitably combined with a supply of glucose and electrolytes in approximately isotonic concentrations i.e. so that their osmotic pressure corresponds with that of blood plasma, so that the ad libitum intake is stimulated and a good supply of liquid is achieved.

From Norwegian Patent No. 128 692 a method is known for feeding furred animals, especially mink and first and foremost mink that is fed raw fish, a fodder containing an iron chelate or an organic iron complex. The method according to said patent has the object of inhibiting in virc) reactions between bivalent iron and trimethyl amino oxide, so that iron oxide hydrates which are not difficult to dissolve, goetlite and lepidierolite, are formed.

The present invention relates to a method for the administration of a solution so that all piglets may be ensured an equal and continuous supply of easily resorbable iron + sodium + glucose by ad libitzxm intake. Iron is known to be necessary for many biological functions in addition to its well documented role as a constituent of the oxygen transporting molecule: haemoglobin. In the case of an iron deficiency, the amount of haemoglobin formed will be reduced, but the iron content each haemoglobin molecule will remain comparatively constant.

In the case of an iron deficiency, the erythrocyte re-creation will thus cause the red corpuscles to be smaller, microcytic and hypochromic because of the reduced content of haemoglobin. Such red corpuscles have a limited, reduced ability to transport oxygen.

This condition will result in anaemia. It is well known that piglets have an intensity of growth in relation to their birth weight that is far greater than usual for other domestic animals.

In the course of its first 3 weeks of life, a piglet will increase its weight 4 to 5 times. The sow milk alone will satisgy most of the piglet's nutritional needs during this early period of growth.

The iron supply is an essential exception.

Sow milk only contains 1 to 1.5 mg iron/kg.

Since the piglet is born with a very low iron reserve (30 to 40) mg) and the assumed need of iron is approximately 7 mg of elementary iron a day, it is evident that the sow with its milk cannot provide the piglet with sufficient amounts of iron to prevent anaemia.

In the course of time various methods have been used to prevent anaemia in piglets. The oldest method was the use of soil. Under extensive conditions, where the sow and its piglets are kept outdoors (pasture), the piglets will usually get enough iron from the soil. In most soil types the iron content is quite low, but most soil bacteria use iron for their metabolism. The incorporation of iron in the body protein of the micro-organism results in the formation of iron protein chelates, which can be effectively utilized by the piglet.

However, in cases of intensive pig breeding, the use of soil as an anaemia-preventing means will require too much work and be less effective than other methods, because of the varying iror concentrations in the soil. However, the iron metabolism of microorganisms has given us an interesting physiological model, inter alia for understanding iron absorption in pigs.

During the last 15 to 20 years, the safest and most used method of iron administration to piglets has been intramuscular injections of high molecular iron dextrans supplying 100 to 200 mg of iron. This method of supplying piglets individually with an iron depot corresponding to 100 to 200 mg during their first days has proved in a series of experiments to be safer if the farrows are given a daily ad libitum addition of iron compound in the form of a powder, pellets, or a paste.

It is known from US Patent No. 3 259 500 to prevent anaemia in piglets by feeding sows with suckling piglets iron salts preferably of dibasic organic acids and phosphoric acid in the form of pills or liquid preparations. These preparations will then act through the milk (or the foetus), but, since the transmission of iron from blood plasma to milk is limited due to the mammae barrier the effect of such an iron administration will be small and unpredictable.

Due to its appetite stimulating characteristics the iron compound according to the present invention, however, will ensure an intake of liquid by the piglets that has not been achieved until now.

Today it is known that iron in the fodder must pass through the ventriculus, with its low pH, and to the alcalic duodenum and jejunum, where the absorption of iron takes place. The liquid in the ventriculus is sufficiently acidic to maintain the iron, in the presence of reducing substances as a divalent ferrosalt. It is known that iron in divalent form (ferro compounds) is more rapidly and more effectively absorbed than trivalent iron (ferric compounds). In the duodenum the presence of various components, such as amino acids, nitrates and sugar, results in the formation of complex compounds with the iron which solubilize the iron and maintain it in solution for absorption.

This chelate forming process increases the iron absorption in the duodenum substantially.

On the other hand inter alia carbonates, phosphates and phytates will cause precipitation of iron in an insoluble form which causes iron to be absorbed only to a very low degree.

There are several barriers limiting the amount of iron which can pass through the normal absorption process in piglets. Due to the complex absorption process to which iron is subjected in a very limited area of the digestive tract, it is usually assumed that only 2 to 10% by weight of the iron content in fodder is absorbed and utilised by the pig.

Iron bound to organic compounds like proteins and amino acids forms a complex or a chelate compound.

The present invention provides a method of feeding piglets during their suckling period with an aqueous iron salt solution to provide liquid and iron by ad libitum intake, wherein the piglets are fed with a substantially isotonic aqueous solution of an iron (III) glutamic acid complex compound (as hereinafter defined) having a pH of 2 to 4 and an iron concentration of up to 2% by weight in amounts sufficient to provide each piglet with 25 to 50 mg Fe a day from the first day of the piglet's life up to and including the 6th week of its life.

The iron (III) glutamic acid complex compound (hereinafter referred to also as "ferriglutamate") comprises a ferric cation complexed with two molecules of glutamic acid, which can be prepared as indicated e.g. in "Die Naturwissenschaften", 42 p. 125-126 (1955). The present invention also provides an aqueous iron solution comprising this iron (III) glutamic acid complex compound and having a pH of 2 to 4 and an iron concentration of up to 2% by weight.

The pH of the ferriglutamate solution should preferably be from 2 to 2.5 to yield the most stable solution and preferably contains the iron in a concentration of about 20 mglg. This concentrated ferriglutamate solution can be administered in undiluted form but to achieve the intended extra liquid supply the solution should preferably be diluted. At a daily intake of e.g. 500 ml liquid per farrow the concentration should preferably be adjusted so that each piglet receives 30 to 50 mg Fe a day. In such a dilution, the pH will suitably be 2.5 to 4.

Preferably, the iron solution has been rendered isotonic (i.e. such that its osmotic pressure corresponds with that of blood plasma) by addition of glucose and the solution fed to the piglets contains sodium chloride in physiologically acceptable concentrations.

It is desirable that the iron solution, at least during the first 8 days, has a temperature as close to the body temperature (38"C) as possible. This can be achieved by placing the drinking container below a warming lamp at the sleeping place of the piglets.

Feeding essentially being based on ad libitum intake and with the consumed amount of liquid in practice varying with the temperature and humidity of the air and the milk production of the sow, the concentration should be varied so that the required intake of 25 to 50 mg per animal per diem is achieved.

Experiments with this form of administration have shown that ALL piglets of a farrow are ensured a continuous and equal access to iron. The low variation of haemoglobin values shows that this is achieved. The following Example serves to illustrate the invention.

EXAMPLE Experiments with 6 farrows of a total of 55 piglets where conducted with ferriglutamate as the sole source of iron. A concentrated ferriglutamate solution containing 20 mg Fe III/ml was diluted with 500 ml water so that the daily iron addition per piglet was 30 to 50 mg, i.e. a farrow of 10 piglets received 15-25 g (ml) of the concentrated ferriglutamate solution diluted in 500 ml of water.The TABLEI 3rd day 7th day 20th day 31st day Ferriglutamate solution 30-50 mg/an./day 8.12 + 0.92 8.62 + 0.51 9.21 + 0.81 9.92 + 0.60 TABLE 2 Average Values and Standard Deviation in Piglets of Different Ages

Days after birth Measured parameter Group Number of amimals 3rd day 17th day 31st day 45th day Bodyweight Feglutamate 10 5 5 2.l4i0.44 5.90+1.14 l0.02i2.00 14.93i3.13 in keg FeH(*) 8 4 4 2.16i0.32 5.90 + 1.26 9.66± 1.45 14.70+217 Control 9 4 5 2.18i0.33 5.29i1.07 7.48#1.46 l1.87i2.06 Haemoglobin Fe glutamate 10 5 5 7.98 i 0.98 8.05 i 1.09 8.18 i 0.81 9.32 i 1.18 g1100 cm3 FeH 8 4 4 8.03 i 0.77 6.83 +0.48 6.94 + 1.14 9.10 i 1.25 Control 9 4 5 8.l0i0.84 4.l0i0.20 3.10i0.77 6.04i2.14 Haemotocrit Fe glutamate 10 5 5 25.2 + 2.0 32.2 i 4.0 33.4 i 2.5 35.9 + 3.64 % by volume FeH 8 4 4 26.0 +3.0 28.6 +2A 30.3 +5.1 35.6 +2A5 Control 9 4 5 26.3 +3.2 17.4 +2.7 14.5 i 3.4 26.1 i 8.65 (*)FeH - iron dextran diluted iron chelate solution was administered in a low drinking container placed below a warming lamp. The temperature of the liquid varied from 25 to 31 C.

The piglets very soon started to drink the solution and already before they were 7 days old 10 piglets in a farrow drank the proper amount of liquid (500 ml).

The haemoglobin concentration g/100 ml was measured when the piglets were 3, 7, 20 and 31 days old.

The results in Table I show the average value and standard deviation of piglets at various ages (55 piglets).

In an orienting experiment the use of the ferriglutamate solution was compared with the injection of ferrodextran and with a control group that was not given any additional iron.

This experiment had the object of measuring the effect of certain amounts of iron addition.

To prevent the piglets from having access to iron from other sources, all bins were varnished to such an extent that the piglets were prevented from having unintended acess to trace elements from the surroundings.

Special additions of copper or vitamins were not given. After birth, the piglets went along with their mothers, but they were treated in three different ways. One group did not receive any addition of iron, another group received injections of ferrodextran corresponding to 200 mg Fe on the third day after birth, whereas the third group received 100 mg ferriglutamate p. o. on the third day after birth and thereafter twice a week up to and including the 6th week.

This ferriglutamate solution was administered with a swallowing probe.

Before the piglets were treated, they were weighed and a blood test was taken for determination of the haemoglobin concentration and haematocrit. Haemoglobin was determined by the cyanomethaemoglobinmethod.

The results appear in Table 2.

The abovementioned results were supplied by clinical experiments on a large number of piglets (214). Most of the piglets had only received ferriglutamate solution by ad libitum intake and the haemoglobin concentration, haemotocrit and body weight were recorded.

In all piglets satisfactory parameters for haemoglobin, as well as haemotocrit and growth, were recorded. In experiments, where the glutamate solution had been added to 10% by weight glucose, a more rapid intake of the ferriglutamate solution and a better growth of the piglets was recorded.

In this manner, the iron chelate solution can simultaneously provide additional iron and also additional liquid and electrolyte to piglets (glucose + sodium). The great importance of the liquid addition was recorded by the fact that the piglets of the different farrows developed more steadily than if they had only been given sow milk. The low pH of the liquid prevents contamination by pathogenic bacteria.

In addition, the specific amino acid in the complex compound - glutamic acid - itself has an advantageous effect on the general metabolism of the piglets, as well as on their resorption of iron.

WHAT WE CLAIM IS: 1. A method of feeding piglets during their suckling period with an aqueous iron salt solution to provide liquid and iron by ad libitum intake, wherein the piglets are fed with a substantially isotonic aqueous solution of an iron (III) glutamic acid complex compound (as hereinbefore defined) having a pH of 2 to 4 and an iron concentration of up to 2% by weight in amounts sufficient to provide each piglet with 25 to 50 mg Fe a day from the first day of the piglet's life up to and including the 6th week of its life.

2. A method according to claim 1 wherein the iron solution has been rendered isotonic by addition of glucose and the solution fed to the piglets contains sodium chloride in physiologically acceptable concentrations.

3. A method according to claims 1 or 2, wherein at least during the first 8 days of the piglet's life, the solution is maintained at a temperature of about 38"C when it is fed to the piglets.

4. A method according to any one of the preceding claims wherein the iron concentration is about 20 mg/g.

5. A method according to claim 1 substantially as hereinbefore described with reference to the Example.

6. An aqueous iron solution comprising an iron (III) glutamic acid complex compound, (as hereinbefore defined) and having a pH of 2 to 4 and an iron concentration of up to 2% by weight.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (6)

**WARNING** start of CLMS field may overlap end of DESC **. (glucose + sodium). The great importance of the liquid addition was recorded by the fact that the piglets of the different farrows developed more steadily than if they had only been given sow milk. The low pH of the liquid prevents contamination by pathogenic bacteria. In addition, the specific amino acid in the complex compound - glutamic acid - itself has an advantageous effect on the general metabolism of the piglets, as well as on their resorption of iron. WHAT WE CLAIM IS:

1. A method of feeding piglets during their suckling period with an aqueous iron salt solution to provide liquid and iron by ad libitum intake, wherein the piglets are fed with a substantially isotonic aqueous solution of an iron (III) glutamic acid complex compound (as hereinbefore defined) having a pH of 2 to 4 and an iron concentration of up to 2% by weight in amounts sufficient to provide each piglet with 25 to 50 mg Fe a day from the first day of the piglet's life up to and including the 6th week of its life.

2. A method according to claim 1 wherein the iron solution has been rendered isotonic by addition of glucose and the solution fed to the piglets contains sodium chloride in physiologically acceptable concentrations.

3. A method according to claims 1 or 2, wherein at least during the first 8 days of the piglet's life, the solution is maintained at a temperature of about 38"C when it is fed to the piglets.

4. A method according to any one of the preceding claims wherein the iron concentration is about 20 mg/g.

5. A method according to claim 1 substantially as hereinbefore described with reference to the Example.

6. An aqueous iron solution comprising an iron (III) glutamic acid complex compound, (as hereinbefore defined) and having a pH of 2 to 4 and an iron concentration of up to 2% by weight.