WO1998020750A1

WO1998020750A1 - Enzymes and their use in the enhancement of soya as a feedstuff

Info

Publication number: WO1998020750A1
Application number: PCT/GB1997/003087
Authority: WO
Inventors: Stephen Charles John Cole; Noel Sheehan
Original assignee: Biotal Limited
Priority date: 1996-11-12
Filing date: 1997-11-11
Publication date: 1998-05-22
Also published as: GB9623539D0; AU4878597A

Abstract

This invention relates to the treatment of vegetable protein sources, e.g. soya, with enzymes such as alpha-galactosidase, invertase, gactomannanase, mannanase or/and mannosidase to enhance the performance, i.e. weight gain, of farm animals (pigs, poultry) and improve their value as feedstuffs by modifying the carbohydrates found therein.

Description

ENZYMES AND THEIR USE IN THE ENHANCEMENT OF SOYA

AS A FEEDSTUFF Field of the Invention

This invention relates to enzymes and their use in the enhancement of soya as a feedstuff. In particular it relates to the use of enzymes to improve or enhance the performance, e.g. weight gain, of farm animals and the value of the feed they receive. The invention relates also to the treatment of vegetable protein and energy sources with enzymes to improve their value as animal feedstuffs, by modifying the carbohydrates found therein. Background of the Invention

The use of vegetable proteins in animal nutrition is widespread. Nevertheless, most vegetable protein sources also contain substantial amounts of other materials. These can be categorised generally as those of potential nutrient value such as carbohydrates and other compounds that have an anti-nutritional (or non-nutritional) value. The latter can be of various composition including short-chain carbohydrates, tannins, lectins, peptides, polypeptides and alkaloids.

By way of example, anti-nutritional factors in seed may be a means of preventing the seed's being consumed or being degraded by micro-organisms such as fungi. These anti-nutritional factors have a variety of effects on the animal consuming the seed or materials extracted from the seed. They cause scours in pigs and birds, and rumen dysfunction in cattle; therefore, they can only be included in feedstuffs at relatively low inclusion rates. The additional protein requirement has traditionally been made up by adding additional concentrated animal protein in the form of meat and bone meal, blood meal, or fish meal. The banning of the two former sources following the advent of BSE and the general feeling that the latter is environmentally undesirable have given rise to the necessity of making better use of the vegetable protein sources.

One suitable and increasingly used protein source is soya. This protein source has a well-balanced amino-acid content, being only slightly deficient in lysine. Soya even in its purer extracted "high-pro" form can contain as much as 20% (w/w) of anti-nutritional carbohydrates in the form of the galacto-oligosaccharides stachyose, raffmose and more substituted oligosaccharides together with long-chain galactomannan polysaccharides. Summary of the Invention

According to the present invention, an enzyme formulation is capable of hydrolysing the complex galactomannan polysaccharide to the sugars galactose and mannose while also degrading the galacto-oligosaccharides to single sugars. This can have significant effects on the use of both full fat soya and processed materials derived from soya.

More particularly, the invention uses the fact that the presence of anti-nutritional carbohydrates has two major effects which can be removed or mitigated by the use of enzyme action. The two groups of carbohydrates have differing effects. The galactomannan polysaccharide will cause an increase in the viscosity of the digesta which in turn reduces the absorption of other nutrients. The reduction of this viscosity will increase the absorption of nutrients and thus improve both the metabolisable (ME) of the feed and the feed conversion ratio (FCR) when fed to monogastric animals. The hydrolysis of the galacto-oligosaccharides to monosaccharides will resolve one of the major problems incurred with such feedstuffs, viz. that such oligosaccharides are not absorbed by the animal but are substrates for the micro-organisms in the lower gut of the host animal. The invention can thus prevent proliferation of enteric bacteria that cause diarrhoea, dehydration, loss of absorption of other nutrients, and general de-habilitation of the animal. The result is that there is no longer a need for strict control of the amounts of the soya material that can be added to the diet. This is important, particularly where the animal is young and not yet acclimatised to such feeds. Description of the Invention

The invention relates to the observation that certain enzymes can be used to reduce the anti-nutritional factors by application to the feed stuff before ingestion or can be administered to the animal in such a way that the enzymes are active in the gastrointestinal tract. The reduction of the digesta viscosity in vivo and the breakdown of galacto-oligosaccharides to monosaccharides allows their absorption by the intestines before reaching the organisms in the lower gut. The effect of such enzymes is to make additional sugars, not previously available to the animal, readily assimilable. The use of one or more enzymes according to the invention may increase the ME of soya by 0.1 to 3 Mjoules. For example, in the case of a substrate such as high-pro soya with 10 % galacto-oligosaccharides, the ME may increase by approximately 1.6 Mjoules. The addition of the enzymes to break the viscous galactomannans will ensure the absorption of this additional energy as well as other nutrients that would not otherwise be absorbed. In addition, other energy from the galactomannan will itself be absorbed. Collectively, this will lead to an increased real as opposed to calculated ME, which in turn will manifest itself in a significant improvement in the FCR when the feed treated with these enzymes is utilised by monogastric animals. The FCR may be improved by, for example, 1 to 20%.

Examples of principal enzymes of value in the invention, any or all of which may be used, are

1 α-galactosidase (e.g. from yeast)

2. Galactomannanase (or arabinoxylanase)

3. Mannanase

4. Invertase 5. Mannosidase

The use of such enzymes will have the function of removing the galactose side chains (1) of the galactomannan polysaccharide and hydrolysing the back-bone (2+3), thus reducing viscosity and releasing sugars. The galacto-oligosaccharides sequentially remove the galactose residue(s), and the remaining sucrose molecule will in turn be hydrolysed by the invertase. The function of the mannosidase is not yet fully understood.

The amounts of the enzymes to be used in the invention can readily be determined by the skilled man, with reference to the desired effect. By way of example only, suitable amounts are 1 to 7 units of α-galactosidase, 100 to 1000 units of invertase, and 1 to 21 units of mannanase or galactomannanase (if present). Enzymes for use in the invention are combined with any feed comprising soya.

The feed may be of conventional type, including known components such as proteins, vitamins and minerals suitable for a monogastric animal, and a source of carbohydrate. Examples of such materials, and appropriate amounts, are well known to those skilled in the art. The following Examples illustrate preparations for use in this invention. Amounts are given per tonne of feed. Examples 1 to 5

To demonstrate the value of the components of the formulations, a series of five enzyme treatments was formulated, as follows:-

(1) 15% w/w α-galactosidase, 1.25% w/w invertase

(2) 30% w/w α-galactosidase, 2.5% w/w invertase

(3) 0.1% w/w mannanase

(4) 1% w/w mannanase

(5) 15% w/w α-galactosidase, 1.25% w/w invertase, 2% w/w mannanase These formulations have approximate activities as follows:-

Example α-Galactosidase Galactomannanase Arabino-xylanase β-glucanase Invertase (IU/g) (IU/g) (IU/g) (IU/g) (IU/g)

1 83.2 0 0 0 771

2 166 0 0 0 1542

3 0 77.8 63.6 63.9

4 <1 778 636 639

5 83.2 778 636 639 771

Using the above formulations at a treatment rate of 1.0 kg per tonne corn-soya feed, the following results were obtained in a feeding study on growing chicks.

Treatment Body Body Average Feed/bird Average Feed wt/bird wt gain daily gain (g) daily feed gain

(g) (g) (g) (g) ratio

Control 734 695 34.76 1070 53.51 1.574

1 758 720 35.99 1061 52.59 1.471

2 811 773 38.64 1084 53.46 1.349

3 755 717 35.86 1044 51.53 1.447

4 773 734 36.72 1091 53.54 1.461

5 778 739 36.95 1088 53.16 1.446

The results demonstrate the valuable effect of the treatments, in particular those containing α-galactosidase and mannanase. In the case of the α-galactosidase, quite low dose rates demonstrate the ability of this enzyme alone to make available to the animal energy that otherwise would not be available to the animals.

Claims

1. An animal feed comprising soya and a first enzyme capable of hydrolysing terminal galactose residues from galacto-oligosaccharides.

2. An animal feed according to claim 1, wherein the first enzyme is an α- galactosidase.

3. An animal feed according to claim 1 or claim 2, additionally comprising a second enzyme capable of reducing sucrose to monosaccharides suitable for assimilation.

4. An animal feed according to claim 3, wherein the second enzyme is invertase.

5. An animal feed according to any preceding claim, additionally comprising a third enzyme capable of reducing the galactomannan polysaccharides to short chain oligomers or monosaccharides suitable for assimilation.

6. An animal feed according to claim 5, wherein the third enzyme is a galactomannanase or a mannanase.

7. An animal feed according to any preceding claim, additionally comprising mannosidase.

8. An animal feed according to any preceding claim, which comprises 1 to 7 units of the first enzyme; 100 to 1000 units of any second enzyme; and 1 to 21 units of any third enzyme.

9. A method of enhancing growth or weight gain in a domesticated animal, which comprises administering to the animal a feed according to any preceding claim.

10. A method according to claim 9, wherein the animal is avian.

11. A method according to claim 9, wherein the animal is porcine.

12. A method according to any preceding claim, which additionally comprises the prior step of determining the presence of the or each enzyme in the feed.