WO2022200795A1

WO2022200795A1 - Animal feed composition

Info

Publication number: WO2022200795A1
Application number: PCT/GB2022/050739
Authority: WO
Inventors: Michael Bedford; Sophie HISCOCKS; Alice KAMPER
Original assignee: Ab Vista - A Divsion Of Ab Agri Limited
Priority date: 2021-03-24
Filing date: 2022-03-24
Publication date: 2022-09-29
Also published as: GB202104173D0

Abstract

The present disclosure provides an animal feed composition at least one source of bioavailable silicon present in an amount from about 10 wt% to about 80 wt% of the total weight of the composition and a phytase. The present disclosure also provides a dry feed composition comprising at least one source of bioavailable silicon present in an amount from about 10 wt% to about 80 wt% of the total weight of the composition and a phytase. Also disclosed herein are processes for producing an animal feed composition comprising combining at least one source of bioavailable silicon with phytase by dry tumbling wherein the at least one source of bioavailable silicon present in an amount from about 10 wt% to about 80 wt% of the total weight of the composition. In another aspect, the present disclosure details use of an animal feed composition comprising at least one source of bioavailable silicon in an amount from about 10 wt% to about 80 wt% of the total weight of the composition and a phytase in an animal feed, animal feed additives, preparation of a composition for use in animal feed, in poultry or swine feed additives and/or for improving poultry or swine growth.

Description

ANIMAL FEED COMPOSITION

BACKGROUND OF THE INVENTION

The present disclosure concerns an animal feed composition comprising at least one source of bioavailable silicon in an amount from about 10 wt% to about 80 wt% of the total weight of the composition and a phytase and methods for preparing said animal feed composition.

Developing feed compositions that can aid the growth of animals is an important part of animal welfare and health. Recent developments and a better understanding of animal development has resulted in animal feed compositions and modified diets that can be used to increase growth rate. However, this increase in growth rate has resulted in significant problems with the skeletal development of the animals, including lameness and death. Therefore, there is a need to provide compositions that can help improve growth rate whilst preventing or offsetting some of the problems with current animal feed compositions.

SUMMARY OF THE INVENTION

Various compositions and processes for preparing these compositions are disclosed and described herein. One such composition is an animal feed composition comprising at least one source of bioavailable silicon in an amount from about 10 wt% to about 80 wt% of the total weight of the composition and a phytase. Another such composition is a dry animal feed composition comprising at least one source of bioavailable silicon in an amount from about 10 wt% to about 80 wt% of the total weight of the composition and a phytase. Also disclosed herein are processes for producing an animal feed composition and a dry animal feed composition comprising combining comprising at least one source of bioavailable silicon in an amount from about 10 wt% to about 80 wt% of the total weight of the composition with a phytase by dry tumbling. In another aspect, the present disclosure provides use of an animal feed composition comprising at least one source of bioavailable silicon present in an amount from about 10 wt% to about 80 wt% of the total weight of the composition and a phytase in animal feed, animal feed additives, preparation of a composition for use in animal feed, in poultry feed additives, in swine feed additives, for improving poultry growth and/or for improving swine growth. FIGURES

FIG. 1 shows the body weight gain (BWG) and feed intake (FI) in broilers from Example 2. FIG. 2 shows the feed conversion rate (FOR) in broilers from Example 2.

FIG. 3 shows the levels of silica in the plasma in broilers from Example 2.

FIG. 4 shows the tibia breaking strength in broilers from Example 2.

DETAILED DESCRIPTION OF THE INVENTION

The present disclosure provides an animal feed composition comprising at least one source of bioavailable silicon present in an amount from about 10 wt% to about 80 wt% of the total weight of the composition and a phytase. The animal feed composition may be a dry animal feed composition that does not comprise any liquid. There are a number of advantages associated with the animal feed compositions of the present disclosure.

The chemical element silicon is known to be important for skeletal development. Silicon is usually found in the form of the chemical compounds silica and silicates, which are stable compounds. The stability of these silica and silicates compounds means more bioavailable forms of silicon are usually sought after. There is an ongoing need to identify animal feed compositions which comprise bioavailable silicon and can be used to aid animal growth and development.

Burton et al. (Schoiey, D.V., Belton, D.J., Burton, E.J. eta!. Bioavailability of a novel form of silicon supplement). Sci Rep 8, 17022 (2018)) reported that for silicon to be bioavailable at the target tissue, silicon must be present in monomeric form. Burton et al. described that maintaining silicon in monomeric form when it is administered to poultry is important for ensuring the silicon is present in a bioavailable form when ingested by the animal. The formulation that Burton et al. identified combined sodium metasilicate with an equal quantity of citric acid and soya oil to produce a formulation which comprised a monomeric form of silica, orthosilicic acid. This orthosilicic acid formulation was then administered to poultry. Both Burton etal. and EP2268161 describe a formulation in which the silicon is provided in the form of orthosilicic acid. In order to achieve this, soya oil is required in the formulation to keep the silica from the sodium metasilicate in monomeric form, as orthosilicic acid. However, there are a number of problems associated with this formulation. One problem is that combining sodium metasilicate with citric acid and soya oil results in a final product that includes high quantities of oil. Even low quantities of oil are not always favourable in animal diets and therefore in those animals in which oil is not favoured, such a composition is unsuitable.

Another problem is that the cost of preparing a liquid or wet composition is expensive. The inclusion of oil is costly and makes the final product more expensive. In addition, the transportation costs of delivering and storing a liquid product are more than that compared to that of a dry product. Special liquid transportation is required to deliver the liquid formulation in an oil slurry. The cost of storing the wet composition is also more expensive as it requires specific storage tanks that are able to hold liquid formulations and keep the formulation in the right conditions. All of these additional processes result in a more expensive product and process. Finally, the shelf life of the dry composition is longer than that of the wet composition.

The animal feed compositions of the present invention, that comprise a bioavailable source of silicon and a phytase, have been found to be advantageous in aiding animal growth and development. Phytases increase the digestibility of phytate phosphorous, which is naturally occurring in plant products, and therefore they improve the availability of dietary phosphorous. Dietary phosphorous is important for metabolic and growth processes in animals, but particularly in poultry and swine. An animal composition that combines a phytase and at least one bioavailable source of silicon is an advantageous composition that can improve animal development and growth.

Surprisingly, and contrary to the teaching of Burton etal. and EP2268161, the present disclosure provides a dry animal feed composition of the present disclosure does not require the use of an oil and/or liquid. Furthermore, when the dry composition of the present invention is administered, it results in improved animal growth, particularly in poultry and swine, that is as effective as a wet animal feed composition.

The animal feed compositions of the present disclosure improves the bone breaking strength, body weight, and feed intake in poultry and swine compared to poultry and swine not treated with the composition.

The animal feed compositions of the present disclosure can stored for at least three months, at least six months, at least nine months, at least twelve months, or at least two years.

These long term storage capabilities of the composition are beneficial, particularly compared to wet or liquid compositions, as the composition has an improved shelf life and does not require specific transportation or storage conditions.

The animal feed compositions of the present invention have a number of advantages. The compositions can help improve the growth rate in poultry and/or swine. The skeletal development in poultry and swine may be a measure of the bone breaking strength of poultry or swine.

The animal feed composition may comprise at least one source of bioavailable silicon present in an amount from about 10 wt% to about 80 wt% of the total weight of the composition and a phytase.

The at least one source of bioavailable silicon may be present in an amount from about 10 wt% to about 70 wt%, in an amount from about 20 wt% to about 70 wt%, in an amount from about 20 wt% to about 60 wt%, in an amount from about 30 wt% to about 60 wt%, in an amount from about 20 wt% to about 50 wt%, or in an amount from about 30 wt% to about 50 wt% of the total weight of the composition. The source of bioavailable silicon may be present in the composition in an amount of about 20 wt%, about 30 wt%, about 40 wt%, about 50 wt%, about 60 wt%, about 70 wt%, about 80 wt%, or about 90 wt% of the total weight of the composition. Alternatively, the source of bioavailable silicon may be present in the composition in an amount of about 10 wt% to about 40 wt%, about 20 wt% to about 40 wt% or about 30 wt% to about 40 wt% of the total weight of the composition.

The source of bioavailable silicon used in the animal feed composition may have a moisture content of less than about 10% or less than about 5%. Preferably, the moisture content is between about 1% and about 5%. The source of bioavailable silicon may be selected from the group comprising or consisting of calcium silicate, hydrophobic silica, sodium silico aluminate, silicon dioxide or sodium metasilicate or any combination thereof. The source of bioavailable silicon may be sodium metasilicate. The source of bioavailable silicon may not be orthosilicic acid.

The animal feed composition may be a dry animal feed composition. The composition may not contain a liquid. The composition may have a moisture content of less than about 10%, less than about 5%, less than about 4%, less than about 3%, less than about 2%, or less than about 1%.

The composition may not contain an oil, such as soya oil, vegetable oil or animal fat or any combination thereof. The composition may not contain citric acid.

The phytase may be present in the composition may be in an amount between about 30 wt% and about 80 wt% of the total weight of the composition. The phytase may be present in an amount between about 10% to about 90%, between about 20 wt% to about 80 wt%, between about 30 wt % to about 70 wt%, between about 40 wt% to about 60 wt%, or about 40 wt % and about 50% of the total weight of the composition. The phytase may be present in the composition in an amount of about 20 wt%, about 30 wt%, about 40 wt%, about 50 wt%, about 60 wt%, about 70 wt%, about 80 wt%, or about 90 wt% of the total weight of the composition. Alternatively, the phytase may be present in the composition in an amount between about 5 wt% to about 15 wt%, about 5 wt% to about 10 wt% or about 10 wt% to about 15 wt% of the total weight of the composition.

The phytase may have an activity between about 125 FTU/kg to about 10,000 FTU/kg, about 500 FTU/kg to about 5,000 FTU/kg, about 500 FTU/kg to about 3,000 FTU/kg or about 500 FTU/kg to about 1,500 FTU/kg. Preferably the phytase has an activity between about 1,000 FTU/kg to about 2,500 FTY/kg, or about 1,500 FTU/kg to about 2,500 FTU/kg.

Commercially available phytases may be used in the composition of the present invention, such as Quantum Blue™ which is available from AB Vista. Other phytases may be used such as phytases produced through plant expression or through fermentation, phytases produced by fermentation where the production host is from the genus Aspergillus; Pichia; Schizosaccharomyces; Trichoderma or phytases produced by fermentation where the phytase gene is obtained from, or is based on the gene from Peniophora ; Escherichia coli, Butiauxella ; or Citrobacter. Possible source organisms for the phytase include Aspergillus niger, Aspergillus orzyae, Aspergillus orzyae expressing the Peniophora lycii phytase gene, Brassica napus (canola) expressing the Aspergillus niger gene (plant expression), Pichia pastoris expressing an Escherichia coli gene, Schizosaccharomyces pombe expressing an E.coii gene, Trichoderma reesei expressing an E.coii altered gene (Quantum Blue), Trichoderma reesei expressing a Buttiauxella sp altered gene, Aspergillus orzyae expressing a synthetic gene coding for a phytase from Citrobacter braakii, Zea Mays (corn) expressing an altered E. coli phytase gene (plant expression). Alternatively, phytase blends comprising one or more phytases may be used or phytase blends comprising phytase and other additives.

The composition may be an animal feed composition, specifically a poultry feed composition or a swine feed composition. The composition of the present disclosure is suitable as a composition for chickens, turkeys, ducks, geese and swine.

The source of bioavailable silicon in animal feed composition may be in, or may substantially be in, polymeric form. The source of bioavailable silicon may be present in at least 60% at least 70%, at least 80%, at least 90% or at least 100% polymeric form.

The source of bioavailable silicon may be in the forms of powder, granulate or particles. When the source of bioavailable silicon is in the form of particles, the particle size may range from about 1 pm to about 1250pm, about 1 pm to about 250pm, or about 200pm to about 1250pm. The composition may further comprise additional ingredients, such as carriers. A particularly preferred additional ingredient is xylanase. A particularly preferred carrier is calcium stearate. Any additional ingredients or carriers may be in dry form or in the form of particulates, powders or granules.

The xylanase, calcium stearate or a combination thereof may be present in an amount from about 10 wt% to about 70 wt%, in an amount from about 20 wt% to about 70 wt%, in an amount from about 20 wt% to about 60 wt%, in an amount from about 30 wt% to about 60 wt%, in an amount from about 20 wt% to about 50 wt%, or in an amount from about 30 wt% to about 50 wt% of the total weight of the composition. The xylanase, calcium stearate or combination thereof may be present in the composition in an amount of about 20 wt%, about 30 wt%, about 40 wt%, about 50 wt%, about 60 wt%, about 70 wt%, about 80 wt%, or about 90 wt% of the total weight of the composition. Alternatively, the source of bioavailable silicon may be present in the composition in an amount of about 10 wt% to about 40 wt%, about 20 wt% to about 40 wt% or about 30 wt% to about 40 wt% of the total weight of the composition.

The present disclosure also provides a method of producing a dry animal feed composition comprising combining at least one source of bioavailable silicon with a phytase by dry tumbling wherein the at least on source of bioavailable silicon is present in an amount from about 10 wt% to about 80 wt% of the total weight of the composition. The dry animal feed composition prepared by this method can include any combination of features disclosed above with reference to the composition.

The present disclosure also includes use of at least one source of bioavailable silicon and a phytase in the preparation of an animal feed composition, wherein the bioavailable silicon is present in an amount from about 30 wt% to about 80 wt% of the total weight of the composition. The present disclosure also includes use of an animal feed composition as described in an animal feed; in animal feed additives; in the preparation of a composition for use animal feed; in poultry feed additives; in swine feed additives; improving poultry and/or for improving swine growth.

The source of bioavailable silicon can be combined with a phytase alone, a combination of phytases, or with a pre-formulated phytase blend that may include one or more additives. EXAMPLES

The invention will be further described with reference to the following examples. EXAMPLE 1 Example 1A

Sodium metasilicate and phytase were combined by dry tumbling to form a dry animal feed composition.

Example 1B

Sodium metasilicate, phytase and calcium stearate were combined by dry tumbling to form a dry animal feed composition.

Example 1C

Sodium metasilicate, phytase and xylanase were combined by dry tumbling to form a dry animal feed composition. Example 1D

Sodium metasilicate, phytase and xylanase were combined by dry tumbling to form a dry animal feed composition. Example 1 E

Sodium metasilicate, phytase, xylanase and calcium stearate were combined by dry tumbling to form a dry animal feed composition.

Example 1F

Calcium silicate and phytase were combined by dry tumbling to form a dry animal feed composition.

Example 1G

Calcium silicate, phytase and xylanase were combined by dry tumbling to form a dry animal feed composition. Example 1H

Calcium silicate, phytase, xylanase and calcium stearate were combined by dry tumbling to form a dry animal feed composition.

Example 11

Silicon dioxide, phytase and xylanase were combined by dry tumbling to form a dry animal feed composition. Example 1J

Sodium dioxide, phytase and calcium stearate were combined by dry tumbling to form a dry animal feed composition. Example 1 K

Silicon dioxide, phytase, xylanase and calcium stearate were combined by dry tumbling to form a dry animal feed composition.

Example 1L

Hydrophobic silica, phytase and xylanase were combined by dry tumbling to form a dry animal feed composition. Example 1M

Hydrophobic silica, phytase and calcium stearate were combined by dry tumbling to form a dry animal feed composition. Example 1N

Hydrophobic silica, phytase, xylanase and calcium stearate were combined by dry tumbling to form a dry animal feed composition.

Example 10

Sodium silico aluminate, phytase and xylanase were combined by dry tumbling to form a dry animal feed composition. Example 1P

Sodium silico aluminate, phytase and calcium stearate were combined by dry tumbling to form a dry animal feed composition. Example 1Q

Sodium silico aluminate and phytase were combined by dry tumbling to form a dry animal feed composition.

Example 1R

Sodium silico aluminate, phytase, xylanase and calcium stearate were combined by dry tumbling to form a dry animal feed composition.

EXAMPLE 2

A study was carried out comparing a control composition comprising a phytase, a composition comprising a phytase and sand, a phytase and silica composition in soya oil produced by the old milling method (one single chamber, 30g capacity), a phytase and silica composition in soya oil produced by an new ball mill method (4 separate chambers, 100g capacity each), a phytase and silica composition with a dry calcium stearate carrier using the new ball milling method. The study was carried out in 192 broilers (Ross 308) with 9 replicates for each treatment.

Table 1 : Diet analysis of broilers after treatment.

Table 2: Review of the Tibia strength, weight, length and width in broilers after treatment.

5

Table 3: Review of body weight gain, feed intake and feed conversion ratio in broilers after 21 days of treatment.

The results of the study are shown in Figures 1, 2, 3 and 4 and were obtained on day 21 of treatment. The results show that the dry formulation which includes calcium stearate as a 0 carrier for the sodium metasilicate, performs as well as the oil formulation. EXAMPLE 3

A study was carried out in male broilers (Ross 308). The study was carried out in 222 birds (Ross 308) with 8 replicates for each treatment.

Sodium metasilicate (97%) comprised 100% of the total product mix (Si). Phytase was included in treatments 2, 3 and 4 at 200 g/t with an analysed activity of around 1400 FTU/kg.

Supplementing broiler diets with a combination of phytase and Si increased (P < 0.01) weight gain on average by 87g (13%) and reduced (P < 0.001) the feed conversion ratio (FCR) by around 6 points (5%) during the first 21 days (Table 4). However, this effect was muted over the entire experimental period (42 days). At day 42, bone breaking strength (BS) was increased (P £ 0.05) by approximately 15% in birds fed 200 g/t phytase and 150 g/t Si compared to the non-supplemented control, with 300 and 600 g/t Si product having intermediate BS (Table 4). dO-21 dO-42 _

Phytase BWG, FCR, BWG, FCR, bwFCR, _BS ^

Treatment g/t Si, g/t g FI, g g g FI, g g _ g _ _

1 0 0 680^b 962 1 360^a 2799 4172 1.514 1.501 _{367 1} b

2 200 150 777^a 1018 1.310^b 2759 4286 1.556 1.550 422.5^a

3 200 300 756^a 983 1.301^b 2714 4232 1.561 1.565 ₃gg -\ ab

4 200 600 769^a 998 1.278^b 2861 4323 1.513 1.487 3972^ab

R2 0.43 0.21 0.47 0.13 0.10 0.19 0.17 0.36

RMSE 47.41 42.51 0.03 154.95 178.02 0.05 0.08 36.96

LSD 67.05 60.11 0.05 219.14 251.75 0.07 0.11 52.27

P-value

Treatment 0.001 0.093 <0.001 0.296 0.372 0.122 0.153 0.052 a^b Data in a column not sharing a common superscript letter significantly differ at P < 0.05 Table 4: Review of body weight gain, feed intake and feed conversion ratio in broilers.

EXAMPLE 4

A study was carried out in pigs (Duroc X Large White X Landrace weaned pigs, 50:50 male and female). The study was carried out in 6 pigs with 10 replicates for each treatment.

Sodium metasilicate (97%) comprised 48% of the total product mix. Phytase was included all diets at 400g/t, with an analysed activity of approximately 1500 FTU/kg and in the form of granulates (particle size between 200-1250 pm)

Increasing Si dose linearly increased (P < 0.001) average daily gain (ADG) of pigs at 42 days, with pigs fed 1250 mg/kg Si gaining approximately 40g extra per day compared to controls and improving overall ADG by 11% (Table 6). Adding Si had no effect on daily feed intake (DFI), but reduced (quadratic, P< 0.001) FCR, with the highest dose of 1250 mg/kg lowering FCR by 7% (10 points) compared to controls (Table 5).

At day 43, the femur bone strength was not significantly affected by treatment. However, numerically there is a clear relationship between increasing Si dose and bone strength, with the highest dose of 1250 mg/kg increasing bone strength by 33.11 kg/cm², which is a 15% improvement from the control.

Si dose, ADG, _n ,_ _D Bone strength, mg/kg_ kg

_ kg/cm²

0 0.37^b 0.55 1 490^a 225.7

250 0.40^a 0.56 1 414^b 241.3

750 0.40^a 0.56 1.390^bc 252.5

1250 0.41^a 0.56 1.386^c 258.8

RMSE 0.02 0.031 0.028 35.82

R2 0.67 0.63 0.85 0.49

LSD 0.029 0.045 0.04 51.93

P-value Si dose <0.001 0.625 <0.001 0.204 Block 0.005 <0.001 <0.001 0.045

Contrasts^*

Linear <0.001 <0.001

Quadratic 0.069 <0.001 ^a_cData in a column not sharing a common superscript letter significantly differ at P < 0.05 ^* Contrast significance accepted at P £ 0.0125

Table 5: Review of average daily gain, daily feed intake and feed conversion ratio in weaner pigs.

Claims

1. An animal feed composition comprising at least one source of bioavailable silicon present in an amount from about 10 wt% to about 80 wt% of the total weight of the composition and a phytase.

2. An animal feed composition according to claim 1, wherein the source of bioavailable silicon is at least one selected from the group consisting of calcium silicate, hydrophobic silica, sodium silico aluminate, silicon dioxide or sodium metasilicate.

3. An animal feed composition according to any preceding claim, wherein the source of bioavailable silicon is sodium metasilicate.

4. An animal feed composition according to any preceding claim, wherein the composition does not contain oil.

5. An animal feed composition according to any preceding claim, wherein the composition does not contain soya oil.

6. An animal feed composition according to any preceding claim, wherein the source of bioavailable silicon is present in the composition in an amount between about 30 wt% and about 50 wt% of the total weight of the composition.

7. An animal feed composition according to any preceding claim, wherein the phytase is present in the composition in an amount between about 30 wt% and about 80 wt% of the total weight of the composition.

8. An animal feed composition according to any preceding claim, wherein the phytase is produced by fermentation and the production host is selected from Aspergillus,

Pichia, Schizosaccharomyces, or Trichoderma.

9. An animal feed composition according to claim 8, wherein the production host is Trichoderma reesei.

10. An animal feed composition according to any proceeding claim, wherein the composition is a dry composition.

11. An animal feed composition according to any preceding claim, wherein the source of bioavailable silicon is in polymeric form.

12. An animal feed composition according to any preceding claim, wherein the phytase has an activity between about 125 FTU/kg to about 10,000 FTU/kg.

13. An animal feed composition according to any preceding claim, wherein the bioavailable source of silicon is in the form of powder or granulate.

14. An animal feed composition according to any of claims 1 to 13, wherein the bioavailable source of silicon is in the form of particles.

15. An animal feed composition according to claim 14, wherein the particles have a particle size ranging from about 1pm to about 1250pm.

16. An animal feed composition according to any preceding claim, further comprising xylanase.

17. An animal feed composition according to any preceding claim, further comprising calcium stearate.

18. An animal feed composition according to any preceding claim, wherein the animal feed composition is a poultry feed composition or a swine feed composition.

19. A method of producing an animal feed composition comprising combining at least one source of bioavailable silicon with a phytase by dry tumbling, wherein the at least one source of bioavailable silicon is present in an amount from about 30 wt% to about 80 wt% of the total weight of the composition.

20. A method according to claim 19, wherein the source of bioavailable silicon is at least one selected from the group consisting of calcium silicate, hydrophobic silica, sodium silico aluminate, silicon dioxide or sodium metasilicate.

21. A method according to claim 19 or claim 20, wherein the source of bioavailable silicon is sodium metasilicate.

22. A method according to any of claims 19 to 21 , wherein the composition does not contain oil.

23. A method according to any of claims 19 to 22, wherein the composition does not contain soya oil.

24. A method according to any of claims 19 to 23, wherein the source of bioavailable silicon is present in the composition in an amount between about 30 wt% and about 50 wt% of the total weight of the composition.

25. A method according to any of claims 19 to 24, wherein the phytase is present in the composition in an amount between about 30 wt% and about 80 wt% of the total weight of the composition.

26. A method according to any of claims 19 to 25, wherein the phytase is produced by fermentation and the production host is selected from Aspergillus, Pichia, Schizosaccharomyces, or Trichoderma.

27. A method according to claim 26, wherein the production host is Trichoderma reesei.

28. A method according to any of claims 19 to 27, wherein the composition is a dry composition.

29. A method according to any of claims 19 to 28, wherein the source of bioavailable silicon is in polymeric form.

30. A method according to any of claims 19 to 29, wherein the phytase is present in an amount between about 10 wt% and about 30 wt%.

31. A method according to any of claims 19 to 30, further comprising adding xylanase and/or calcium stearate to the animal feed composition.

32. A method according to any of claims 19 to 31 , wherein the animal feed composition is a poultry feed composition or a swine feed composition.

33. Use of at least one source of bioavailable silicon and a phytase in the preparation of an animal feed composition, wherein the bioavailable silicon is present in an amount from about 30 wt% to about 80 wt% of the total weight of the composition.

34. Use according to claim 33, wherein the source of bioavailable silicon is at least one selected from the group consisting of calcium silicate, hydrophobic silica, sodium silico aluminate, silicon dioxide or sodium metasilicate.

35. Use according to claim 33 or claim 34, wherein the source of bioavailable silicon is sodium metasilicate.

36. Use according to any one of claims 33 to 35, wherein the composition does not contain oil.

37. Use according to any one of claims 33 to 36, wherein the source of bioavailable silicon is present in the composition in an amount between about 30 wt% and about 50 wt% of the total weight of the composition.

38. Use according to any one of claims 33 to 37, wherein the composition is a dry composition.

39. Use according to any one of claims 33 to 38, wherein the source of bioavailable silicon is in polymeric form.

40. Use according to any one of claims 33 to 39, further comprising xylanase in the composition.

41. Use according to any one of claims 33 to 40, wherein the animal feed composition is a poultry feed composition or a swine feed composition.

42. Use of an animal feed composition according to any one of claims 1 to 18: in animal feed; in animal feed additives; in the preparation of a composition for use in animal feed; in poultry feed additives; in swine feed additives; improving poultry and/or for improving swine growth.