NZ549705A - Animal production - Google Patents

Abstract

A method of increasing animal production by introducing a nitrification inhibitor into the digestive tract of a non-human animal, which affects the conversion of nitrogen containing compounds in animal waste, once the waste has been excreted from the animal. A preferred embodiment is a sustained slow release device administered orally to grazing animals with targeted delivery to the digestive tract. Other embodiments include animal feed and water trough applications.

Description

New Zealand Paient Spedficaiion for Paient Number 549705 *10054165910 / 3 0 Ab'B 2007 j [ft P Q £ j y p- |-», j PATENTS FORM NO. 5 ' Fee No. 4: $250.00 PATENTS ACT 1953 COMPLETE SPECIFICATION After Provisional No: 549705 Dated: 5 September 2006 ANIMAL PRODUCTION WE AGRESEARCH LIMITED, a New Zealand company duly incorporated pursuant to the Crown Research Institutes Act 1992 and having its Registered Office at 5th Floor Tower Block, Ruakura Research Centre, East Street, Hamilton, NEW ZEALAND hereby declare the invention for which I/We pray that a patent may be granted to me/us, and the method by which it is to be performed to be particularly described in and by the following statement: 549705 James & Wells Ref: 231549/47 ANIMAL PRODUCTION TECHNICAL FIELD The present invention relates to a method of increasing animal production. Particularly, although not exclusively, the present invention relates to chemical 5 inhibitors and animal production.

BACKGROUND ART One of the most important considerations surrounding livestock is to increase animal production such as milk, wool and live-weight gain.

A number of methods have been used in the industry to increase animal 10 production.

Hormone-dependent sex differences in growth rate have been known for a long time. It has also been known that growth rate and FCE (Feed Conversion Efficiency) are higher in intact males than in castrates. It was a natural progression with the availability of hormones and other natural or synthetic 15 substances displaying hormone activity which led to experiments aiming at their use to increase production.

Beginning in the mid-1950's, DES (diethyl stilboestrol) and hexoestrol were administered to cattle increasingly in the US and the UK respectively, either as feed additives or as implants, and other types of substances also gradually 20 became available.

In general, such treatment has resulted in 10-15% increases in daily gains, similar improvements in FCE and improvement of carcass quality (increased lean/fat ratio). 2 549705 James & Wells Ref: 231549/47 Another example of hormone control in animal production are studies of prolactin. This is a hormone of the anterior pituitary whose secretion varies seasonally in many species, has previously been implicated in the control of hair growth in various species including wool growth cycles in primitive and shedding breeds of 5 sheep.

Prolactin receptors have been identified in the wool follicle revealing a physiological mechanism whereby circulatory prolactin can mediate wool growth cycles.

While the use of hormonally active substances in animal production rose, a disadvantage of this animal production means is the opposition to the use which 10 also has increased, because of the theoretical possibility that residues in edible tissues might endanger consumers.

These factors led to the ban in DES in the US, first imposed in 1973. Several reports confirm that DES endangers the health of animal and humans, when repeatedly used in large doses.

In all the animal industries, one of the primary reasons for the use of antibiotic drugs is for production enhancement (increased growth rate and efficiency of feed use). A significant disadvantage of antibiotic use is that resistance to antibiotics can build up, not only in the animal microflora, but also in humans as residual amounts of antibiotics may enter the food chain.. For this reason, dairy cows 20 treated with antibiotics are required to have their milk withheld for a considerable time, resulting in potential economic penalties for the producer..

Other studies that have been conducted to increase animal production include attempts to increase utilisation of protein from animal feeds.

It was thought that forages containing protected protein (proteins that are protected 25 from rumen digestion) would help more protein uptake up by the animals. The 3 549705 James & Wells Ref: 231549/47 theory was that the animals should grow faster.

Condensed tannins have increased animal performance by increasing the flow of non-ammonia nitrogen into intestine of ruminants. See Want, Y., Douglas, G.B., Waghorn, G.C., Barry, T.N., and Foote, A.G. 1996. Effect of condensed tannins in 5 Lotus corniculatus upon lactation performance in ewes. Journal of Agricultural Science, Cambridge. 126:353-362 and Waghorn, G.C., Shelton, I.D., McNabb, W.C., and McCutcheon, S.N. 1994. Effects of condensed tannins in Lotus peduncalatus on its nutritive value for sheep. 2. Nitrogenous aspects. Journal of Agricultural Science. 123:109-119.

Tannins increase animal production in spite of reductions in the digestibility of nitrogen (i.e. more nitrogen ends up in the dung). This could be argued as a benefit of tannins, as more nitrogen goes into faeces relative to urine.

However, plants containing condensed tannins can be difficult to grow, their yield per hectare is generally lower than other grasses and legumes, and have low 15 resistance to grazing. Therefore, their use is limited in pastoral systems.

Although some of the methods of animal production discussed, result in conversion of feeds into valuable products such as meat, milk, eggs and wool, it may also create residues which are undesirable.

None of the prior art methods mentioned above disclose a method of increasing 20 animal production while benefiting the environment. A possible exception is condensed tannin plants which may theoretically reduce environmental nitrogen losses by reducing urinary nitrogen, although such environmental benefits are relatively untested Therefore, it would be an advantageous to have a method of increasing animal 25 production which is non-toxic to the animal and benefits the environment. 4 549705 James & Wells Ref: 231549/47 All references, including any patents or patent applications cited in this specification are hereby incorporated by reference. No admission is made that any reference constitutes prior art. The discussion of the references states what their authors assert, and the applicants reserve the right to challenge the accuracy and 5 pertinency of the cited documents. It will be clearly understood that, although a number of prior art publications are referred to herein, this reference does not constitute an admission that any of these documents form part of the common general knowledge in the art, in New Zealand or in any other country.

It is acknowledged that the term 'comprise' may, under varying jurisdictions, be 10 attributed with either an exclusive or an inclusive meaning. For the purpose of this specification, and unless otherwise noted, the term 'comprise' shall have an inclusive meaning - i.e. that it will be taken to mean an inclusion of not only the listed components it directly references, but also other non-specified components or elements. This rationale will also be used when the term 'comprised' or 15 'comprising' is used in relation to one or more steps in a method or process.

It is an object of the present invention to address the foregoing problems or at least to provide the public with a useful choice.

Further aspects and advantages of the present invention will become apparent from the ensuing description which is given by way of example only.

DISCLOSURE OF INVENTION According to one aspect of the present invention there is provided a method of increasing animal production, characterised by the step of, introducing a nitrification inhibitor into the digestive system of an animal. 549705 James & Wells Ref: 231549/47 The term 'animal production' should be taken to mean any product(s) or qualities of value derived from animals for market or research.

In preferred embodiments of the present invention the animal production which may be measured is live-weight gain. However, this should not be seen as a 5 limitation on the present invention in any way. Other embodiments of animal production which may be measured include increased gains and quality in animal by products such as milk, wool and meat or any other such animal derived products.

In preferred embodiments of the present invention the animal will be a farm animal, 10 and more preferably dairy or beef cattle. Once again, this should not be seen as a limitation as it is anticipated the present invention could be used on other intensively farmed ruminants such as sheep, goats and so forth.

The term 'nitrification inhibitor' refers to any substance including at least one compound capable of directly or indirectly affecting the conversion of nitrogen 15 containing compounds.

The term "nitrogen containing compound" should be taken to mean any compound which contains nitrogen as part of its chemical structure.

Specifically, a nitrification inhibitor is known to affect the conversion of ammonium to nitrate by inhibiting the bacterial species responsible for transformation of 20 ammonium to nitrate in soil (Nitrosomonas spp).

It is desirable to use inhibitors that can be used in small amounts, and which are non-toxic to the animal. The amount of inhibitor administered will be dependent upon a number of factors, including the choice of inhibitor, as well as the body weight of the animal. It is anticipated effective amounts of each inhibitor could be 25 readily discernable to a skilled addressee. 6 549705 James & Wells Ref: 231549/47 A number of nitrification inhibitors are known in the art which may find use in the present invention. For example, a nitrification inhibitor suitable is dicyandiamide (DCD), which has been shown to inhibit nitrification of fertiliser nitrogen and animal 5 urinary nitrogen when applied at relatively low rates and is non-toxic.

Another nitrification inhibitor which may find use is 3,4-dimethylpyrazole phosphate (DMPP).

However, this should not be seen as a limitation of the present invention. Any other nitrification inhibitor known in the art could conceivably be used in the 10 invention.

The nitrification inhibitor may optionally also include one or more other beneficial compounds which function to improve or condition micro-organisms already present in the animal's digestive system or possibly the soil, allowing them to increase protein utilisation by the animal. Additionally, much of the nitrification 15 inhibitor passes through unaltered in the animal urine and reduces environmental losses from the urine-nitrogen. Urine from animals is recognised as the main source of nitrogen loss to the environment in grazed pastures.

In preferred embodiments of the present invention the nitrogen inhibitor may be referred to simply as a 'nitrogen process modifier'.

A nitrogen inhibitor is introduced to an animal as a means of increasing animal production while being a carrier for the introduction of nitrogen process modifiers which affect the conversion of nitrogen containing components in the environment.

The nitrogen inhibitor not only increases animal production, but delivers the nitrogen process modifiers to the environment via animal waste. This means no or 25 little delay occurs in modifying the conversion of nitrogen containing compounds. 7 549705 James & Wells Ref: 231549/47 Further, this ensures the nitrogen process modifiers are only delivered to the portion of pasture/soil on which the animal urinates, eliminating the need to apply the modifiers over a large area of pasture.

The nitrogen process modifiers (inhibitors) of the present invention may be 5 introduced to the animal by a number of mechanisms.

In preferred embodiments the present invention inhibitors may be introduced to the animal through the digestive system of the animal using a delivery device.

When delivering the inhibitors via the digestive system, it is essential to ensure that inhibitors largely maintain their activity and are not denatured or inactivated through 10 the passage of the animal's digestive system.

In some embodiments, the delivery device may be encapsulated to provide protection against full denaturation and subsequent absorption in the rumen or intestine.

The delivery device may be in the form of a sustained slow release device 15 administered orally to an animal such as a ruminal bolus.

As understood by persons skilled in the art, a bolus is typically in the form of an elongate cylinder designed to slowly dissolve in the rumen of an animal.

One advantage of having sustained release devices is that the amount of modifiers released can be accurately known. This makes the treatment and analysis of the 20 effects of the treatment of the animal much more precise than previously, The bolus will preferably be composed of a solid matrix, coated with an impervious material having an opening through which the modifiers can be released, or a bio-erodeable coating which release the modifiers as they are exposed.

A wide variety of boluses and other delivery mechanisms are well known in the art 8 549705 James & Wells Ref: 231549/47 and it is anticipated these technologies could readily be adapted by a skilled addressee for use in the present invention.

In particular, the present invention may be used with a sustained slow release device consisting of a series of capsules within a housing which dissolve at a 5 controlled rate in the stomach of the animal. One such example is the Captec™ bolus.

Other delivery mechanisms may also be used for the application of the inhibitor to the animal. These may include incorporating the inhibitor in animal feed, adding onto feed or into a water trough, or by other traditional delivery mechanisms such 10 as drenches or injections.

The delivery device may optionally include other compounds beneficial to the animal being treated, or micro-organisms residing in the digestive tract of the animal in addition to the nitrification inhibitor. For example, the delivery device may also include trace elements such as zinc, copper and/or selenium.

Alternatively, the delivery device may include an anthelmintic in addition to the nitrification inhibitor.

It is anticipated that the use of nitrogen process inhibitors will be most effective for reducing environmental impacts over seasonal time periods such as from mid-autumn to late-winter, an extended period of approximately three to four months. 20 As such it will be desirable to have a composition or delivery device that slowly released inhibitors over this time period. Weight gain can be at any time.

During the winter period, nitrogen is the most prone to loss by processes of leaching and/or denitrification/nitrous oxide emission.

However, this should not be seen as a limitation for other embodiments or in other 25 embodiments. The inhibitors may be delivered over a shorter time period, with a 9 549705 James & Wells Ref: 231549/47 number of treatments administered to the animal as required.

A preferred embodiment of the present invention is the use of a nitrogen inhibitor (modifier) to increase animal live-weight.

Nitrogen modifiers in the rumen can alter the utilisation of nitrogen by the rumen 5 microflora. If such changes in microbial metabolism result in an increased amount of non-ammonia nitrogen (i.e. more microbial protein and/or more undegraded dietary protein) reaching the small intestine, the overall effect would be similar to offering a forage with low protein degradability. Besides the effect on the total post-ruminal supply of protein, there would be expected a reduction in the energy 10 expenditure associated to ammonia detoxication. The postulated extra supply of protein and energy will be used by the animal metabolic processes responsible for production (i.e. growth, milk production).

Part of the increase in nitrogen utilisation may also be due to nitrogen being slowly released from the nitrification inhibitor in the digestive system (i.e. the nitrification 15 inhibitor acting as a source of slowly degradable nitrogen in the rumen).

There are secondary advantages of the nitrogen inhibitor which include slowing the rate of transformation of ammonium to nitrate in soil.

Inhibiting or modifying the conversion of nitrogen containing compounds allows more time for the nitrogen excreted in animal waste to be absorbed by plants, 20 before being lost by soil processes such as leaching from the soil as nitrate. This will also reduce the level of nitrate entering ground water and affecting water quality in drinking water supplies.

It is also likely to reduce the levels of nitrous oxide released in the environment thus reducing levels of greenhouse gases emitted from intensive farming 25 operations. 549705 James & Wells Ref: 231549/47 The present invention thus encompasses a range of different mechanisms by which nitrogen inhibitors could be introduced into the digestive system of animals to achieve an increase in animal production with a reduction in loss of nitrogen containing compounds into the environment.

Specific advantages of this approach include: 1. animals treated with certain dosages and types of nitrogen inhibitor retain nitrogen mirrored by increases in live-weight gain, 2. tests of hepatic and renal functions show no evidence of deleterious effect caused by the treatment with nitrogen inhibitors, 3. offering a broader feed base as the nitrogen inhibitor may be introduced into the digestive system by a number of methods e.g. bolus or water trough supply, 4. multiple animal production benefits including increased gains and/or quality to animal products such as milk, wool and meat, 5. reduction in loss of nitrogen containing compounds into the environment which includes both nitrate leaching and nitrous oxide emissions.

BEST MODES FOR CARRYING OUT THE INVENTION As defined above, in its primary aspect, the present invention is directed to a novel method of increasing animal production by introducing to the digestion system of an animal a nitrification inhibitor that increases animal production and affects the conversion of nitrogen containing compounds in animal waste, once the waste has been excreted from the animal.

The invention is based upon the inventors' investigation into the delivery of nitrogen process modifiers, animal production and the modification of nitrogen containing 11 549705 James & Wells Ref: 231549/47 compounds in animal waste.

One preferred embodiment of the present invention consists of a sustained slow release device administered orally to grazing animals with targeted delivery to the digestive system then processed into animal waste, and urine in particular.

In preferred embodiments the sustained slow release device is in the form of a slow release bolus which is inserted into the rumen and which releases nitrogen transformation modifiers over a sustained period of up to four months. A bolus may additionally include a rumen-stable delivery system to deliver the modifiers post-ruminally.

A generic composition of the bolus is as follows, i) a core comprising a substantially homogeneous mixture of: a) a water insoluble physiologically acceptable binder comprising wax, fat, oil, fatty acid, fatty acid ester, fatty acid amide, fatty acid alcohol or the like organic compound having a melting point above 50°C; b) a physiologically acceptable solubilising agent, such as polyethylene glycol stearate or the sodium salt of a long-chain fatty acid, c) at least one nitrogen transformation modifier, d) where required, a physiologically acceptable inert densifier of sufficient density and in sufficient quantities to give the bolus a minimum density of 1.5g/cm3; and ii) a coating of a physiologically acceptable material over substantially all of the surface of the core but leaving exposed a core portion whereby in use liquid in the rumen will dissolve said core allowing release of the nitrogen transformation modifier into the rumen. 12 549705 James & Wells Ref: 231549/47 One preferred embodiment of the bolus may include a nitrogen transformation modifier in the form of nitrification inhibitor such as DMPP or DCD with a binding agent such as glycerol monostearate.

The size of the bolus and the amount of modifier required will be dependent on a 5 number of factors, including the identity and concentration of the inhibitor the body weight of the animal and the desired length of treatment. Such factors would be readily discernable to a skilled addressee.

EXAMPLE ONE Sheep study on live-weight gain and DCD nitrogen inhibitor Experimental Design A modified cross-over design involving 12 sheep was used with 2 treatments and 2 time periods. During each period, the following treatments, with 6 replicate sheep, were infused via the rumen continuously over 5 days: 1. Control, 500 ml distilled water daily 2. DCD solution with 15 g in 500 ml water daily All animals then had a 9 day non-treatment clearance/rest period, before treatments were reversed. A second 5-day infusion period then commenced, followed by a 9 day non-treatment clearance/rest period. The cross-over design meant that the 12 sheep received both treatments, thereby enabling within-sheep 20 comparisons.

Animal Management and Sampling Twelve Romney cryptorchid lambs (c. 35 kg live-weight at the beginning of the experiment) were implanted with custom made Teflon ruminal cannulae under 13 549705 James & Wells Ref: 231549/47 general anesthesia as described by Bermingham (2004). The sheep were placed in individual metabolism crates for two experimental periods. Each experimental period comprised 5 days for infusion of the treatments; and 9 days for collection of a 'wash-out1 sample after infusion. They were fed 0.95 kg (dry basis) of a 70:30 5 mix of alfalfa/maize pellets and molassed alfalfa hay providing 15.5% crude protein in the total mix (dry matter basis). Animals had free access to water at all times during the course of the experiment.

All treatment solutions were infused using a peristaltic pump (Watson Marlow; Watson Victor Ltd., Auckland, New Zealand). Infusion lines were washed with 10 warm de-ionised water between each infusion period.

A custom-made urine collection device (200 ml capacity) was tied around the middle of the sheep at the start of each day. When urination had occurred, samples were placed in sterile sample jars, frozen at -20°C and retained for N process measurements and DCD analysis. After collection, the device was 15 removed and subsequent urination was funnelled from the metabolism crate into a container with sufficient HCI (17% w/v) to maintain the pH of the urine below 2 to avoid ammonia volatilisation. At the end of each 24 hour period, urine volumes were recorded and samples were frozen and retained for analysis. Total faecal output over 24 h was collected into faecal collection bags harnessed to the 20 animals. Faecal samples were placed in sterile sample jars, frozen at -20°C and retained for DCD analysis. Urine and faeces over the 5 d collection period were pooled according to weight and analysed for measurements of N balance according to the methods described by Pinares-Patino et al. (2003). The N concentration of the faeces and urine samples was analysed in a Nitrogen 25 Analyser 1500 (Carlo Erba Instruments, Milan, Italy) using an instrumental combustion method. 14 549705 James & Wells Ref: 231549/47 Fourteen days after the final infusion period, the sheep were slaughtered at the AgResearch Grasslands Animal Handling facility and various animal tissue samples were collected from each sheep, including muscle, fat, liver, kidney and wool. Sheep live-weights were measured at the start and end of the DCD infusion 5 period.

Animal tissue samples were first homogenised in distilled water and centrifuged. The supernatant was then mixed in 20% trichloroacetic acid, before further centrifugation, solid phase extraction of the resulting supernatant and analysis for DCD by HPLC.

Statistical Analysis Data for the nitrogen balance variables was analysed as a mixed model, with treatment being the fixed effect, with period, sheep and their interaction being the random effects. Estimates were calculated using restricted maximum likelihood method in Genstat v. 8.11 (2005). Significance of fixed effects was assessed by 15 means of Wald test statistics compared to a chi-square distribution.

RESULTS DCD in Urine and Faeces In all sheep treated with DCD, the concentration of DCD in urine increased within the first day of infusion, doubled by the second day and remained at this level 20 during the subsequent and last 2 days of the infusion period, after which it declined.

Sheep N Balance and Health The apparent digestibility of dietary N was not affected by the DCD treatment (78.1 vs. 75.0 g/100 dietary N for the Control group, SED = 2.2). 549705 James & Wells Ref: 231549/47 The amount of nitrogen retained (dietary N input minus excreta N) was higher for the DCD-treated group (7.07 vs. -0.18 g N/d; SED = 2.23; P < 0.01). This effect on nitrogen retention was mirrored by the changes in live-weight measured during the experiments; animals treated with DCD gained weight (1.23 Kg) while control 5 animals lost weight (-0.85 kg) over the 5 d of the infusion period (SED = 0.67; P < 0.01).

The tests of hepatic and renal function showed no evidence of deleterious effects caused by the treatment. This was evident in blood analyses for GGT of 57.6 and 56.1 IU/L (SEM = 3.9, not significant) for Control and DCD treatments, 10 respectively. Similarly, most of the other clinical parameters were not significantly affected by the treatments. The only exception was albumin, which was 26 and 24 (SEM = 0.8 ) g/L, for the Control and DCD treatments. However, both values were within the reference range for sheep (21-41 g/L).

DISCUSSION Sheep treated with DCD had significantly higher live-weight gain than untreated sheep. This coincided with an increase in the amount of nitrogen retained by the sheep indicating grater retention and utilisation of dietary nitrogen. It is postulated that this was largely due to DCD interacting with rumen microflora resulting in less rumen degradation of feed protein and greater post-ruminal absorption of 20 protein/amino compounds. Potentially, part of the increase in apparent nitrogen absorption (up to 25%) could have been due to DCD acting as a source of slowly-degradable nitrogen in the rumen.

Most of the DCD was recovered unaltered in the urine. An associated study with the urine applied to soil revealed that the DCD in it was highly effective in inhibiting 25 nitrification of the urine-nitrogen over a total measurement period of 69 days (Ledgard et al. paper in preparation). Thus, DCD administered into the rumen of 16 549705 James & Wells Ref: 231549/47 sheep over 5 days increased sheep growth and absorption of dietary nitrogen, and most of the DCD was excreted in urine resulting in inhibition of nitrification in soil thereby reducing the potential for environmental losses.

Aspects of the present invention have been described by way of example only and 5 it should be appreciated that modifications and additions may be made thereto without departing from the scope thereof as defined in the appended claims. 17 549705 James & Wells Ref: 231549/47

Claims (50)

WHAT WE CLAIM IS:

1. A method of increasing animal production, characterised by the step of, introducing a nitrification inhibitor into the digestive system of an animal.

2. A method of increasing animal production as claimed in claim 1 where the increase in animal production is live-weight gain.

3. A method of increasing animal production as claimed in claim 1 where the increase in animal production is animal by-products.

4. A method of increasing animal production as claimed in claim 3 where the animal by-product is milk.

5. A method of increasing animal production as claimed in claim 3 where the animal by-product is wool.

6. A method of increasing animal production as claimed in any one of claims 1 to 5 where the animal is a ruminant.

7. A method of increasing animal production as claimed in any one of claims 1 to 6 where the nitrification inhibitor inhibits the bacterial species Nitrosomonas.

8. A method of increasing animal production as claimed in any one of claims 1 to 7 where the nitrification inhibitor is dicyandiamide (DCD). 18 549705 James & Wells Ref: 231549/47

9. A method of increasing animal production as claimed in any one of claims 1 to 7 where the nitrification inhibitor is 3,4-dimethylpyrazole phosphate (DMPP).

10. A method of increasing animal production as claimed in any one of claims 1 to 9 characterised by the step of introducing an agent beneficial to microorganisms residing in the animal's digestive tract with the nitrification inhibitor.

11. A method of increasing animal production as claimed in any one of claims 1 to 10 characterised by the step of introducing an agent beneficial to microorganisms residing in the soil.

12. A method of increasing animal production as claimed in any one of claims 1 to 11 where the nitrification inhibitor is delivered orally to the animal.

13. A method of increasing animal production as claimed in any one of claims 1 to 12 where the nitrification inhibitor is delivered by a liquid drench to the animal.

14. A method of increasing animal production as claimed in any one of claims 1 to 12 where the nitrification inhibitor is delivered to feed to be consumed by the animal.

15. A method of increasing animal production as claimed in any one of claims 1 to 12 where the nitrification inhibitor is delivered to a water trough.

16. A method of increasing animal production as claimed in any one of claims 1 to 12 where the nitrification inhibitor is delivered to the animal by a 19 549705 James & Wells Ref: 231549/47 sustained slow release device.

17. A method of increasing animal production as claimed in claim 16 where the sustained slow release device includes a series of capsules.

18. A method of increasing animal production as claimed in claim 16 where the sustained slow release device is a bolus.

19. A method of increasing animal production as claimed in any one of claims 16 to 18 where the sustained slow release device includes a core comprising a substantially homogeneous mixture of: a) a water insoluble physiologically acceptable binder comprising wax, fat, oil, fatty acid, fatty acid ester, fatty acid amide, fatty acid alcohol or the like organic compound having a melting point above 50°C; b) a physiologically acceptable solubilising agent, such as polyethylene glycol stearate or the sodium salt of a long-chain fatty acid, c) at least one nitrification inhibitor.

20. A method of increasing animal production as claimed in any one of claims 16 to 19 where said sustained slow release device also includes a physiologically acceptable inert densifier of sufficient density and in sufficient quantities to give the bolus a minimum density of 1.5g/cm3.

21. A method of increasing animal production as claimed in any one of claims 16 to 20 where said the sustained slow release device also includes one or more compounds beneficial to the animal. 20 549705 James & Wells Ref: 231549/47

22. A method of increasing animal production as claimed in claim 21 where said compound is a trace element.

23. A method of increasing animal production as claimed in claims 21 or 22 where said compound is an anthelmintic.

24. A method of increasing animal production as claimed in any one of claims 16 to 23 where the sustained slow release device has a bio-erodable coating.

25. A method of increasing animal production as claimed in claims 16 to 23 where the sustained slow release device is coated with an impervious material and is configured with an opening through which the nitrification inhibitor is released.

26. A sustained slow release device for increasing animal production wherein the sustained slow release device is a bolus.

27. A sustained slow release device for increasing animal production wherein the sustained slow release device is a series of capsules.

28. A sustained slow release device as claimed in claims 26 or 27 wherein the sustained slow release device includes a core comprising a substantially homogeneous mixture of: a) a water insoluble physiologically acceptable binder comprising wax, fat, oil, fatty acid, fatty acid ester, fatty acid amide, fatty acid alcohol or the like organic compound having a melting point above 50°C; 21 549705 James & Wells Ref: 231549/47 b) a physiologically acceptable solubilising agent, such as polyethylene glycol stearate or the sodium salt of a long-chain fatty acid, c) at least one nitrification inhibitor.

29. A sustained slow release device as claimed in any one of claims 26 to 28 where said sustained slow release device also includes a physiologically acceptable inert densifier of sufficient density and in sufficient quantities to give the bolus a minimum density of 1.5g/cm3.

30. A sustained slow release device as claimed in any one of claims 26 to 29 where said sustained slow release device also includes one or more compounds beneficial to the animal.

31. A sustained slow release device as claimed in claim 30 where at least one of the compounds is a trace element.

32. A sustained slow release device as claimed in claim 30 or 31 where at least one of the compounds is an anthelmintic.

33. A sustained slow release device as claimed in any one of claims 26 to 32 where the sustained slow release device has a bio-erodable coating.

34. A sustained slow release device as claimed in any one of claims 26 to 32 where the sustained slow release device is coated with an impervious material and is configured with an opening through which the nitrification inhibitor is released.

35. An animal feed for increasing animal production where the feed includes a nitrification inhibitor. 22 549705 James & Wells Ref: 231549/47

36. An animal feed as claimed in claim 35 where the nitrification inhibitor inhibits the bacterial species Nitrosomonas.

37. An animal feed as claimed in claim 35 or 36 where the nitrification inhibitor is dicyandiamide (DCD).

38. An animal feed as claimed in claim 35 or 36 where the nitrification inhibitor is 3,4-dimethylpyrazole phosphate (DMPP).

39. An animal feed as claimed in any one of claims 35 to 38 where the animal feed includes an agent beneficial to micro-organisms residing in the animal's digestive tract with the nitrification inhibitor.

40. An animal feed as claimed in any one of claims 35 to 39 where the animal feed includes an agent beneficial to micro-organisms beneficial to microorganisms residing in the soil with the nitrification inhibitor.

41. A trough for increasing animal production where the contents of the trough includes a nitrification inhibitor.

42. A trough as claimed in claim 41 where the nitrification inhibitor inhibits the bacterial species Nitrosomonas.

43. A trough as claimed in claims 41 or 42 where the nitrification inhibitor is dicyandiamide (DCD). 44. A trough as claimed in claim 41 or 42 where the nitrification inhibitor is 3,4-dimethylpyrazole phosphate (DMPP). 45. A trough as claimed in any one of claims 41 to 44 where the contents of the 23 549705 James & Wells Ref: 231549/47 trough includes an agent beneficial to micro-organisms residing in the animal's digestive tract with the nitrification inhibitor. 44. A trough as claimed in any one of claims 41 to 45 where the contents of the trough includes an agent beneficial to micro-organisms beneficial to microorganisms residing in the soil with the nitrification inhibitor.

44. A trough as claimed in claim 39 to 42 where the contents of the trough includes one or more compounds beneficial to the animal.

45. A trough as claimed in claim 44 where said compound is a trace element.

46. A trough as claimed in claims 44 or 45 where said compound is an anthelmintic.

47. A method for increasing animal production substantially as hereinbefore described with reference to and as illustrated by the accompanying description and drawings.

48. A sustained slow release device for increasing animal production substantially as hereinbefore described with reference to and as illustrated by the accompanying examples.

49. An animal feed for increasing animal production substantially as hereinbefore described with reference to and as illustrated by the accompanying examples. 24 549705 James & Wells Ref: 231549/47

50. A trough for increasing animal production substantially as hereinbefore described with reference to and as illustrated by the accompanying examples. AGRESEARCH LIMITED by their Attorneys 25 549705 James & Wells Ref: 231549/47 ABSTRACT In its primary aspect, the present invention is directed to a novel method of increasing animal production by introducing to the digestion system of an animal a nitrification inhibitor that increases animal production and affects the conversion of nitrogen containing compounds in animal waste, once the waste has been excreted from the animal. One preferred embodiment of the present invention consists of a sustained slow release device administered orally to grazing animals with targeted delivery to the digestive system. Other embodiments of the present invention include animal feed and water trough applications. 26