General News

I had a most enjoyable trip to Europe. The report back on my visit forms a major part of this news letter. Now it is Walter’s turn. He will be attending VIV in Holland in November and will also travel to the UK to spend some time with NUTEC and PIC. Look forward to the report back on his trip in the next news letter.

This is the last news letter that Charmaine will be involved in as her baby is due in November. I am sure that you will all join us in wishing her well in this new phase of her life. Her role in the company will be filled by Laetitia Büchner who is an Animal Science graduate from the University of Stellenbosch. She also holds and Honours degree in Wildlife Management form TUKS and we envisage that she will become more involved in wildlife nutrition as time goes on.

Our first dairy course went off most successfully, due largely to the hard work put in by Shaun. We had 19 attendees, whose number included feed company sales staff, nutritionists and veterinarians but sadly no producers.

As we all know 70% of the inputs into intensive animal agriculture are feed related, and the difference between feeding an adequate diet as opposed to an optimal diet may often make the difference between a profit or a loss. For this reason alone we believe that all players in the pig and poultry industry should have at least a working knowledge of nutrition and we will be holding both poultry and pig nutrition courses next year:

Poultry course: 17 - 19^th February

Pig course: 17 - 19^th March

Please let Laetitia know if you would like to attend.

We now have a web site at spesfeed.co.za as well as new email addresses for everyone (rick@spesfeed.co.za, walter@spesfeed.co.za and shaun@spesfeed.co.za).

My first attempt at building a site is now there for all to see. We will endeavor to keep it up to date at all times and envisage having a password protected area for our clients where we will post fast breaking news and events.

I have just downloaded a book (57 pages) published by the National Swine Improvement Federation (America) entitled "Guidelines for Uniform Swine Improvement Programs". It covers genetic principles on farm programs, evaluation of animals and testing programs. There is also a small appendix dealing with nutrition. We also have a copy of the Nebraska and South Dakota Swine Nutrition Guide (42 pages) which is nutrition specific. Should you be interested in either of these booklets please let us know and we can arrange copies for you.

I have just discovered a huge scientific and medical database called Biomednet on the net. It allows you to search through hundreds of different Journals on different key words and then extract abstracts of papers that are of interest to you. It is interesting that you can get abstracts of British Poultry Science from the site which you can’t do from British Poultry Science’s own home page.

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When buying Soya oilcake please be aware that there is a lot of material on the market being sold on a "Profat" basis. There is nothing wrong with expressing the quality of Soya on this basis but it must be remembered that the figure quoted includes both the protein and the fat components of the product. In practical terms Soya and Sunflower oilcake usually contain 2 to 2.5 % fat and this must be subtracted from the profat value to give a protein value.

We still have a few copies of the second edition of Leeson & Summers’ book "Commercial Poultry Nutrition" available. This is a highly recommended publication! If you would like a copy please contact Laetitia.

The irony of the Information Age is that it has given new respectability to uninformed opinion.

How to cope with mycotoxins in feed

I think it is true to say that we are all aware that mycotoxins exist and that if feed ingredients, particularly maize, are contaminated with fungi there is a likelihood that it also contains the toxins produced by those fungi. Hundreds of different toxins have been identified. These toxins in turn, may cause various production problems on the farm. Much has been published about mycotoxins , but a lot of this work has been rather technical. We felt that it would be worth trying to distill the mumbo jumbo into something simple and then to make some practical suggestions as to how to best deal with the problem.

Pigs tend to be more susceptible to mycotoxicosis than do poultry, but ducks are known to be the most susceptible of all species. Young animals tend to be more susceptible. Mycotoxins generally effect the liver (hepatotoxins) or the kidney (nephrotoxins), as a result of which several adverse conditions may result because of their effect on the critical metabolic processes in the animal. Some of the common effects include:

Fungi contaminate feed ingredients in one of two places, either in the field where they are grown, or in the silos and bins where they are stored. Fuzarium sp. are the most common fungi found in field and they tend to proliferate when conditions are damp and the harvest is delayed. The toxins produced by Fuzarium are deoxynivalenol (vomitoxin), zearalenone and fumonisin. The Aspergillus Sp are the major fungal contaminates of stored maize and they are responsible for the production of aflatoxins. This fungus normally germinates at moisture levels of greater than 15% and where temperatures are in the range 25 to 32 degrees. The storage of wet maize and kernel damage lends itself to increased fungal contamination (Table 1).

The severity of response depends largely on the specific mycotoxin present and the level of contamination. Establishing "safe" levels for mycotoxins is literally impossible as this is not only influenced by the mycotoxins themselves but also factors such as the nutritional adequacy of the diet, the age and specie of animal, the environment and the level of disease stress. A combination of different mycotoxins has been shown to have the most dilatarious effects.

Dealing with a mycotoxin problem requires a multi-faceted approach. Once mycotoxins have been formed they are not easily destroyed or eliminated from the feed and prevention is definitely better than cure. However, care must be taken to ensure that mycotoxins do not get into the feed in the first place. Here are the steps that should be followed to prevent mycotoxin contamination from occurring.

1. If you have any choice in the matter do not accept any maize that has a significant number of kernels that have been infected by Fuzarium.
2. Reject consignments of maize that contain a high proportion of broken and/or small kernels. Alternatively try to sift out this material.
3. If you are accepting high moisture maize into a silo ensure that it is treated with an anti-fungal spray (proprionic acid) of which there are a number on the market. This will prevent Aspergillus from developing in the silo and retard the growth of any existing Fuzarium. It must be remembered that these fungal inhibitors will have no effect on mycotoxins already present in the grain at the time of application.
4. Routine analysis of incoming ingredients for mycotoxins is important and is possible. When you do take samples make sure that they are representative of the load or consignment. Even so, it is very difficult to pick up "pockets" of contamination within a load. There are many ELIZA assay kits now available which are relatively inexpensive and do not require elaborate laboratory facilities. Investigate their use.
5. A rigid and routine sanitation program in both the feed mill and in feed distribution and handling systems will aid in reducing mycotoxin build up in feed.
6. Pelleting of feed, when combined with propionic acid, will significantly reduce the mould burden.
7. Minimise feed residence time on farm, especially in hot, humid conditions (Table 2). This has a dramatic effect on aflatoxin levels.

Once you become aware that you may well have a mycotoxin problem in your diet there are a number of steps which can be taken.

1. Try to obtain maize from another source.
2. If possible, avoid feeding contaminated grain to young pigs, breeding sows or replacement gilts.
3. Increasing the protein level of the diet helps to alleviate but does not eliminate the effects of mycotoxin. The addition of any amino acids which may be limiting may be a more cost effective approach.
4. Diets high in fat (linoleic acid) have been found to support better feed conversion and lower mortality in chicks fed diets contaminated with aflatoxin.
5. The use of anti-oxidants and Vit E have been shown to overcome the effect of aflatoxin.
6. Increasing the levels of Vitamins that are known to be a problem may be required in order to overcome the negative effect that toxins have on nutrient absorption.
7. The addition of broad spectrum anti-biotic such as chlortetracycline helps alleviate but not overcome the effects of aflatoxin.
8. Several non-nutritive adsorbents are available for use (Table 3). These sequester mycotoxins and reduce their adverse effects. They range from the simple inclusion of Lucerne in the diet to the use of some types of hydrated sodium calcium aluminosilicates (HSCAS) and certain of the colloidal clays (Bentonite). Some yeasts have also been shown to have a similar effect. The specificity of these products varies widely and care should be taken in selecting a specific product for a particular problem.

As can be seen, the entire supply chain of animal feed may be implicated in the presence of mycotoxins. Co-operation from all of the people involved is required if the problem is to be minimized.

Acknowledgment:

In preparing this article I relied heavily on the following papers:

"Managing moulds and mycotoxins in poultry feeds" by P.W. Waldroup. This paper was presented at the American Soybean Association’s Technology and nutrition workshop held in Thailand in May 1997.

"Mycotoxins and Swine Performance" By M.A. Diekman and co-workers of Purdue University, Indiana. (1992)

"Mycotoxins and bird performance: 1.Aflatoxin" by Dr S Leeson and published by Hubbard Farms. August (1997).

Feedstuffs (Aug 4) report that on July 23 a U.S. district court in Iowa ruled that a U.S. Department of Agriculture regulation allowing up to 8% (chicken) or 9% (turkey) retention of water in poultry is invalid, but the ruling fell short of calling absorbed water an "adulterant".

The action was brought forward by the Red Meat Industry because any water added to red meat during processing must be removed as added water is considered a form of adulteration. It is contended that the difference between meat and poultry regulations represents a major inequity between the two inspection systems.

Whilst the Red Meat Producer organizations are delighted at the outcome of the trial, they feel that this is only the first step in addressing the disparities between the red meat and poultry inspection systems. The broiler and turkey industries have made a low key response, suggesting that it will not have any significant impact because companies will continue to follow good manufacturing practices, including the monitoring of moisture retention. They maintain that water chilling is necessary to meet the USDA’s time and temperature requirements for poultry, which are not imposed on red meat processors. They do admit that moisture tolerances should be revisited in the light of modern technology for processing poultry.

The USDA has said that it will consult with the Justice Department on what path to follow given the court’s decision. This is likely to be the first step of what could be a long, drawn out battle, the results of which could have some global repercussions. For a start poultry meat in the USA is likely to become more expensive but it is likely that the poultry industry world wide may well have to fit in with the USDA’s new recommendations with time. We await the outcome of these distant rumblings with interest.

A new concept in the pork production industry in the USA, apparently gives rise to more efficient operations and improved production strategies. The concept, called "wean-to-finish", has been developed to eliminate costly "bottlenecks" in pig transportation and to add to productive performance. This money-saving concept may be implemented by all producers: small, medium and large.

A contract pork producer in Oakville, Iowa, gave birth to the concept 4 years ago. He moved baby pigs straight from the farrowing facilities to the finishing facilities. The pigs are moved around less, which is less labour intensive and leads to lower levels of stress and disease, as well as fewer growth setbacks.

A practising veterinarian from Carthage, Ill., Dr. Joe Connor, estimates savings of:

Connor also found an inexplicable improvement in lean production, worth quite a bit of money. His findings are tabulated below.

Connor points out that it will cost R14 - R47 to adapt present or erect new pig houses by inter alia implementing feeders and waterers for use by baby as well as older pigs, but the advantages definitely outweigh the disadvantages.

Prosessering van Varkvoere

Indien voere fyner gemaal word, word die volgende voordele verkry:

1. Die blootgestelde oppervlak van die voedingsbestanddele aan verterings-ensieme neem toe, met ‘n gepaard gaande toename in verteerbaarheid.
2. ‘n Verkleinde partikelgrootte vertraag ook deurvloeitempo in die spysverteringskanaal.

Die Universiteit van Kansas het ‘n proef gedoen om die effek van partikelgrootte op verteerbaarheid te toets. In hierdie studie, het partikelgrootte gewissel van 500 mikron vir baie fyn poeier tot 1 600 mikron vir gekraakte mielies. Die verteerbaarheid van growwe meel het met meer as 2.4% toegeneem waar die voer fyn gemaal is. In die geval van ‘n groeivoer, is dit ‘n besparing van meer as R25/ton voer.

‘n Fyner voer is veral belangrik vir speenvarke. In die geval van volwasse varke (sôe), is die digesta deurvloeitempo stadiger en is partikelgrootte dus van minder belang.

Die volgende partikelgroottes word aanbeveel: Speenvarke <700mikron Groei/Afrondingsvark 700 - 800 mikron.

Daar moet gewaak word teen sekere potensiële nadele van fyngemaalde graan:

Daar is ‘n neiging by produsente om voer growwer te maal as wat wenslik is. Al word bestuur vermoeilik deur die gebruik van fyngemaalde voere, maak die winste wat in voeromset en in nutriëntverbruik verkry word, dit die moeite werd.

Universiteit van Kansas (VSA), 1983.

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Volatility of the Lysine Market

Most of us involved in the feeding of monogastric animals will be aware of the way in which the price of Lysine Hydrochloride (synthetic lysine) has increased steadily over the past year. The price peaked at around R 25.00 per kg and then during September, plunged to about half of the peak price. The editorial in the October 6 issue of Feedstuffs addresses this phenomenon and makes a few interesting points which may help put this incident in perspective.

One US analyst has published a document where it is pointed out that although prices of Lysine have changed rapidly, they are not unlike stock prices in that they traditionally tend to be both unrealistically high or unrealistically low.

Demand for Lysine is also increasing by about 6% per annum in the USA and between 8 and 12% globally. However, the price of Lys HCl and that of Soya Oilcake are closely related. The increases in price that we have seen were as a direct result of the strong Soya bean prices which resulted from the limited supplies following a relatively poor 1996 crop. This price has fallen significantly and it is felt that the current Lysine price will probably persist for some time if the American Soya bean crop is as

large as has been predicted. It is also known that the Koreans are gearing up to produce large quantities of Lysine for export. There are a number of other new production facilities being planned world-wide and these include a new Degussa/Cargill project, and the expansion of existing Heartland Lysine and ADM facilities. It is predicted that some of these manufactures may not follow through with their plans.

With the market signalling lower futures prices (for Soya bean), Lysine manufacturers quickly reduced their prices in order to move stock. Lysine production is a continuous process which involves the growth of micro-organisms. This process must be maintained and can’t be shut down until the price improves.

Rick Kleyn's Trip to Europe

I arrived in London on Sunday 20 September and then spent the following day at FORMAT’s office in Woking. Apart from performing some quality control on "Old Speckled Hen", the preferred bitter in Surrey, I had little to do with our industry.

On Tuesday morning, I traveled to Donington in the Midlands of England, and attended a workshop for the poultry industry. Although much of the ground covered was familiar to me or applicable to Europe only, John Hine of Trouw Nutrition presented an excellent paper on rearing the modern layer hybrid. Achieving the correct weight for age, has become a real problem, perhaps even more so than we experience in SA. He made some suggestions as to specifications to help overcome the problem, the most significant of which was the introduction of a crumbled ‘Pre-starter’ diet for the first three weeks. The specifications he suggests are considerably higher than the UK’s "Standard" Starter, but only marginally higher than the specifications we are currently using.

I spent the Wednesday and Thursday at the NUTEC offices in Lichfield. In general terms, we had a joint look at all of the software that they currently use, including their new Metabolisable Protein dairy programme, their pig simulation model and their database system called LARS. I spent the time with their poultry nutritionists, Ian Makinson and Mascus Kenny. We had some interesting discussions about the use of available phosphorus for poultry and then had a look at typical diets used in the UK. There were few differences in terms of layer diets, but the Broiler diets, particularly the Finisher feeds, differ from our own considerably. The protein contents are far higher than our own in order to maximise breast meat yield. I was also shown some typical - and some record farm results:

Note: The record flock were all males. I’m not sure that the PEF calculation is the same as ours. The growth curves achieved, differed from our own:

Interestingly, the Starter specs used are almost identical to our own. Whilst I was at NUTEC, Ian logged in (via modem) to a Flockman feeding system on a farm 300km’s away. We were able to watch scale read outs directly from the house and see how weight changed as birds climbed on and off the automatic weights. The nutritionist / manager, has a large degree of control over the environment and nutrient intake with this system. Ian feels, however, that the system may have limitations if management is not skilled and/or dedicated.

The last working day of my visit to the UK was spent at the British Feed Expo, at the Birmingham Exhibition Centre. There were some papers presented at the meeting, but most had to do with industry ‘politics’. Considering that the registration fee was £ 200.00, I decided not to attend. There was also a trade exhibition which enabled me to become acquainted with Bühler’s new high speed mixers and much other milling equipment. As with previous trips to Europe I was again struck by how many flavourants / sweeteners are used in the animal feed industry in Europe. They must work, or people would not continue to use them. Both FORMAT and computer Applications (CAL) had stands at the show.

My trip to the FORMAT agents’ meeting in Barcelona, was less eventful. It was attended by 20 people from 11 countries. We were introduced to a number of new features in FORMAT such as:

We also spent some time discussing the use of LP technology in the human food industry. Where it has been employed, it has been done to stunning effect. Unfortunately, its use is limited by the fact that many of those in the industry are suspicious of computers or anything else which may impact on food ‘quality’.

Barcelona is a beautiful city, and Spanish cuisine is good. Needless to say, I enjoyed my fill of seafood. My faith in human nature was restored when Steve Fountain had his wallet stolen at the station one night. Fortunately he immediately realised that something was wrong and shouted at the Spaniard concerned, whereupon a Greek, a Turk and two Chinese gentlemen from our party, attacked the man and recovered the wallet. We continued home and on to the comparative safety of Gauteng.

This article is the second in a series on feed enzymes.

Lots of enzyme products are on the market which can be used in poultry diets. A basic understanding of their action in the bird's digestive tract is essential before correct decisions can be made concerning their usage. The majority of feed enzymes presently available to the poultry industry improve energy and nutrient utilization. The major contributors of energy to diets are the cereal grains. An understanding of cereal grain structure helps to explain how enzyme supplementation increases energy availability.

The main source of energy in cereal grains is starch. Starch is a carbohydrate (i.e., molecules made up primarily of carbon and hydrogen atoms) which is composed of energy yielding sugar (glucose) molecules. The starch is located in the endosperm of the seed. The endosperm is enclosed by the aleurone layer which is a single layer of cells with very thick cell walls. This aleurone layer contains the enzymes which are involved in the release of nutrients from the endosperm during seed germination. The aleurone layer is enclosed by several layers of cells known as the pericarp. The tough fibrous pericarp protects the intact grain.

Before chickens can utilize the energy-rich starch in grains, the seed's pericarp, aleurone layer, and finally the endosperm cell wall, must be penetrated. All these layers contain cellulose, non-starch polysaccharides (NSP), phenolic compounds, pectins, and proteins. The cell walls of the pericarp, aleurone layer and endosperm differ in the relative proportions of each of the above constituents. The endosperm cell wall is the least fibrous of the three and is, therefore, more easily ruptured by feed processing and mechanical grinding of the gizzard than other cell types.

No animal can synthesize the enzymes needed for breaking down cellulose and NSPs. Instead, animals rely on microorganisms in their digestive tract to accomplish this job. In ruminant animals (i.e., cattle, sheep, goats, etc.) this microbial population is primarily in one of the stomach chambers, the rumen. In the chicken, as with most single-stomach animals (i.e., monogastrics), this microbial population is located near the end of the digestive tract, in the ceca. This is past the major site of nutrient digestion and absorption, the small intestine. Approximately 80-90% of all dietary nutrients are absorbed prior to the intestinal contents (digesta) reaching the last one-third of the small intestine. Considering a normal rate of passage, the digesta reaches this section within 1.5 hours following feed consumption. Many of the nutrients released by microbes in the ceca are unavailable to the bird, since they are beyond the major site of absorption, and they are simply excreted with the faeces. It would be advantageous, therefore, to introduce specific enzymes into the diet that break down and release cell wall constituents early during the digestive process. If the cell wall constituents can be broken down prior to reaching the small intestine, the nutrients released are available to the bird.

The exact mechanism responsible for the improved energy and nutrient utilization resulting from the incorporation of feed enzymes into the diet, is not yet totally understood. These enzymes may cause rupturing of the cell walls, release of cell bound nutrients or increased cell wall permeability to pancreatic enzymes. It is thought that the majority of the improvement is caused by a breakdown in the integrity of the cell wall matrix allowing the bird's pancreatic and intestinal enzymes access to the nutrients.

If the diet contains certain cereal grains such as wheat, rye, oats or barley, which contribute high levels of NSP, the viscosity of the digesta will be increased. Viscosity is a measure of how well a liquid flows. The more viscous a substance, the more resistant it is to flow. High levels of NSPs increase the viscous nature of the digesta. As viscosity increases, the digesta becomes more sticky and slow-flowing. This results in reduced digestive efficiency which reduces growth rate, feed efficiency and the apparent metabolisable energy of the diet. If the above cereals are used in poultry diets, enzymes can be supplemented to break down the NSPs, thus reducing the digesta viscosity and improving performance and litter quality.

Enzymes can be added to feeds as "multi-enzyme" products that contain a variety of different activities or "specific-enzyme" products which are responsible for a single type of enzymatic activity based on a particular dietary substrate (such as NSPs). If the bird is going to benefit from feed enzymes, however, the digestive tract must be healthy so as to maximize the absorption of the released nutrients. The enzyme must also be stable and active at the pH and temperature found inside the digestive tract.

During the past few weeks we have had a stream of international visitors to our offices. From my point of view, the most interesting was Ria Wiltenburg, a commercial nutritionist from Henrdicks in Holland. Ria is a layer specialist who came to South Africa to talk about Phosphorus in layer diets.

Both her company and the Dutch government have done a lot of research in this area, and together with the use of phytase enzymes they have successfully managed to reduce the P in both the diet and more importantly in the manure. It was interesting that even at very low P levels in the diet, production was normal. It was found, however, that mortality was unacceptably high.

The use of synthetic phytase at a level of 60 g/ton of feed allowed for a reduction in the inorganic P supplied by about 4 kg/ton. The cost of this phytase is currently about R 12.00 per ton of feed and is still not an attractive option.

Apart from the information she passed on in terms of P, we were able to glean other interesting information from her.

In broad terms, Dutch Layers are fed on a three phase feeding system with increasing energy levels in the diet, as the birds age. The energy level of these diets is higher than our own and they practise some form of feed restriction during the middle phase of lay. Nearly all houses are environmentally controlled, and apart from during the first few weeks, temperatures are maintained at 22 degrees. All of this enables Dutch producers to achieve feed conversion figures of between 2.0 and 2.1. We still have a long way to go!