Spring 2005

General News

This is the final edition of the SPESFEED News for 2005.  In broad terms this year has been kind to those of us in animal agriculture.    Feed prices have softened while the prices of our products (except perhaps milk) have remained fair.

An area of the industry that impacts on us all is some way or another is the premix industry.  This is a highly specialised part of the animal feed industry.  In the past it has been rocked by a major price collusion scandal in the US , which has resulted in a far more competitive industry than it was previously.  The local industry has had recent problems with the contamination of ingredients, which we have yet to hear the end of.  Against this background, it is surprising that the number of players in the market has increased.  This means that we are spoiled for choice.  When dealing with a premix supplier, please ensure that appropriate quality control procedures are in place; that they are able to maintain the service levels that you would expect; and that product liability insurance has been taken out to protect you in the event of any problems occurring.

All that remains is for us at SPESFEED to wish you all a peaceful Christmas and New Year.  As in the past we will make a donation to the Avril Elizabeth Home in lieu of Christmas cards.

Poultry Nutrition Course

Our poultry nutrition course, which we held during the first week of October, went off well.  We had a class of 15 people, who represented both feed companies and poultry producers.

Broiler Stocking Density

Two papers on stocking density have appeared in the August 2005 edition of Poultry Science, one by Dozier et al., from the United States , and one by Jones et al., who are European.

Although both papers deal with the technical and welfare aspects of higher stocking densities, as measured in terms of kg or chicken produced per m² of floor space, it is the information contained in the preamble to each experiment that has caught my attention.  

I quote Dozier “Stocking density during grow out has been regarded as a concern to food retailers and wholesalers (Food Marketing Institute and National Council of Chain Restaurants, 2003). High stocking density has been reported to increase ammonia production, foot pad lesions, litter moisture, locomotion, heat stress, and preening.  As a result, welfare specialists have suggested reducing stocking density from 43 to 30 kg of BW/m². The optimum density for broilers marketed to heavy weights is debated among broiler companies, contract growers, and welfare auditors.”

Jones et al. have this to say “The European Union is currently considering legislation to limit the maximum stocking density of broiler chickens to 30 kg/m².  It is now becoming increasingly clear that, at least under commercial conditions, stocking density may have less effect on welfare than its consequences, such as the deterioration in air and litter quality, unless specific measures are taken.  This distinction is of critical importance for the welfare of the birds themselves and for the economic future of the industry.  If the problems of high stocking density can be mitigated by buildings with good indoor environmental conditions, any recommendations for limiting stocking density should take this into account (European Commission, 2000).”

I do not need to dwell on the implications of this sort of legislation on South African producers, but this may well become an issue in the future. I have copies of both papers available.

Visit to Morocco

In May I was invited by the American Soybean Association (ASA) to visit Morocco to provide nutritional support and input to their clients in that country.  This was my third visit to this North African gem.  Unlike my previous visits, where I was principally involved in lecturing at the University (Institut Agronomique et Vétérinaire Hassan II) in Rabat , on this trip I visited 5 of the major feed millers.  

Obvious changes and developments have occurred in both the poultry and feed milling industries since my first visit in 2002.  Morocco now produces some 5 million broilers per week, and has some 12 to 13 million laying hens.  Both sectors are growing rapidly.  

The structure of the Moroccan broiler industry differs from that of most other countries.  It is estimated that some 85 to 90% of all broilers are sold live, mostly through small dealers/shops who will slaughter birds on order.  Consequently, integration as we know and understand it does not exist. Four of the five feed mills that we visited had hatcheries as sister companies.  The remaining mill was in the process of setting up its own breeder operation and hatchery.  It would appear that it is essential that a feed miller supply both chicks and feed if they are to retain market share. Three broiler strains are used in the country, namely the Ross 308, the Hubbard and a smaller number of Cobb birds.  

Poultry housing varies from modern open sided housing through to plastic hot house tunnels.  This form of housing is cheap and easy to build.  All of the houses that I saw were covered in thatch or reed to provide some form of insulation.  I was told that most of them go out of production during the hot summer months. Stocking densities used are 10 birds/m in winter and as low as 6/m during the warmer months.  These houses do reduce brooding costs, and some producers use them for this and then move the birds.  This type of farming is a Bio-Security nightmare, and the government is about to outlaw their use.  They probably don’t really need to do this, as I saw far more abandoned farms than those in production and I would expect that commercial realities will prevail and this type of farming would have ceased anyway.  

Most broilers are fed on two phase rations.  From what I was able to establish the nutrient densities used are lower than those that we are used to.  As a result of this the growing period on most farms tends to be about 44 days.  

The one thing of interest that I did see there was the bunker system that they use for storing ingredients.  Instead of building fixed bunkers with walls, they have a series of pre-cast concrete blocks, a little like the blocks they use as safety barriers on freeways.  These are then moved around to create storage capacity to fit in with ingredient inventories.   

A smaller mill, Omnia Intaj, in El Jadida, was highly focused on quality and although their volumes were comparatively small they had an excellent laboratory.  

All in all, the Moroccan poultry industry is dynamic and growing at a rapid rate.  If they have not already got there, it would appear that they will soon be the second largest poultry producing country in Africa . 

Rick Kleyn  

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Essential Details of Broiler Breeder Management: Robinson's Top Ten

Maximizing chick production from broiler breeders is one of the most challenging components of the poultry industry. The hatching egg producer is faced with optimizing reproductive traits from a chicken that has been intensively selected for growth rate, feed efficiency and breast muscle yield. Part of the challenge faced by producers relates to the changes in broiler breeder reproductive potential with each generation.

Today, a broiler breeder manager needs to know how broiler breeders work to react to what is encountered in their barns, rather than basing management decisions on historical management habits. The more that can be learned about how birds react to feed, photoperiod and social encounters the better equipped we will be to respond in the way that best suits breeder welfare and productivity.

Defining the essential details of breeder management is not easy. Most of them are common sense (and bird sense). There are hundreds of essential details, but I have picked my favourite 10.

1.   Know the actual weight of your birds. Weigh lots of birds. Get yourself some corrals, some scales and USE THEM REGULARLY. There is no magic number about how many birds to weigh. Weigh as many as necessary to give you confidence about the mean flock weight and the uniformity score.

2.  Weigh birds the same time each day, particularly when breeder pullets or cockerels are fed on skip-a-day  feeding, they can vary tremendously in body weight depending on the time elapsed from the previous feeding. Weigh as many birds as possible on the non-feed day, and do so at the same time each week.

3.  Uniformity is very important. Wouldn't it be easy if all birds were identical? They would be in the same reproductive condition at the same time. As this is not the case, know that factors that impact on flock uniformity include: initial chick weight and quality, competition for limited resources (feed, water, good air), and strain and individual bird differences in aggressiveness.

4. Avoid high nutrient density diets. One of the principles to keep in mind is that the more volume of feed is available, the greater likelihood is there that all birds will be able to eat to gut capacity. If they eat to meet their gut capacity, flock uniformity should be better. Don't feed such a low  density diet that would preclude feed clean-up. Feed left in the feeders is the bird's way of saying that they can not or will not consume that much feed (above requirements). The challenge is to be able to tell why the requirement may have been reduced (decreased egg production, less activity in hot weather, reduced drinking water availability etc.).

5.  Make sure pullets are at the minimum threshold weight at lighting. Lighting underweight pullets results in fat hens and poor egg production. If birds are under the breeder target body weight, delay photo stimulation until they meet or exceed the target. In most cases, delayed photo stimulation does not reduce egg number, and it should increase egg weight to what is required for shipping to a hatcher sooner. It will help bring together flock uniformity if birds are lighted later rather than earlier.

6.  Don't make fast increases in feed intake coming into production.  The critical time in a pullet's life is from 20 wk of age until peak production. The role of an active ovary producing oestrogen hormones at this time should not be underestimated. Estrogens change the liver to result in the production of yolk lipid. Unfortunately, breeders are not too good at knowing when enough of this yolk deposition is enough, and they produce excessive follicle development. The situation gets worse when birds are overfed during this critical time. Consider trying very small feed daily increases instead of a larger increase once a week. A bird's metabolism is more fine-tuned than needing a once a week adjustment. Remember broiler breeder management is all about fine tuning.

7.  Know what you are doing in managing post-peak feed withdrawal.  Knowing when to take away feed it much like knowing when to sell stocks on the stock market....(follow egg production, body weight, egg weight).

8.  Keep and open mind - birds are changing every year (what worked for the last flock may not work this year). Pay attention to technical reports from breeder companies and keep an open mind.

9.  Don't put your flock on "AUTO-PILOT".   Good things come to those who stay on top of their productionefficiency before problems happen.  Be a detail person. Keep a journal about day-to-day observations. Record the following: drinking water intake, feed clean-up time, egg quality (membranous eggs), floor eggs, mortality, egg size etc.

10.Stop complaining and be a positive person who is learning more all the time!  Be thankful for what we have: Light-controlled housing, usually good spacing between poultry production units, Long cold winters (better long hot summers?) a committed informed service personnel.

      F. E. Robinson

      University of Alberta , Canada  

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Effects of Water Acidification on Broiler Performance

I was first introduced to the concept of acidifying the drinking water of broiler chickens by a Spanish visitor to South Africa . It is always a good idea to investigate a concept further when one hears of things that are being used commercially but that we are not doing ourselves, Other people were thinking about same thing.  In the Fall 2004 issue of Avian Advice, published by the University of Arkansas , Division of Agriculture, Susan Watkins and her co-workers looked into the “Effects of Water Acidification on Broiler Performance”.  This brief article is based largely on this publication.

Acidifiers such as sodium bisulphate, citric acid or vinegar are often used by poultry producers to lower the pH of the drinking water they give their birds. Many claim that adding these products results in an increase in water consumption, less feed passage or firmer droppings from the birds.

Low pH water is aggressive and can dissolve metal pipes releasing lead, copper and other minerals into the water. While the use of PVC pipes minimizes the concern of mineral leaching, the question still remains: what water pH level is optimum for broiler performance?  

Two trials were conducted to study the impact of different water pHs on broiler weight gains, feed conversion, water consumption and liveability.  In addition, the issue of adjusting the water pH on a continuous or intermittent basis was addressed.  The results are summarized below:

Table 1: Impact of drinking water pH on male broiler performance characteristics.

* c = continuous supply.  I = intermediate program: day 1-7, 48 hours before feed change,72 hours prior to end of trial.  

There were no significant differences for most parameters.  The FCR values were different, but not significantly so. When the crops and gizzards of birds receiving the different pH water were tested for pH, it was found that the birds receiving the pH 3, 4 and 5 water had a significantly lower crop pH than birds receiving the 6 and control pH water. No difference was found in the gizzard pH and this would be expected since the bird adds hydrochloric acid to the digestion process.

Table 2: Impact of drinking water pH on crop and gizzard pH

The results indicate that birds are very tolerant of a wide range of pH water. The findings that the crop pH was significantly lowered by reducing the water pH might explain why producers have reported that bird droppings become firmer when acidifiers are added to the water.

Given the diversity of drinking water sources it is a very good idea to measure the pH of the drinking water when using acidifiers at manufacturer’s recommendations because the natural buffering capacity of water may result in reduced impact of the acidifier on pH. It may even be necessary to add more acidifier to the stock solution to achieve a lower drinking water pH.

Some interesting Brazilian work (de Nascimento et al., (2003)) showed that use of lactic or citric acid in drinking water during pre-slaughter feed withdrawal had a decreasing effect on Salmonella recovery from the crop. The addition of acids, if started 24 hours before the beginning of pre-slaughter feed withdrawal, might help to reduce crop contamination by Salmonella.

 After Watkins et al.

University of Arkansas . 

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The Importance of Feed Intake in a Piggery

Surveys have shown that feed intake varies by at least 25% among commercial farms. This may under-estimate the problem, since accurate data on feed intake is not readily available on many farms. Some of the data which is available, if estimated from long-term averages or calculated on an inventory basis, fails to identify short-term deviations from this average. Once feed intake has been identified as a problem, the next step, obviously, is to resolve it. Where one look does and what does one do to assist farms?

Management practices should be scrutinized to ensure that feed intake is being optimized under all circumstances, no matter what the genotype.

High temperatures depress feed intake as the animal seeks to minimize the generation of metabolic heat associated with the consumption and digestion of food. For example, the optimum temperature for pigs weighing more than 55 kg, housed on partial slats, and free from drafts and wetness, is 14°C (Zhang, 1994). Mount (1975) has suggested the following adjustments to the measured temperature to determine the effective ambient temperature: straw bedding, +4°C; concrete slats, -5°C; wet floors, -5°C to -10°C. In addition, air movement of 0.2, 0.5 and 1.5 m/sec reduces the effective ambient temperature by 4°C, 7°C and 10°C, respectively.

Recent research by Dr. Harold Gonyou compared 12 different feeders, including both single and multiple spaces across dry or wet/dry designs. He observed a range in feed intake of about 15% across all feeders; the simple choice of wet/dry feeders as opposed to dry feeders resulted in a 5% increase in feed intake.

Floor space, or lack thereof, is known to impact on feed intake. The following equations were developed by Kornegay and Notter (1984) to relate floor space per pig to voluntary feed intake. S is floor space per pig m².

 ADF (kg/pig/day) = 1.542 + 0.856S - 0.494S².

         ADF (kg/pig/day) = 1.619 + 1.833S - 0.837S².

An imbalanced diet will affect feed intake. For example, it is well understood that deficiencies of most amino acids will depress appetite, as will inadequate sodium or chloride. Excesses of some nutrients are known to be appetite suppressants as well. Clearly, a balanced diet is essential to maximizing voluntary feed intake.

The form of the diet will also affect feed intake. For example, liquid feeding systems increase feed intake by as much as 10 to 15%.

Feed Intake Checklist

A.    Have you determined what your feed intake target is?

B.    Do pigs have ready access to feed?

C.    Do the pigs have a continuous supply of

D.    Is the room environment conducive to

E.    What is the health status of the herd? Is

F.    Do you suspect that diet composition (nutrients or ingredients) may be a problem?

 Dr John Patience

Prairie Swine Centre , Canada .

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Calcium Uniformity Check for Laying Hens

This article was published by Hubbard Feeds on their web site.  It is of great interest and relevance to all egg and hatching egg producers.

The calcium requirements in laying hen feeding programs are well established. Even when calcium is accurately formulated in a laying diet, there is no guarantee that the proper calcium levels will end up in front of all the hens. There are several possible reasons for this, one being that the calcium sources are considerably more dense than the other major feed ingredients in the laying feed formula. Therefore, there is a risk that calcium separation can occur along the feeding system resulting in uneven distribution along the laying house feeding line.

High calcium will cause reduced feed intake, visceral calcification, and other problems as well as a deficiency of other important nutrients. Low calcium will cause poor shell quality, cage fatigue, and eventually death.

In order to assure that all birds are receiving proper calcium levels, producers should periodically evaluate their feeding system for calcium separation. This can be accomplished by collecting laying feed samples from various locations along the feeding system, testing the sample for calcium, and analyzing the data. If calcium separation is taking place, corrective measures must be taken.

Procedure: Immediately after the completion of a feeding line cycle, representative samples will be collected as quickly as possible from a minimum two laying house feeding lines at the feeder line locations described below. Sample size is 500 grams minimum.  

Figure: Feeder Sampling Location

Use a small plastic spoon to collect the feed from the feeding trough. Collect samples in front of several cages at each sample location to obtain a big enough sample. Do not sample from areas where significant feed has already been consumed from the trough because birds may have already picked out certain feed components.

For safety reasons, disconnect and lock out feeder power source before sampling!

Once all samples are analyzed, the calcium data must be statistically evaluated according to the following steps:

1.    Measuring the Coefficient of Variation (CV).  A CV of 10% or less indicates that the calcium is distributed uniformity through the   laying feed. CV’s over 10% indicate that the birds may be receiving either excessive or inadequate calcium and efforts are needed to improve nutrient uniformity (availability) in the laying house feed. This can be accomplished by changing calcium particle size, laying feed particle size, readjusting feeder systems, formula change, etc.

2.   The calcium assay of each sample should be within +/- 25% of the expected calcium level. Based upon this standard, the following possibilities exist:

·     If the hopper sample is either low or high (<75% or >125% of expected), the feed may be either mis-manufactured, be non-uniform from an unsatisfactory mix, or calcium segregation has occurred.

·     If 3 out of 4 cage row samples are either low or high (<75% or >125% of expected), the feed may be either mis- manufactured, be non-uniform from an unsatisfactory mix, or calcium segregation has occurred.

If either of the above situations is found, then check for correct limestone usage (inventory) and verify that feed formula contains the correct calcium level.  

·     If hopper sample is within 75% to 125% of expected and the calcium content is progressively decreasing in the cage row samples #2 through #5, then supplemental calcium is separating out as the feed moves along the feeding line. This indicates that the calcium particle size may be too small (<900 microns, i.e. pulverized limestone) and larger supplemental calcium particle size may be needed, i.e. calcium chips.

·     If hopper sample is within 75% to 125% of expected and the calcium content is progressively increasing in the cage row samples #2 through #5, then supplemental calcium is not being discharged uniformly along the feeding line. This may be due to the calcium particle size being too large (>2000 microns) and a small average particle size may help.

In the above circumstances are found, calcium is not being distributed evely along the feeder system.  If changing the calcium particle size did not reduce segregation to acceptable limits, it is possible that the problem is due to a poorly functioning feeding system. We recommend that you contact your feeding system’s technical representative for assistance.