Summer 2007

General News  

Welcome to the first newsletter of 2007. We trust that you have all had a peaceful Christmas break.  As we have done in the past we have donated to the Avril Elizabeth Home for the Mentally Handicapped (www.avril.org.za) in lieu of sending out Christmas cards.

2007 promises to be a busy year.  The AFMA Forum will be held at Sun City during March, and this years VICTAM trade show, which will be held in May in The Netherlands, promises to be bigger and better than ever.

News from SPESFEED is that we have changed our office facilities around a little.  We have remained in the same building but have moved to a smaller office suite.    A move is always difficult, but in this case, I believe there are certain advantages to SPESFEED. We will be sharing resources with Afrisoft, a software company owned by my brother Russell and his partner Roger Graham.

News from our former college Shaun Storer is that he has managed to get himself married and ordained as a minister of religion – all within 2 month.  Well done Shaun and good luck!

My presence in Ghana last year was reported in the October the 4^th edition of the Daily Graphic as follows: “Mr Rick Klyen (sic), the Director of SPESFEED South Africa, a poultry farm, took the participants through quality procedures, ingredient composition, variability and its alternatives and practical diet and its examples.” 

It all seem so clear to me at the time – I hope the rest of the audience understood my talk better than the reporter did.

SPESFEED EXPRESS

SPESFEED EXPRESS, the Windows version of our feed formulation program is now shipping.

There are differences from the version that we are all familiar with but the program flow has remained the same.  The new program is faster and easier to use than ever – hence the EXPRESS part of the name.  There will always be ways in which the functionality of the program can be improved, and as always we would be only to happy to get feedback – positive or negative.

Importantly, it will be possible to import all of your existing data libraries and client file into SPESFEED EXPRESS, although moving platforms does offer the opportunity of “cleaning out the attic” in as far as redundant data is concerned, so it may well be advisable to start from scratch.

Some example screens appear on our website (www.spesfeed.co.za) so feel free to have a look at them.

We will no longer be shipping or supporting the DOS version of the software, as many of the newer operating systems (Window Vista for example) will not support DOS software.

We will be holding a training session/workshop for the new program on the 7^th of March at the Country Club at Woodmead.  Our intension is not only to demonstrate how the new program works, but also to help people load the software and convert their data.

The cost will be R 450.00 (excluding VAT) for the day.  Should you be interested in attending please let us know soon as space will be limited.

Poultry Nutrition Course

This years Poultry Nutrition Course will be held at the Country Club at Woodmead from the 17^th to 19^th of September.  We also intend to hold a one-day pig nutrition course on the 20^th of September but will only do this if the numbers justify it.

Please let Bianca know if you are interested in attending either course.

“Kiss of the hops”

Poultry scientists at the University of Arkansas Division of Agriculture have found that Hops, an herb used in brewing beer, might work as a substitute for growth promoting antibiotics in broiler diets.

Susan Watkins and co-workers conducted a feeding trial in which broiler diets containing either hops or a growth-promoting antibiotic were compared along with a control diet with neither treatment (International Journal of Poultry Science, Vol. 5 pp. 134-136. 2006).

Hops serve as an antimicrobial to keep beer from spoiling, and there are a number of U.S. patents relating to the use of hops as an antimicrobial for several food products.

Their findings indicated that addition of ground hops to poultry feed improved early growth rate of broiler chicks and reduced the overall feed needed to produce a pound of gain.  Although the response from the addition of hops was not as great as that obtained from the antibiotic treatment, it was significantly greater than that of birds fed the control diet.

The workers report that this is the first “alternative product” that they have tested in which a response of this magnitude was achieved.  Hops lend bitterness to beer might mean that it could possibly impart some off flavours to the meat.  Additional research is needed to determine how consistent the response to hops might be under more stringent growth conditions.

Broilers and Anti-Biotics

A paper in the recent Journal of Applied Poultry Research, written by Griggs and co-workers, deals with the issue of microbial safety of chickens raised in an anti-biotic free system.

They report that in December 2002, a report published jointly by the Sierra Club and the Institute for Agriculture and Trade Policy claimed that consumers could reduce their exposure to antibiotic-resistant micro- organisms by purchasing poultry products that were raised without antibiotics. This claim was made without doing any research, seriously weakening the assumption. The authors of this report set out to verify whether there was any validity to this claim.

It was found that raising chickens without anti-biotics, especially when the birds are kept outdoors, could result in higher levels of Campylobacter and Salmonella contamination than in conventionally raised chickens. In addition, the removal of antibiotics from chicken feed has not been shown to reduce the incidence of anti-biotic resistance. In the samples collected from chickens raised without antibiotics, high levels of multiple antibiotic resistances were noted.

30 Pigs/Sow/Year

At this years Banff Pork seminar there was a session intriguingly named “30 Pigs/Sow/Year”. 

Henrik Jensen, a Danish farmer, reported that his unit that has achieved high performance. It has consistently marketed 30 pigs/sow over the last few years.   This can only be done where there is the genetic potential for very high litter size. Gilts brought into the unit are purchased from a multiplier operating within the Danbred breeding program, which is run by the Danish Bacon and Meat Council.

Over the 10 years to 2004, litter size in female nucleus herds (Landrace and Large White), within the Danish breeding program, has increased by 3.5 total born/litter with Landrace herds now averaging over 15 pigs per litter.

In addition to the genetic potential for litter size, there are a number of important management practices essential for getting the required results:

been made in just over two years. The biggest gains are yet to come, with the injection of prolific genes into the multiplication units.

Rick Kleyn

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Feeding the young broiler chick

The young chick is not an “immature” broiler, but rather has unique requirements in terms of its management, feeding and nutrition.  Birds that get off to a good start tend to perform better throughout the production period. Whilst there is much that we still do not know or understand about feeding the young chick, a considerable amount is known. It is these areas that will be covered here.

Feeding the broiler during the first week of life represents a challenge for producers and nutritionists. The bird has yet to develop fully from both physiological and anatomical perspectives. The post-hatch nutrition of the broiler needs to take cognisance of this fact. As the genotypes we use in commercial agriculture grow faster, the growth achieved during the first 7 days of life represents an ever-increasing proportion of the production cycle.

The production of a broiler with a good 7-day weight, with good uniformity and with a sound skeleton is a not an unrealistic goal.  It is important to appreciate though, that the nutrition and management of the young chick is a continuum.  It begins with the nutrition and health of the parent flock, moves through the egg handling and hatching process, and then through to the nutrition and management of the chick itself.  These processes may influence the efficiency of growth and ultimate profitability.

Little is know about the effect of marginal levels of nutrient reserve (brought about by feed restriction) and its impact on the quality of the egg, fertility, embryo viability or chick quality. Dietary protein is not believed to play a significant role on chick quality. Mineral excesses and deficiencies have been associated with embryo mortality, but there is little reference to chick performance and transfer of antibodies from parent to the chick.  Zinc and Selenium have been implicated in improving maternal antibody transfer and chick quality.  The dietary inclusion of vitamins has a significant effect on fertility and embryo viability. Specific fat-soluble vitamins (ß-carotene and Vitamin E) can increase lymphocyte proliferation and the ability to mount an immune response.

Ferket has demonstrated that in ovo feeding (injecting a solution into the embryonic amnion of hatching eggs at day 18 of incubation), increased the nutrient reserves for embryos and chicks and stimulated more rapid maturation of the GIT post hatch. The full implication of this technology has yet to be explored, but the development of equipment to carry out the process automatically will accelerate research in this field.

Hatch Day:  Represents the time when the chick must make the transition from the energy supplied by the yolk (endogenous) to the utilisation of carbohydrate-rich feed (exogenous) through the intestine, at which time dramatic changes occur to the size, morphology, and function of the intestine.  

Under natural conditions, chicks will forage for food soon after hatching, which is not possible in a hatchery. Withholding feed from chicks results in a body weight loss because of moisture loss and yolk utilisation. Ross Breeders report that by delaying placement by 15 hours, 7-day weight was reduced by 20 g and 40-day weight by 80 g.

At hatch, the chick is immature with regards the development the GIT, immune system and thermo-regulatory system.  These areas need to develop:

Anatomical development: At the time of hatching, the cells lining the GIT (the enterocytes) of the small intestine are round and immature.  These form the finger like villi that are essential for nutrient uptake. Access to nutrients initiates growth about 24 hours after first ingesting food, with both the number and size (height) of the villi increasing. The weights of the gizzard, proventriculus, and small intestine increase more when compared the other organs. This enhanced growth rate reaches its maximum between day 4 and 8 of age.

Enzymatic Development: The secretion of enzymes by the pancreas and the small intestine are low at the time of hatch. The secretion of pancreatic enzymes is triggered by feed intake. Pancreatic amylase activity increases 3 fold from 1 to 10 days of age while trypsin and lipase activities increase 5 to 6 fold.  Bile secretion takes 3 weeks to reach “adult” levels.

Development of GIT microflora:  The chick hatches with what is effectively a sterile GIT and the early post-hatch stage is critical for the establishment of GIT microbial community. The micro-organisms that colonise the GIT during the early post-hatch period form a synergistic relationship with their poultry host.  By day 3, significant numbers of faecal streptococci and coliforms have been isolated so colonisation begins very soon after hatching.  The microflora is fully established in the small intestine by 2 weeks of age and the manner in which we manage the birds can determine whether the micro-flora is “good” (the lactobacilli) or bad (the anaerobic faecal streptococci, clostridia, enterobacteria).

The immune system:  The GIT is the largest lymphoid tissue in the body, making it an integral part of the immune system. The gut associated lymphoid tissue (GALT), has evolved to provide protection against pathogens encountered in the GIT.   Fasting chicks post hatch impairs development of the Bursa of Fabricius.

The thermo-regulatory system:  Function of the thermo-regulatory system has a direct bearing on nutrient utilisation and feed intake, and thus forms an important part of any discussion on the nutrition of the young chick.

Birds are homoeothermic and have a highly developed control system for the regulation of both heat production and heat loss.  These two processes maintain the chick in a thermal comfort zone, which is the temperature at which the metabolic rate is minimal and the homoeothermic state is maintained at the lowest energy cost.  This maximises amount of net energy available for productive purposes.

In practical terms, chicks maintained at too low a temperature will huddle in an attempt to reduce their heat loss into the environment. Consequently, they visit feed and water points less often, reducing their intake of both. High temperatures also impact on in feed intake.   Birds will move away from the heat source, which is often where the feeding stations are.  They also strive to reduce the level of heat production brought about by nutrient metabolism

Importantly, early access to nutrients triggers the development of all aspects of the GIT.

Practical Nutrition and Feeding: Both energy and amino acid utilisation are compromised for at least the first ten days of the chicks life. How best do we feed the recently hatched broiler chick? Bear in mind that we wish to maximize the development of the GIT and the immune system, achieve a good 7-day weight and still make money.

Figure 1: Changes in Lysine digestibility as chicks age (after Batal and Parsons, 2002)

The tactics that we can employ in practice mostly involve ensuring that the birds consume and metabolise as much nutrient as possible: 

Much of the responsibility for the improvement in feed intake lies with the farm manager.

Figure 2: The relationship between water intake and weight gain.

Both the particle size of feed ingredients as well as the physical form of the diet itself needs to be considered. Particle size should be between 500 and 600 µm for the first 7 days of the broiler life.   Ideally, feed should be fed as a uniform crumble, between 1 and 2mm in diameter.  The level of fines in the diet should be minimal.  Alternatively, use a mini-pellet, but take care that they are not too big (long) as this inhibits feed intake.

Dietary Nutrient Specification:  The bird’s nutrient uptake will increase by increasing the nutrient content of the diet.  Modern broiler genotypes have the ability to respond to and utilize the amino acids in an almost linear manner (Figure 3). The decision that needs to made, is not what level of amino acid should be included in the diet, but rather what level of amino acid will give us the best return. This decision is complicated by the fact that the level of protein offered to young birds, impacts on their lifetime performance. Moreover, any delay in body weight gain brought about by suboptimal ideal protein levels in the starter diet, is only partially compensated for in later in life.

Other aspects of the specification of chick diets do bear some discussion. Sodium is required for the absorption of glucose and methionine. It also stimulates water and feed intake. Weight gain is maximized at considerably higher sodium level than are traditionally used in broiler diets.  It is of interest that excreta moisture levels only increased by a few percentage points.

Figure 3:  Response of broilers (1 to 7 days) to sodium levels in the diet (Maiorka et al., 2004)

Choice of ingredients:  The choice of ingredients should be addressed from the perspective of formulating to maximize the availability of nutrients, especially carbohydrates, as opposed to formulating to meet a published set of energy or amino acid levels.

Firstly, ensure that all ingredients meet normal quality control standards, with regards their visual appearance, taste, smell and physical form. Secondly, improve digestibility by eliminating indigestible components form the diet. Grain low in non-starch polysaccharides (NSP) lead to improved results in young birds (maize vs. wheat). Reducing the NSP level in maize by de-germing and de-hulling it (mealie meal), resulted in significant improvements in weight at 17 days of age as well as an improvement in dry matter retention. Interestingly, gelatinising (cooking) the starch in maize did not improve chick performance.

Soybean meal containing low NSP levels and higher protein levels resulted in the higher feed intake, weight gains and improved feed conversion efficiency.

Lastly, it would make little sense to use ingredients high in ash in the diets of young birds. For example, a 72% protein fishmeal contains about half the ash that a 60% protein fishmeal would contain. Thus, the prudent nutritionist would use high quality fishmeal in starter diets.

Table: Overview of the steps required to maximize young chick development.

Rick Kleyn

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Protein and Amino Acid levels in Layer Diets

I have recently come across some Brazilian work – published in Portuguese but with English abstract and tables (Pavan et al., R. Bras. Zootec., 34, 568-574), which is of interest. They examined the effect of feeding differing levels of Crude Protein (CP) and  total sulphur amino acids (TSAA) on egg production, egg quality and nitrogen excretion in brown hens (ISA Browns).  It was demonstrated that hens will respond to increasing levels of amino acid in the diet, but that simply increasing the protein levels had no effect, other than increasing the level of nitrogenous waste in the manure.

Three CP levels (140, 155 and 170 g/kg) together with 3 TSAA levels (5.7, 6.4 and 7.1 g/kg) were used. The birds were 52 weeks old and the experiment ran for 140 days.  The diets appear to be similar to those used in South Africa, and contained 8.1 g/kg of Lysine.  This level of Lysine is more than adequate, which would indicate that that the TSAA levels were first limiting in all treatments.

It was not possible to appreciate from the discussion or from the manner in which the results were presented whether the correct method of statistical analysis was used.  No consolidated data for each factors or interactions were shown, indicating that the data may not have been analysed multi-factorally.

It was reported that there were no significant differences in feed consumption, egg production, broken eggs, egg mass, feed efficiency or mortality.

Significant differences were reported for the percentages of yolk and albumen of the eggs.  In addition, it was concluded that a diet containing 140 g/kg of CP and 5.7 g/kg of TSAA could be used without causing a decrease in performance. Nitrogen excretion was significantly higher for the layers fed with a 170 g/kg CP diet.

Firstly, there is a definite response in egg number, egg weight and egg output to increasing level of TSAA in the diet (as would be expected for increasing level of the first limiting amino acid). It should thus be possible to select to a level that would result in maximum economic return. This would be especially true if a premium was realised for larger and extra large eggs.

Table 1: Summary data for response to different levels of TSAA in the diet.

When examining the effect of protein level in the diet, it will be observed that there may well be negative trends (other than an increase in the nitrogen content of the manure). These data were not submitted to statistical analysis; however, it would perhaps be safe to say that there was no effect of increasing the protein level of a layer diet.

Table 2: Summary data for response to different levels of CP in the diet.

Pavan et al. (2006)

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Effect of the Processing of Full Fat Soya on Broiler Performance

In more Brazilian work, Brito et al., (R. Bras. Zootec., 35, 457-461) examined the effect of the processing of Extruded Full Fat Soya (EFFS), with or without the addition of an enzyme complex on broiler performance. It was found that both under and over processing of EFFS negatively impacted on broiler performance, while the addition of the enzyme has a positive effect.

The different extruded full fat soybeans (EFFS) used were under processed (91% KOH and 0.5 Urease), standard (88% KOH and 0.05 Urease) and over processed (66% KOH and 0.005% Urease). The multi-enzymatic complex was composed of cellulase, amylase, and protease.

As expected, the addition of the enzyme complex had no effect on either KOH or Urease values of the ingredients.

The diet used contained  34% Full Fat Soya, which is a higher inclusion that most South African nutritionists are comfortable with, so the results reported on below may be slightly exaggerated.

From the tables below, it can be seen that broiler performance was negatively impacted on by both the under and over cooked EFFS, clearly demonstrating just how important it is to correctly cook any full fat soya that is to be used in broiler diets

Table 1:  The effect of Full Fat Soya processing on broiler performance 1 to 21 days.

The addition of the enzyme complex did bring about a significant improvement in gain and feed conversion in broilers. The use of such a product would, as always, be determined by an economic evaluation of it’s inclusion in the diet. However, it would appear that you would get a far better response to its inclusion if the EFFS were not correctly processed.

Table 2:  The effect of using an enzyme complex on broiler performance 1 to 21 days.

This experiment highlights just how sensitive broilers, in particular, are to the inclusion of incorrectly process EFFS.  I believe that by using a simple test such as the Cresol red test, manufacturers can test the quality of their product on an ongoing basis (I know one who does this every hour on the hour). Alternatively, feed millers should be testing every load of Full Fat, as it is delivered – using more than a single sample. In addition, this experiment would indicate that the inclusion of enzymes did improve performance.  Whether this is cost effective or not would need to be determined.

Brito et al., (2006)