At the turn of the last century it took a broiler 96 days to grow to slaughter weight (about two kilograms),

today it takes between 40 and 42 days as a result of selective breeding for quick meat growth.

Broiler producers carefully guard their production costs, and most data from the USDA is at least 5 years old. As one might imagine, costs are calculated to several decimal points when dealing with flocks numbering in the millions, and profit margins that can fluctuate with changes in any number of variables. These variables determine each producer`s bottom line.

I have based the following cost projections on some “averages” obtained from the USDA, and have rounded UP, so as to err on the side of caution. An average broiler eats a little less than 14 lbs. of feed in his lifetime.

Feed costs vary greatly, based on quantity purchased (discounts), protein content, etc. Based on Average USDA figures, a fair price would be $235/ton or 11 ¾ cents per pound. That means that an average broiler eats $1.645 worth of feed in his lifetime.

The published trials using YBG recommended a pre-mix of 40 grams of YGB/1000 kilograms feed for the first 2 weeks and 20 grams of YBG/1000 Kilograms of feed for the last 4 weeks.

At a cost of $175/kilo, YBG costs 17.5 cents per gram. At the richest recommended mix of 40g/1000kg, it would cost $7.00 to treat 1000kg (or 1.1 tons) of feed. However, this is the time of a broiler’s life when feed consumption is at the lowest rate (just over 1 pound in the first 2 weeks). The cost to treat 1000 kg (or 1.1 tons) with 20g of YBG would be $3.50, or $3.19 per ton.

Since the first pound or so (out of 14 lbs) is double the cost, lets just average up to $3.25 per ton, just to be safe. That averages out to a cost of adding YBG to a pound of feed to be .001625 per pound. The total cost to add YBG (AgrastimTM) to the 14 lbs of feed consumed by each broiler would be 2.275 cents per broiler. Consumers have already shown a willingness to pay a much higher premium for ``all Natural`` poultry products. I believe that even an increase in cost of 3 cents per broiler would not negatively impact the market.

Benefits of using AgrastimTM

There are a number of studies that have shown yeast Beta Glucan (YBG) to be an effective broad spectrum immunostimulant1 and a valuable management tool in the prevention/treatment of bacterial and viral infections.

With the recent elimination of the use of growth promoting antibiotics in food producing animals, suitable natural (nutricine) substitutes have been sought to control both clinical and sub-clinical Necrotic Enteritis2 in broilers, and to promote growth. Yeast Beta glucan, such as that contained in AgrastimTM, has shown to produce results comparable to antibiotics in “livability, feed conversion, average daily gain, incidence of clinical Necrotic Enteritis, condemnations and uniformity. Almost identical livability, weight for age and feed conversions have been obtained.”

Yeast beta glucan is effective in combating bacterial infections, such as bacteria E. coli, Salmonella sp., Campylobacter jejuni, Staphylococcus aureus, Listeria monocytogenes, and Bordetella avium.3

Mannans and manno-protein complexes found in AgrastimTM, are beneficial in preventing the attachment of bacteria such as Escherichia coli to the gut lining, thus reducing the overall infection challenge in the body. 4

Accelerated growth rates of broilers and turkeys can cause leg and joint problems, typical of osteoporosis. Yeast Beta glucan has been found to have some effect in combating effects of osteoporosis, and research is ongoing at the Nova Scotia College of Agriculture. A presentation was made at the 2006 International Poultry Expo by the people involved in this research. 5

Yeast Beta Glucan and Avian Influenza

While vaccines seem to be effective, the cost per bird makes widespread use prohibitive for commercial poultry producers. In addition to cost, there is significant concern that trade restrictions will prevent the use of the vaccine in poultry entering the food chain.

While there are currently no field trial results showing that AgrastimTM is effective in either prevention or treatment of “bird flu”, there have been a number of studies showing the effectiveness of yeast beta glucan against other, closely related viruses including swine flu6 and other forms of avian flu7.

Dr. Young Park, of BioAgra, is currently working with BioAgra’s Director of Research and Development in seeking approval for field trials of Agrastim in Asia, using the H5N1 virus. Because of the high profile of this work, and the very serious pandemic risks involved, there is a significant amount of international “red tape” that must be overcome.

As the H5N1 virus continues to spread across Asia, Europe, and now Africa, a universal sense of urgency is developing, and “red tape” may soon be reduced.

When I spoke to BioAgra’s director of Research and Development (who wrote the protocol for these trials) he was cautiously optimistic as to the anticipated results.

Footnotes:

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1. Yeast Beta Glucan’s Mode of Action

Beta-1,3/1,6-glucan binds specifically to receptors on specialized white blood cells (macrophages, granulocytes and natural killer cells) that constitute the front line of defense when animals or humans suffer from microbial attacks.

The beta-1,3/1,6-glucan receptors on white blood cells are present in cells in all animal groups from the simplest invertebrates to man. Beta-1,3/1,6-glucan has therefore the same basic biological mode of action in the whole animal kingdom.

When the receptors are engaged by beta-1,3/1,6-glucan, white blood cells are alerted and become prepared to meet eventual infections by enhanced engulfing and killing of micro-organisms.

White blood cells activated by beta-1,3/1,6-glucan also produce signal molecules called cytokines that stimulate the formation of new white blood cells and send messages to B- and T-cells, to enhance their capacity to mobilize defense against specific disease organisms.

Activation with beta-1,3/1,6-glucan results in enhanced overall resistance to all possible infectious agents (virus, bacteria, fungi, parasites). Due to its very basic mode of action, beta-1,3/1,6-glucan also affects many other biological processes, such as wound healing, degradation of dead body cells, killing of tumor cells, inflammation, repair of cells and tissues damaged by ultraviolet light.

2. Necrotic enteritis is an acute enterotoxemia characterized by sudden onset, explosive mortality, and confluent necrosis of the mucosa of the small intestine. It primarily affects broilers and turkeys 2-12 wk old and also has been reported in other avian species in the same age range. Infected birds are depressed and may have diarrhea. Clinical signs progress rapidly, and death occurs within a few hours. The breast is dehydrated and darkened, and the liver is usually swollen and congested. The small intestine is ballooned and friable and contains foul-smelling, brown fluid; the mucosa is covered with a brownish, diphtheritic membrane. The disease persists in a flock for 5-10 days, and mortality is 2-50%.

3. http://www.ars.usda.gov/research/projects/projects.htm?ACCN_NO=405551

4.

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15698692&itool=iconabstr&query_hl=2

5.

http://www.eggsite.com/PDF/2004_Annual_Report_FINAL.pdf

6. Journal of Veterinary Medicine

B Infect Dis Vet Public Health, 2004 Mar, 51(2), 72 - 6

Antiviral effect of Saccharomyces cerevisiae beta-glucan to swine influenza virus by increased production of interferon-gamma and nitric oxide; Jung K et al.

The aim of these experiments was to investigate the potential antiviral effect of Saccharomyces cerevisiae beta-glucan on the pneumonia induced by swine influenza virus (SIV) . Forty colostrum-deprived 5-day-old piglets were randomly divided into four groups of 10 . The 20 pigs in groups 1 and 2 were administered Saccharomyces cerevisiae beta-glucan orally (50 mg/day/pig; En-Bio Technology Co., Ltd) for 3 days before SIV infection and those in groups 3 and 4 were given culture medium/diluent alone . Groups 1 and 3 were inoculated intranasally with 3 ml of tissue culture fluid containing 2 x 10(6) tissue culture infective doses 50% (TCID(50))/ml of SIV and those in groups 2 and 4 were exposed in the same manner to uninfected cell culture supernatant . The microscopic lung lesions induced by SIV infection (group 1 pigs) were significantly more severe than those induced by infection in animals pre-administered beta-glucan (group 3) These findings support the potential application of beta-glucan as prophylactic/treatment agent in influenza virus infection.

7.

Tumor Necrosis Factor Alpha Exerts Powerful Anti-Influenza Virus Effects in Lung Epithelial Cells

Sang Heui Seo and Robert G. Webster*

Department of Virology and Molecular Biology, St. Jude Children’s Research Hospital, Memphis, Tennessee 38105-2794

Received 30 August 2001/ Accepted 23 October 2001

Previous studies have associated influenza virus-induced expression of inflammatory cytokines, including tumor necrosis factor alpha (TNF-), with influenza pathogenesis in the human respiratory tract and have suggested that alpha and beta interferons are the first cytokines recruited to counteract such infection. However, we report here that TNF- has powerful anti-influenza virus activity. When infected with influenza virus, cultured porcine lung epithelial cells expressed TNF- in a dose-dependent manner. Expression of TNF- was induced only by replicating virus. TNF- showed strong antiviral activity against avian, swine, and human influenza viruses, and the antiviral effect of TNF- was greater than that of gamma or alpha interferon. These findings suggest that TNF- serves as the first line of defense against influenza virus infection in the natural host.

Full article available online at http://jvi.asm.org/search.dtl

See also: Pathogenesis of Hong Kong H5N1 influenza virus NS gene reassortants in mice: the role of cytokines and B- and T-cell responses, Aleksandr S. Lipatov, Samita Andreansky, Richard J. Webby, Diane J. Hulse, Jerold E. Rehg, Scott Krauss, Daniel R. Perez, Peter C. Doherty, Robert G. Webster and Mark Y. Sangster

http://vir.sgmjournals.org/cgi/content/full/86/4/1121

-zties