Poultry Studies

1.  Effect of adding beta-1,3/1,6-D-glucan supplement on necrotic enteritis in broilers.  To define the effect of beta-1,3/1,6-D-glucan on necrotic enteritis, on Day 14 all birds were orally inoculated with a mixed coccidial inoculum containing approximately 25,000 oocysts of E. acervulina per bird and 5,000 oocysts of E. maxima per bird; on day 19 and 20 birds the experimental groups were given a broth culture of C. perfringens 10⁸ cfu/ml once daily.   Birds were given feed and water ad libitum throughout the study. This study was done by Dr. Greg Mathies at the Southern Poultry Institute, Athens. GA.

A summary of the results (Table 1) shows that the chicks fed the feed containing beta-1,3/1,6-D-glucan performed as well as those fed an antibiotic.  There is no significant statistical difference between antibiotic-treated and beta-1,3/1,6-D-glucan fed chickens in relation to weight gain or feed conversion over the 28 day of the study.

Based on the estimate (McDevitt et al, 2006) that necrotic enteritis costs the industry 5 cents per bird, the cost to the industry of this disease is approximately $8.75 million dollars per week. The cost to feed beta-1,3/1,6-D-glucan is approximately 2.4 cents for the lifetime of the bird. Feeding beta-1,3/1,6-D-glucan could result in a potential net savings of $4.55 million per week in current losses attributable to necrotic enteritis for the entire US broiler industry.

 

Table 1

Effect of beta-1,3/1-6-D-glucan  on feed conversion and weight gain in a necrotic enteritis model

 

 

 

2.  Comparison of the effect of beta-1,3/1,6-D-glucan and antibiotics on growth parameters of broilers.  To assess the effect of beta-1,3/1,6-D-glucan on various parameters of growth of a commercial strain of broilers, 1400 day-old chicks were divided into 4 groups and fed a feed containing the following additives: Group 1, beta-1,3/1,6-D-glucan plus antibiotic; group 2, beta-1,3/1,6-D-glucan; group 3, antibiotic; group 4 no additives. In all case the antibiotic was BMD at a concentration of 0.05%; beta-1,3/1,6-D-glucan was used at 20Grams/ton for the first 2 weeks and 20 grams/ton for the remainder of the trial.  The beta-1,3/1,6-D-glucan used in this study was 90% pure beta-1,3/1,6-D-glucan isolated from Saccharomyces cereviciae cell walls.

The results of the following study (Table 2) clearly show that beta-1,3/1,6-D-glucan can replace antibiotics without any loss of performance.  Since this was a laboratory study, the animals were not subject to the stress of the commercial-growing environment.  We recognize that under commercial growing conditions beta-1,3/1,6-D-glucan would give superior results because of increased resistance to bacterial and viral infections. 

Table 2

Performance of broilers treated with beta-1,3/1,6-D-glucan and/or antibiotics

 

Treatment	Feed Conversion Ratio (kg/kg) + SD	Body Weight per Bird d 29 (kg) + SD	Mortality (%)
beta glucan +Antibiotic	1.8357 + 0.0680	1.4135 + 0.1051	1.1905 + 2.130
beta glucan/ No Antibiotic	1.8296 + 0.0435	1.4366 + 0.1009	0.3125 + 1.250
No beta glucan/ Antibiotic	1.8151 + 0.0673	1.4171 + 0.0984	0.2976 + 1.190
No beta glucan/ No Antibiotic	1.8397 + 0.0728	1.3905 + 0.1159	0.2976 + 1.190
ANOVA  p-value	0.7185	0.7073	0.2348
Product	0.7389	0.1618	0.2189
Antibiotic	0.5603	0.9079	0.2341
Product + Antibiotic	0.3355	0.1032	0.2341

 

 

3. Effect of beta-1,3/1,6-D-glucan on growth performance of drug-free broilers.  In a recently completed trial, a producer of “All-Natural Broilers”, who farmed broilers without antibiotics in the feed, in the water or as therapeutics, added beta-1,3/1,6-D-glucan to the feed at 40 grams/ton for the first two weeks and 20 grams/ton thereafter in one house with 20,000 broilers.  The data from this house were compared to the data from a similar house of 20,000 broilers. The results are shown in Figure 2.

 

 

 

 

Figure 2.  beta-1,3/1,6-D-glucan added to broilers feed resulted in 13 points better feed conversion, 50% lower mortality, 86% lower condemnation and decreased the time to reach 5.25 lbs from 48 to 45 days.

 

 

 

 

 

 

 

 

 

 

4.  Evaluation of beta-1,3/1,6-D-glucan Efficacy in Commercial Broilers Challenged with E. coli Infectious Process.  Infectious process is an E. coli infection that causes significant cellulites in broilers resulting in increase mortality and condemnation and significant economic losses to the producer.   A trial was conducted at the Colorado Quality Research, Inc. to evaluate the effectiveness of beta-1,3/1,6-D-glucan in preventing and/or ameliorating the disease. For this purpose 864 1-day old chicks were divided into 6 groups and treated as follows:

 

Table 3.

Treatment protocol for a study of “infectious process”

 

 

 

On day 28 the birds were challenged with either of two E. coli isolates from field cases. On study day 42 all birds per pen will be removed and sacrificed and scored for air sacculitis and cellulitis.  The following scale will be used for scoring:

 Cellulitis: 0 = normal, 1 = < 0.5 cm lesion, 2 = > 0.5 cm - <5.0 cm lesion,

3 = >5.0 cm – ¾ of breast, 4 = whole breast or more involved

Airsacculitis: 0 = normal, 1 = mild suds or focus of exudate, 2 = Heavy suds or multifocal exudate, 3 = severe profuse exudates

 

Results.  It is evident from Figure 3 that beta-1,3/1,6-D-glucan added to the feed of broilers decreases the incidence of airsacculitis and subcutaneous cellulites significantly especially at the dosage of 40 grams/ton in the starter feed followed by 20 grams/ton in the grower and finisher feed.

 Figure 3. Beta-1,3/1,6-D-glucan effect on a model of Infectious Process in broilers. 

 

 

 

 

A: Effect on subcutaneous cellulites.

 

B: Effect on air sacculitis

 

 

 

 

 

Day 42 data, termination of study, shows that beta-1,3/1,6-D-glucan addition to the feed increases performance significantly Treatment No 4 is an exception and is related to the fact that this group did not perform well even before challenge (Fig. 4).

 

 

Figure 4. Effect of beta-1,3/1,6-D-glucan in broilers

challenged with “infectious process” E. coli.

 

 

The effect of beta-1,3/1,6-D-glucan is clearly evident by comparing the number of birds that contacted sever disease.  Table  4 shows the number of broilers that scored from 0 to 3.  It is evident that the number of broilers with no disease is much higher in the broilers fed beta-1,3/1,6-D-glucan.

 

 Table 4

Scores for percent of broilers challenged with two strains of infectious process E. coli from day 28 to 43.

Score	E. coli 1 Challenge						E. coli 2 Challenge
	Treatment						Treatment
	0		40-20		40-40		0		40-20		40-40
	Airsac.	Cellul.	Airsac.	Cellul.	Airsac.	Cellul.	Airsac.	Cellul.	Airsac.	Cellul.	Airsac.	Cellul.
0	42.6	9.6	63.2	37.6	61.0	44.0	19.6	3.1	45.9	12.9	36.8	7.4
1	26.9	28.7	24.8	23.9	23.7	25.6	32.9	7.2	30.6	10.6	33.7	8.6
2	25.2	37.4	11.1	29.9	14.4	23.7	42.3	38.0	20.0	44.7	22.1	49.5
3	5.2	24.3	0.85	8.5	.85	7.6	5.2	51.5	3.5	31.8	7.4	34.7

 

5.  The Effect of beta-1,3/1,6-D-glucan on Cellulitis in Turkeys. The purpose of the trial was to determine the effectiveness of beta-1,3/1,6-D-glucan in alleviating the effects of Clostridium septicum in tom turkeys.  Clostridium septicum causes cellulitis or dermatitis in turkeys, a skin disease that is also referred as necrotic dermatitis in broilers. For this purpose 144 10-week old turkeys that had been fed a feed containing 40 grams/ton of beta-1,3/1,6-D-glucan for 6 weeks and 40 grams/ton for the following 4 weeks and 72 turkeys that had been fed a standard diet were obtained from a commercial grower. The 144 turkeys were divided into two groups; one group was fed a feed containing 20g/ton beta-1,3/1,6-D-glucan and one group was fed a feed containing 40 grams/ton beta-1,3/1-6-D-glucan; the 72 turkeys fed the standard feed were fed a feed containing the standard antibiotics used to treat cellulites. At day 28 after the turkeys arrived at the experimental facility, all turkeys received a subdermal injection of Clostridium septicum (10⁹ cfu).  At day 42 all turkeys were sacrificed, lesion score and weight gain determined.

The result of the study showed a decrease in average lesion score of 15% in the turkeys fed 20g/ton beta-1,3/1,6-D-glucan and a 33% in the turkeys fed 40g/ton beta-1,3/1,6-D-glucan. It is noteworthy that in the turkeys fed beta-1,3/1,6-D-glucan, 33/97 or 33% of the turkeys had minimal evidence of skin lesion (score = 0 or 1) and none showed evidence of severe lesion (score 4).  In the turkeys fed the diet without beta-1,3/1,6-D-glucan only 15% (9/60) of the turkeys had minimal evidence of skin lesion (score = 1) and none had a score = 0, whereas 7% had evidence of severe skin lesions (score = 4).

Control turkeys and in the group fed 20 grams/ton of beta-1,3/1,6-D-glucan gained a similar amount of weight (an average of 2.462Kg/bird and 2.408 Kg/bird respectively); however, the group fed 40g/ton beta-1,3/1,6-D-glucan gained an average of 3.175 kg/bird. The results of this study clearly show that beta-1,3/1,6-D-glucan alleviates the toxic effects of Clostridium septicum and that given the right dose of beta-1,3/1,6-D-glucan turkeys can continue to gain weight even though severely challenged.

6.  The Effect Of beta-1,3/1,6-D-glucan on the Growth and Health of Ducks. This trial was done by a company that raises ducks in the United States with the purpose of determining whether beta-1,3/1,6-D-glucan affected (1) Immune parameters and (2) whether it affected performance.

Ducklings were fed a feed containing beta-1,3/1,6-D-glucan at 45 grams/ton for 35 days. At 35 the ducklings were processed and the following parameters measured: complement activity, anti-galactose titers (anti-gal: IgG and IgM), total IgA, weight gain, feed conversion and mortality.  Anti-gal are antibodies developed against gut bacteria; animals grown in sterile environments do not develop anti-gal antibodies; likewise IgA is in part produced in response to noxious gut bacteria. 

Results. Anti-gal titer (both IgG and IgM) was lower in ducklings fed the diet containing beta-1,3/1,6-D-glucan.  The lower titer of anti-gal suggests that beta-1,3/1,6-D-glucan in the diets reduces levels of various bacteria known to be inducers of anti-Gal, such as E. coli, Klebsiella, and Salmonella.

There was a significant decrease in the level of IgA in the ducklings fed the diet containing beta-1,3/1,6-D-glucan.  Since IgA is produced in response to infectious agents in the intestine, a decrease in IgA suggests a decrease in infectious agents in the intestine. In fact, the decrease in IgA and the concomitant decrease in infectious agents were correlated with a decrease in mortality in the flock.

In ducks used for breeding  beta-1,3/1,6-D-glucan at 40 grams/ton for the first 2 weeks and 20 grams/ton thereafter decreases duck mortality by 2.2% and increased egg laid by 3.7 eggs/duck resulting in a net 2.4 day-old ducklings hatched. 

Conclusions.  The results of the trial clearly show that beta-1,3/1,6-D-glucan affects immune parameters in ducks, e.g. the lower titers of anti-gal and IgA, indicating a decrease in noxious bacteria in the gut. In support of these results is data we obtained in a preliminary experiment in turkeys, in which early morning cloacal load of Salmonella was decreased by 30% and the cloacal load of Clostridium was decreased by 50% in turkeys fed beta-1,3/1,6-D-glucan. The number of turkeys in the experiment was small and will have to be repeated to obtain significant data.  In breeding ducks beta-1,3/1,6-D-glucan lowered mortality and increased the number of eggs produced significantly.