Microbial/yeast blend benefits broilers

Microbial/yeast blend benefits broilers

Feeding broilers a microbial/yeast/glucan blend may offer unique modes of action to help stabilize gut microflora and improve gut health.

By DANNY HOOGE*

*Dr. Danny M. Hooge is with Hooge Consulting Service LLC in Eagle Mountain, Utah.

A BLENDED product containing Bacillus subtilis C-3102 spores (CALSPORIN by Calpis America Inc.) and yeast cell walls providing mannan oligosaccharide and beta-glucans (IMW50, ICC, Brazil) has recently been evaluated in broiler chicken pen trials.

This microbial/yeast/glucan feed additive blend (BacPack by Quality Technology International Inc.) was designed to offer the advantage of a dual product with unique modes of action that help stabilize gut microflora, improve gut health and feed utilization and reduce pathogen loads. The product contributes 300,000 colony-forming units (CFU) of bacillus spores per gram of feed, along with the yeast-derived component.

This article summarizes live performance results from three litter pen trials with the product at Southern Poultry Research Group Inc. in Athens, Ga. The pen trials were designed to replicate current U.S. broiler industry management, nutrition and production methods.

1. Heavy broiler trial using antibiotic growth promoters. A 56-day pen trial (trial 1) on used litter was conducted with 1,800 Ross 344 x 708 straight-run chicks during March and April 2013.

There were four dietary treatments with 10 replicate pens and 45 chicks per pen (initial stocking density was 1.11 sq. ft. per bird, with equipment space deducted). Chicks received a live coccidia vaccine on the day of hatch.

The treatments were: (1) negative control (basal diets), (2) bacitracin methylene disalicylate (BMD) at 50 g per ton of feed for days 0-35 and virginiamycin (Stafac) at 20 g per ton of feed for days 35-56 (AGP), (3) AGP plus microbial/yeast/glucan blend at 1 lb. per ton and (4) AGP plus C-3102 at 1 lb. per ton (9.072 g spores; 300,000 CFU/g of feed).

A four-phase feeding program, in cooperation with a U.S. broiler integrator, was fed for days 0-18 as crumbles and for days 18-35, 35-49 and 49-56 as pellets. The diets were based on corn, soybean meal, dried distillers grains plus solubles (DDGS), animal byproduct blend and soybean oil with phytase and other exogenous enzymes.

Results for trial 1 are presented in Table 1. Broilers given feeds supplemented with AGP, AGP plus C-3102 or AGP plus microbial/yeast/glucan blend had significantly greater bodyweight gain and lower feed:gain ratios than birds on unsupplemented feeds (negative control) at 56 days. Adding C-3102 or the microbial/yeast/glucan blend in combination with AGP significantly enhanced bodyweight gain and the European Poultry Efficiency Factor (EPEF) compared to AGP alone.

2. Heavy broiler trial without antibiotics. A 56-day pen trial (trial 2) on used litter was conducted with 1,080 Ross 344 x 708 straight-run chicks during March and April 2013.

There were two dietary treatments with 12 replicate pens and 45 chicks per pen (initial stocking density was 1.11 sq. ft. per bird, with equipment space deducted). A four-phase feeding program, in cooperation with another U.S. broiler integrator, was fed for days 0-18 as crumbles and for days 18-35, 35-49 and 49-56 as pellets. Narasin/nicarbazin (Maxiban) was added at 72 g per ton to feeds as a coccidiostat for days 0-35.

The dietary treatments were: (1) negative control (basal diets) and (2) the microbial/yeast/glucan blend at 1 lb. per ton.

Results for trial 2 are shown in Table 2. Mortality percentages were not significantly different for the two treatments, but feeds with the microbial/yeast/glucan blend produced significantly higher bodyweight gain and EPEF values and lower feed:gain ratios than basal feeds (negative control). Significant benefits were obtained when the blend was used alone without antibiotics.

3. Broiler pen trial with salmonella challenge. Trial 3 was conducted for 42 days during September through November 2013 with a total of 1,200 Cobb x Cobb male broiler chicks randomly allocated to 24 pens with 50 chicks each (0.83 sq. ft. per bird stocking density with equipment space deducted). All chicks received a live coccidia vaccine, and half of the chicks in each pen were tagged and orally inoculated with 5 x 107 nalidixic acid-resistant Salmonella heidelberg per chick prior to placement (day 0).

Three-phase diets were used with the starter (days 0-21 as crumbles), grower (days 21-35 as pellets) and finisher (days 35-42 as pellets). The feeds were based on corn, soybean meal, vegetable fat and phytase.

Dietary treatments were: (1) negative control (basal diets), (2) bacitracin methylene disalicylate at 50 g per ton and (3) double-strength microbial/yeast/glucan blend at 1 lb. per ton (provided B. subtilis C-3102 spores at 600,000 CFU/g of feed plus yeast cell walls). Boot sock litter swabs by pen and cecal contents of both ceca per bird sampled (five dosed and five undosed per pen) were evaluated for prevalence (percent positives) of S. heidelberg identified as serogroup B.

Trial 3 results for performance and prevalence of salmonella in pens and in ceca of birds are shown in Table 3. Broiler feeds supplemented with bacitracin or the double-strength blend significantly increased bodyweight and improved feed conversion ratio (FCR) and mortality-adjusted FCR compared to unsupplemented diets (negative control).

Boot sock litter swabs at 42 days resulted in significantly lower salmonella serogroup B percent positives in pens given the blend than in pens given bacitracin, with negative control pens being intermediate. Cecal contents of both ceca from five orally dosed and five undosed birds produced significantly lower salmonella serogroup B percent positives for bacitracin and blend birds than for negative control birds.

 

Conclusions

Three 42-day broiler chicken litter pen trials, two with Ross straight-run and one with Cobb male chicks, were conducted to evaluate the effects of feeds with bacitracin or a microbial/yeast/glucan blend compared to unsupplemented feeds. Built-up litter was used in two pen trials, and fresh pine shavings were used in the third trial in which half of the chicks per pen were orally inoculated with salmonella prior to placement (day 0).

In trial 1 with antibiotics, the combination treatments both significantly reduced feed:gain compared to the negative control treatment. In trial 2 without antibiotics, birds given the feed supplemented with the blend had significantly greater bodyweight gain and EPEF values and lower feed:gain ratios than negative control birds.

In trial 3, birds on feeds supplemented with bacitracin or double-strength blend significantly increased bodyweight and decreased FCR and mortality-adjusted FCR values compared to birds on negative control feeds. Salmonella serogroup B percent positives were significantly reduced in boot sock swabs by pens and in cecal content samples per bird sampled in the blend group compared to the negative control group, with bacitracin being intermediate for boot sock positives and greater in cecal contents than negative controls.

Therefore, supplementation of broiler feeds with the microbial/yeast/glucan blend is recommended because it may improve bodyweight, FCR and EPEF results.

 

1. Trial 1 results (March-April, 2013)

Dietary

Bodyweight

 

Mortality,

 

treatment

gain, lb.

Feed:gain

%

EPEF*

Negative control

7.773c

2.051a

5.333

290.7b

AGP

7.903b

2.008b

5.333

302.0b

AGP + B. subtilus

7.994a

2.000b

4.667

308.7a

AGP + blend product

8.010a

1.984b

5.111

310.4a

P-value

<0.001

0.001

0.855

0.001

*EPEF = [(bodyweight gain, lb. x livability, %)/(age, days x feed:gain)] x 100.

a,b,cMeans in a column with the same letter superscript are not significantly different at P < 0.05.

 

2. Trial 2 results (March-April, 2013)

Dietary

Bodyweight

 

Mortality,

 

treatment

gain, lb.

Feed:gain

%

EPEF

Negative control

7.959b

2.043a

5.185

299.3b

Plus blend

8.083a

2.009b

5.741

307.2a

P-value

0.001

0.007

0.555

0.046

a,bMeans for a parameter with different letter superscripts differ at P < 0.05.

 

3. Trial 3 results (September-November, 2013)

 

Body-

 

Mort.-

 

Boot sock

Cecal contents

Dietary

weight,

 

adj.

Mortality,

by pen, %

by bird,

treatment

lb.

FCR1

FCR

%

pos. Sh+2

% pos. Sh3

Negative control

3.882b

2.037a

1.949a

13.50

64.38ab

65.00a

Plus bacitracin

4.096a

1.851b

1.805b

9.50

70.00a

71.67a

Plus double-strength blend

4.027a

1.898b

1.841b

9.00

46.25b

54.17b

P-value

0.001

<0.001

<0.001

0.312

0.040

0.042

1FCR is feed weight/survivor weights. Mort.-Adj. FCR is feed weight/weight of survivors plus dead and culls.

2Boot sock litter swab Salmonella heidelberg (serogroup B) positive pens (Sh+ %) at 42 days.

3Cecal contents from both ceca per sampled bird (five dosed and five undosed per pen), Salmonella heidelberg (serogroup B) positive birds (Sh+ %) at 42 days.

a,b,cMeans in a column with the same letter superscript are not significantly different at P < 0.05.

 

Volume:86 Issue:04

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