Login   |   Register
pagepress

Effect of dietary mannan oligosaccharide from Saccharomyces cerevisiae on live performance of broilers under Clostridium perfringens challenge

Alaeldein M. Abudabos, 1 Hany M. Yehia2

1 Department of Animal Production, King Saud University, Riyadh, Saudi Arabia

2Department of Food Science and Nutrition, King Saud University, Riyadh, Saudi Arabia

Abstract

A 30-day broiler cage trial was conducted to evaluate the effect of dietary mannan oligosaccharide (MOS) from one commercial product (SAF-Mannan) on growth parameters, gut health and control pathogen colonization of broilers under Clostridium perfringens (C. perfringens) challenge. One hundred, 0-day-old male Ross 308 broilers were allocated in 4 experimental treatments for 30 days. The four dietary treatments were T1, standard broiler basal diets without any medication as a control (+CONT); T2, basal diets as in T1 plus C. perfringens challenge (-CONT); T3, enramycin 0.1 g/kg of feed plus C. perfringens challenge (ENRA); T4, SAF-Mannan at 0.5 g/kg in starter and finisher diets plus C. perfringens challenge (SAF). Overall, feed conversion ratio (FCR) and body weight gain (BWG) in treatments ENRA and SAF were significantly better (P<0.01) than the -CONT treatment, whereas treatment +CONT was intermediate and not different from SAF. Feed intake (FI) was not influenced by treatment. SAF-Mannan supplementation was able to lower the ileal C. perfringens count as compared to all other treatments (P<0.05). The changes in C. perfringens count appear in parallel to observed improvement in the cumulative FCR. The results from this study clearly indicated that SAF-Mannan could act as a replacement for antimicrobial growth promoters in broilers (AGPs). SAF-Mannan level of 0.05% was enough to achieve a response competitive with that of the antibiotic.

Corresponding author: Dr. Alaeldein M. Abudabos, Department of Animal Production, College of Food and Agricultural Sciences, King Saud University, P.O. Box 2460, Riyadh 11451, Saudi Arabia.

Tel. +966.5.97634578 - Fax: +966.1.4678474.

E-mail: alabudabos@gmail.com

Key words: Broiler, SAF-Mannan, Performance, Clostridium perfringens, Gut health.

Acknowledgments: this project was supported by King Saud University, Deanship of Scientific Research, College of Food & Agricultural Sciences, Research Center.

Received for publication: 23 November 2012.

Revision received: 15 February 2013.

Accepted for publication: 9 March 2013.

This work is licensed under a Creative Commons Attribution NonCommercial 3.0 License (CC BYNC 3.0).

©Copyright A.M. Abudabos and H.M. Yehia, 2013

Licensee PAGEPress, Italy

Italian Journal of Animal Science 2013; 12:e38

doi:10.4081/ijas.2013.e38

Introduction

There are increasing concerns about the risk of developing cross-resistance and multiple antibiotic resistances in pathogenic bacteria in both humans and poultry linked to the therapeutic and subtherapeutic use of antibiotics in livestock (Castanon, 2007). Current trends in poultry production point to reduction or total elimination of antimicrobial growth promoters (AGPs) use and increase the use of non-antibiotic feed additives that offer similar benefits, such as to improve the growth of broilers and improve the utilization of feed (Mountzouris et al., 2007). Several groups of these additives are in use such as probiotics, prebiotics, acidifiers, antioxidants and phytogene additives.

Prebiotics are a possible alternative to antibiotics in poultry diets. Prebiotic usually refers to oligosaccharides which are not digested by the animal enzymes, but can selectively stimulate certain intestinal bacteria species, which have potential beneficial effects on the host health. While probiotics are meant to bring beneficial microbes to the gut, oligosaccharides are supposed to selectively stimulate the beneficial microbes that already live there (Yang et al., 2009). Prebiotic have two advantages relative to probiotics: a technological, because there are no problems with the thermal processing of the feed and the acidic conditions of the digestive system, and a safety, because there is no introduction of any foreign microbial species into the gut. However, similar to probiotics, results of the effects of prebiotics on broiler performance are contradictory.

Mannan oligosaccharide (MOS) is derived from the outer layer of yeast cell walls, Saccharomyces cerevisiae. The effects of MOS on poultry production can be expressed in reduction of diseases by inhibition of pathogenic bacterial colonization to gut lining by binding to them and thus preventing them of proliferating and producing toxins (Benites et al., 2008), reducing intestinal pathogen counts (Benites et al., 2008), improving the immune system (Ferket, 2002) and exhibit influence on morpho-functional characteristics of intestines (Ferket, 2002; Zhang et al., 2005; Podmaniczky et al., 2006). These effects lead to better growth of broilers (Blake et al., 2006), improvement of FCR (Podmaniczky et al., 2006; Rosen, 2007). However, results of the effects of MOS on broiler performance are contradictory. Other reports showed that MOS had no positive influence on the performance of poultry (Waldroup et al., 2003).

There are limited reports on the effect of MOS on broilers under bacterial challenge. The objective of this study was to further determine the effects of MOS supplementation from SAF-Mannan® (S.I. LeSaffre, Marcq en Baroeul, France) to broiler diets compared to a growth promoting antibiotic (enramycin) on growth performance, histomorphology and bacterial count of small intestinal mucosa in broilers raised in cages under subclinical C. perfringens model and to determine the product with the most return and pathogen colonization control.

Materials and methods

Animals, husbandry and treatments

A total of 100, 0-day-old Ross 308 male broiler chicks obtained from a commercial hatchery (Al-Wadi Poultry Farm Co., Riyadh, Saudi Arabia) were placed in 20 cages (50 cm length, 60 cm width and 36 cm depth) in a four-deck cage system and received the experimental diets in electrically heated battery brooders with raised wire floors. The chicks had been vaccinated for Marek’s disease, Newcastle and infectious bronchitis. Birds were maintained at 23 h light schedule. The four dietary treatments were T1, standard broiler basal diets without any medication as a control (+CONT); T2, basal diets as in T1 plus C. perfringens challenge (-CONT); T3, 0.1 g/kg enramycin plus C. perfringens challenge (ENRA); T4, basal diets plus 0.5 g/kg SAF-Mannan plus C. perfringens challenge (SAF). On d 16, birds in treatments 2 to 4 were challenged by C. perfringens using overdose of anticoccidial vaccine namely Paracox-8 (10-fold dose) orally, on d 18 and 20 chicks were gavaged with 1 mL of a cocktail containing C. perfringens inoculations (4 × 108 CFU). Culture of C. perfringens was obtained commercially (MicroBiologics, Cloud, MN, USA) and was propagated under anaerobic conditions for 16 hours at 37°C in screw cap tubes, cells were harvested by centrifugation (4500 g at 4°C) and diluted in physiological saline. Typical isocaloric and isonitrogenous starter (0-16 d) and finisher (17-30 d) diets based on corn-soybean meal diets were formulated in mashed form according to Table 1, which met or exceeded the recommendations in commercial practice in Saudi Arabia. Ambient temperature and relative humidity were concurrently and continuously recorded at 3-hour interval using two data loggers (HOBO Pro Series Data Logger, Model H08-032-08, Onset Co., Cape Cod, MA, USA) placed inside the chamber. The average temperature and relative humidity for the whole period were 24.95°C±0.26 (SD) and 26.63%±3.30 (SD), respectively. The study was conducted in April and May, 2012 under a protocol approved by King Saud University and complies with the current laws of animal protection in Saudi Arabia.

Measurements

Feed consumption and body weight gain (BWG) were recorded weekly by pen and feed conversion ratio (FCR) computed at 16 and 30 d. Mortality was checked daily and weights of dead birds were used to adjust FCR. At the conclusion of the trial at 30 d, five birds per treatment were selected, after euthanasia, feather, heads, necks, and shanks were removed, and the remaining carcasses were dissected to breast and leg quarter and were weighed. The percentage of yield of each part was calculated on the basis of dressed weight.

Histopathology and morphometric measurements

At 16 and 30 d, the entire gastrointestinal tract from five birds per treatment was removed aseptically, small intestine was weighed and the total length was measured, then was separated into duodenum, jejunum and ileum and for each part measurements of length and weight were taken. A 2-cm-long sample from each portion of the small intestine was collected for histology measurements. Samples were fixed in phosphate-buffered formalin for at least 48 h, after which they were embedded in paraffin. Sections of 5 mm were cut and stained with haematoxylin and eosin. Measurements of height and width were based on at least 5 well-oriented villi per section per broiler using an IX71 Inverted Olympus Microscope (Eyepiece: WH10X, Objective Lens: 4X) and a PC-based image analysis system (Olympus DP72 Microscope Digital Camera; Olympus NV, Aartselaar, Belgium) with software Analysis (Cellsens Digital Imaging Software for Research Application).

Enumeration and identification of bacterial cells

Ileal digesta contents were aseptically emptied in a new sterile bag and kept in ice until time of analyses. Samples were weighed and diluted in 0.9% saline proportionally, and 0.1 mL of each sample was plated on duplicates by using selective agar media for enumeration of target bacterial groups. C. perfringens was counted on tryptose sulfite-cycloserine (TSC) agar for C. perfringens (Oxoid CM587 with the addition of SR88 and SR47). Colonies on TSC agar that were suspected to be C. perfringens were plated secondarily on blood agar (Garridol et al., 2004). Enterobacteriaceae were isolated on MacConkey agar (Oxoiod CM7) after an incubation time of 24 h in an aerobic atmosphere at 37° (Garridol et al., 2004). Isolates of Enterobacteriaceae and Salmonella were identified by API 20E. The API 20E strips (bioMérieux, Craponne, France) were inoculated, incubated at 37°C for 24 h and interpreted as recommended by the manufacturer. Reactions were recorded and identifications were determined by using a computer program [API Lab Plus software version 3.2.2 (bioMérieux)]. Results were expressed as log10 colony-forming units per ml of ileal digesta (log10 CFU/g).

Statistical analysis

All statistical analysis was performed using the Statistical Analysis System (SAS, 2002). A cage constituted the experimental unit. Four treatments were replicated 5 times in a randomized complete block design. Means for measurements showing significant differences in the analysis of variance were tested using the PDIFF option. Means ± standard error of the mean (SEM) are presented in the tables and differences were considered statistically significant at P<0.05.

Table 1. Dietary composition of broiler chick starter and finisher diets.

  Treatment
  1 & 2   1 & 2
  Starter   Finisher
Ingredients, %  
Yellow corn 56.00 55.99 55.95   57.75 57.74 57.70
Soybean meal 36.10 36.10 36.10   34.0 34.0 34.0
Palm oil 3.80 3.80 3.80   4.80 4.80 4.80
DCP 2.30 2.30 2.3   2.0 2.0 2.0
Ground limestone 0.72 0.72 0.72   0.64 0.64 0.64
Choline chloride 0.10 0.10 0.10   0.05 0.05 0.05
DL-methionine 0.23 0.23 0.23   0.16 0.16 0.16
L-lysine 0.15 0.15 0.15   - - -
Salt 0.30 0.30 0.30   0.30 0.30 0.30
Vitamin premix# 0.25 0.25 0.25   0.25 0.25 0.25
Trace mineral mix§ 0.05 0.05 0.05   0.05 0.05 0.05
Enramycin - 0.01 -   0.00 0.01 -
Saf-mannan - - 0.05   - - 0.05
Total 100 100 100   100 100 100
Calculated analysis  
ME, kcal/kg 3000 3000 3000   3100 3100 3100
Crude protein, % 22.0 22.0 22.0   21.0 21.0 21.0
Non phytate P, % 0.45 0.45 0.45   0.40 0.40 0.40
Calcium, % 1.0 1.0 1.0   0.9 0.9 0.9
Lysine, % 1.25 1.25 1.25   1.1 1.1 1.1
Methionine, % 0.55 0.55 0.55   0.47 0.47 0.47

°Diet 3 had 0.01% Enramycin, diet 4 had 0.05% Safmannan on the expense of corn during starter and finisher. #Vitamin mix is supplied in the following per kg of diet: retinyl acetate, 3.41 mg; cholecalciferol, 0.07 mg; DL-α-tocopheryl acetate, 27.5 mg; menadione sodium bisulphate, 6 mg; riboflavin, 7.7 mg; niacin, 44 mg; pantothenic acid, 11 mg; cyanocobalamin, 0.02; choline, 496 mg; folic acid, 1.32 mg; pyridoxine HCl, 4.82 mg; thiamine mononitrate, 2.16 mg; D-biotin, 0.11 mg. §Mineral-mix is supplied in the following per kg of diet: manganese, 67 mg; zinc, 54 mg; copper, 2 mg; iodine, 0.5 mg; iron, 75 mg; and selenium, 0.2 mg.

Results

Performance observations at 16 and 30 d are listed in Table 2. During the starter period, BWG, FI and FCR were not influenced (P>0.05) by treatment. During the finisher period, no significant differences in FI was observed however, BWG was affected by dietary treatment (P<0.05); birds which had received the -CONT had the lowest BWG as compared to all other treatments but it was similar to those which had received +CONT. On the other hand, birds which had received ENRA or SAF had better FCR as compared to +CONT OR -CONT (P<0.01). During the cumulative period (0 to 30 d) birds which had received ENRA or SAF gained more weight as compared to those which had received - the CONT treatment (P<0.01). Also, cumulative FCR was affected by treatment (P<0.01); birds which had received ENRA or SAF had the best FCR among all groups. ENRA or SAF supplementation to the challenged birds resulted in 16 points improvement in FCR as compared to the challenged birds without medications (-CONT). No difference in cumulative FI due to treatment was observed. The mean percentage of carcass parts in different treatments is documented in Table 3. No difference in dressing percentage, breast muscle yield, leg quarter yield or abdominal fat was noticed between treatments (P>0.05).

The morphometric measurements of the intestinal epithelium samples at 16 d are given in Table 4. Ileal villus height was longer from birds which had received the +CONT or SAF as compared to the other treatments (P<0.05). Intestine length, weight and relative weight were not affected by any treatment (P>0.05). The morphometric measurements of the intestinal epithelium samples at 30 d are given in Table 5. Shorter small intestine was obtained from birds which had received +CONT or SAF as compared to all other treatments (P<0.05). On the other hand, birds which had received ENRA had the lowest duodenal length percent as compared to all other treatments (P<0.001). Ileal villus height and width were similar among all treatments (P>0.05).

Data related to ileal bacterial counts in broilers at 16 and 30 d are presented in Table 6. Similar bacterial count of C. perfringens and gram negative Bacilli were found in the starter period (before the challenge). At the end of the experiment, the ileal C. perfringens counts in the SAF birds were lowest among all groups (P<0.05). Populations of C. perfringens were reduced by 5 logs in the group which had received SAF as compared to the unmediated group (-CONT). No differences in gram negative Bacilli were found because of the treatment.

Table 2. Body weight gain, feed intake and feed conversion ratio of broiler chickens given experimental diets at different ages.

Treatment SEM P
  T1 T2 T3 T4  
Performance 0-16 d  
BWG, g 474.7 482.7 517.2 499.6 ±16.1 ns
FI, g 668.2 663.4 697.7 681.6 ±16.1 ns
FCR, g:g 1.414 1.375 1.349 1.366 ±0.03 ns
Performance 17-30 d  
BWG, g 820.6ab 784.0b 856.7a 847.9a ±16.9 *
FI, g 1521.4 1540.2 1461.6 1425.5 ±51.2 ns
FCR, g:g 1.855a 1.964a 1.706b 1.681b ±0.05 **
Cumulative 0-30 d  
BWG, g 1295.3bc 1266.7c 1373.9a 1347.5ab ±19.47 **
FI, g 2189.6 2203.6 2159.2 2107.0 ±50.9 ns
FCR, g:g 1.692a 1.734a 1.571b 1.565b ±0.04 **

T1, unmedicated diet, unchallenged birds (+CONT); T2, unmedicated diet, birds were challenged with C. perfringens (-CONT); T3, 0.1 g/kg enramycin was added to the diet, birds were challenged with C. perfringens (ENRA); T4, 0.5 g/kg SAF-Mannan was added to the diet, birds were challenged with C. perfringens (SAF). BWG, body weight gain; FI, feed intake; FCR, feed conversion ratio. a,b,cMeans in the row with different superscripts differ significantly. *P<0.05; **P<0.01; ns, not significant.

Table 3. Effect of different treatments on parts yield as percentages of broiler dressed weight at d 30.

  Treatment SEM P
  T1 T2 T3 T4  
Dressed yield, % 60.9 60.7 62.1 59.8 ±1.38 ns
Breast°, % 35.6 35.2 34.2 35.2 ±0.77 ns
Leg quarter°, % 40.4 40.3 40.2 40.9 ±0.66 ns
Abdominal fat, % 1.05 0.80 1.26 1.09 ±0.17 ns
Liver, g/100 g 0.31 0.24 0.28 0.32 ±0.02 ns

T1, unmedicated diet, unchallenged birds (+CONT); T2, unmedicated diet, birds were challenged with C. perfringens (-CONT); T3, 0.1 g/kg enramycin was added to the diet, birds were challenged with C. perfringens (ENRA); T4, 0.5 g/kg SAF-Mannan was added to the diet, birds were challenged with C. perfringens (SAF). BWG, body weight gain; FI, feed intake; FCR, feed conversion ratio. a,b,cMeans in the row with different superscripts differ significantly. *P<0.05; **P<0.01; ns, not significant.

Table 4. Intestinal morphology and histology of broilers at d 16.

  Treatment SEM P
  T1 T2 T3 T4  
Intestine length, cm 129.7 132.0 127.0 128.3 ±7.20 ns
Intestine weight, g/cm 0.28 0.21 0.27 0.28 ±0.02 ns
IRW, g/100g BW 7.4 7.6 7.2 9.4 ±0.81 ns
Ileal villus height°, µm 4509a 3765b 3804b 4253ab ±185.8 *
Ileal villus width°, µm 693 766 653 691 ±50.8 ns

T1, unmedicated diet, unchallenged birds (+CONT); T2, unmedicated diet, birds were challenged with C. perfringens (-CONT); T3, 0.1 g/kg enramycin was added to the diet, birds were challenged with C. perfringens (ENRA); T4, 0.5 g/kg SAF-Mannan was added to the diet, birds were challenged with C. perfringens (SAF). IRW, intestine relative weight; BW, body weight. °Measurements of height and width were based on at least 5 well-oriented villi per ileum per broiler for a total of 5 birds per treatment. a,bMeans in the row with different superscripts differ significantly. *P<0.05; ns, not significant.

Discussion

The results revealed a significant improvement in FCR at 30 d for birds which had received the ENRA or SAF treatments. This could be explained by the significant improvement in BWG which was associated with birds which had received ENRA or SAF, while FI was similar among all groups. These results are in line with the findings of Podmaniczky et al. (2006); Rosen (2007), both groups reported a positive effect for yeast cell wall products on the performance of broilers. Birds which were subjected to the C. perfringens challenge without any medication (–CONT) had the highest FCR but not significantly different from the +CONT. According to Porter (1998) C. perfringens are counted among the most gut-specific pathogens which are assumed to be the main health problem associated with removing the antibiotics from feed. C. perfringens infection of broilers may cause impairment of production performance (Lovland and Kaldhusdal, 2001) and subclinical disease associated with necrotic enteritis which is characterized by damage to the intestinal mucosa that decreases digestion, absorption and reduces weight gains (Kaldhusdal et al., 2001).

On the other hand, the improvement in BWG and FCR could be also related to the lower microbial population in the gastrointestinal tract in broilers (Thongsong et al., 2008). Wilson et al. (2005) explained that the growth suppressing effect of intestinal bacteria was due to the production of toxic metabolites that irritate the gut mucosa, thereby inhibiting nutrient absorption. The ileal C. perfringens populations of birds were altered when SAF-Mannan was added to their diets. This came in accordance with the findings of Spring et al. (2000), Yang et al., (2007, 2008), where SAFMannan was found to have a positive effect in lowering C. perfringens populations. The significant reduction of ileal C. perfringens reported in this study could be explained by the ability of MOS to bind with pathogens in the small intestine by offering competitive binding sites for undesirable pathogens (Newman, 1994). MOS is not digested in the small intestine therefore; bacteria bound to MOS are likely exit the intestine without attaching to the epithelium and this cause a reduction or prevention of colonization of undesirable bacteria in the small intestine (Spring et al., 2000). The gross examination of the responses in birds challenged orally with C. perfringens showed sub-clinical inflammatory responses throughout various sections of gizzard, duodenum, jejunum, ileum and ceca associated with intestinal lesions and hemorrhages. This observation may partly explain the poor performance of the –CONT group.

Table 5. Intestinal morphology and histology of broilers at d 30.

  Treatment SEM P
  T1 T2 T3 T4  
Intestine length, cm 152.0b 178.0a 176.2a 181.7b ±6.60 *
Duodenum length, % 15.7ab 16.6a 14.8c 15.3bc ±0.24 **
Jejunum length, % 52.1 41.8 43.2 40.5 ±4.19 ns
Ileum length, % 32.2 41.7 42.1 44.2 ±4.19 ns
Intestine weight, g/cm 0.36 0.44 0.49 0.44 ±0.03 ns
IRW, g/100g BW 4.7 5.7 5.5 6.0 ±0.36 ns
Villus height°, µm  
Duodenum 8964 9124 8480 10017 ±368 ns
Jejunum 7208 8449 6467 10002 ±505 ns
Ileum 5869 6643 4692 5893 ±732 ns
Villus width°, µm  
Duodenum 1245 1298 1635 1491 ±215 ns
Jejunum 1109 938 1088 1297 ±54 ns
Ileum 843 882 851 1028 ±110 ns

T1, unmedicated diet, unchallenged birds (+CONT); T2, unmedicated diet, birds were challenged with C. perfringens (-CONT); T3, 0.1 g/kg enramycin was added to the diet, birds were challenged with C. perfringens (ENRA); T4, 0.5 g/kg SAF-Mannan was added to the diet, birds were challenged with C. perfringens (SAF). IRW, intestine relative weight; BW, body weight. °Measurements of height and width were based on at least 5 well-oriented villi per section per broiler for a total of 5 birds per treatment. a,b,cMeans in the row with different superscripts differ significantly. *P<0.05; **P<0.01; ns, not significant.

Table 6. Ileal bacterial count mean, (log10 CFU/g) in broilers at d 16 and 30.

  Treatment SEM P
  T1 T2 T3 T4  
Starter  
C. Perfringens 4.2 3.9 4.3 4.2 ±0.16 ns
Gram negative Bacilli 3.8 4.3 4.3 3.6 ±0.32 ns
Finisher  
C. Perfringens 4.7a 6.0a 4.8a 1.0b ±0.57 *
Gram negative Bacilli 4.8 4.7 5.0 4.7 ±0.16 ns

T1, unmedicated diet, unchallenged birds (+CONT); T2, unmedicated diet, birds were challenged with C. perfringens (-CONT); T3, 0.1 g/kg enramycin was added to the diet, birds were challenged with C. perfringens (ENRA); T4, 0.5 g/kg SAF-Mannan was added to the diet, birds were challenged with C. perfringens (SAF). Measurements were based on 5 broilers per treatment. a,bMeans in the row with different superscripts differ significantly. *P<0.05; ns, not significant.

Histological examination revealed a significant difference in villi height between the treatment groups at 16 d but not at 30 d. Birds which had received SAF improved villi height to a level which was similar to the unchallenged birds (+CONT). This indicated changes occurred in villi morphology between treatments during the starter period, and thus absorptive surface area in the small intestine and superior gut health. Several other reports observed greater villi height and superior ileal mucosa development in chickens supplemented with a yeast cell wall product prepared from Saccharomyces cerevisiae, particularly during the first week of a chicken’ life (Santin et al., 2001; Zhang et al., 2005). However, Yang et al. (2007) and Brümmer et al. (2010) reported no effect of MOS supplementation on gut morphology in chickens.

Conclusions

The present study demonstrated that supplementation of 0.05% SAF-Mannan in broiler diets improved BWG and FCR at 30 d. Improved FCR was not associated with FI but it was associated with a significant reduction in the ileal C. perfringens populations in the small intestine. This finding supports the idea that broiler gut health and function can be improved by dietary supplementation such as SAF-Mannan which can serve as a safe alternative to AGPs in broilers diet.

References

Benites, V., Gilharry, R., Gernat, A.G., Murillo, J.G., 2008. Effect of dietary Mannan Oligosaccharide from Bio-Mos or SAF-Mannan on live performance of broiler chickens. J. Appl. Poultry Res. 17:471-475.

Blake, J.P., Hess, J.B., Maklin, K.S., Bilgili, S.F., Sefton, A.E., Kocher, A., 2006. Mannan oligosaccharide (Bio-Mos®) supplementation of wheat-based diets for broilers. Available from: http://www.cabi.org/animalscience/Uploads/File/AnimalScience/additionalFiles/WPSAVerona/10926.pdf

Brümmer, M., Jansen van Rensburg C., Moran, C.A., 2010. Saccharomyces cerevisiae cell wall products: the effects on gut morphology and performance of broiler chickens. S. Afr. J. Anim. Sci. 40:14-21.

Castanon, J.I.R., 2007. History of the use of antibiotic as growth promoters in European poultry feed. Poultry Sci. 86: 2466-2471.

Ferket, P.R., 2002. Use of oligosaccharides and gut modifiers as replacements for dietary antibiotics. pp 169-182 in Proc. 63rd Nat. Minnesota Nutrition Conf., Eagan, MN, USA.

Garridol, M.N., Skjervheim, M., Oppegaard, H., Sørum, H., 2004. Acidified litter benefits the intestinal flora balance of broiler chickens. Appl. Environ. Microbiol. 70:5208-5213.

Kaldhusdal, M., Schneitz, C., Hofshagen, M., Skjerve, E., 2001. Reduced incidence of Clostridium perfringens-associated-le sions and improved performance in broiler chickens treated with normal intestinal bacteria from adult fowl. Avian Dis. 45:149-156.

Lovland, A., Kaldhusdal, M., 2001. Severely impaired production performance in broiler flocks with high incidence of Clostridium perfringens-associated hepatitis. Avian Pathol. 30:73-81.

Mountzouris, K.C., Tsistsikos, P., Kalamara, E., Nitsh, S., Schatzmayr, G., Fegeros, K., 2007. Evaluation of the efficacy of a probiotic containing Lactobacillus, Bifidobac - terium, Enterococcus, and Pediococcus strains in promoting broiler performance and modualting cecal microflora composition and metabolic activities. Poultry Sci. 86:309-317.

Newman, K., 1994. Biotechnology in the feed industry. In: T.P. Lyons and K.A. Jacques (eds.) Mannan-Oligosaccharides: natural polymers with significant impact on the gastrointestinal microflora and the immune system. Nottingham University Press, Nottingham, UK, pp 167-174.

Podmaniczky, B., Kocher, A., Szabo, Z.S., Vegi, B., Horel, K., Korosi L., Molnar, A., 2006. The effect of mannan oligosaccharides on growth performance of challenged broilers. World. Poultry Sci. J. 62(Suppl.):319.

Porter, R.E. Jr., 1998. Bacterial enteritides of poultry. Poultry Sci. 77:1159-1165.

Rosen, G.D., 2007. Holo-analysis of the efficacy of Bio-Mos in broiler nutrition. Brit. Poultry Sci. 48:21-26.

Santin, E., Maiorka, A., Macari, M., 2001. Performance and intestinal mucosa development of broiler chickens fed diets containing saccharomyces cerevisiae cell wall. J. Appl. Poultry Res. 10:236-244.

SAS, 2002. SAS Users Guide: Statistics, ver. 9.1.3. SAS Inst. Inc., Cary, NC, USA.

Spring, P., Wenk, C., Dawson K.A., Newman, K.E. 2000. The effects of dietary mannanoligosaccharides on cecal parameters and the concentrations of enteric bacteria in the ceca of Salmonella-challenged broiler chicks. Poultry Sci. 79:205-211.

Thongsong, B., Kalandakanond-Thongsong, S., Chavananikul, V., 2008. Effects of the addition of probiotic containing both bacteria and yeast or an antibiotic on performance parameters, mortality rate and antibiotic residue in broilers. Thai J. Vet. Med. 38:1726.

Waldroup, P.W., Fritts, C.A., Yan, F., 2003. Utilization of Mos mannan oligosaccharide and Bioplex® copper in broiler diets. Int. J. Poultry Sci. 2:44-52.

Wilson, J., Tice, G., Brash, M.L., Hilaire, S., 2005. Manifestations of Clostridium perfringens and related bacterial enteritides in broiler chickens. World. Poultry Sci. J. 61:435-449.

Yang, Y., Iji, P.A., Choct, M., 2009. Dietary modulation of gut microflora in broiler chickens: a review of the role of six kinds of alternatives to in-feed antibiotics. World. Poultry Sci. J. 65:97-114.

Yang, Y., Iji, P.A., Kocher, A., Mikkelsen L.L., Choct, M., 2007. Effects of mannanoligosaccharide on growth performance, the development of gut microflora and gut function of broiler chickens raised on new litter. J. Appl. Poultry Res. 16:280-288.

Yang, Y., Iji, P.A., Kocher, A., Mikkelsen, L.L., Choct, M., 2008. Effects of dietary mannanoligosaccharide on growth performance, nutrient digestibility and gut development of broilers given different cerealbased diets. J. Anim. Physiol. An. N. 92:650-659.

Zhang, A.W., Lee, B.D., Lee, S.K., Lee, K.W., An, G.H., Song, K.B., Lee, C.H., 2005. Effects of yeast (Saccharomyces cerevisiae) cell components on growth performance, meat quality, and ileal mucosa development of broiler chicks. Poultry Sci. 84:1015-1021.

Article Metrics

Metrics Loading ...

Metrics powered by PLOS ALM


 

The Italian Journal of Animal Science [eISSN 1828-051X] is the official journal of the Animal Science and Production Association and it is published by PAGEPress®, Pavia, Italy. Reg. Pavia, n. 2/2010-INF. All credits and honors to PKP for their OJS.