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Open access

Mohamed Nabil Alloui and Witold Szczurek

Abstract

The primary aim of this study was to investigate the impact of three dietary levels of lactose (LAC) originating from conventional dried whey (DW) and the duration of these treatments (from 8 to 21 or to 42 days of age) on growth performance, basic post-slaughter traits and excreta quality of broiler chickens kept in cages. A secondary purpose was to investigate the effect of LAC level on some parameters of the caecal micro-environment and gross morphology in these birds. A total of 560 Ross 308 chickens (sex ratio 1:1) were assigned to 7 dietary combinations with 10 replicate cages of 8 birds per cage. The control group was fed basal diets consisting of maize, wheat and soybean meal. The other 6 groups received the same basal diets with DW added in amounts equivalent to a LAC dietary levels of 1, 2 or 3%. Only continuous feeding (day 8 to 42) with 1% and 2% levels of LAC was found to yield the overall body weight gain (BWG) during the whole 42-day rearing period, which was significantly higher than that on the control diet, with a larger share of breast meat in carcass at a 2% LAC. However, these effects were associated with greater faecal score values indicating more watery excreta compared with the control. Increasing levels of LAC augmented the relative caecal weight and length. A reduction in the caecal pH was confirmed at day 21 for birds fed 1% and 2% of dietary LAC. The lower pH values were correlated to an increased sum of total volatile fatty acids (VFA), causing large increases in the concentration of undissociated forms of individual VFA. The decline in plate counts of coliform bacteria was observed with 2% and 3% LAC, whereas the counts of lactic acid-producing bacteria (LAB) were higher at these two LAC levels. The present findings lead to the conclusion that the dietary level of 2% LAC originated from DW is the most effective in enhancing the productivity of broilers, with moderate occurrence of undesirable side effects.

Open access

Witold Szczurek, Mohamed Nabil Alloui and Damian Józefiak

Abstract

The principal goal of this study was to assess the responses of broiler chickens raised on floor litter to the 2% dietary level of lactose (LAC) originating from dried whey fed in combination with live culture of Lactobacillus agilis bacteria (90 million cells/kg diet) in terms of the performance and basic postslaughter parameters, the lumen pH in some alimentary tract segments, concentration of volatile fatty acids (VFA ) in the total (T) and undissociated (UD) forms and count of selected microbial populations in the caeca determined by fluorescent in-situ hybridisation (FISH). A parallel aim was to evaluate the outcomes from the combined supplementation in comparison with feeding of LAC and the L. agilis bacteria as separate dietary supplements. Six hundred and forty Ross 308 chickens were placed in 16 floor pens (40 birds per pen having equal sex ratio) and were provided with free access to the feed (a mash maize-wheat-soybean meal-based diet) and water. Dietary treatments provided from day 8 to 42 of age were: LAC-free basal diet (CON), LAC-containing diet (CON + LAC), LAC-free diet with the addition of L. agilis (CON + BAC) and LAC-containing diet with addition of L. agilis (CON + LAC + BAC). The LAC supplementation caused significant decreases in the luminal pH of the crop, ileum and caeca, and the addition of the L. agilis bacteria reduced the pH in the crop and caeca. The overall concentration of total (T) volatile fatty acids was higher in the caeca of broilers receiving the LAC-containing diets. Both the LAC and the BAC supplements, independently from one another, resulted in significantly greater caecal levels of UD acetate, propionate and butyrate. The FISH analysis revealed that counts of Bacteroides sp./Prevotella sp. group were higher after the inclusion of LAC in the feed. All three dietary supplementations significantly reduced the total counts of the family Enterobacteriaceae and decreased the number of naturally occurring C. perfringens bacteria compared with the basal control diet (CON). Neither LAC inclusion nor BAC addition to the diet affected the counts of the Clostridium coccoides/Eubacterium rectale group. The synergistic effects of the simultaneous supplementation of LAC and L. agilis were found on the T butyrate concentration and on C. perfringens and the Enterobacteriaceae counts. No improvements in the body weight gains and post-slaughter traits were observed due to uncombined and combined supplementation with 2% LAC and L. agilis, indicating that the shifts in composition of the caecal microbiota toward a healthier composition by using these additives were not large enough to create the positive growth rate and processing yields responses in broilers maintained in a litter-floor environment.

Open access

Mohamed Nabil Alloui, Witold Szczurek and Sylwester Świątkiewicz

Abstract

A probiotic is a culture of live microorganisms that can manipulate and maintain a beneficial microflora in the gut. Prebiotics are nondigestible feed ingredients that can positively affect the animal organism by stimulating the activity and growth of beneficial native bacteria in the gastrointestinal tract and eliminate the pathogenic ones. Some studies have shown their beneficial effects when they have been used separately or simultaneously in the form of synbiotics, to obtain enhanced mutual effect. These supplements were proposed with success as alternatives to antibiotic growth-promoting feed additives but further studies are needed to better understand their mode of action and effects. This review article presents growing interest in using these antibiotic alternatives, the potential mechanism of their action in the live organism, and discusses some recent data on the effects of these supplements in poultry nutrition.

Open access

Sylwester Świątkiewicz, Anna Arczewska-Włosek, Józefa Krawczyk, Witold Szczurek, Michał Puchała and Damian Józefiak

Abstract

The aim of the experiment with 240 ISA Brown hens fed the diets with standard or decreased Ca level was to evaluate the effect of selected feed additives on laying performance and eggshell quality. The hens were allocated to 10 treatments, each containing 12 cages (replicates) of 2 birds. A 2 × 5 experimental arrangement was used. From 26 to 70 wks of age, experimental diets containing 3.20 or 3.70% Ca were used. The diets were either not supplemented, or supplemented with sodium butyrate, probiotic bacteria, herb extracts blend or chitosan. The decreased dietary Ca reduced eggshell quality indices in older hens (43-69 wks) (P<0.05) without effect on performance indices. The addition of the probiotic, herb extracts, or chitosan increased the laying rate (P<0.05). In older hens, i.e. at 69 wk, chitosan increased eggshell thickness and breaking strength, while herb extracts increased eggshell thickness (P<0.05). There was no interaction between the experimental factors in performance and eggshell quality. The used feed additives had no influence on fatty acid profile of egg lipids, however diet supplementation with chitosan decreased cholesterol concentration in egg yolk lipids (P<0.05). It can be concluded that such feed additives as probiotic, herb extracts, or chitosan may positively affect performance and eggshell quality, irrespective of Ca dietary level.

Open access

Sylwester Świątkiewicz, Anna Arczewska-Włosek, Witold Szczurek, Jolanta Calik, Józefa Krawczyk and Damian Józefiak

Abstract

The trial with 240 caged ISA Brown laying hens was performed to evaluate the effect of selected feed additives on mineral utilisation as well as biomechanical (breaking strength, yielding load, stiffness) and geometrical (cortex thickness, cross-section area, weight, length) indices of tibia and femur bones. At 26 wks of age the layers were randomly assigned to 10 treatments with 12 replicates (cages) of two birds. In the study a 2 × 5 experimental scheme was used i.e. to 70 wks of age, the layers were fed isocaloric and isonitrogenous experimental diets containing reduced (3.20%) or standard (3.70%) Ca level. The diets with both Ca levels were either not supplemented, or supplemented with the studied feed additives i.e. sodium butyrate, probiotic bacteria, herbal extract blend and chitosan. There were no statistically significant effects of the experimental factors on the indices of the tibia bones. However, the diet with reduced Ca level decreased bone breaking strength, yielding load, stiffness, and mineralisation of the femur bones (P<0.05). The majority of used feed supplements, i.e. probiotic, herb extracts, and chitosan, increased biomechanical indices (breaking strength and yielding load) and mineralisation of the femur bones (P<0.05). Neither dietary Ca level nor feed additives affected dry matter, organic matter, ether extract, N-free extracts, crude fibre and ash digestibility, and P retention and excretion; however, Ca excretion and retention was lower in the hens fed the diets with reduced Ca level (P<0.05). Relative Ca retention (Ca retained as % of Ca intake) was improved by diet supplementation with probiotic, herb extracts and chitosan (P<0.05). In conclusion, this study has shown that decreased Ca dietary level (3.20%) can negatively affect bone quality in layers, while probiotic, herb extracts and chitosan addition may improve the selected biomechanical indices of the femurs, irrespective of Ca dietary concentration.

Open access

Beata Szymczyk, Witold Szczurek, Sylwester Świątkiewicz, Krzysztof Kwiatek, Zbigniew Sieradzki, Małgorzata Mazur, Dariusz Bednarek and Michał Reichert

Abstract

Introduction

The influence of feeding genetically modified MON 810 hybrid maize on the growth and haematological and biochemical indices of rats was tested.

Material and Methods

Two conventional (non-GM) and two test (MON 810) lines of maize were used in semi-purified diets at the level of 40% w/w. The non-GM I, MON 810 I, non-GM II, and MON 810 II maize lines were near-isogenic. A total of 40 male 6-week-old Wistar-derived rats were assigned to four equal feeding groups corresponding to the four maize lines for 16 weeks. Overall, health, body weight gain, clinical pathology parameters, gross changes, and appearance of tissues were compared between groups.

Results

There were no statistically significant differences in the weight gain or relative organ weights of rats, but there were some non diet-related histopathological changes in the liver, kidneys, and spleen. Except for creatinine level, no diet-related effects were observed in haematology or most of the biochemical indices. Transgenic DNA of MON 810 maize was not detected in the tissues or faeces nor in the DNA of E. coli isolated from the rectum digesta of rats given transgenic feeds. In our experiment, various metabolic indices of rats fed non-GM diets or genetically modified (MON 810) maize for 16 weeks were similar. No adverse nutrition-related health effects were detected.

Conclusion

MON 810 maize seems to be as safe as the conventional maize lines.