Influence of enzymes on performance and digestive parameters of broilers fed rye-based diets

Diet composition influences probiotic and postbiotic effects on broiler growth and physiology

Dietary ingredient and nutrient composition may affect the efficacy of additives in broilers. Specific feed ingredients can represent dietary challenging conditions for broilers, resulting in impaired performances and health, which might be alleviated by dietary probiotics and postbiotics. We assessed the effects of a Lactobacilli probiotic (Pro) and postbiotic (Post) when added to a standard (SD) and challenge (CD) diet. A completely randomized block study with 2 diets (SD, CD) and 3 additive conditions (Control, Pro and Post) involving 1,368 one-day-old Ross male broilers, equally distributed among 36 pens, from d1 to d42 was conducted. Both diets were formulated to contain identical levels of nutrients, with CD formulated to be richer than SD in nonstarch polysaccharides using rye and barley as ingredients. Readout parameters included growth performance parameters, footpad lesions score, blood minerals and biochemical parameters, and tibia health, strength, and composition. Compared to SD, CD decreased BW (1,936 vs. 2,033 g; p = 0.001), increased FCR (p < 0.01) and impaired tibia health and strength (p < 0.05) at d35, thereby confirming the challenging effect of CD. Pro and Post increased BW in CD (+4.7 and +3.2%, respectively, at d35; P < 0.05) but not in the SD group, without affecting FCR. Independently of the diet, Pro increased plasma calcium, phosphorus and uric acid at d21 (+6.2, +7.4, and +15.5%, respectively) and d35 (+6.6, +6.2 and +21.0%, respectively) (P < 0.05) while Post increased plasma magnesium only at d21 (+11.3%; P = 0.037). Blood bile acids were affected by additives in an age- and diet-dependent manner, with some opposite effects between dietary conditions. Diet composition modulated Pro and Post effects on broiler growth performance. Additionally, Pro and Post affected animal metabolism and leg health diet-dependently for some but not all investigated parameters. Our findings show that the effects of pro- and postbiotics on the growth performance and physiology of broilers can be dependent on diet composition and thus possibly other factors affecting diet characteristics.

Insoluble fibre and enzyme supplementation in mash or pellets diets on growth performance, apparent ileal digestibility and intestinal morphology of broiler chickens fed barley containing diets

BACKGROUND

Enzyme supplementation and the inclusion of fibre in the barley-based diets have been some of the alternatives proposed to improve productivity in the absence of growth promoters.

OBJECTIVE

This study was performed to investigate the effect of adding sunflower hulls (SFH), a multi-enzyme carbohydrate, and feed forms (mash and pellet) on performance and some physiological parameters in broiler chickens fed barley containing diets.

METHODS

Treatments were two feed forms (mash vs. pelleted), and four diets consisted of a barley-based diet (control, CTL) or test diets which contained either SFH at 30 g/kg, enzyme (ENZ; 0.2 g/kg) or combination of SFH and enzyme (SFH + ENZ).

RESULTS

The results showed that average daily feed intake and average daily gain were significantly increased in chickens that were fed ENZ (p < 0.05). The highest digestibility of ether extract (EE) was observed in the treatment containing SFH and SFH + ENZ (p < 0.05). The highest population of Lactobacillus spp. was observed in the treatment containing SFH (p < 0.05). The villus height and villus height to crypt depth ratios of duodenum and jejunum were significantly higher (p < 0.05) in broilers fed pellet diets compared to the mash.

CONCLUSION

It can be concluded that pellet diets reduce digesta viscosity and harmful microorganisms (Escherichia coli), increase growth performance, and improve intestinal morphology in barley-based diets. Moreover, SFH and ENZ had favourable effects on EE digestibility and caecal microbial population of broilers fed with barley containing diets.

Inclusion of a Bacillus-based probiotic in non-starch polysaccharides-rich broiler diets

This study examined the effects of a 3-strain Bacillus-based probiotic (BP; Bacillus amyloliquefaciens and two Bacillus subtilis) in broiler diets with different rye levels on performance, mucus, viscosity, and nutrient digestibility. We distributed 720 one-d-old female broilers into 72 pens and designed nine diets using a 3 × 3 factorial approach, varying BP levels (0, 1.2 × 106, and 1.2 × 107 CFU/g) and rye concentrations (0, 200, 400 g/kg). On d 35, diets with 200 or 400 g/kg rye reduced broiler weight gain (BWG). Diets with 400 g/kg rye had the highest FCR, while rye-free diets had the lowest (p ≤0.05). Adding BP increased feed intake and BWG in weeks two and three (p ≤0.05). It should be noted that the overall performance fell below the goals of the breed. Including rye in diets reduced the coefficient of apparent ileal digestibility (CAID) for protein, ether extract (EE), calcium, phosphorus, and all amino acids (p ≤0.05). Rye-free diets exhibited the highest CAID for all nutrients, except for methionine, EE, and calcium, while diets with 400 g/kg of rye demonstrated the lowest CAID (p ≤0.05). BP in diets decreased phosphorus CAID (p ≤0.05). Diets containing 1.2 × 107 CFU/g (10X) of BP exhibited higher CAID of methionine than the other two diets (p ≤0.05). Diets containing 10X of BP showed higher CAID of cysteine than diets with no BP (p ≤0.05). Ileal viscosity increased as the inclusion level of rye in the diets increased (p ≤0.05). The ileal concentration of glucosamine in chickens fed diets with 400 g/kg of rye was higher than in those fed diets with no rye (p ≤0.05). Furthermore, ileal galactosamine concentrations were elevated in diets with 200 and 400 g/kg of rye when compared to rye-free diets (p ≤0.05). However, BP in diets had no impact on ileal viscosity, galactosamine, or glucosamine (p > 0.05). In conclusion, the applied Bacillus strains appeared to have a limited capacity to produce arabinoxylan-degrading enzymes and were only partially effective in mitigating the negative impacts of rye arabinoxylans on broilers.

Effect of type of fiber and its physicochemical properties on performance, digestive transit time, and cecal fermentation in broilers from 1 to 23 d of age

The effects of insoluble fiber (IF) sources differing on particle size and hydration capacity (HC) on growth performance, gastrointestinal tract (GIT) development, cecal fermentation, and digestive transit time were investigated from 1 to 23 d of age in 550 Ross-308 broiler males housed in 50 cages. The experimental design was based on the administration of a common corn-soybean meal nonsupplemented with additional IF sources diet in mash form (Control), and 4 dietary treatments consisting in the Control diet diluted with 1.5% of different IF: lignocellulose (LC), fine-ground straw (FS) and coarse-ground straw (CS), all characterized by high HC; and almond shell (AS) having low HC. Cecal fermentation was assessed by in vitro fermentation of the IF sources using the cecal content of 22-day broilers as inoculum. Compared with control birds, the inclusion of IF sources tended to impair the FCR (P = 0.053), with birds fed the HC-IF sources (LC, FS, and CS) showing lower ADFI (P = 0.005) and ADG (P = 0.001) than those fed the AS diet. The relative weight of gizzard and cecum, small intestine length, and digestive transit time decreased in AS group (P ≤ 0.050) compared with the average value of the groups fed the other IF sources. The inclusion of IF reduced (P = 0.006) the excreta moisture content, with no differences among IF sources. Dietary treatments had no effect either on cecal short fatty acids concentration or on intestinal morphology. As indicated by the in vitro gas production results, both LC and AS were less fermented than FS and CS, although all IF sources were low fermentable. None of the IF sources were able to influence the fermentation capacity of cecal microbiota after 22 d of feeding. In summary, animals fed AS presented smaller gizzard and cecum relative size, showed higher ADFI and ADG, and tended to improve fed conversion ratio in comparison to those fed the rest of IF sources.

Immobilization and docking studies of Carlsberg subtilisin for application in poultry industry

Carlsberg subtilisin from Bacillus licheniformis PB1 was investigated as a potential feed supplement, through immobilizing on bentonite for improving the growth rate of broilers. Initially, the pre-optimized and partially-purified protease was extracted and characterized using SDS-PAGE with MW 27.0 KDa. The MALDI-TOF-MS/MS spectrum confirmed a tryptic peptide peak with m/z 1108.496 referring to the Carlsberg subtilisin as a protein-digesting enzyme with alkaline nature. The highest free enzyme activity (30 U/mg) was observed at 50°C, 1 M potassium phosphate, and pH 8.0. the enhanced stability was observed when the enzyme was adsorbed to an inert solid support with 86.39 ± 4.36% activity retention under 20 optimized conditions. Additionally, the dried immobilized enzyme exhibited only a 5% activity loss after two-week storage at room temperature. Structural modeling (Docking) revealed that hydrophobic interactions between bentonite and amino acids surrounding the catalytic triad keep the enzyme structure intact upon drying at RT. The prominent hygroscopic nature of bentonite facilitated protein structure retention upon drying. During a 46-days study, supplementation of boilers' feed with the subtilisin-bentonite complex promoted significant weight gain i.e. 15.03% in contrast to positive control (p = 0.001).

Effects of adaptation diet and exogenous enzymes on true metabolizable energy and cecal microbial ecology, short-chain fatty acid profile, and enzyme activity in roosters fed barley and rye diets

Three experiments evaluated effects of adaptation diet and exogenous β-glucanase and xylanase on TME_n of barley and rye. Single Comb White Leghorn roosters were fed adaptation diets based on corn/soybean meal (SBM), barley/SBM with and without β-glucanase, or rye/corn/SBM with and without xylanase for 4 wk. In Experiments 1 and 2, after the adaptation period, TME_n was determined using a 48 h precision-fed rooster assay for 100% barley or 100% rye diets with or without β-glucanase or xylanase, respectively. Experiment 3 consisted only of feeding adaptation diets for 4 wk. Cecal samples were collected at the end of experiments for microbial ecology, short-chain fatty acid (SCFA) profiles, and enzyme activity analyses. In Experiments 1 and 2, β-glucanase increased (P < 0.05) TME_n of barley, and there was no significant effect of adaptation diet on TME_n values. Total cecal Eubacteria and Ruminococcaceae were decreased (P < 0.05) and Escherichia coli were increased (P < 0.05) at the end of the TME_n assay compared with the end of the adaptation period (with no TME_n assay). There was a large decrease (P < 0.05) for most cecal SCFA at the end of the TME_n assay compared with the end of the adaptation period. Both cecal β-glucanase and xylanase activity were increased for birds fed adaptation diets containing the respective enzyme. In Experiment 3, there were no consistent effects of adaptation diet on cecal microbial profiles or SCFA but cecal β-glucanase activity was increased (P < 0.05) by exogenous β-glucanase for barley and cecal xylanase activity was increased (P < 0.05) by exogenous xylanase for rye. Overall, the results indicated that TME_n of barley was increased by exogenous β-glucanase, adaptation diet did not significantly influence the TME_n response to the dietary enzymes, and cecal fermentation (based on cecal SCFA) was greatly reduced by the TME_n assay. Cecal β-glucanase and xylanase activity, however, were often increased by feeding high barley and high rye diets containing exogenous enzymes.

Effect of emulsifier and multicarbohydrase enzyme supplementation on performance and nutrient digestibility in broiler diets containing rapeseed meal

The aim of this study was to determine the effect of emulsifier and multicarbohydrase enzyme supplementation on performance, nutrient utilization, and apparent metabolizable energy-nitrogen (AME_N) value of broiler diets containing rapeseed meal (RSM) as well as their influence on the gut morphological structures, excretion of total and free sialic acid, and cecum concentration of short-chain fatty acids (SCFAs) in broiler chickens. A total of 384 male broiler chicks were assigned to four dietary treatments. The diet of the control treatment (CON) consisted of soybean, maize, and RSM (5% in starter, 7% in grower, 15% in finisher) with soybean and palm oils. The diets used for the experimental treatments were the control diet supplemented with an emulsifier (EMU), enzyme (ENZ), or both (EMU + ENZ). The duodenum (n = 10/treatment) and ileum (n = 10/treatment) digesta samples were assessed to determine nutrient digestibility: crude protein (CP), ether extract (EE), starch, Ca. Throughout the experimental period, EMU + ENZ treatment indicated the lowest total average feed intake and feed conversion ratio, with the highest average weight gain among the studied treatments (P < 0.05). The EMU + ENZ treatment also resulted in higher (P < 0.05): apparent prececal digestibility (APD) of CP, total tract neutral detergent fibre (NDF) degradation, apparent total tract digestibility (ATTD) of EE, villus height to crypt depth ratio (P < 0.1). The highest APD of EE was noted in the EMU treatment (P < 0.05). No significant differences were found in the AME_N values of the diets. A greater jejunum villi surface area was found in groups supplemented by enzyme compared to CON (P < 0.05). The EMU + ENZ treatment presented lower sialic acid excretion in the ileum and concentration of cecum SCFAs compared to the CON treatment (P < 0.05). The obtained results indicate that simultaneous usage of additives had beneficial effect on production parameters, nutrient digestibility, NDF degradation, as well as gut mucosa morphology. Based on the SCFAs concentration results, separate or simultaneous addition of emulsifier or/and enzyme did not provoke excessive fermentation activity of cecal bacteria.

Effects of diet hulless barley and beta-glucanase levels on ileal digesta soluble beta-glucan molecular weight and carbohydrate fermentation in laying hens

Exogenous β-glucanase (BGase) improves nutrient digestibility and production performance in laying hens fed barley-based diets, but the effect of enzyme and the dosage on β-glucan depolymerization and fermentation in the gastrointestinal tract is poorly understood. The objectives of the study were to determine the effects of hulless barley (HB) and BGase levels on digestive tract β-glucan depolymerization and fermentation in laying hens. A total of 108 Lohman-LSL Lite hens were housed in cages and fed 2 levels of HB (CDC Fibar; 0 and 73%) by substituting wheat in the diet and graded levels of BGase (Econase GT 200 P from ABVista; 0, 0.01 and 0.1% – 0, 20,000, and 200,000 BU/kg) in a 2 × 3 factorial arrangement. Birds were fed experimental diets for 8 weeks, starting at 35 wk of age. Digestive tract samples were collected at the end of the experiment. Statistical significance was set at P ≤ 0.05. Beta-glucan peak molecular weight was lower with the 0.1 compared to both 0 and 0.01% BGase levels, whereas weight average molecular weight was lower with the 0.1 compared to 0% BGase for 73% HB. The maximum molecular weight for the smallest 10% β-glucan molecules decreased with the increasing BGase. Overall, β-glucan molecular weight in the ileum was higher when the birds were given 73 in comparison to 0% HB diets. Total and major short chain fatty acids (SCFA) in the ileum were lower with 0.1 and 0.01 (except propionic acid) compared to 0% BGase in the birds fed 73% HB, but not 0% HB. Interactions between the main effects were found for the cecal acetic and isobutyric acids. In conclusion, exogenous BGase depolymerized high molecular weight β-glucan in HB and wheat. The effects of HB and BGase on carbohydrate fermentation were not apparent, although it appears ileal SCFA concentrations were lower with increasing levels of BGase.

Effect of graded dietary inclusion levels of hybrid rye grain on productive performance, the cost-effectiveness of nutrition and egg quality in laying hens

The study was designed to investigate productivity parameters, egg quality and the cost effectiveness of feeding laying hens with diets where ground wheat was replaced with varying levels of whole hybrid rye grain cv. Brasetto. A total of 396 Hy-Line Brown hens at 34 weeks of age were allocated to three treatment groups with 66 replicates (cages) of two hens each, and were fed isocaloric and isonitrogenous pelleted diets for 12 weeks. The diet for control group hens (R0) did not contain rye grain. In diets for hens from groups R100 and R200, ground wheat grain was partially replaced with whole rye grain at 100 g/kg and 200 g/kg, respectively. Whole intact rye grains were included in the diets. The cost of diets containing 10% and 20% of whole rye grain was by approximately 1.0% and 1.9% lower, respectively, compared with the control diet that contained no rye grain. During the entire 12-week feeding period, dietary treatments had no effect on laying rate (95.64% to 97.07%), egg weight (62.51 g to 62.74 g) or egg mass output (5.04 kg to 5.12 kg per hen). The inclusion of whole rye grain in layer diets caused a linear increase in feed intake (P < 0.047) and tended to linearly increase the feed conversion ratio (FCR, P = 0.078). Both groups of hens fed diets containing whole rye grain were characterized by a linear decrease in the dry matter (DM) content of excreta (P = 0.001). Increased excreta moisture was accompanied by a tendency towards a higher incidence of dirty eggshells in R200 hens (P = 0.068). The inclusion of 100 g/kg of whole rye grain in layer diets decreased the cost of feed per kg of eggs by 1.9%. Dietary treatments had no significant effect on eggshell thickness (0.330 mm - 0.345 mm), albumen quality (Haugh units, 83.46 – 85.84) or yolk color (3.8 - 4.0). The results of this experiment indicate that pre-pellet inclusion of whole rye (at up to 200 g/kg) in diets with supplemental NSP-degrading enzymes and phytase can be an effective and economically viable alternative to ground wheat in pelleted layer diets.

Protease supplementation in maize-based diet influenced net energy and nutrient digestibility in broilers

This experiment evaluated the effects of supplemental protease in maize-based diets formulated with reduced density of digestible amino acids (dAA) on net energy (NE) utilisation and nutrient digestibility in broilers. A total of 312, one-day-old, male broilers (Ross 308) were randomly distributed into 24 floor pens and fed one of three treatments, with eight pen replicates per treatment throughout the starter (1 to 14 d of age) and grower (15 to 28 d of age) phases. Dietary treatments consisted of a positive control (PC) reference diet, a negative control diet (NC; dAA density 60 g/kg less than PC diet), and a NC diet with supplemental protease (200 mg/kg). All diets contained supplemental phytase (200 mg/kg) and xylanase (200 mg/kg). The reduction in dAA density between the PC and NC did not affect (P>0.05) NE, but protease supplementation in the NC diet increased (P<0.05) NE by 0.27 MJ/kg, compared with those receiving the NC diet without protease. The reduction in dAA for broilers fed the NC and PC diets did not (P>0.05) affect nitrogen, starch, or DE in the jejunum or ileum. Likewise, no differences (P>0.05) in jejunal (nitrogen, starch, and DE) and ileal (starch and DE) digestibility values were observed between those offered the NC diets without or with protease, but a small difference (P<0.05) in ileal nitrogen digestibility was observed.

Effects of Dietary Fiber on Nutrients Utilization and Gut Health of Poultry: A Review of Challenges and Opportunities

Simple Summary

The inclusion of agricultural co-products has been increased to utilize the nutrients in these products available at low cost, but inherently, it adds a high dietary fiber content in the poultry diets. The use of exogenous feed enzymes along with advancements in feed milling, feed formulation, and processing of these non-conventional ingredients to improve their digestibility and utilization have played an emphatic role in boosting their use globally. Despite such developments, the presence of a high level of dietary fibers (DF) acting in an anti-nutritive manner still poses challenges in poultry feeding. Various isolated forms of fiber or feed enzymes to break DF into fermentable substrates are being used extensively to provide potential prebiotics to support beneficial gut microbiota or probiotics to improve the gut health of poultry raised without antibiotic growth promoters (AGP). This review reports and discusses the existing challenges in feeding high-DF feed ingredients to poultry and the opportunities that are available to improve the nutritive value of such non-conventional feed ingredients by adopting various technologies.

Abstract

Many fibrous ingredients incorporated in poultry feed to reduce production costs have low digestibility and cause poor growth in poultry. However, all plant-based fibers are not equal, and thus exert variable physiological effects on the birds, including but not limited to, digestibility, growth performance, and microbial fermentation. Several types of fibers, especially oligosaccharides, when supplemented in poultry diets in isolated form, exhibit prebiotic effects by enhancing beneficial gut microbiota, modulating gut immunity, boosting intestinal mucosal health, and increasing the production of short-chain fatty acids (SCFA) in the gut. Recently, poultry producers are also facing the challenge of limiting the use of antibiotic growth promoters (AGP) in poultry feed. In addition to other alternatives in use, exogenous non-starch polysaccharides digesting enzymes (NSPase) and prebiotics are being used to provide substrates to support the gut microbiome. We also conducted a meta-analysis of different studies conducted in similar experimental conditions to evaluate the variability and conclusiveness in effects of NSPase on growth performance of broilers fed fibrous ingredients. This review presents a holistic approach in discussing the existing challenges of incorporating high-fiber ingredients in poultry feed, as well as strategies to fully utilize the potential of such ingredients in improving feed efficiency and gut health of poultry.

Physiological parameter values for physiologically based pharmacokinetic models in food-producing animals. Part II: Chicken and turkey

Physiologically based pharmacokinetic (PBPK) models are growing in popularity due to human food safety concerns and for estimating drug residue distribution and estimating withdrawal intervals for veterinary products originating from livestock species. This paper focuses on the physiological and anatomical data, including cardiac output, organ weight, and blood flow values, needed for PBPK modeling applications for avian species commonly consumed in the poultry market. Experimental and field studies from 1940 to 2019 for broiler chickens (1-70 days old, 40 g - 3.2 kg), laying hens (4-15 months old, 1.1-2.0 kg), and turkeys (1 day-14 months old, 60 g -12.7 kg) were searched systematically using PubMed, Google Scholar, ProQuest, and ScienceDirect for data collection in 2019 and 2020. Relevant data were extracted from the literature with mean and standard deviation (SD) being calculated and compiled in tables of relative organ weights (% of body weight) and relative blood flows (% of cardiac output). Trends of organ or tissue weight growth during different life stages were calculated when sufficient data were available. These compiled data sets facilitate future PBPK model development and applications, especially in estimating chemical residue concentrations in edible tissues to calculate food safety withdrawal intervals for poultry.

Effectiveness of using a hybrid rye cultivar in feeding broiler chickens

The aim of this research was to evaluate the effectiveness of the use of hybrid rye in rations for broiler chickens. The study covered 160 chickens split into four equal groups [I (control), II, III, IV] and kept for 42 d. Rye was introduced into the above-mentioned diets as a partial substitute for maize in the following quantities: (I), no rye; (II), 5% rye in starter feed and 10% rye in grower and finisher feed; (III), 10% rye in starter feed and 20% rye in grower and finisher feed; (IV), 15% rye in starter feed and 30% rye in grower and finisher feed. During the 42 d rearing period, the most favourable body weight gain (P ≤ 0.05) and feed conversion ratio (P ≤ 0.01) were observed in chickens fed with rations containing the highest share of hybrid rye (group IV). The rye did not affect the dressing percentage and muscularity but diversified the fatness of birds. The muscles of chickens from group IV showed higher (P ≤ 0.01) red saturation and lower (P ≤ 0.01) yellow saturation and hue compared with the muscle of birds receiving diets with the lowest rye content (group I). The results of the study show that the inclusion of hybrid rye can be recommended in broiler chicken diets at a share of 15% in starter feed and 30% in grower and finisher feed, respectively.

Effects of main cereal type and feed form on production performance, egg quality and egg sanitary indices of laying hens

1. The experiment was conducted to evaluate the effects of cereal types (maize or wheat) and feed forms (pelleted or mash feed) on production performance, egg quality and egg sanitary indices in laying hens.2. Three hundred and sixty hens (Jinghong No. 1) at 18 weeks of age were randomly assigned to four treatments with six replicates of 15 hens per replicate according to a 2 × 2 factorial design with two cereal types (maize or wheat) and two feed forms (pelleted or mash feed).3. Compared with the wheat-based diet, the maize-based diet improved (P < 0.05) average egg weight of laying hens. Yolk colour of hens fed with the maize-based diet was higher (P < 0.05) in comparison to those fed the wheat-based diet, while Haugh units were lower (P < 0.05) for the maize-based treatment. Egg mass and average daily feed intake of hens fed the pelleted diet were higher (P < 0.05) than of those fed the mash diet. However, the mash diet improved (P < 0.05) yolk colour compared with the pelleted diet. The percentage of dirty eggs for the wheat-based diet was higher (P < 0.05) than for the maize-based diet. The percentage of dirty eggs was higher (P < 0.05) in birds fed the pelleted diet compared with those fed the mash diet. There were interactions (P < 0.05) between cereal type and feed form, with regard to average egg weight and shell thickness.4. In conclusion, dietary cereal type affected average egg weight, yolk colour and Haugh units in eggs, while feed form influenced egg mass, average daily feed intake and yolk colour.

Maintenance of broiler performance on commercial diets diluted with copra meal and supplemented with feed enzymes

Context Dilution of commercial feed with moderate levels of copra meal (CM), a byproduct of coconut oil extraction, was shown to maintain broiler performance in older breeds, but reports on its use in modern fast-growing broilers are limited. Aims We evaluated feed dilution with CM and enzyme supplementation in broiler chickens. We hypothesised that (i) diluting commercial feed with CM will maintain performance of modern fast-growing broilers, and (ii) enzyme supplementation will improve utilisation of the diluted diets. Methods Experiment 1 studied the performance of growing broilers (10–21 days of age) fed commercial grower diet alone (control), or diluted with one of two levels of CM (50 and 100 g/kg) and with or without enzyme supplementation. Cobb 500 broiler chicks (10 days old), 200 in total, were assigned to five dietary treatments with four replicates, in a completely randomised design. Experiment 2 investigated higher levels of dilution (100 and 200 g CM/kg) and enzyme supplementation of commercial finisher diet in 200 finishing broilers (22–42 days of age) assigned to five treatments with four replicates each. Key results In Experiment 1, feed intake was reduced (P &lt; 0.05) on the 100 g CM/kg diet without enzyme compared with 50 g CM/kg without enzyme and both of the enzyme-supplemented diets but was not different (P &gt; 0.05) from the control. Bodyweight gain and feed conversion ratio were not affected (P &gt; 0.05) by dietary treatment. In Experiment 2, feed intake was reduced on 200 g CM/kg with enzyme but did not differ (P &gt; 0.05) among the control and other CM-based diets. Bodyweight gain (P &lt; 0.05) was reduced on the 200 g CM/kg diet without enzyme compared with the 100 g CM/kg diet without enzyme. Feed:gain was not affected (P &gt; 0.05) by diet. The relative weight of carcass and cuts, gut segments and annex organs was not affected (P &gt; 0.05) by diet. Conclusions Diluting commercial grower and finisher diets with 50 and 100 g CM/kg has no adverse effects on performance of modern broilers. At higher levels of dilution (100 and 200 g/kg), enzyme supplementation may be required. Implications These findings will reduce the cost of broiler production and add value to CM in coconut-producing regions. We recommend more research into higher rates of dilution, sources of CM, and enzyme sources and levels that might improve performance and reduce cost of production.

Supplemental boric acid does not prevent the development of footpad dermatitis in broilers subjected to high stocking density

The present study was conducted to evaluate the protective effect of dietary boric acid supplementation on the development of incidence and severity of footpad dermatitis (FPD) in broiler chickens subjected to normal or high stocking densities (NSD or HSD). A total of 576 1-day-old ROSS 308 broiler chickens were randomly allocated to 4 treatments (8 replicate pens per treatment) in a 2 × 2 factorial arrangement of dietary boric acid (0 and 60 mg/kg) and stocking density (NSD 14 birds/m2 and HSD 22 birds/m2). Basal diets were formulated for starter, grower, and finisher phases. Growth performance, litter quality (litter pH, moisture, temperature, and NH3 volatilization), serum and litter boron levels, and incidence and severity of FPD were recorded. The HSD affected the body weight gain and feed intake of broiler chickens during all phases and 0 to 42 (P < 0.05), whereas feed conversion ratio (FCR) was poor at 0 to 21 days only. Dietary boric acid had no effect on the growth performance of broiler chickens. Litter pH, moisture, and NH3 volatilization were higher in broiler chickens subjected to HSD (P < 0.05). Thus, the incidence and severity of FPD increased in response to HSD (P < 0.05). Dietary boric acid reduced the litter pH and NH3 volatilization on day 42 of experiment (P < 0.05). However, dietary boric acid supplementation had no effect on the incidence and severity of FPD. Boric acid supplementation in broiler diets increased the serum and litter boron levels at day 42 in broiler chickens subjected to NSD or HSD (P < 0.05). In conclusion, HSD resulted in poor growth performance, litter quality, and greater incidence and severity of FPD in broiler chickens. Dietary boric acid was ineffective against FPD in broiler chickens although it improved the litter quality by lowering the litter pH and NH3 volatilization.

Evaluation of dried vegetables residues for poultry: II. Effects of feeding cabbage leaf residues on broiler performance, ileal digestibility and total tract nutrient digestibility

A study was conducted to investigate the effects of partial replacing corn and soybean meal with dried cabbage leaf residues (DCR) on broiler growth performance, apparent ileal nutrient digestibility, and apparent total tract nutrient utilization. Dietary treatments include 4 levels of DCR (0, 3, 6, and 9%). Two hundred and twenty-four day-old male broilers were randomly assigned to one of 4 groups (8 cage replicates; 7 birds/cage) and grown over a 35-d experimental period. Results showed that feeding DCR had no effects on daily body weigh gain (average 53.4 g/d), daily feed intake (average 94.9 g/d), and feed conversion ratio (average 1.78 g of feed/g of gain). Inclusion of DCR reduced apparent ileal DM (quadratic effect, P < 0.001), OM (linear effect, P = 0.012), and CP (quadratic effect, P = 0.001) digestibility of younger birds (d 21) while incremental levels of DCR had no effect on apparent ileal nutrient digestibilities of older birds (d 35). Apparent total tract digestibility of DM, OM, and CP increased (linear effect, P < 0.001) as the level of DCR increased. It was concluded that the inclusion of DCR in broiler diets up to 9% had no negative impact on bird performance and apparent ileal digestibility of older birds and improved apparent total tract nutrient digestibility.

Multiple-enzyme supplementation on digestive traits, carcass characteristics, blood lipid parameters and growth performance of broilers fed a wheat-based diet

OBJECTIVE

A trial was conducted from 11 to 42 d post-hatch to investigate the effectiveness of the supplementation of a multiple-enzyme preparation (Natuzyme Plus) in a wheat-based diet on digesta viscosity, pH and microbial population, villus morphology, feed passage time, nutrient retention, carcass characteristics, blood lipid parameters and growth performance of broiler chickens.

METHODS

Three hundreds 10-d-old male Ross 308 chicks were allocated to three diets with five replicates of 20 birds per replicate. Dietary treatments were i) a wheat-based diet (W), ii) W+Natuzyme Plus (WN; 500 mg/kg of the diet), and iii) a corn-based diet (C).

RESULTS

Birds fed on the C diet had higher average daily gain (ADG, p<0.01), villus height (VH, p<0.01), total tract apparent retention (TTAR) of nitrogen (NT, p<0.01) and ether extract (EE, p<0.01), nitrogen-corrected apparent metabolizable energy (AME_n, p<0.05), relative weight (RW, % of body weight) of carcass (p<0.05), blood concentration of triglyceride (TG, on d 40 [p<0.01]), total cholesterol (TC, on d 22 [p<0.05]) and low density lipoprotein (LDL, on d 22 [p<0.01] and 40 [p<0.05]), and also lower feed conversion ratio (FCR, p<0.01), digesta viscosity (p<0.01), count of coliforms (p<0.01) and Escherichia coli (p<0.01) and epithelium thickness (ET, p<0.05) than those fed on the W diet. ADG, FCR, VH, ET, TTAR of NT and EE, RW of carcass, blood concentration of TG (on d 40), TC (on d 22) and LDL (on d 22 and 40) values of the WN diet did not show a significant (p>0.05) difference compared to those of the C diet. Compared to those of the W diet, the WN diet showed the higher count of Lactobacilli and lower count of coliforms (p<0.01) and digesta viscosity (p<0.01).

CONCLUSION

In general, the results of this study showed that Natuzyme Plus supplementation in a wheat-based diet can be appropriate to achieve a comparable growth performance in broiler chickens to those given the C diet probably through improving digesta viscosity, VH, ET, TTAR of NT and EE, AME_n, count of Lactobacilli and coliforms.

Influence of the main cereal and feed form of the rearing phase diets on performance, digestive tract, and body traits of brown-egg laying pullets from hatch to 17 weeks of age

The effects of the main cereal and feed form of the rearing phase diets on growth performance, gastrointestinal tract characteristics, and body traits were studied in brown-egg pullets from hatch to 17 wk of age. Eight dietary treatments that were a combination of 2 main cereals (corn vs. wheat) and 4 feeding programs were used. The feeding program consisted in feeding crumbles from 0 to 5, 0 to 10, or 0 to 17 wk of age followed by mash until 17 wk, or feeding mash continuously from 0 to 17 wk. Each treatment was replicated 9 times. From hatch to 17 wk of age, pullets fed corn had similar ADG but poorer feed conversion ratio (FCR; P < 0.001) than pullets fed wheat. Also, pullets fed crumbles continuously (0 to 17 wk) had greater ADG (12.3 vs. 11.5 g; P < 0.001) and better FCR (4.21 vs. 4.36; P < 0.001) than pullets feed mash continuously, with pullets that were changed at any age of the rearing period from crumbles to mash feeding showing intermediate results. At 17 wk of age, the relative weights (% BW) of the gastrointestinal tract and gizzard were greater in pullets fed corn than in pullets fed wheat (P < 0.01) but the relative length (cm/kg full BW) of the small intestine, body, and tarsus was not affected. Pullets fed crumbles continuously had lighter gizzards (P < 0.001), higher gizzard pH (P < 0.001), and were shorter (P < 0.01) than pullets fed mash continuously, with pullets fed the other 2 treatments being intermediate. In summary, wheat can be used in substitution of corn in pullet diets without any adverse effect on growth performance. Feeding crumbles improves pullet performance but hinders gizzard and gastrointestinal tract development. Growth performance, gastrointestinal tract, and body traits of the pullets re-adapt quickly to changes in feed form of the rearing diets.

Effect of dietary probiotic and high stocking density on the performance, carcass yield, gut microflora, and stress indicators of broilers

A study was carried out to evaluate the effect of dietary probiotic supplementation and stocking density on the performance, relative carcass yield, gut microflora, and stress markers of broilers. One-day-old Ross 308 male broiler chickens (n = 480) were allocated to 4 experimental groups for 42 d. Each treatment had 8 replicates of 15 chicks each. Two groups were subjected to a high stocking density (HSD) of 20 birds/m² and the other 2 groups were kept at low stocking density (LSD) of 10 birds/m². A basal diet supplemented with probiotic 1 and 0.5 g/kg of diet (in starter and finisher diets, respectively) was fed to 2 treatments, one with HSD and the other with LSD, thereby making a 2 × 2 factorial arrangement. There was no interaction between stocking density (LSD and HSD) and dietary probiotic (supplemented and unsupplemented) for all the variables. Feed intake and weight gain were significantly low and feed conversion ratio was poor in broilers at HSD. Dietary probiotic significantly enhanced the feed intake and weight gain in starter phase only. Dietary probiotic supplementation had no effect (P > 0.05) on total aerobs, Salmonella sp., and Lactobacilli populations in the intestines of broilers. However, HSD reduced the Lactobacilli population only (P < 0.05). Relative breast yields were significantly higher in broilers reared at LSD than HSD. Thigh meat yield was higher in broilers in HSD group compared to LSD. Dietary probiotic did not affect the relative carcass yield and weight of lymphoid organs. Serum malondialdehyde, corticosterone, nitric oxide, and plasma heterophil:lymphocyte ratio were not affected either by stocking density or dietary probiotic supplementation. In conclusion, HSD negatively affected the performance and intestinal Lactobacilli population of broilers only, whereas probiotic supplementation enhanced the performance of broilers during the starter phase only. Total aerobes, Salmonella, Lactobacilli carcass yield, and stress indicators of broilers were not affected by the dietary supplementation of probiotic under the conditions of the present study.

Evaluation of dietary multiple enzyme preparation (natuzyme) in laying hens

The current experiment was designed to evaluate the efficacy of adding the multi-enzyme mixture (Natuzyme) into layers' diets with different levels of energy and available phosphorus in relation to laying performance, egg qualities, blood cholesterol level, microflora and intestinal viscosity. Two hundred and fifty 43-wk-old Hy-Line commercial layers were divided into five groups with five replicates per group (10 birds per replicate) and fed one of five experimental diets. A corn and soybean meal-based control diet was formulated and used as a control diet. Two experimental control diets were formulated to reduce energy and crude protein contents (rE) or energy, crude protein and phosphorus contents (rEP). In addition, Natuzyme was added into either rE (rE-Natu500) or rEP (rEP-Natu500) diet to reach a concentration of 500 mg per kg of diet. The experiment lasted 8 weeks. There were no significant differences in feed intake, egg production, egg weight, egg qualities such as eggshell color or Haugh unit, total cholesterol, relative organ weights and cecal microflora profiles between any dietary treatments. Natu500 supplementation into the rE diet, but not rEP diet significantly increased egg mass and eggshell qualities such as strength and thickness, but it decreased cecal ammonia concentration and intestinal viscosity in laying hens. In conclusion, the present study shows that adding multiple enzyme preparation could improve performance of laying hens fed energy and protein restricted diets.

Effect of supplementing direct-fed microbials on broiler performance, nutrient digestibilities, and immune responses

Direct-fed microbials (DFM) are used to improve livestock health and performance. The effects of 2 DFM products, a blend of 3 Bacillus strains (DFMB) and a Propionibacteriumspp. (DFMP), on broiler performance, nutrient utilization, and immune responses were investigated. Day-old (n = 120) male broilers were divided into 24 groups of 5 birds and fed 3 wheat-based diets in mash form (8 groups per diet) from d 1 to 22. The control diet was fed without or with 7.5 × 10(4) cfu/g of either DFMB or DFMP. From d 19 to 21 fecal samples were collected for determination of total tract apparent retention (TTAR) of nutrients and AMEn. On d 21, feed intake and BW were determined. On d 22, 5 birds per treatment were killed by cervical dislocation to collect jejunal and ileal contents for determination of digesta viscosity and apparent ileal digestibility (AID) of nutrients, respectively, and ileum, cecal tonsil, and spleen tissues for Toll-like receptors (TLR) and cytokine expressions. Compared with the control, DFM did not affect BW gain and feed intake but DFMP reduced G:F (P < 0.01). Compared with the control (2,875 kcal/kg), birds fed on DFMB and DFMP had higher AMEn (2,979 and 2,916 kcal/kg, respectively; P < 0.05), whereas both DFM reduced the AID of DM (P < 0.001) and CP (P < 0.01). Furthermore, DFMP reduced TTAR of NDF (29.0 vs. 18.4%; P < 0.001), whereas both DFM increased TTAR of DM and fat (P < 0.001). Supplementing DFMP downregulated ileal expression of TLR-2b, IL-2, IL-4, IL-6, IL-10, and IL-13, whereas DFMB downregulated TLR-2b, IL-2, IL-4, and IL-6 in all 3 tissues, IL-10 in the spleen, and upregulated IL-13 in the spleen. In conclusion, the DFM did not improve performance but increased the AMEn of diet by possibly increasing DM and fat retention. Overall, both DFM showed an antiinflammatory effect in the ileum, but DFMB had more effects on local and systemic immunity than DFMP.

Xylanase supplementation improves the nutritive value of diets containing high levels of sorghum distillers' dried grains with solubles for broiler chickens

BACKGROUND

An experiment was conducted to investigate the effect of sorghum distillers' dried grains with solubles (sDDGS) and xylanase supplementation in broiler chicken diets. A total of 432 Cobb-500 day-old male broiler chicks were used in a 4 × 2 factorial design (0, 100, 200 or 300 g kg(-1) sDDGS with or without xylanase supplementation). Each treatment was replicated six times with nine birds per replicate in a 35 day study.

RESULTS

Feed intake was increased (P < 0.001) throughout the study with the inclusion of dietary sDDGS. Body weight gain (BWG) was unaffected except for the last 2 weeks of study, when birds that received 200 and 300 g kg(-1) sDDGS had higher (P < 0.001) BWG. Feed conversion ratio (FCR) increased (P < 0.05) as sDDGS in the diet rose to 100 g kg(-1) during the starter phase and the whole period of study. Over the starter period, xylanase supplementation improved (P < 0.05) FCR, particularly for the highest inclusion of sDDGS. Protein digestibility deteriorated (P < 0.001) as sDDGS in the diet rose to 300 g kg(-1) . Xylanase reduced (P < 0.001) the concentration of xylose in the ileum of birds. The activities of sucrase and maltase in the jejunal mucosa were reduced when birds were offered 200 and 300 g kg(-1) sDDGS. Incorporation of sDDGS increased (P < 0.01) the total short-chain fatty acid concentration in the caeca.

CONCLUSION

The results showed that diets containing large amounts of sDDGS will benefit from xylanase supplementation, particularly in terms of FCR.

Effects of Enzyme Complex Supplementation to a Paddy-based Diet on Performance and Nutrient Digestibility of Meat-type Ducks

Paddy rice is rarely used as a feed because of its high fiber content. In this study, two experiments were conducted to study the effects of supplementing an enzyme complex consisting of xylanase, beta-glucanase and cellulase, to paddy-based diets on the performance and nutrient digestibility in meat-type ducks. In the both experiments, meat-type ducks (Cherry Valley) were randomly assigned to four treatments. Treatment 1 was a basal diet of corn-soybean; treatment 2 was a basal diet of corn-paddy-soybean; treatment 3, had enzyme complex added to the corn-paddy-soybean basal diet at levels of 0.5 g/kg diet; and treatment 4, had enzyme complex added to the corn-paddy-soybean diet at levels of 1.0 g/kg diet. The results showed that the enzyme complex increased the ADG, and decreased the ADFI and F/G significantly (p<0.05) in the ducks, and the ADFI for the ducks fed the corn-paddy-soybean diet showed no difference compared to the ducks fed corn-soybean diets at all stages of the experiment (p<0.05). When corn was partially replaced by paddy, the digestibility of CP and NDF was decreased and increased, respectively (p<0.05), and the level of enzyme complex had a significant effect on both CP and NDF digestibility (p<0.05). As for the AME, addition of enzyme complex increased it significantly (p<0.05), but both diet types and levels of enzyme complex had no effect (p>0.05). The outcome of this research indicates that the application of enzyme complex made up of xylanase, beta-glucanase, and cellulase, in the corn-paddy-soybean diet, can improve performance and nutrition digestibility in meat-type ducks.

Effects of diet type and ingredient composition on rate of passage and apparent ileal amino acid digestibility in broiler chicks

This experiment evaluated rate of passage (ROP) and apparent ileal amino acid digestibility (AIAAD) of 4 diets varying in ingredient composition fed to broilers from 14 to 22 d of age. Two hundred and 88 Ross × Ross 708 chicks (12 birds per cage; 0.45 m(2) per bird) were randomly assigned to 24 cages (6 replicate cages per treatment) at 1 d of age. Experimental diets were 1) corn-soybean meal-based (CSM) diet containing porcine meat and bone meal (MBM; 5% inclusion), 2) CSM diet containing distillers dried grains with solubles (DDGS; 5% inclusion), 3) semipurified (SP) diet containing MBM (38% inclusion), and 4) SP diet containing DDGS (76% inclusion). Diets were formulated to contain 20% CP and were adequate for vitamins and minerals. Experimental diets were provided from d 14 to 22. On d 18, a total excreta collection was conducted every hour for 12 h from 0800 to 1900 h to determine ROP, and AIAAD was determined on d 22. Time of 1% TiO(2) excretion (T1), 50% TiO(2) excretion (T50), and mean retention time (MRT) were used to express ROP. The SP-MBM diet reached T1 (P < 0.05) faster than the SP-DDGS or 2 CSM diets. However, T50 indicated a faster (P < 0.05) ROP for SP-DDGS than the 2 CSM diets, and no significant difference was observed between the 2 SP diets. The MRT of the SP-DDGS diet (5.13 h) was less (P < 0.05) than the MRT of the SP-MBM, CSM-MBM, and CSM-DDGS diets, which resulted in values of 5.48, 5.62, and 5.58 h, respectively. In general, the AIAAD values were higher (P < 0.05) for the 2 CSM diets than for SP diets. Except for His, no statistical differences were observed between the AIAAD of the 2 CSM diets. Comparing the 2 SP diets, AIAAD was usually similar or higher (P < 0.05) for SP-DDGS, except for His, Lys, and Gly, which were higher (P < 0.05) for SP-MBM. Based on T50 and MRT, SP diets containing DDGS had a faster ROP in broilers than CSM diets or SP diets containing MBM.

Effects of exogenous enzymes in corn-based and Canadian pearl millet-based diets with reduced soybean meal on growth performance, intestinal nutrient digestibility, villus development, and selected microbial populations in broiler chickens

An experiment was conducted to compare a commercial corn-soybean meal diet with a pearl millet diet containing less soybean meal (-27%), alone or in combination with exogenous enzymes, on growth performance, jejunal villus development, ileal CP, and AA digestibility, and cecal microbial populations in broilers. One hundred sixty 1-d-old male Ross 508 broilers (5/cage) were randomly allocated to one of the following dietary treatments: 1) a standard corn-soybean meal control diet (CTL); 2) a pearl millet-soybean meal diet (PM); 3) CTL + exogenous enzymes (CE); and 4) PM + exogenous enzymes (PE) with 8 replicate cages/treatment. The PM and PE diets contained less soybean meal because of greater CP and AA contents of pearl millet. All diets were isonitrogenous and isocaloric. Body weight and feed intake were recorded weekly over 35 d. At d 21 and 35, 8 broilers per treatment were euthanized for sample collection and analyses. Gain-to-feed was greater (P < 0.01) for pearl millet- than corn-based diets. Apparent ileal digestibility (AID) of CP and most AA was similar between corn-based and pearl millet-based diets, and enzyme supplementation improved AID of CP (P < 0.01) and most AA at both d 21 and 35. However, for AID of some AA at d 21, the response to enzyme supplementation was less pronounced in broilers fed pearl millet-based diets than those fed corn-based diets (grain × enzyme, P ≤ 0.05). The villus was longer (P < 0.01) in broilers fed PM and PE than CTL and CE at d 35. Similarly, at d 35, lactobacilli loads were greater (P < 0.01) in broilers fed PM and PE than CTL and CE. It is concluded that, in comparison with corn, broiler diets formulated with pearl millet require less soybean meal and can be used to improve growth performance traits, intestinal lactobacilli populations, and villus development, whereas enzyme supplementation increases AID of CP and AA.

Review: Supplementation of phytase and carbohydrases to diets for poultry

Woyengo, T. A. and Nyachoti, C. M. 2011. Review: Supplementation of phytase and carbohydrases to diets for poultry. Can. J. Anim. Sci. 91: 177–192. Feedstuffs of plant origin contain anti-nutritional factors such as phytic acid (PA) and non-starch polysaccharides (NSP), which limit nutrient utilization in poultry. Phytic acid contains phosphorus, which is poorly digested by poultry, and has the capacity to bind to and reduce the utilisation of other nutrients, whereas NSP are indigestible and have the capacity to reduce nutrient utilisation by encapsulation. Supplemental phytase and NSP-degrading enzymes (carbohydrases) can, respectively, hydrolyze PA and NSP, alleviating the negative effects of these anti-nutritional factors. In feedstuffs of plant origin, PA is located within the cells, whereas NSP are located in cell walls, and hence it has been hypothesized that phytase and carbohydrases can act synergistically in improving nutrient utilization because the carbohydrases can hydrolyze the NSP in cell walls to increase the accessibility of phytase to PA. However, the response to supplementation of a combination of these enzymes is variable and dependent on several factors, including the type of carbohydrase supplement used, dietary NSP composition, calcium and non-phytate phosphorus contents, and endogenous phytase activity. These factors are discussed, and areas that need further research for optimising the use of a combination of phytase and carbohydrases in poultry diets are suggested.

The cereal type in feed influences gut wall morphology and intestinal immune cell infiltration in broiler chickens

In broiler chickens, a diet where the major cereal types are wheat, rye and/or barley has a lower digestibility compared with a diet in which maize is the major cereal type. In the present study, the effects of two different dietary cereal types, maizev.wheat/rye, on host factors (inflammation and gut integrity) and gut microbiota composition were studied. In addition, the effects of low-dose Zn-bacitracin supplementation were examined. Broilers given a wheat/rye-based diet showed more villus fusion, a thinner tunica muscularis, more T-lymphocyte infiltration, higher amount of immune cell aggregates in the mucosa, more and larger goblet cells and more apoptosis of epithelial cells in the mucosa than those given a maize-based diet. Adding Zn-bacitracin generally reversed these alterations. The microbiota composition was analysed by the use of terminal-restriction fragment length polymorphism, showing changes in the microbiota composition depending on the cereal type used in the diets. The effect of the change of cereal type on the gut microbiota composition was larger than that of Zn-bacitracin supplementation. In conclusion, a wheat/rye-based diet evoked mucosal damage, an alteration in the composition of the microbiota and an inflammatory bowel type of condition.

Effect of main cereal of the diet and particle size of the cereal on productive performance and egg quality of brown egg-laying hens in early phase of production

A total of 960 Lohmann Brown laying hens were used to study the effects of the main cereal of the diet and geometric mean diameter (GMD) of the cereal on productive performance and egg quality from 20 to 48 wk of age. The experiment was a completely randomized design with 6 treatments arranged factorially with 2 cereals (dent corn vs. durum wheat) and 3 GMD of the cereal (hammer-milled to pass through 6-, 8-, or 10-mm screens). Each treatment was replicated 8 times (20 hens per replicate). All diets were formulated to be isonutritive and contained 50% of either corn or wheat. Productive traits were recorded every 4 wk and egg quality was measured at 48 wk of age. The only significant effect detected was for feed intake (P < 0.05) that was greater for hens fed coarse-ground cereals (10-mm screen) than for hens fed medium and fine-ground cereals (8- or 6-mm screen). None of the egg quality parameters studied were influenced by dietary treatment. We conclude that neither type of cereal nor GMD affected productive performance or egg quality of young brown hens, except for feed intake that increased with the coarser particle size.