Feed processing and structural components affect starch digestion dynamics in broiler chickens.

1. A 2 × 2 factorial design was used to test the hypothesis that impaired intestinal starch digestibility is attributable to rapid passage of digesta from the gizzard to the intestine, and that, compared to steam pelleting, increasing the availability of starch through extrusion cooking may alleviate the potential negative effect of rapid digesta flow on starch utilisation. 2. Thus, 7-d-old-broiler chickens were distributed to 48 cages and given a wheat-based (WB) pelleted diet containing either coarse oat hulls (OH-Pel) or fine cellulose (Cel-Pel) until d 19 to stimulate divergent development of the gizzard. Thereafter, both groups were further subdivided and challenged with a WB diet containing cellulose in either pelleted (Cel-Pel) or extruded (Cel-Ext) form on d 20 and 22. Either excreta or intestinal contents were collected at time intervals after feeding and analysed for marker and starch. 3. OH-Pel increased gizzard size and holding capacity. No excessively high starch levels (maximum 25 g/kg) were detected in the excreta. However, 8 h feed-deprived birds given Cel-Pel and challenged with Cel-Pel exhibited higher starch excretion and showed large individual variation during the first 135 min of collection. 4. Contrary to the OH-Pel group, more digesta and starch passed to the jejunum at 1 and 2 h and ileum at 2 and 3 h after feeding for birds given Cel-Pel, resulting in lower jejunal and ileal starch digestibility. 5. Increased starch gelatinisation through extrusion processing significantly improved starch digestibility regardless of gizzard function. However, at 1, 2 and 3 h after feeding, more digesta was retained in the foregut of birds given Cel-Ext. 6. The current data showed that starch degradation rate is associated with the flow of digesta which is linked to gizzard development, and that enzymatic hydrolysis of intact starch granules may be limited with more rapid feed passage through the gut.

Wheat particle size, insoluble fibre sources and whole wheat feeding influence gizzard musculature and nutrient utilisation to different extents in broiler chickens.

A 21-day experiment was conducted to investigate the effects of wheat particle size, insoluble fibre source and whole wheat (WW) inclusion on the gizzard musculature, intestinal architecture and nutrient utilisation of broiler chickens. The following seven treatments, all in mash form, were tested: control diet using finely ground wheat (Fine); control diet using medium-ground wheat (Medium); control diet using coarsely ground wheat (Coarse); fine diet diluted with 10 g/kg lignocellulose (LC); fine diet diluted with 30 g/kg oat hulls (OH); fine diet diluted with 30 g/kg wood shavings (WS); and ground wheat in the fine diet replaced with 50 and 100 g/kg WW during the second (day 8-14) and third (day 15-21) weeks of the study respectively. Except for the LC diet, all treatments increased (p < 0.05) the thickness of the caudodorsal thick muscle of gizzard compared to the fine diet. The highest (p < 0.05) caudoventral thin and cranioventral thick muscle diameters in the gizzard walls were achieved with the OH and WS diets. Feeding OH, WS and WW diets improved (p < 0.05) starch digestibility compared with the fine diet, while medium, coarse and LC diets had no effect (p > 0.05). All diets containing fibre sources (LC, OH and WS) reduced (p < 0.05) the energy digestibility compared to the fine diet. Birds fed OH and WS diets gained the lowest (p < 0.05) weights. Feeding LC, OH, WS and WW diets increased (p < 0.05) the feed per gain compared with the fine diet. The current results suggest that there is a potential for coarse particles, insoluble fibre sources and WW feeding to improve the gizzard musculature and digestibility of some nutrients, with the effect being more pronounced with the inclusion of structural fibre sources.

Haematological, biochemical and organ changes in broiler chickens fed varying levels of Morinda lucida (brimstone) leaf meal supplementation in the diets.

The aim of this study was to evaluate the effects of dietary supplementation of Morinda lucida leaf meal (MLLM) on the haematology, biochemical and organ changes of broiler chickens. One hundred and ninety-eight day-old Marshall broiler chicks were completely randomised into 6 treatments in a 3 × 2 factorial arrangement of three levels of M. lucida leaf meal supplementation (0, 0.1 and 0.2 g/kg) with or without medication. The treatment consisted of both negative (without MLLM and routine medication) and positive (containing no MLLM but with routine medication) control groups while each treatment was replicated thrice. MLLM-supplemented diets and routine medication decreased (p < 0.05) the white blood cell count compared to the negative control. Dietary supplementation with MLLM in combination with normal routine medication increased (p < 0.05) total serum protein when compared with treatment group without MLLM and routine medication. Dietary supplementation with MLLM and routine medication reduced (p < 0.05) serum creatinine concentration of the broiler chickens. Birds fed with 0.2 g/kg MLLM supplement coupled with medication and those on negative control had higher (p < 0.05) creatinine values. Serum enzyme activities reduced (p < 0.05) following supplementation. MLLM supplementation recorded no significant effect (p > 0.05) on the liver, kidney, heart and gizzard. M. lucida leaf meal can be compared to routine medication for improved health status of broiler chickens. Dietary inclusion with 0.1 g/kg MLML combined with routine medication could be used in producing healthy and safe chickens.

Effect of diet phase change, dietary Ca and P level and phytase on bird performance and real-time gizzard pH measurements.

In this study, a novel capsule technique was used to capture real-time pH readings from the gizzard over several hours, in response to different dietary treatments. 1. The first experiment was a preliminary study into capsule administration and pH recordings using 9 male Ross 308 broilers from 20 d. In the second experiment, broilers (576) were fed in two phases (0-21 and 21-42 d) with 4 treatment groups; low and adequate Ca and AvP diets with and without Quantum Blue phytase (1500 FTU/kg). Capsules were administered to 8 birds from each treatment group, pre and post diet phase change, with readings captured over a 2.5 h period. 2. Phytase addition improved body weight gain (BWG) and feed conversion ratio (FCR) of birds fed low dietary Ca, while having no significant effect on birds fed adequate Ca diets. Unexpectantly, diets with higher Ca levels gave a lower average gizzard pH compared to the low Ca diet. Phytase addition, irrespective of Ca level, increased average gizzard pH. Fluctuations in gizzard pH (0.6-3.8) were observed across all treatment groups. Higher frequencies of pH readings below pH 1.0 were seen in birds fed an adequate Ca diet and with phytase supplementation of a low Ca diet. 3. These results signify the potential use of capsule techniques to monitor real-time pH changes. The implication on gastric protein and fibre hydrolysis as a result of large fluctuations in pH should be considered.

Evaluation of ground grain versus pre- and post-pellet whole grain additions to poultry diets via a response surface design.

1. The objective of this study was to compare the effects of pre- and post-pellet whole grain wheat additions to diets on growth performance, gizzard and pancreas development, nutrient utilisation and starch and protein (N) digestibility coefficients in broiler chickens via an equilateral triangle response surface design. 2. The three apical treatments of the equilateral triangle comprised (1A) a standard diet containing 600 g/kg ground wheat, (2B) the same diet containing 600 g/kg pre-pellet whole wheat and (3C) the same diet containing 300 g/kg ground wheat and 300 g/kg post-pellet whole wheat. Seven blends of the three apical diets were located within the triangle to complete the design and a total of 360 male Ross 308 chicks were offered the ten experimental diets from 7 to 28 d post-hatch. Model prediction and response surface plots were generated with R 3.0.3 software. 3. The most efficient FCR of 1.466 was observed in birds offered an almost equal mixture of the pre- and post-pellet whole grain apical dietary treatments, which corresponded to 172 g/kg ground grain, 256 g/kg pre-pellet whole grain, 172 g/kg post-pellet whole grain in a diet containing 600 g/kg wheat. 4. The most efficient energy utilisation (ME:GE ratio of 0.766) was observed in birds offered a blend of the ground grain and pre-pellet whole grain apical dietary treatments which corresponded to a mixture of 384 g/kg pre-pellet whole grain and 216 g/kg ground grain. 5. Pre-pellet whole grain feeding generated the most pronounced responses in increased relative gizzard contents, reduced gizzard pH and increased relative pancreas weights. Consideration is given to the likely differences between pre- and post-pellet whole grain feeding.

Effects of thermo-resistant non-starch polysaccharide degrading multi-enzyme on growth performance, meat quality, relative weights of body organs and blood profile in broiler chickens.

This research was conducted to study the performance and carcass parameters of broiler chickens fed diets supplemented with heat-treated non-starch polysaccharide degrading enzyme. A total of 432 one-day old Ross 308 broiler chickens were allocated to five treatments: (i) CON (basal diet), (ii) E1: CON + 0.05% multi-enzyme, (iii) E2: CON + 0.1% multi-enzyme, (iv) E3: CON + 0.05% thermo-resistant multi-enzyme and (v) E4: CON + 0.1% thermo-resistant multi-enzyme, each treatment consisted of six replications and 12 chickens in each replication. The chickens were housed in three floor battery cages during 28-day experimental period. On days 1-7, gain in body weight (BWG) improved by feeding the diets supplemented with thermo-resistant multi-enzyme. On days 7-21 and 1-28, chickens fed the diets containing thermo-resistant multi-enzyme showed improved (p < 0.05) BWG and feed conversion ratio (FCR) compared to CON group. Supplementing the diets with multi-enzyme or thermo-resistant multi-enzyme affected the percentage of drip loss on d 1 (p < 0.05). Drip loss percentage on days 3 and 5 and also meat colour were not affected significantly. Supplementing the diets with multi-enzyme or thermo-resistant multi-enzyme did not affect the relative weights of organs but compared to CON group, relative weight of breast muscle increased and abdominal fat decreased (p < 0.05). Among measured blood constituents, chickens fed supplemented diets with thermo-resistant multi-enzyme showed higher (p < 0.05) IgG. Counts of red and white blood cells and lymphocyte percentage were not affected. In conclusion, the results demonstrated that supplementing pelleted diets with thermo-resistant multi-enzyme improved performance of broiler chickens.

Effects of feed form and dietary coarse ground corn on broiler live performance, body weight uniformity, relative gizzard weight, excreta nitrogen, and particle size preference behaviors.

In this 14-d cage study, the effects of feed form (mash and crumble) and 6 coarse ground corn ( CC: ) inclusions [0, 10, 20, 30, 40, and 50% CC that replaced fine corn ( FC: )] on broiler live performance, BW uniformity, gizzard weight, excreta nitrogen, and particle size preference were investigated. The geometric mean diameter by mass ( DGW: ) of mash diets increased from 422 µm to 431, 471, 509, 542, and 640 µm, respectively, as the percentage of CC increased. Feed intake and BW were decreased by CC and mash at 7 d. Interactions between feed form and CC were observed for feed conversion ratio ( FCR: ) at 7 d of age (P < 0.01), and feed intake (P < 0.05), BW (P < 0.01), and gizzard weight (P < 0.01) at 14 d of age. Feed intake for all CC inclusions in crumble diets was similar and exceeded (P < 0.01) that of mash diets at 14 d. Among mash diets, the 10 and 30% CC feed intake was greater (P < 0.05) than 40 and 50% CC with 0 and 20% CC intermediate. Crumble diets produced a similar BW but greater 14-d BW than mash diets (P < 0.01). Within mash diets, 40 and 50% CC produced a smaller BW (P < 0.01). The FCR at 7 d of CC inclusions in crumble diets was improved (P < 0.01) versus the same CC in mash diets. Within mash diets, 40% CC performed poorer than 0, 10, 20, and 30% CC diets with 50% CC diet intermediate (P < 0.01). Crumble diets improved FCR at 14 d, but CC worsened FCR. Gizzard weight at 14 d was not affected by CC in crumble diets, while it increased with CC in mash diets (P < 0.01). Excreta nitrogen was increased (P < 0.01) by crumble diets. These data demonstrated that pelleting and crumbling reduced the impact of CC, produced a more consistent feed intake, and reduced selective feeding, and that CC stimulated gizzard weight in a linear manner in mash diets.

Effects of trypsin inhibitor and particle size of expeller-extracted soybean meal on broiler live performance and weight of gizzard and pancreas.

Soybean meal (SBM) is a co-product that remains after the oil is removed from whole soybeans by either solvent extraction or mechanically pressing soybeans using an expeller. Expeller-extracted soybean meal (ESBM) contains more fat and less protein than solvent-extracted soybean meal (SSBM), but has higher trypsin inhibitors (TI) that limit its inclusion in poultry diets. We hypothesized that increasing the particle size of ESBM could enhance chick tolerance to dietary TI. The experiment consisted of a 2 × 6 factorial arrangement of 2 ESBM particle sizes (coarse, 1,300 µm, and fine, 530 µm) and 6 TI levels (6, 9, 12, 15, 18, and 21 TIU/mg). A total of 672 male broiler chicks was randomly assigned among the 12 treatment combinations with 8 replicates per combination. The birds were provided with 1 kg/bird of starter diet in a crumble form. The pancreas and gizzard were excised and weighed at 16 d of age and organ weights relative to BW calculated. Feed consumption, BW, and feed conversion ratio (FCR) were determined at 7 and 14 d of age. Increasing TI level produced a quadratic effect (P < 0.01) on BW and FCR at 14 d of age. The best performance was obtained when chicks were fed diets containing ESBM at intermediate TI levels. Increasing the particle size of the ESBM from 530 to 1,300 µm improved BW and feed intake (P < 0.01) without affecting FCR. The relative weight of the pancreas increased linearly as TI level increased (P < 0.001). The results of this study indicated that chicks performed better when fed coarse ESBM at an intermediate TI level.

Evaluation of soybean meal source and particle size on broiler performance, nutrient digestibility, and gizzard development.

Although there have been several reports concerning the effects of particle size of cereal grains on productive performance of poultry, there is limited information about the effects of soybean meal (SBM) particle size on broiler performance. The objective of the present experiments was to evaluate the effects of SBM source and particle size on broiler performance, gizzard weight, and nutrient digestibility. The first experiment was a 2 × 2 factorial arrangement of 2 SBM sources: expeller-extracted (ESBM) and solvent-extracted (SSBM), and 2 particle sizes: coarse grind, 971 µm, and fine grind, 465 µm. The second experiment was a 2 × 2 factorial arrangement of 2 ESBM particle sizes: coarse grind, 1,290 µm, and fine grind, 470 µm, and 2 corn particle sizes: coarse grind, 1,330 µm, and fine grind, 520 µm. In the first experiment, there was an interaction (P < 0.05) between SBM source and particle size on BW at 49 d of age. No differences in BW were observed when birds were fed coarse SSBM or ESBM, whereas birds fed diets containing fine ESBM exhibited lower BW than birds fed diets containing fine SSBM. In the second experiment, fine-grind ESBM (P < 0.05) and corn (P < 0.01) produced greater 19-d BW than did coarse grind. A significant interaction (P < 0.01) between ingredient type and particle size revealed that chicks fed coarse particles of corn or ESBM exhibited higher protein digestibility compared with chicks fed only fine particles. Corn particle size had a greater effect on gizzard weight than ESBM particle size. Birds fed diets that contained coarse corn had larger gizzards than birds fed fine corn (P < 0.01), but differences in gizzard weight were not observed when birds were fed coarse or fine ESBM. Particles greater than 1,300 µm depressed BW but improved protein digestibility.

Non-soluble fibres and narasin reduce spontaneous gizzard erosion and ulceration in broiler chickens.

The prevalence and severity of gizzard erosion and ulceration syndrome (GEU) in broilers is affected by a number of predisposing and preventive factors. Two broiler experiments with almost identical basal diets were conducted to investigate the effect of dietary oat hulls, access to litter and the antimicrobial compound narasin on GEU. The effects on particle size of duodenal digesta, ileal starch concentration, caecal Clostridium perfringens counts, necrotic enteritis and production performance were also examined. Oat hulls reduced GEU severity and starch levels in the ileum in both experiments. Access to litter reduced GEU scores when oat hulls were included in the feed. Access to litter also improved feed efficiency and reduced C. perfringens counts. Narasin reduced GEU severity when the feed was supplemented with oat hulls. Oat hulls were associated with improved feed efficiency in Experiment 1 and impaired feed efficiency in Experiment 2. The inconsistent effect of oat hulls on production performance appeared to be related to an association between oat hulls and high C. perfringens counts in Experiment 2; an association that was absent in Experiment 1. In general, oat hulls interacted with litter access and narasin in exerting a positive effect on gizzard health. However, the association between oat hulls and necrotic enteritis detected in Experiment 2 suggests that the positive effect of oat hulls on GEU occasionally may be outweighed by a negative effect on gut health. In conclusion, our findings demonstrate that the severity of GEU in broilers was influenced by non-soluble fibres and narasin.

Incidence and antimicrobial resistance profiling of Campylobacter in retail chicken livers and gizzards.

Campylobacter species are one of the leading causes of foodborne disease in the United States. Campylobacter jejuni and Campylobacter coli are the two main species that are of concern to human health, and they cause approximately 95% of human infections. The number of studies investigating Campylobacter in chicken livers and gizzards is very limited in the literature. The objective of this study was to determine the prevalence of Campylobacter jejuni and Campylobacter coli in retail chicken livers and gizzards purchased from grocery stores in the Tulsa, Oklahoma, area and to further characterize the isolates obtained through antimicrobial susceptibility testing. A total of 202 retail chilled chicken livers and gizzards (159 livers and 43 gizzards) were purchased on a weekly basis from several grocery stores. The overall prevalence of Campylobacter in chicken livers and gizzards was 136/202 (67%), where 69/202 (34%) of the samples were contaminated with Campylobacter jejuni and 66/202 (33%) with Campylobacter coli. While the prevalence of Campylobacter in chicken livers was 77%, its prevalence in chicken gizzards was lower at 33%. The prevalence of Campylobacter jejuni was slightly higher in chicken livers (36%) than gizzards (26%), while the prevalence of Campylobacter coli was significantly higher in the chicken livers (40%) than chicken gizzards (7%). The prevalence of resistance among C. jejuni and C. coli isolates recovered against 16 antimicrobials were as follows: amoxicillin (98%, 99%), ampicillin (32%, 55%), azithromycin (10%, 25%), cephalothin (92%, 99%), chloramphenicol (4%, 12%), ciprofloxacin (58%, 48%), clindamycin (5%, 19%), doxycycline (39%, 66%), erythromycin (6%, 32%), gentamicin (9%, 43%), kanamycin (11%, 43%), nalidixic acid (50%, 43%), oxytetracycline (99%, 100%), streptomycin (3%, 18%), tetracycline (37%, 60%), and tilmicosin (9%, 16%). Multidrug resistance was higher among Campylobacter coli than Campylobacter jejuni isolates.

Effects of rearing system and narasin on growth performance, gastrointestinal development, and gut microbiota of broilers.

This study was conducted to evaluate the effects of 3 rearing systems (FL: flooring litter rearing, MC: multilayer cage rearing, PN: plastic net rearing) with or without supplemental narasin on growth performance, gastrointestine development and health of broilers. A total of 2,400 one-day-old Ross 308 mixed-sex broilers (1:1 ratio of males and females) were used in a completely randomized design utilizing a 3 × 2 factorial arrangement of treatments, with 12 replicates per treatment. Each replicate for FL, MC, and PN consisted of 34 birds per floor pen, 30 birds per cage, and 36 birds per net pen, respectively, ensuring the same stocking density (12 birds/m2) across the 3 systems. Results showed that lower ADG (average daily gain), ADFI (average daily feed intake), and FCR (feed conversation ratio) observed in the MC group than those of the other 2 systems from 1 to 36 d of age (P < 0.05). Narasin inclusion in the diets decreased ADFI and FCR significantly (P < 0.05). Multilayer cage and PN rearing systems reduced the relative weight of the gizzard significantly (P < 0.05). Compared with FL, MC reduced the relative weight of the duodenum, jejunum, and ileum (P < 0.05). The mRNA expression levels of the ileal IL-1ß and IFN-γ in FL were higher than those in PN and MC (P < 0.05). Narasin decreased the ileal mRNA expression of TNF-α (P < 0.05). Different rearing systems changed the ileal microflora structure of broilers. The FL system increased the ileal microbial diversity of broilers and the relative abundance of Actinobacteria. Narasin combined with MC increased the relative abundance of Proteobacteria. In conclusion, birds reared in PN had a higher body weight. The MC birds had poorer intestinal development and health condition, higher abundance of Proteobacteria, but better FCR. The FL rearing appeared to be propitious for gastrointestinal development and health. Narasin inclusion in the diets improved FCR and changed the relative abundance Proteobacteria of broilers.

Effects of chitooligosaccharide supplementation on performance, blood characteristics, relative organ weight, and meat quality in broiler chickens.

This study was conducted to evaluate the effects of dietary supplementation with chitooligosaccharide (COS) on growth performance, blood characteristics, relative organ weight, and meat quality in broilers. A total of 480 broilers with an average initial BW of 45.04 g per chick were randomly allocated into 1 of the following 4 dietary treatments (20 broilers per pen with 6 pens per treatment): 1) CON (basal diet), 2) ANT (basal diet + 44 mg/kg of avilamycin), 3) COS0.2 (basal diet + 14 g/kg of COS), 4) COS0.4 (basal diet + 28 g/kg of COS). The experiment lasted for 5 wk and avilamycin was administered from d 0 to 21. Growth performance was measured on d 0, 21, and 35, and all other response criteria were measured on d 35. No change in feed conversion (G:F) was observed in response to any of the treatments throughout the experimental period (P > 0.05). However, BW gain and feed intake were greater (P < 0.05) in broilers provided with feed supplemented with COS than in those in the control group. In addition, broilers had significantly greater (P < 0.05) red blood cell and high-density lipoprotein cholesterol concentrations when they were provided with the COS0.4 diet, whereas the triglyceride concentration was lower (P < 0.05) in broilers in the COS0.2 treatment group. No other blood characteristics were affected by the treatments. Additionally, as the dietary COS concentration increased, the liver weight increased (P < 0.05). Conversely, as the concentrations of dietary COS increased, abdominal fat decreased (P < 0.05). Furthermore, meat yellowness decreased (P < 0.05) as the concentration of COS increased. Finally, the breast meat and abdominal fat of birds provided with feed supplemented with COS had a lower (P < 0.05) saturated fatty acid concentration but a greater concentration of total monounsaturated fatty acids (P < 0.05) than that of birds in the control. In conclusion, COS can improve the performance and breast meat quality of broilers while increasing the red blood cell and high-density lipoprotein cholesterol concentrations in blood. In addition, COS can induce a decrease in abdominal fat and improve meat quality.

Elemental imbalance elicited by arsenic and copper exposures leads to oxidative stress and immunotoxicity in chicken gizzard, activating the protective effects of heat shock proteins.

Arsenic (As) and copper (Cu) are ubiquitous pollutants that pose a threat to the environment. Our aim is to study the underlying mechanisms by which As and Cu act on the chicken gizzard. In order to detect ionic disorders in chicken gizzard under chronic treatment with As3+ and/or Cu2+ and whether they can induce oxidative damage as well as immune disorders, 30 mg/kg arsenic trioxide (As2O3) and/or 300 mg/kg copper sulfate (CuSO4) were added to the chicken's basal diet. After 12 weeks of exposure, trace elements were found to have significant interference, accompanied by damage to the antioxidant system. In addition, As3+ and/or Cu2+ activated the nuclear factor kappa B (NF-κB), inducing severe inflammation. At the same time, damaged structural integrity which might be caused by inflammation was discovered after hematoxylin and eosin (H&E) staining. Moreover, symbolic Th1/Th2 (Th, helper T cell) drift was also observed in treatment groups, meaning that immune function is left to be affected, and the increment in heat shock proteins may be a self-protective mechanism of gizzard. Interestingly, we found that the damage to the gizzard of chicken was aggravated in a time-dependent manner, and the combined exposure was more pathogenic than the single exposure, of which the mechanism needs further exploration. Together, this work helps move us toward a better understanding of the molecular mechanisms that mediate the interactions between Cu excess and As3+ exposures and possible health consequences in susceptible species.

Growth performance, pH value of gizzard, hepatic enzyme activity, immunologic indicators, intestinal histomorphology, and cecal microflora of broilers fed diets supplemented with processed lignocellulose.

This study was performed to investigate the hypothesis that supplementation of processed lignocellulose (PL) in the diets of broilers has a positive effect on growing performance, pH value of gizzard, hepatic enzyme activity, immunologic indicators, histomorphological character of small intestine, and cecal microflora populations. A total of 720 one-day-old Ross 308 broiler chicks were allotted to 4 treatment groups and fed maize-soybean meal based diets. The basal diet was supplemented with PL with an amount of 0 kg (control), 0.5 kg, 1 kg, and 2 kg per ton feed. Growing performance parameters, were determined weekly until 35 D of age. Blood samples for enzyme activities and immunoglobulins, jejunum and cecum samples for histomorphological characters for villus growth, and microbial population were collected from 12 broilers from each group. At 35 D of age, body weight of broilers supplemented with 1 kg of PL was found to be the highest with a value of 2305.0 g, when compared to the broilers supplemented with control, 0,5 and 2 kg of PL groups (2154.0, 2201.0, and 2141.7 g, respectively, P = 0.001). An increased activity of aspartate amino transferase (AST) was observed in the control and 1 kg PL supplementation groups (633.6 and 597.4 IU/L, respectively), whereas alkaline phosphatase (ALP) activity was the highest in the control group (5404 IU/L, P < 0.05). Broilers in the control group had the lowest level of IgY and IgA (122.2 and 25.8 mg/dL, respectively, P < 0.05). Villus height increased by 22.0%, 40.7%, and 34.8% in 0.5, 1, and 2 kg PL supplementation groups, respectively, when compared to the control (P < 0.001). The processed lignocellulose supplemented as 1 kg of PL decreased the average count of Staphylococcaceae, E. coli, and Enterobacteriaceae, whereas it increased the population of Lactobacillus spp. in the cecum (P < 0.05). These data indicate that the supplementation of processed lignocellulose had positive effects for performance via changes in hepatic enzyme activities, immunoglobulin levels, villus growth in jejunum, and microflora in cecum.

Dissolution of copper, tin, and iron from sintered tungsten-bronze spheres in a simulated avian gizzard, and an assessment of their potential toxicity to birds.

The rates of dissolution of copper, tin, and iron from sintered tungsten-bronze spheres (51.1%W, 44.4%Cu, 3.9%Sn, 0.6%Fe, by mass) were measured in an in vitro simulated avian gizzard at pH 2.0, and 42C. Most of the spheres had disintegrated completely to a fine powder by day 14. Dissolution of copper, tin, and iron from the spheres was linear over time; all r>0.974; all P<0.001. The mean rate of release of copper, tin, and iron was 30.4 mg, 2.74 mg, and 0.38 mg per g tungsten-bronze per day, respectively. These rates of metal release were compared to those in published studies to determine whether the simultaneous ingestion of eight spheres of 3.48 mm diameter would pose a toxic risk to birds. The potential absorption rates of iron and tin (0.54 mg Fe/day, and 3.89 mg Sn/day) from eight tungsten-bronze spheres of total mass 1.42 g would not prove toxic, based on empirical studies of tin and iron ingestion in waterfowl. The release of 43.17 mg copper/day from eight tungsten-bronze spheres, while exceeding the daily copper requirements of domesticated birds, is far below the levels of copper known to cause copper toxicosis in birds. We conclude that sintered tungsten-bronze material made into gunshot, fishing weights, or wheel balance weights, would not pose a toxic risk to wild birds when ingested.

Dose-dependent effects of T-2 toxin on performance, lipid peroxidation, and genotoxicity in broiler chickens.

The objective of the present study was to evaluate the effects of different concentrations of T-2 toxin in feed on performance, lipid peroxidation, and genotoxicity in vivo. For a 17-d period, T-2 toxin was added to the diet of the chickens. Fifty 22-d-old male broiler chickens were divided into 5 groups that were supplemented with different concentrations of T-2 toxin: control (0.0 mg/kg of feed), T 0.5 (0.5 mg/kg of feed), T 1.5 (1.5 mg/kg of feed), T 4.5 (4.5 mg/kg of feed), and T 13.5 (13.5 mg/kg of feed). Deoxyribonucleic acid fragmentation in spleen leukocytes, malondialdehyde in plasma and liver, total plasma antioxidative status, glutathione peroxidase activity, and total serum Ig (IgA and IgG) were measured. Feed consumption and BW gain decreased when the concentration of T-2 toxin was 4.5 and 13.5 mg/kg of feed. Compared with the control group, the rate of DNA damage increased significantly in the group fed 13.5 mg of T-2 toxin/kg of feed. In contrast to DNA fragmentation, indicators of oxidative stress did not show differences between groups fed T-2 toxin and the control. More serum IgA was detected in the group T 13.5 compared with the control, whereas there were no differences in serum IgG levels. The results of the present study indicate that impaired performance, DNA fragmentation in spleen leukocytes, and elevated serum IgA levels induced by T-2 toxin are dose-dependent. Based on our results, we could not confirm the hypothesis that oxidative stress is among the mechanisms by which T-2 toxin induces DNA fragmentation.

Effects of dietary coarsely ground corn and 3 bedding floor types on broiler live performance, litter characteristics, gizzard and proventriculus weight, and nutrient digestibility.

The effects of zero or 50% dietary coarsely ground corn (CC) in pelleted and screened grower and finisher diets on broilers reared on 3 bedding floor types (plastic net [NET], new pine wood shavings litter [NEW], or old pine wood shavings litter [OLD]) on broiler live performance, litter characteristics, gizzard and proventriculus weight, and apparent ileal digestibility (AID) were studied in a 2 × 3 factorial arrangement of treatments. Fine corn was produced with a hammermill (271 µm) and CC with a roller mill (1145 µm). Utilization of CC reduced milling cost by 9.47 cents per MT with similar nutrient content of screened pellets. The 50% CC treatment exhibited improved (P ≤ 0.05) feed intake at 42 d (2.5%) and 49 d (3.0%), and BW (5.4%) and FCR from 28 d (1.4%). Birds on NEW litter exhibited improved (P < 0.05) BW at 28 and 35 d and 42 d FCR as compared to NET and 49 d FCR compared to NET and OLD. The 50% CC treatment exhibited increased (P < 0.05) gizzard weight but decreased proventriculus weight at 49 d. NEW litter birds exhibited increased (P ≤ 0.05) gizzard weight at 28 d and 49 d and decreased proventriculus weight as compared to NET at 49 days. The 50% CC treatment exhibited decreased (P ≤ 0.05) litter moisture at 35 and 42 d, litter N at 35 and 49 d, and litter pH at 49 days. OLD litter birds exhibited greater (P < 0.05) litter N at 14, 35, and 49 d, as well as litter moisture, pH, and ammonia concentration at 49 days. The 50% CC group also exhibited improved AID of nitrogen (P < 0.05). Broilers fed pelleted and screened diets containing 50% CC exhibited improved live performance and reduced litter moisture while use of NEW litter resulted in a somewhat similar effect, which indicated that consumption of NEW litter also facilitated gastric development and function.

Dietary sugarcane bagasse and coarse particle size of corn are beneficial to performance and gizzard development in broilers fed normal and high sodium diets.

An experiment was conducted to evaluate the effects of sugarcane bagasse (SB) and particle size on broiler performance, gizzard development, ileal microflora, litter quality, and bird welfare under a wet litter challenge model. A total of 672 one-day-old Ross 308 male broilers was allocated to 48 pens using a 2 × 2 × 2 factorial arrangement of treatments with corn particle size-coarse 3,576 µm (CC) or fine 1,113 µm (FC) geometric mean diameter, SB - 0 or 2% and sodium (Na) - 0.16 or 0.40% with increased Na level to induce wet litter. A 3-way particle size × Na × SB interaction (P < 0.05) was observed for weight gain at d 10. Birds fed FC showed a higher weight gain compared to birds fed CC when 0.40% Na without SB diet or 0.16% Na with 2% SB diet was offered. A significant particle size × SB interaction was observed at d 24 on feed conversion ratio (FCR; P < 0.001) and weight gain (P < 0.05). FCR was reduced by 2% SB supplementation in birds fed CC but increased in birds fed FC. Further, weight gain of birds fed 2% SB was higher in birds fed CC but not in those fed FC. On d 35, birds fed 2% SB had a higher weight gain (P < 0.001) compared to those without SB, and a SB × particle size interaction on relative gizzard weight (P < 0.05) and pH (P < 0.05) was present. SB reduced gizzard pH and increased the relative gizzard weight in birds fed the FC diet but not the CC diet (P < 0.05). Counts of ileal Bacillus spp. were increased in birds fed SB (P < 0.05) on d 24. No effects of SB and particle size on litter quality and bird welfare were observed, but higher Na increased litter moisture and footpad dermatitis (FPD) scores (P < 0.001). These findings suggest that SB independently or in combination with CC improves performance in older birds regardless of Na level in diets, possibly through improved gizzard development and gut microflora of birds.

Effect of dietary fiber levels on performance, gizzard development, intestinal morphology, and nutrient utilization in meat ducks from 1 to 21 days of age.

The objective of this experiment was to determine the effects of dietary fiber levels on growth performance, gizzard development, intestinal morphology, and nutrient utilization in Cherry Valley meat ducks. In total, 720 1-day-old ducklings were fed with starter diets (120 ducklings, 8 pens of 15 ducklings, on each diet) containing 6 levels of crude fiber (CF, 1.46, 3.09, 4.15, 6.18, 7.52, and 9.03%, based on analysis) for 21 d. Then, on d 22, ducks fed all of the starter diets were transferred to a grower diet (containing 4% CF) to examine the residual effect of starter dietary fiber levels until 35 d. Body weight (BW), body weight gain (BWG), feed intake (FI), feed to gain ratio (F:G) were recorded/calculated weekly. Ducks were sampled for gizzard development and intestinal morphology determination on d 7, 14, and 21. Nutrient utilization was assessed using 25- to 27-day-old ducks. The results showed that BW (d 21), BWG (d 15 to 21, d 1 to 21), and F:G (d 15 to 21, d 1 to 21, and d 1 to 35) were increased quadratically (P < 0.01), and FI (all periods except for d 22 to 35) was increased linearly (P < 0.01), when starter dietary CF levels increased from 1.46 to 9.03%. Ducks under 3.09% and 4.15% CF starter diets had decreased 1 to 35 d FI and F:G when compared to ducks under other starter diets. When compared to ducks fed 1.46% and 3.09% CF starter diets, ducks fed starter diet containing 7.52% CF had increased gizzard development, jejunal morphology, energy retention, excreta nutrients availability, and standardized ileal digestibility (SID) of Arg, Ile, Leu, Thr, Val, Asp, Ala, Glu, Gly, Pro, Ser, and total amino acids. In conclusion, meat ducks from 1 to 21 d of age could adapt to a wide range (3.09% to 7.52%) of dietary fiber levels.