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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/m 2 ) 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-1β 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., (Copyright © 2020 The Authors. Published by Elsevier Inc. All rights reserved.)

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 As 3+ and/or Cu 2+ and whether they can induce oxidative damage as well as immune disorders, 30 mg/kg arsenic trioxide (As 2 O 3 ) and/or 300 mg/kg copper sulfate (CuSO 4 ) 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, As 3+ and/or Cu 2+ 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 As 3+ exposures and possible health consequences in susceptible species.

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., (© 2019 Poultry Science Association Inc.)

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.

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., (© 2018 Blackwell Verlag GmbH.)

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.

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.

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., (© 2017 Poultry Science Association Inc.)

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., (© 2017 Poultry Science Association Inc.)

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., (© 2017 Poultry Science Association Inc.)

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.

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., (Journal of Animal Physiology and Animal Nutrition © 2015 Blackwell Verlag GmbH.)

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., (© 2015 Poultry Science Association Inc.)

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., (© 2014 Poultry Science Association Inc.)

The influence of dietary cadmium on the accumulation and effects of dietary lead, examined in chicken. This experiment was conducted to investigate the toxic effects of dietary Cd and Pb on chick's body weight and organ, content of the tissues of these two metals was also detected. One day age chicks of Gallus gallus domesticus fed diet supplemented with 25, 50, 100 ppm of Cd, second group exposure to 300, 500, 1000 ppm of Pb in feed daily during 4 weeks. The control groups were fed without supplementation of metals. The concentrations of Cd and Pb resulted in increased of Cd and Pb content in liver, gizzard and muscle. While Cd 100 ppm and Pb 1000 ppm were increased metals content in feather. Body weight of chicks was not influenced by Cd treatment. In contrary Pb treatment was significantly (p < 0.05) decreased body weight of chicks after dietary treatment. On the other hand, Liver weigh in chicks was significantly (p < 0.05) decreased after Cd and Pb treatments.

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.

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.

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.

Effects of Aspergillus niger-fermented Terminalia catappa seed meal-based diet on the activities of alkaline phosphatase (ALP), alanine transaminase (ALT), aspartate transaminase (AST) and gamma-glutamate transferase (gamma-GT) in the crop, small intestine, gizzard, heart, liver and serum of broiler chicks were investigated. Milled T. catappa seed was inoculated with spores of A.niger (2.21 x 10(4) spores per ml) for 3 weeks. Forty-five day-old broiler chicks weighing between 27.62 and 36.21 g, were divided into three groups. The first group was fed soybean-based (control) diet; the second on raw T. catappa seed meal-based diet; and the third on A. niger-fermented T. catappa seed meal-based diet for 7 weeks. The results revealed a significantly increased (p<0.05) activity of ALP in the tissues. Contrarily, there were significant reductions (p<0.05) in the activities of ALP, ALT, AST and gamma-GT in the liver and heart of the broilers fed the raw T. catappa seed meal-based diet while there were significant increase (p<0.05) in the activities of these enzymes in the serum of the broilers in this group. The data obtained showed that A. niger-fermented T. catappa seed meal reduced the toxic effects of the raw seed meal on the tissues of broiler chicks., (Copyright (c) 2010 Elsevier Ltd. All rights reserved.)

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.

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.

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.

This study describes the toxicity signs that developed when the diet of male broiler chickens was artificially contaminated with different levels of the mycotoxin ochratoxin A (OTA). Chicks were assigned randomly to three groups of 80 chicks that were fed a diet containing 0 parts per billion (ppb) (control, group 1), 400 ppb (group 2) or 800 ppb (group 3) OTA from day 1 to 5 weeks of age. Signs of ochratoxicosis were assessed on the basis of changes in the following criteria: body weight, relative weights of two representative internal organs (gizzard and thymus), feed consumption, feed conversion ratio, mortality, thyroid activity, blood profile, humoral and cell mediated immunity. Feeding OTA at levels of 400 and 800 ppb (groups 2 and 3) significantly decreased the body weight, thymus weight, feed consumption, feed conversion ratio and thyroxine concentration (P < 0.05). The OTA groups developed anaemia manifested by a significant decrease in the red blood cell count, packed cell volume percentage and haemoglobin concentration (P < 0.05). By the end of the experiment both groups that received OTA showed a 37% reduction in red blood cell count compared with the control group. Furthermore, a significant decrease in the white blood cell count, humoral immune response and cell-mediated immunity was found in both groups fed ochratoxin compared with the control group (P < 0.05). The reduction in the above parameters was more noticeable with time and was proportional to the level of OTA exposure. A significant increase in relative gizzard weight, cumulative mortality and triiodothyronine concentration was found in OTA-fed chicks (P < 0.05). These data provide a description of ochratoxicosis in broilers that should be useful in diagnosis and in improved understanding of the practical implications on broiler performance and health, a problem that can threaten the poultry industry.

This study is to reveal the characteristics of bidirectional regulation of emodin (1,3,8-trihydroxy-6-methyl-anthraquinone) and quercetin on gizzard smooth muscle myosin. Our results indicate that: (a) emodin demonstrates stimulatory effects, and quercetin produces inhibitory effects on myosin phosphorylation and Mg(2+)-ATPase activities of Ca(2+)/calmodulin-dependent phosphorylated myosin in a dose-dependent manner; (b) a combination of emodin and quercetin enhances phosphorylation and Mg(2+)-ATPase activities for partially phosphorylated myosin and inhibits those activities for fully phosphorylated myosin; (c) 1-(5-Chloronaphthalene-1-sulfonyl)-1H2-hexahydro-1,4-diazepine inhibits myosin phosphorylation in the presence of emodin and/or quercetin. A combination of emodin and quercetin indicates its potential for modulating gastric-intestinal smooth muscle.

Organisms adjust their phenotype to fluctuating conditions of the environment and to changing internal demands. We report flexible responses of the gizzard and the small intestine of Japanese quail to a high-fibre diet. Switching from a standard diet to a high-fibre diet results in a highly significant increase in gizzard size, intestine length, mucosal surface, thickness of the intestinal muscular layer and vascularization of the mucosa. After diet switching, increased or decreased gizzard size results from changes in cell size, i.e. smooth muscle cell hypertrophy and hypotrophy, respectively. Increased cell proliferation is not the cause of increase in gizzard size. In the small intestine, however, we found elevated levels of cell proliferation after diet switching and conclude that increased capacity (upregulation) of the small intestine is based on increased rates of mitosis in the intestinal crypts. It is highly probable that elevated levels of cell proliferation in the crypts are balanced by elevated levels of cell extrusion at the tip of intestinal villi. The lipid contents of the liver were reduced, indicating that lipid stores in the liver were mobilized to fuel the flexible response of the gastrointestinal tract. During changes of organ size in response to changes in food composition, resting metabolic rate was not altered.

The effects of trichothecene nivalenol (NIV) on the health and production of laying hens were determined in a feeding study. White Leghorn hens, 55 weeks old, were fed diets containing 0, 1, 3 and 5 mg NIV/kg during 50 days. Feed intake was reduced by NIV, but there were no effects on body weight, egg production and egg quality. Traces of unaltered NIV were found in liver and bile. Alkaline phosphatase in the blood plasma increased in the hens fed 0, 1 and 3 mg NIV/kg diet but decreased in the birds fed 5 mg NIV/kg feed. Total protein and glucose were slightly reduced in hens fed 5 mg NIV/kg diet. Pathological examination revealed that 40-75% of hens fed NIV (3 and 5 mg/kg) supplemented diet showed gizzard lesions, haemorrhages in the duodenum and swollen cloaca and oviducts with immature eggs while certain birds in the 1 mg NIV group showed light and fragile livers. NIV and the metabolite de-epoxy-NIV in faeces were found to constitute up to 10% of ingested NIV.

1. The aim of this study was to investigate pathomorphological changes in broiler chicks fed with different doses of gizzerosine, a substance produced during the heat treatments of fish meal. 2. The experiment was carried out in Ross broiler chicks which were divided into three groups: group A received 100% of non-medicated commercial mash for broiler chicks. During an experimental 5-d period, 50% of commercial mash was replaced with unheated fish meal (0.65 ppm gizzerosine) in group B and in group C with heated fish meal (1.15 ppm gizzerosine). Fourteen chicks from each group were killed every day. Samples of gastrointestinal and lymphoid organs, lung, pancreas, liver, brain and kidney tissue were sampled for histopathological analysis. Organs were embedded in paraffin and stained with hematoxylin-eosin stain and using periodic acid-Schiff reagent (PAS) and Sudan III (frozen sections). 3. Necropsy did not reveal notable differences between treated groups. There were no significant histopathological changes in immunocompetent organs nor in the lungs, the pancreas, the kidney or the brain. Sharply demarcated multiple vacuoles were observed in the myocardium in group C toward the end of the experiment. In group C, the prevalent changes in the gizzard and the proventriculus were slight to severe cuticle erosions and oedema of the lamina propria with or without multiple vacuoles, respectively, towards the end of the experiment. The most prominent changes toward the end of the experiment were dispersed cell vacuolisation in duodenal, jejunual, ileal and caecal lamina propria in group C. 4. In conclusion, it should be emphasised that extra-gizzard gizzerosine-induced lesions are probably not mediated by H2-receptor stimulation, but could be a consequence of cellular hypoxia.

The magnitude of agonist-induced Ca(2+) sensitization of force is tissue-dependent, but an explanation for this diversity is unknown. Ca(2+) sensitization is thought to involve a G-protein-mediated inhibition of myosin light chain phosphatase activity by phosphorylation of the myosin-targeting subunit (MYPT). The MYPT has two isoforms that differ by a central insert, which lies near this phosphorylation site. Expression of MYPT isoforms is both developmentally regulated and tissue-specific. We hypothesized that the presence or absence of the central insert determines the magnitude of agonist-induced Ca(2+) sensitization. Throughout development, the chicken aorta exclusively expresses the splice-in MYPT isoform, and guanosine 5'-O-(thiotriphosphate) (GTPgammaS) produces a significant force enhancement. Early during development, the chicken gizzard expresses the splice-in MYPT isoform, and GTPgammaS produced a Ca(2+) sensitization. In the gizzard coincident with the shift in expression from the splice-in to splice-out MYPT isoform, GTPgammaS no longer produced force enhancement. In addition, adenosine 5'-O-(thiotriphosphate) (ATPgammaS) phosphorylated only adult gizzard tissue, the only tissue that did not demonstrate a Ca(2+) sensitization. These results suggest that the relative expression of splice-in/splice-out MYPT isoforms determines the magnitude of agonist-induced force enhancement and that MYPT phosphorylation is not required for Ca(2+) sensitization.

Research was focussed on investigating the influence of different quantities (0, 10, 20 and 30%) of rapeseed meal (RM), 00-cultivar Silvia on production results, as well as on the morphological and pathohistological changes in the internal organs of chicks during the course of the experiment, measured on the 21st and 42nd days of the 42-day experiment. The experiment involved 120 chicks divided into four groups: a control group (C) and three experimental groups (E1-3). It was found that chicks in Groups C, E1 and E2 realised significantly (P < 0.05) higher gains than those in Group E3, both after the test period and at the end of the experiment. No significant differences with regard to feed conversion were found between groups of chicks. Throughout the experiment chicks in Groups E1-3 were found to have a significantly (P < 0.05) heavier liver. Compared to Groups E1-3, Group C chicks had a significantly (P < 0.05) heavier gizzard after 21 days, but following the finisher diet Group E3 had a significantly (P < 0.05) lighter gizzard. Compared with birds in Group C, those in Groups E2-3 had significantly heavier (P < 0.05) unevacuated intestines when fed the starter diet, and those in Groups E1-2 showed a similar result when fed the finisher diet. Chicks in Group E3 had a significantly lower grill weight than those in Groups C, E1 and E2, both in the first half of the experiment and at the end. The starter diet did not result in any differences in the quantity of abdominal fat among groups, but following the finisher diet Groups E2-3 showed significantly less abdominal fat in comparison to Groups C and E1 (P < 0.05). Group C showed a significantly higher carcass yield than Groups E1-3 (P < 0.05) in the first half of the experiment and at the end. Groups E1-3 manifested a slight to medium hypertrophy of thyroid epithelial tissue as well as slight thymus hypertrophy and slight atrophy of the cloacal bursa follicles.

Forensic evaluation of aldicarb exposure is difficult due to the rapid hydrolysis and oxidation of the parent compound. Oxidation products-aldicarb sulfoxide and aldicarb sulfone-are commonly analyzed, but hydrolytic products-aldicarb nitrile, aldicarb nitrile sulfoxide, aldicarb nitrile sulfone-are infrequently analyzed even though they are the primary stable products of aldicarb degradation. Nitrile analyses provide an important avenue to verify aldicarb exposure or aldicarb-induced mortality. Our aproach allows lethal and sublethal exposure assessment. Extraction of samples with acetonitrile:water is followed by chromatographic determination. Sublethal exposure assessment utilizes excreta samples, which is nonlethal and requires holding animals in captivity for 12 h or less. Sublethal exposures of northern bobwhite Colinus virginianus to aldicarb can be identified with greater than 80% confidence for 6 h after dosing. By analyzing GI tracts, lethal exposures of bobwhite to aldicarb can be identified with greater than 90% confidence for 4 days post mortem and with 75% confidence for 8 days post mortem. Sublethal exposures to aldicarb was identified in greater than 80% of Peromyscus maniculatis for 6 h after dosing. Aldicarb and its transformation products were detected for 8 days post mortem in all mice that received aldicarb doses at or above the LD50.

1. This study was conducted to evaluate the protective effect of natural sodium bentonite (NaB) in the prevention of toxic effects of aflatoxins. Five hundred and twenty-eight 1-d-old Ross male broiler chickens were housed in pens (22 chickens per pen) for 42 d. There were 3 inclusion rates of NaB (0, 2.5, and 5 g/kg) and 2 of aflatoxins (0 and 3 mg/kg food). Each treatment had 4 replicates of 22 chickens. 2. All chickens treated with aflatoxin and without bentonite were adversely affected. NaB treatment at 5.0 g/kg improved body weights at 42 d of age by 31.3%, increased food intake by 23.8% and improved productive efficiency by 40.1%. Weights of liver, heart, pancreas and crop and biochemical variables were not affected by dietary NaB. However, serum phosphorous concentration was reduced by 30% compared with chickens that received aflatoxin. 3. NaB caused no adverse effects on chickens that did not receive aflatoxin. 4. It is concluded that NaB at pH 7.9 partially neutralises the effects of aflatoxins on broiler chickens when included at 5.0 g/kg in the diet.

Extracellular nucleotides, e.g., ATP, ADP, and UTP, are important signaling molecules which elicit various physiological responses in different tissues. Their degradation is catalyzed by ectonucleotidases which are located on cell surfaces. Most tissues have a mixed population of ectonucleotidases. In this report, the ATP and ADP hydrolyzing ectonucleotidases of chicken gizzard smooth muscle and liver plasma membranes were studied. The two membranes exhibited marked differences in the ratio of ATPase/ADPase activities, activation by divalent cations, thermal stability, responses to detergents and cross-linking agents, and sensitivity to several enzyme inhibitors. The ATPase activity of chicken gizzard membranes is (i) labile to heat and detergents; (ii) activated by concanavalin A and disuccinimidyl suberate, both cross-linking agents; (iii) inhibited by mercurials; and (iv) insensitive to high concentrations of azide, a known inhibitor of ecto-ATP diphosphohydrolases (ecto-ATP/Dase). In contrast, the liver membrane ATPase and ADPase activities are more stable to treatment by heat and detergents and insensitive to cross-linking agents and mercurials, but are inhibited by azide. A low ADP hydrolase activity in the gizzard membranes could be distinguished from both the gizzard ATPase and the liver ATPase/ADPase. This ADP hydrolase, which is markedly stimulated by NBD-Cl, accounts for most of the ADP hydrolysis activity in gizzard membranes. It is concluded that the major ectonucleotidase in the gizzard membranes is an ecto-ATPase whereas that in the liver membranes is an ecto-ATP/Dase. That both membranes contain a mixed population of the ecto-ATPase and ecto-ATP/Dase, but in different proportions, is further demonstrated by immunochemical characterization. The different composition of ectonucleotidases in the two membranes is expected to have an important effect on the regulation of hydrolysis of extracellular ATP as well as the concentration of extracellular adenine nucleotides in the gizzard and liver tissues., (Copyright 1999 Academic Press.)

The work describes the effects of cimetidine on stress-induced gizzard erosions (Experiment A) and the influence of the long-term application (42 days) of the same drug on weight gain and feed consumption during broiler fattening (Experiment B). For Experiment A, 60 male, three-day-old chicks were divided into two groups: C (n = 30)--control chicks treated with 0.5 ml saline; CIM (n = 30)--chicks treated with cimetidine in a dose of 5 mg/kg body weight (b. w.) intragastrically. All chicks were stressed using a modified water-immersion stress method according to which the chicks, after 24 h of feed deprivation, were immersed in tap water (17 degrees C) for a few seconds. Under chloroform anaesthesia ten chicks from each group were killed 1, 2 and 3 h after the stressing. The morphometric analysis of gizzard erosion (GE) and histopathological examinations of gizzards were performed for each chick. In Experiment B, 32 one-day-old broilers of both sexes were used. The control group was untreated (n = 16) while the CIM group (n = 16) was fed the same diet supplemented with 10 mg of cimetidine per kilogram of feed throughout the fattening period (42 days). The results of Experiment A showed decreased mean length of the GE in the cimetidine-treated birds as compared with the GE lesions of the controls. In Experiment B, the treated chicks had reduced liveweight (1835.1 g), carcass weight (1474.6 g) and increased feed consumption (2115 g of feed per kilogram of weight gain) compared to the controls in which the same parameters were 1898.5 g, 1574.2 g and 1797 g, respectively. The results show that while stress-induced GE of chicks can be medicated pharmacologically, long-term application of the same substance impairs the results of fattening.

The objective of this study was to examine possible interactions between drinking water contaminants and suboptimal nutritional status for performance and immune function in male broiler chickens. Experimental drinking water contained a mixture of arsenic, benzene, cadmium, lead, and trichloroethylene (TCE) at low concentrations (0.80, 1.3, 5.0, 6.7, and 0.65 ppm) and high concentrations (8.6, 13, 50, 67, and 6.5 ppm). These chemicals were selected because they are among the most common contaminants found in ground water near hazardous waste sites. The experimental diets included feed containing 50% added vitamins and minerals (V&M) and feed without added V&M. Increasing levels of drinking water contaminants and decreasing levels of V&M in diet resulted in significantly (P < or = 0.05) decreased water and feed intake, decreased weight gain, and suppression of natural, humoral, and cell-mediated immune response. In a paired-water study, feed consumption, body weight, and immune function were decreased in chickens provided low and high concentrations of the chemical mixture in drinking water compared with chickens given control drinking water equal to the volumes consumed by the chickens given the low and high concentration of mixture, respectively. A deficiency of dietary V&M caused increased sensitivity to adverse effects of drinking water contaminants.

The relation between gizzard erosion-black vomit (GE-BV) and gastric secretion is not completely understood. A pharmacological approach to reduce the presence of GE-BV in chicks due to fish meal in diets is also unknown. In this study the use of omeprazole, a H+/K+ ATPase inhibitor, and fish meals of different biotoxicological characteristics, showed that: 1) Omeprazole decreased total gastric acid content, GE scores and severe GE (SGE) cases, in a dose-dependent manner. This reduction was significant at levels higher than 20 mg omeprazole/Kg body weight (BW)/day (p < 0.01). The addition of 50 mg omeprazole/kg BW/day almost completely prevented the incidence of SGE cases and reduced in 50% GE score in chicks (p < 0.01). 2) A significant reduction in specific mortality, near 90%, was also seen with all toxic fish meals when omeprazole (50 mg/Kg BW/day) was added to experimental diets in comparison to control groups. However, no mortality was observed when omeprazole was added to diets containing non-toxic fish meals. 3) In chicks fed with toxic fish meals, addition of different amounts of omeprazole to diets changed the relative weight of proventriculus (p < 0.01) and gizzard (p < 0.05). Maximum effect was obtained with omeprazole concentration higher than 50 mg/Kg BW/day. 4) Omeprazole did not change feed intake in chicks fed with toxic fish meal. However, in some fish meal a reduction on weight gain was observed with the addition of omeprazole.

Smooth muscle tissues may be classified into phasic (fast) or tonic (slow) contractile phenotypes. This study was initiated to examine the specification of these phenotypes during development and the role of growth factors in this process. We used myosin light chain 17 (MLC17) and myosin heavy chain transcript splice variants as markers of the tonic (aortic) and phasic (intestinal) smooth muscle phenotypes in chick embryos. By reverse transcription-polymerase chain reaction, we determined embryonic days 6 to 16 to be a critical period for the establishment of these phenotypes. During this period, endothelin-1 is present at 40-fold-higher levels in aortic compared with intestinal tissues. To test the hypothesis that endothelin-1 may be involved in establishing the aortic (tonic) phenotype, we developed a system in which embryonic smooth muscle cells exhibit phasic and tonic contractile properties in vitro. Single-cell force measurements showed that cultured embryonic gizzard (phasic) cells developed force more rapidly (8 +/- 2 seconds) and achieved greater force (3.0 +/- 0.7 microN) than did cultured embryonic aortic (tonic) cells (20 +/- 0.7 seconds, 0.76 +/- 0.01 microN; P < .05) in response to depolarization. Chronic exposure of the phasic (gizzard) cells to endothelin-1 prolonged the time to peak force (24 +/- 3 seconds) and reduced the peak force (1.0 +/- 0.1 microN), so that the contraction resembled the tonic type. This effect, mediated by the endothelin-A receptor, was associated with a shift in MLC17 splicing to the tonic pattern. These results demonstrate that endothelin-1 is highly enriched in developing aortic compared with intestinal tissues and can convert phasic smooth muscle cells to the tonic type in vitro, suggesting a role for this growth factor during development in determining the contractile phenotype of smooth muscle cells.

1. The individual and combined effects of aflatoxin B1 (AFB1) and DL-gizzerosine (GIZZ) in growing broiler chickens were investigated in a 7-d fully randomised trial consisting of 7 dietary treatments (1 and 4 mg GIZZ/kg, 0.66 and 3 mg AFB1/kg, the combinations 1 mg GIZZ/kg/0.66 mg AFB1/kg and 4 mg GIZZ/3 mg AFB1/kg, and a control basal diet without GIZZ or AFB1). 2. Dietary GIZZ at 1 mg/kg caused moderate gizzard erosions without affecting performance, whereas 4 mg/kg GIZZ induced severe erosion, ulceration and perforation of the gizzard; and significantly affected performance. 3. Dietary AFB1 at 0.66 or 3 mg/kg did not induce lesions in the gizzard or cause any adverse effects on chick performance. 4. No apparent toxicologic interaction was observed between AFB1 and GIZZ when they were given simultaneously at relatively low dietary concentrations (0.66 mg/kg AFB1 + 1 mg/kg GIZZ). However, at higher dietary concentrations (3 mg/kg AFB1 + 4 mg/kg GIZZ), AFB1 potentiated the lethality of GIZZ. 5. The combination 3 mg/kg AFB1/4 mg/kg GIZZ was more toxic than the same concentrations of single toxins and may pose a greater economic threat to the poultry producer than either toxin individually.

Dose- (5, 10 and 15 mg/kg body mass) and time-dependent (2, 6, 12 and 24 h after treatment) effects of histamine on gizzard lesions and serum AST, ALT and CK activities of chickens are reported. Morphometric results and histopathological examination revealed that the most effective histamine dose which induced severe gizzard lesions was 10 mg/kg b.m., especially 2, 6 and 12 h after administration. No difference from the control values was found after 24 h. That dose also induced an elevation of serum enzyme (AST, ALT, CK) activities, which was most expressed for the activity of ALT.

The effect of Cd2+ on myosin light chain kinase (MLCK) reported in the literature is controversial, apparently because the level of Ca2+ contaminating the reaction mixture could not be accurately controlled by the addition of a metal chelator when Cd2+ was also present. In the present study, we have reduced the contaminating Ca2+ to a trace level that did not interfere with the enzyme activity; thus the use of a metal chelator was not necessary. We showed that Cd2+, or Pb2+ had a biphasic effect on MLCK isolated from chicken gizzard: stimulation at low and inhibition at high concentrations. (The stimulatory effect of on the enzyme activity isolated from chicken gizzard: stimulation at low and inhibition at high concentrations). The stimulatory effect of Cd2+ or Pb2+ on MLCK activity was not seen in the absence of calmodulin, and was abolished by trifluoperazine, a calmodulin antagonist, indicating that the heavy metals exert their activation via calmodulin. The inhibition of the enzyme activity by Cd2+ or Pb2+ at higher concentrations was also seen with the calmodulin-independent catalytic fragment of MLCK, suggesting that the inhibition is probably through their binding to sulfhydryl groups that are essential for catalytic activity. Pb2+ was more effective than Cd2+ in stimulating the enzyme activity, but less potent in inhibition. The extent of stimulation by heavy metals most likely resulted from a combination of the biphasic effects. Dithiothreitol and N,N,N',N'-tetrakis (2-pyridylmethyl) ethylenediamine selectively chelated Cd2+ and Pb2+ over Ca2+, and reversed their stimulatory or inhibitory effect on MLCK.(ABSTRACT TRUNCATED AT 250 WORDS)

The development of the vagal innervation to the gizzard has been investigated in chick embryos and young chicks. The membrane potential, first measurable on the 15th day of incubation, was -54 +/- 0.5 mV and increased with development to -67 +/- 0.4 mV. The latter value was attained 5 days after hatching and persisted thereafter. Stimulation of intramural nerves elicited a cholinergic, excitatory junction potential (EJP) for the first time, only in a small fraction of cells, on the 20th day of incubation. Within 3 days after hatching, cholinergic transmission showed the same features as in older chicks. Stimulation of the vagus nerve elicited no membrane potential responses before hatching but as early as 4 days after hatching, non-adrenergic, inhibitory junction potentials (IJPs) were evoked. In the next 10 days or so, the IJP was replaced with a cholinergic EJP as seen in mature tissues. After atropine (0.1-1 microM) treatment, both vagal and intramural nerve stimulation evoked a non-adrenergic IJP in a small fraction of cells immediately after hatching. The fraction of cells exhibiting the IJP increased with growth and reached 100% 5 days after hatching. Hexamethonium (50 or 100 microM) abolished the vagally-evoked EJPs. The vagally-evoked IJPs remained unchanged after application of hexamethonium in the early days after hatching, but later they were abolished in about half of the cells.(ABSTRACT TRUNCATED AT 250 WORDS)

The effects of dietary fumonisin B1 were evaluated in young broiler chicks. The experimental design consisted of 5 treatments each with 9 randomly allotted male broiler chicks. Day-old chicks were fed diets containing 0 (feed control), 100, 200, 300, or 400 mg fumonisin B1/kg feed for 21 days. Response variables measured were chick performance, organ weights, serum biochemistry, and histologic parameters. Body weights and average daily gain dramatically decreased with increasing dietary fumonisin B1, and liver, proventriculus, and gizzard weights increased. Diarrhea, thymic cortical atrophy, multifocal hepatic necrosis, biliary hyperplasia, and rickets were present in chicks fed diets containing fumonisin B1. Serum calcium, cholesterol, and aspartate aminotransferase levels all increased at higher fumonisin dietary levels. Results indicate that fumonisin, from Fusarium moniliforme culture material, is toxic in young chicks.

Copper sulfate was added to the diet of broiler chickens from 1 day to 3 weeks of age at the rate of 0.05% to 0.20% in order to evaluate its influence on the incidence of oral lesions. Both the incidence and severity of oral lesions showed a significant linear increase as the concentration of copper sulfate increased. Adding a level of sulfate equivalent to that produced by the highest level of copper sulfate failed to induce oral lesions. The severity of gizzard erosion also increased as the concentration of copper increased. Dietary copper sulfate supplementation should be considered a possible cause of oral lesions seen during the necropsy of avian species.

Scirpentriol (STO) (3 alpha,4 beta,15-trihydroxy-12,13-epoxytrichothec-9- ene), the parent alcohol of the family of acetylated scirpenol mycotoxins produced by several Fusarium species, has been implicated in mixed toxicoses of animals, but there is not a general description of its toxicity in chickens. Dietary STO (0, 2, 4, 8, 16, and 32 micrograms/g feed) was fed to four groups of 10 male day-old broiler chickens for 3 wk. The minimum effective dose (MED) for reducing growth rate significantly (P less than .05) was 4 micrograms/g. The same MED was found for increased serum alkaline phosphatase and relative weight of the gizzard. Unlike literature reports for two other trichothecene mycotoxins, T-2 toxin and diacetoxyscirpenol (DAS), STO impaired feed conversion efficiency but did not alter spleen or pancreas size. The MED of STO for decreases in serum lactic dehydrogenase and aspartate aminotransferase was 8 micrograms/g, but the MED for decreased serum albumin and total proteins and regression of the bursa of Fabricius was 16 micrograms/g. Serum sodium, potassium, and calcium were not altered at the highest dose, 32 micrograms/g, but serum phosphate, uric acid, and cholesterol were decreased by 32 micrograms/g. Serum chloride was increased slightly but significantly (P less than .05) at 16 and 32 micrograms/g. Based on these results, STO toxicosis of chickens can be differentiated from those of T-2 toxin and DAS and its toxicity appears sufficient to warrant further attention.

Fenthion, an irreversible cholinesterase inhibitor, was used to study the role of the cholinergic system on the development of gizzard erosion. Fenthion increases the gizzard erosion score in a dose-dependent manner and this effect became significant at levels higher than .1 ppm (p less than .05). An inverse relationship between plasma cholinesterase activity and pesticide concentration was also observed at doses higher than 1 ppm (P less than .05). These results show the necessity to evaluate organophosphate pesticide levels during the selection of fish meals in poultry.

ATP-dependent movement of actin filaments on smooth muscle myosin was investigated by using the in vitro motility assay method in which myosin was fixed on the surface of a coverslip in a phosphorylated or an unphosphorylated state. Actin filaments slid on gizzard myosin phosphorylated with myosin light chain kinase (MLCK) at a rate of 0.35 micron/s, but did not slide at all on unphosphorylated myosin. The movement of actin filaments on phosphorylated myosin was stopped by perfusion of phosphatase. Subsequent perfusion with a solution containing MLCK, calmodulin, and Ca2+ enabled actin filaments to move again. The sliding velocities on monophosphorylated and diphosphorylated myosin by MLCK were not different. Actin filaments did not move on myosin phosphorylated with protein kinase C (PKC). The sliding velocity on myosin phosphorylated with both MLCK and PKC was identical to that on myosin phosphorylated only with MLCK. Gizzard tropomyosin enhanced the sliding velocity to 0.76 micron/s. Gizzard caldesmon decreased the sliding velocity with increase in its concentration. At a 5-fold molar ratio of caldesmon to actin, the movement stopped completely. This inhibitory effect of caldesmon was relieved upon addition of excess calmodulin and Ca2+.

The individual and combined effects of kojic acid and aflatoxin were studied in male broiler chicks (Peterson x Hubbard). The experiment had a two by two factorial arrangement of treatments with dietary treatments of 0 and 2,500 mg kojic acid/kg feed and 0 and 2.5 mg aflatoxin/kg feed. The broilers were obtained at 1 day of age and housed in electrically heated batteries with feed and water available for ad libitum intake until they reached 3 wk of age. The toxicity of kojic acid was characterized by significant (P less than .05) reductions in body weight, the relative weight of the bursa of Fabricius, serum cholesterol concentration, and serum alkaline phosphatase activity, and by significant (P less than .05) increases in the relative weight of the pancreas, proventriculus, and gizzard, and serum concentrations of uric acid and triglycerides. Aflatoxicosis was characterized by significant (P less than .05) reductions in body weight, serum concentrations of total protein, albumin, cholesterol, and inorganic phosphorus, serum glutamic oxalacetic transaminase activity, and mean corpuscular volume, mean corpuscular hemoglobin, and mean corpuscular hemoglobin concentration. Significant (P less than .05) increases in the relative weight of the liver, kidney, spleen, pancreas, proventriculus, and heart, and the serum pyruvic transaminase activity were also caused by aflatoxin alone. The only significant (P less than .05) interaction between kojic acid and aflatoxin, which can best be described as antagonistic, was seen through an increase in mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration. These data indicate that kojic acid is not an aflatoxin synergist at the levels used in the present study.

The regulatory light chains (RLCs) located on the myosin head, regulate the interaction of myosin with actin in response to either Ca2+ or phosphorylation signals. The RLCs belong to a family of calcium binding proteins and are composed of four "EF hand" ancestral calcium binding motifs (numbered I to IV). To determine the role of the first EF hand (EF hand I) in the regulatory process, chimaeric light chains were constructed by protein engineering, by switching this region between smooth muscle and skeletal muscle myosin RLCs. For example, chimaera G(I)S consisted of EF hand I of the smooth muscle (gizzard) RLC and EF hands II to IV of the skeletal muscle RLC, whereas chimaera S(I)G consisted of EF hand I of the skeletal muscle RLC and EF hands II to IV of the smooth muscle RLC. The chimaeric RLCs were expressed in Escherichia coli using the pLcII expression system, and after isolation and purification their regulatory properties were compared with those of wild-type smooth and skeletal muscle myosin RLCs. The chimaeric RLCs bound to the myosin heads in scallop striated muscle myofibrils from which the endogenous RLCs had been removed ("desensitized" myofibrils) with similar affinities to those of the wild-type smooth and skeletal muscle RLCs. Both chimaeric RLCs were able to regulate the actin-activated Mg(2+)-ATPase activity of scallop myosin: G(I)S inhibited the ATPase in the presence and absence of Ca2+, like the wild-type skeletal muscle RLC, while S(I)G inhibited the myosin ATPase in the absence of Ca2+, and this inhibition was relieved on Ca2+ addition, in the same way as the wild-type smooth muscle RLC. Thus the type of regulation that the RLCs confer on the myosin is determined by the source of EF hands II to IV rather than that of EF hand I.

The toxicological effects induced by the administration of kojic acid were characterized in young male broiler chickens (Hubbard x Peterson). The experimental design consisted of six dietary treatments of kojic acid (0, .5, 1, 2, 4, and 8 g/kg feed) and four replicates of 10 broilers per replicate. Kojic acid significantly (P less than .05) decreased growth rates at concentrations greater than 2 g basic acid/kg feed. Kojic acid in higher concentrations also significantly increased the relative weights of the proventriculus, gizzard, pancreas, and liver, and significantly decreased the relative weight of the bursa of Fabricius at necropsy (Day 21). Hematological changes included a significant increase in the number of red blood cells, a significant increase in packed-cell volume, and a significant decrease in mean corpuscular volume. Also occurring was a significant increase in the serum concentrations of total protein, albumin, cholesterol, and triglycerides. Hepatotoxicity of dietary kojic acid was evident through a significant increase in the activities of serum glutamic oxalacetic transaminase and creatine kinase and a significant decrease in the activity of alkaline phosphatase. A significant increase in serum uric acid concentration was indicative of nephrotoxicity, and a significant increase in serum glucose concentration was indicative of pancreatic toxicity. A significant decrease in colonic temperature was also observed. Because the toxic effects of kojic acid were only observed at concentrations greater than 2 g kojic acid/kg feed, this mycotoxin alone does not appear to pose a serious economic threat to the poultry industry.

Water soluble 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide was used to internally cross-link carboxyl and lysyl groups of caldesmon. The modification did not involve the two cysteines of the molecule which were previously labelled with N-iodoacetyl-N'-(5-sulfo-1-naphthyl)ethylenediamine. The modified caldesmon exhibited a smaller Stokes radius (4.0 nm instead of 6.3 nm) and its electrophoretic mobility corresponded to an apparent molecular mass of approximately 82 kDa, appreciably lower than that of the native molecule (120 kDa), but more similar to the reported true molecular mass of 86,974 Da of chicken-gizzard caldesmon (Bryan, J., Imai, M., Lee, R., Moore, P., Cook. R. G. & Lin, W. (1989) J. Biol. Chem. 264, 13,873-13,879). Comparative circular dichroism analysis indicated a decrease of the alpha-helix content from 43% to 36% resulting from the chemical modification. The 1H-NMR spectra of the native and modified caldesmon showed that the covalent cross-linking affected mainly the central and N-terminal parts of the molecule. The C-terminal part, rich in aromatic amino acids, was unmodified by the carbodiimide treatment. This was also corroborated by the continued ability of the modified caldesmon to bind to actin and calmodulin, and by the property of the 90-kDa proteolytic N-terminal fragment to give an internally cross-linked species of 60 kDa. Using electron microscopy, the modified protein was shown to have a more compact shape and a reduced capacity to induce tight and long F-actin bundles. These conformational changes were obtained when the carbodiimide reaction was conducted at pH 6.0 and were not observed at pH 8.0. This suggests that local variation of the pH might affect the conformation of caldesmon which changes from an elongated to more compact shape, stabilized by electrostatic interactions. It is proposed that the flexibility of caldesmon might be involved in the regulatory function of this protein in the smooth muscle and might favour tightly packed F-actin bundles or weaker interactions between actin filaments.

Caldesmon, an actin/calmodulin binding protein, inhibits acto-heavy meromyosin (HMM) ATPase, while it increases the binding of HMM to actin, presumably mediated through an interaction between the myosin subfragment 2 region of HMM and caldesmon, which is bound to actin. In order to study the mechanism for the inhibition of acto-HM ATPase, we utilized the chymotryptic fragment of caldesmon (38-kDa fragment), which possesses the actin/calmodulin binding region but lacks the myosin binding portion. The 38-kDa fragment inhibits the actin-activated HMM ATPase to the same extent as does the intact caldesmon molecule. In the absence of tropomyosin, the 38-kDa fragment decreased the KATPase and Kbinding without any effect on the Vmax. However, when the actin filament contained bound tropomyosin, the caldesmon fragment caused a 2-3-fold decrease in the Vmax, in addition to lowering the KATPase and the Kbinding. The 38-kDa fragment-induced inhibition is partially reversed by calmodulin at a 10:1 molar ratio to caldesmon fragment; the reversal was more remarkable in 100 mM ionic strength at 37 degrees C than in 20 or 50 mM at 25 degrees C. Results from these experiments demonstrate that the 38-kDa domain of caldesmon fragment of myosin head to actin; however, when the actin filament contains bound tropomyosin, caldesmon fragment affects not only the binding of HMM to/actin but also the catalytic step in the ATPase cycle. The interaction between the 38-kDa domain of caldesmon and tropomyosin-actin is likely to play a role in the regulation of actomyosin ATPase and contraction in smooth muscle.