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The objective of this in vitro study was to evaluate the effects of combining a prebiotic with alfalfa on fermentation by laying hen cecal bacteria. Cecal contents from laying hens were diluted to a 1:3,000 concentration with an anaerobic dilution solution and added to serum tubes filled with ground alfalfa or a layer ration with or without fructooligosaccharide (FOS) prebiotic. Samples were processed in an anaerobic hood, pressurized by using a pressure manifold, and incubated at 37 degrees C. Volatile fatty acid (VFA) and lactic acid concentrations were quantified at 6 and 24 h of substrate fermentation. In this study, fermentation of alfalfa resulted in greater production of acetate, VFA, and lactic acid compared with the layer ration. Although with a relative inconsistency in data between trials, the amendment of FOS to both alfalfa and the layer ration appeared to further increase fermentation as demonstrated by overall higher propionate, butyrate, VFA, and lactic acid concentrations. The effect was more pronounced after 24 h of fermentation, implying time constraints for the optimal production of fermentation products in the chicken gastrointestinal tract. These data indicate that in vitro cecal fermentation can be enhanced by the addition of FOS.

Immunological responses of molting hens either infected or not infected with Salmonella enterica serovar Enteritidis were compared in 2 trials with Single Comb White Leghorn hens >50 wk old. The hens were placed into 6 treatment groups with 12 hens per group: nonmolted Salmonella Enteritidis positive (FF+), non-molted Salmonella Enteritidis negative (FF-), feed withdrawal Salmonella Enteritidis positive (FW+), FW Salmonella Enteritidis negative (FW-), alfalfa Salmonella Enteritidis positive (ALC+), and ALC Salmonella Enteritidis negative (ALC-). Each hen in the Salmonella Enteritidis-positive groups was challenged on d 4 of the study with 1 mL of 10(6)-cfu Salmonella Enteritidis, and diets were administered for 12 d. Blood samples were collected on d 2, 5, 9, and 12, and blood smears were enumerated for heterophil to lymphocyte (H:L) ratios. Serum samples were also analyzed for alpha(1)-acid glycoprotein (AGP) levels and antibody level. On d 12, hens were euthanized and bile samples from the gall bladder and sections of the ileum and the ceca were collected, and an ELISA was used to determine the intestinal, serum, and bile antibody responses. The FW+ hens produced more (P

The objective of this study was to examine microbial population shifts and short-chain fatty acid (SCFA) responses in the gastrointestinal tract of Salmonella Enteritidis-challenged molted and nonmolted hens fed different dietary regimens. Fifteen Salmonella-free Single Comb Leghorn hens (>50 wk old) were assigned to 3 treatment groups of 5 birds each based on diet in 2 trials: 100% alfalfa crumbles (ALC), full-fed (FF, nonmolted) 100% commercial layer ration, and feed withdrawal (FW). A forced molt was induced by either a 12-d alfalfa diet or FW. In all treatment groups, each hen was challenged by crop gavage orally 4 d after molt induction with a 1-mL inoculum containing 106 cfu of Salmonella Enteritidis. Fecal and cecal samples (d 4, 6, 8, 11, and necropsy on d 12) were collected postchallenge. Microbial population shifts were evaluated by PCR-based 16S ribosomal RNA gene amplification and denaturing gradient gel electrophoresis, and SCFA concentrations were measured. Total SCFA in fecal and cecal contents for FW molted hens were generally lower (P ≤ 0.05) in the later stages of the molt period when compared to ALC and FF treatment groups. The overall trend of SCFA in cecal and fecal samples exhibited similar patterns. In trials 1 and 2, hens molted with ALC diet generally yielded more similar amplicon band patterns with the FF hens in both fecal and cecal samples by the end of the molting period than with FW hens. The results of these studies suggest that ALC molted hens supported microflora and fermentation activities, which were more comparable to FF hens than FW hens by the end of the molting period.

A study was conducted to evaluate the effects of alfalfa-based molt diets on molting performance and bone qualities. A total of 36 Single Comb White Leghorn hens were used for the study. There were 6 treatments: pretrial control (PC), fully fed (FF), feed withdrawal (FW), 90% alfalfa:10% layer ration (A90), 80% alfalfa:20% layer ration (A80), and 70% alfalfa:30% layer ration (A70). For the PC treatment, hens were euthanized by CO(2) gas, and bones were collected before molt was initiated. At the end of the 9-d molt period, hens were euthanized, and femurs and tibias were collected to evaluate bone qualities by peripheral quantitative computed tomography, mechanical testing, and conventional ash weights. The hens fed alfalfa-based molt diets and FW stopped laying eggs within 5 d after molt started, and all hens in these groups had reduced ovary weights compared with those of the FF hens. In the FW and A90 groups, total femur volumetric bone mineral densities (vBMD) at the midshaft were significantly lower, but those of the A80 and A70 groups were not significantly different from the values for the PC and FF hens. In cortical bone density, the midshaft tibial vBMD were significantly higher for FF and A70 hens than for PC hens. The medullary bone densities at the midshaft femur or tibia of the FW, A90, A80, and A70 hens were reduced compared with those of the PC hens. Femur cancellous densities at the distal femur for the FW and A90 hens were significantly reduced compared with those of the PC and FF hens. The FW, A80, and A70 hens yielded significantly higher elastic moduli, and the A80 hens had higher ultimate stress compared with the PC hens, suggesting that the mechanical integrity of the midshaft bone was maintained even though the medullary vBMD was reduced. These results suggest that alfalfa-based molt diets exhibit molt performance similar to FW, that medullary and cancellous bones are labile bone compartments during molting, and that alfalfa-based molt diets may be beneficial to maintain the mechanical properties of bones during molt.

The objectives of this study were to enumerate Salmonella enterica serovar Enteritidis colonization in fecal, cecal, and internal organs, and to compare the level of virulence gene expression (hilA) of experimentally challenged laying hens fed different dietary molt-induction regimens. Twelve Salmonella-free Single Comb Leghorn hens (50 wk old) hens were randomly assigned to each of 6 treatment groups designated based on diet in 2 trials: 1) feed withdrawal Salmonella Enteritidis-positive (FW+), 2) fully fed Salmonella Enteritidis-positive (FF+), 3) 100% alfalfa crumble Salmonella Enteritidis-positive (ALC+), 4) feed withdrawal Salmonella Enteritidis-negative, 5) fully fed Salmonella Enteritidis-negative, and 6) 100% alfalfa crumble Salmonella Enteritidis-negative. A forced molt was induced by a 12-d alfalfa diet and a feed-withdrawal regimen. On d 4 of the molt, all hens in groups 1, 2, and 3 were challenged by crop gavage with 1 mL of inocula containing approximately 10(6) cfu of nalidixic acid- and novobiocin-resistant Salmonella Enteritidis (phage type 13A). At the conclusion of both trials, all hens were euthanized and Salmonella Enteritidis colonization was enumerated in the cecal contents, liver, spleen, and ovaries. In addition, fecal (d 4 and 8) and cecal samples (necropsy at d 12) were collected postchallenge from treatment groups 1, 2, and 3 (Salmonella Enteritidis-positive) to quantify hilA expression by PCR. In both trials, all nonchallenged birds were Salmonella Enteritidis-negative; therefore, no further analysis was done. In trial 1, a 2-fold reduction in Salmonella Enteritidis colonization was observed in the ALC+ hens (log10 Salmonella Enteritidis of 1.99) compared with the FW+ hens (log(10) Salmonella Enteritidis of 3.89). In trial 2, a 4-fold reduction in Salmonella Enteritidis colonization was observed in the ALC+ hens (log(10) Salmonella Enteritidis of 1.27) compared with the FW+ hens (log(10) Salmonella Enteritidis of 5.12). In trial 2, Salmonella Enteritidis colonization in spleens was higher (Por= 0.05) in FW+ hens compared with ALC+ and FF+ hens. Relative expression of hilA was higher (Por= 0.05) in FW+ compared with FF+ hens, whereas the FF+ and ALC+ groups were not different (P0.05). In trial 2, hilA expression in FW+ hens was higher (Por= 0.05) for d 6, 11, and 12, respectively, when compared with ALC+ and FF+ hens. The results of these studies support the concept that changes in the gastrointestinal tract microenvironment, such as those created during feed deprivation, encourage Salmonella Enteritidis virulence and susceptibility in molted hens.

Previously, an experimental chlorate product (ECP) has been observed to reduce Escherichia coli and Salmonella infections in swine, cattle, and broilers. The following studies were performed to investigate the effects of different concentrations and durations of administering ECP on crop and ceca Salmonella typhimurium (ST) colonization of turkeys. In 2 separate trials, each conducted with 2 replicates, 15-wk-old turkey toms were challenged with 10(7) to 10(9) cfu of ST. In Experiment 1, toms were administered 0, 0.5, 1.0, 2.0, or 4.0x of ECP (a 1.0x concentration is equivalent to a 15 mM chlorate ion concentration) in the drinking water for 38 h. In Experiment 2, toms were administered a 2x concentration of ECP in the drinking water for 0, 14, 26, or 38 h prior to water withdrawal. All treatments were followed by a 10-h water withdrawal and an 8-h feed withdrawal prior to organ sampling. In Experiment 1, turkeys provided ECP had significantly (P0.05) lower populations and incidences of crop (1.4 log reduction) and ceca (0.6 log reduction) ST as compared with control birds (2.1 and 0.94 log ST average for all trials, respectively), with little or no additional benefit from administration of higher ECP concentrations. In Experiment 2, toms provided ECP had lower populations of crop (2.2 log reduction) and ceca (1.5 log reduction) ST when compared with controls (3.1 and 1.8 log ST, respectively). Again, there appeared to be little benefit in longer administration intervals on quantitative reduction of ST. These experiments suggest that the ECP significantly reduces Salmonella colonization in commercial turkeys when administered prior to feed and water withdrawal.

Feed deprivation is the most common method used to induce molting and stimulate multiple egg-laying cycles in laying hens for commercial egg production. Unfortunately, an increased risk of Salmonella enteritidis (SE) colonization may result from the use of this method. Methods to stimulate multiple egg-laying cycles without increasing the risk of SE are needed. In each of 3 experiments, hens over 50 wk of age were divided into groups of 12 and placed in individual laying cages. One week before dietary changes, hens were put on an 8L:16D photoperiod that continued for the 9-d experimental period. Hens in all treatments were challenged orally with 10(4) cfu of SE on the fourth day. Treatments were full fed hens (nonmolted, NM), nonfed hens (molted, M), a zinc acetate diet (ZAC), and a zinc propionate diet (ZPR). The zinc diets contained 10,000 mg of zinc per kilogram of diet. Body weight losses were significantly higher in the M, ZPR, and ZAC treatments than in the NM treatment. Crop lactic acid decreased more in M, ZPR, and ZAC treatments than in NM hens in trial 2. Crop pH was significantly (P0.05) lower in NM hens than in M, ZAC, and ZPR hens in trial 2. Although cecal individual or total volatile fatty acids (VFA), and lactic acid were not significantly (P0.05) different between NM hens and M, ZAC and ZPR hens in trial 1, lactic acid was significantly (P0.05) higher in NM hens than in M, ZAC and ZPR hens (trial 2), and cecal total VFA were lower in M hens than in NM, ZAC and ZPR hens (trial 3). Colonization of SE in the crop and ceca was higher in the M and ZPR hens (trials 1 and 2). Liver, spleen, or ovary invasion by SE was higher in the M and ZPR hens (trials 1 and 2) than in NM hens. At the zinc concentration used in these studies, the zinc dietary regimens may be effective for reducing the risk of SE during induced molt.

This study was conducted to determine the effects of refrigeration and frozen storage on tibia breaking strength (kg/g) and tibia ash (%) in bones obtained from hens of different ages. A total of 75 Single Comb White Leghorn hens were divided into three equal groups according to age (72, 80, and 92 wk of age). Both tibias of each hen were harvested and immediately defleshed. The tibias from each hen were randomly assigned to either 1 d of refrigeration or 7 d of frozen storage. Tibia breaking strengths were determined using an Instron Universal Testing Machine with 50-kg-load cell at 50-kg-load range with a crosshead speed of 50 mm/min. Tibia ash weights were determined by ashing for 24 h at 615 degrees C. Bone breaking strength in 72 wk of age hens was significantly (P0.05) higher in refrigerated tibias (2.48 kg/g) than those in frozen storage (1.75 kg/g). However, there was no difference (P0.05) for bone ash (percentage of tibia ash) in all three groups between refrigerated storage (72 wk: 38.840%, 80 wk: 46.40%, 92 wk: 46.99%) and frozen storage (72 wk: 39.12%, 80 wk: 44.88%, 92 wk: 45.35%). This study indicated that frozen storage only influenced assessment of bone strength in 72-wk-old laying hens but could be used for sample storage of bones from older hens.

The crop is a known source of Salmonella and Campylobacter contamination. Previously, we evaluated lactic acid in the drinking water during a simulated pretransport feed withdrawal (FW) and reported 0.44% lactic acid significantly (P < 0.05) reduced the number of Salmonella recovered in market-age broiler crops. However, total consumption of the organic acid-treated drinking water was reduced. Presently, we evaluated the effect of experimental chlorate product (ECP; 1x ECP is equivalent to a 15 mM chlorate ion concentration) during a 10-h pretransport FW. Market-age broilers were obtained from a commercial processing plant and randomly assigned to ECP-treated or control (nontreated) groups. Broilers were challenged by crop gavage with 10(8) Salmonella Typhimurium (ST) immediately upon arrival and 1 d prior to termination of the experiment. One day later, broilers were killed for ST enumeration (cfu) in the crop and ceca. Broilers provided ECP 24 h prior to slaughter consumed slightly more ECP water than broilers provided distilled water. Treatment with ECP caused a significant decrease (P < 0.05) in the incidence of ST in crop contents (2%) as compared to the controls (36.7%). Similarly, ECP treatment caused a significant decrease (P < 0.05) in number of ST (0.96 log10 ST/g cecal content) detected in the ceca when compared to controls (2.52 log10 ST). This study suggested that incorporation of ECP in the drinking water 24 to 48 h prior to slaughter could reduce Salmonella contamination in broilers.

Populations of digestive microflora in chickens change with age and are affected by diet, stressors, and performance enhancers. Culturing techniques used to profile a bacterial community inadvertently select for some organisms while excluding others. Several molecular-based techniques have been used to profile mixed microbial populations on the basis of DNA extracted from the entire community. Denaturing gradient gel electrophoresis was used in the present study to examine PCR-amplified fragments (amplicons) of a 16S ribosomal DNA variable region from predominant digestive bacteria. The objective of the study was to examine changes in digestive microbial communities of developing Leghorn chicks and molted Leghorn hens. Dendrograms of amplicon patterns indicated approximately 51% similarity between cecal bacteria composition in Leghorn chicks less than 20 d old and chicks greater than 20 d old. Cecal communities in Leghorn chicks given a competitive exclusion culture exhibited 21% correlation at all ages with those in control chicks. Nonmolted and molted hens had 40% similarity between cecal communities, whereas diets with low calcium (0.8% wt/wt) and excess zinc (2,800 mg/kg) lessened population differences (90% similarity). Results indicated the potential usefulness of the molecular-based denaturing gradient gel electrophoresis to monitor changes in digestive bacterial communities in chickens.

Linalool is a natural plant-product used in perfumes, cosmetics, and flavoring agents. Linalool has proven antimicrobial and insect-repellent properties, which indicate it might be useful for control of enteropathogens or insect pests in poultry production. However, there are no published reports that linalool may be safely administered to or tolerated by chickens. Linalool was added to the diets of day-of-hatch chicks, and they were fed linalool-supplemented diets for 3 wk. We studied the effects of linalool on serum chemistry, gross pathology, feed conversion, and relative liver weights. Linalool had a dramatic negative dose-dependent effect on feed conversion at concentrations in the feed exceeding 2% linalool, but not on gross pathology. Liver weights were significantly increased in the 5% linalool-treated birds. There was a statistical effect on blood glucose, but this parameter remained below the cut-offs for elevated serum glucose, and the result is likely of no biological significance. Linalool caused serum aspartate aminotransferase (AST) levels to increase, but it did not increase serum gamma-glutamyl transferase levels. The linalool effect on AST was dose-dependent, but in linalool doses between 0.1 and 2% of the feed, AST was not elevated beyond normal parameters. Linalool at 2% or less may be safely added to chicken feed. We suggest future studies to evaluate the addition of linalool to the litter, where it may be used as an antimicrobial or an insect repellent or to produce a calming effect.

The crop is a known source of Salmonella and Campylobacter contamination. We evaluated the use of selected organic acids (0.5% acetic, lactic, or formic) in drinking water during a simulated 8-h pretransport feed withdrawal (FW). Salmonella typhimurium was recovered from 53/100 control crops and from 45/100 of crops from acetic acid-treated broilers. However, treatment with lactic acid (31/100) or formic acid (28/76) caused significant (P < 0.05) reduction in incidence. Reductions of recovered incidence were also associated with reduced numbers of S. typhimurium recovered (e.g., control, log 1.45 cfu/crop; lactic acid, 0.79 cfu/crop). In an additional commercial farm study, broilers were provided 0.44% lactic acid during a 10-h FW (4 h on the farm and 6 h transport) and pre-FW crop, post-FW crop, and pre-chill carcass wash samples were collected for Campylobacter and Salmonella detection. Crop contamination with Salmonella was significantly reduced by lactic acid treatment (6/175) as compared with controls (29/175). Importantly, Salmonella isolation incidence in prechill carcass rinses was significantly reduced by 52.4% with the use of lactic acid (26/175 vs. 55/176). Crop contamination with Campylobacter was significantly reduced by lactic acid treatment (62.3%) as compared with the controls (85.1%). Lactic acid also reduced the incidence of Campylobacter found on pre-chill carcass rinses by 14.7% compared with the controls. These studies suggest that incorporation of lactic acid in the drinking water during pretransport FW may reduce Salmonella and Campylobacter contamination of crops and broiler carcasses at processing.

Beginning at 24 wk of age, control diets or diets containing 50 or 100 mg/kg moniliformin (M), 100 or 200 mg/kg fumonisin B1 (FB1), or a combination of 50 mg M and 100 mg FB1/kg of diet were fed to White Leghorn laying hens for 420 d. The hens were then fed the control diet for an additional 60 d. At the beginning of the experiment, each treatment consisted of four replicates of six hens. Egg production was reduced by approximately 50% by the end of the second 28-d laying period and remained at approximately this level for the 420 d in only the hens fed the diet containing 100 mg M/kg feed. Production returned to control levels or above within 60 d after hens were fed the control diet. Egg weights were reduced by the 100-mg M diet during the first three 28-d laying periods before returning to weights comparable with controls. The hens in this group also had significantly lower body weights than the other treatments. Mortality was minimal except in hens fed the 100 mg M/kg diet and the 100 mg FB1/kg diet, on which approximately 20% of the hens died. The hens were artificially inseminated with semen from males fed control diets, and fertility was not affected by the dietary treatments. Importantly, toxic synergy between M and FB1 was not observed for any of the parameters measured. Results indicate that laying hens may be able to tolerate relatively high concentrations of M and FB1 for long periods of time without adversely affecting health and performance. Interestingly, hens fed the 100-mg M/kg diet were able to recover when returned to control diets. The likelihood of encountering M or FB1 at these concentrations in finished feed is small.

Experiments were conducted to determine the efficacy of three inorganic sorbents, S1, S2, and S3, to reduce the toxicity of aflatoxins (AF) and T-2 toxin in male broiler chickens from day of hatch to 21 d of age. The compounds had been reported to bind to AF and T-2 toxin in vitro. S1 and S2 were the same basic compound that had been stored for different lengths of time following activation. In Experiments 1, 2, and 3, the appropriate diets were produced to contain no mycotoxins, the specific adsorbent at 0.5% of diet, AF alone at 5 mg/kg of diet, T-2 alone at 8 mg/kg of diet, AF at 5 mg/kg of diet plus the specific sorbent at 0.5% of diet, or T-2 at 8 mg/kg of diet plus the specific sorbent at 0.5% of diet. The specific sorbents used were: 1) Experiment 1, S1; 2) Experiment 2, S1 and S2; and 3) Experiment 3, S3. In Experiments 1 and 3, S1 and S3, respectively, showed no protection against AF or T-2 toxin as measured by BW gain, when compared to AF alone group. In Experiment 2, S1 showed no protection; however S2 reduced the effects of AF on BW gain by 25% as compared to AF alone diet. The data demonstrate that under the conditions of our experiment: 1) one of the sorbents provided some protection against aflatoxicosis; 2) there was variability in protection against aflatoxicosis between two different samples of the same sorbent that had been stored for different lengths of time following activation; 3) protection by the sorbents against the effects of T-2 toxin was not observed.

Experiments were conducted to determine the ability of a hydrated sodium calcium aluminosilicate (T-Bind) sorbent to reduce the toxicity of aflatoxins (AF) or T-2 toxin in male broiler chickens from day of hatch to 21 d of age. In Experiment 1, the sorbent was added at 0.250 or 0.375% to diets containing AF at 5 or T-2 toxin at 8 mg/kg of diet. When compared with controls, AF reduced BW gain by 27% and T-2 toxin reduced BW gain by 17%. The addition of the sorbent at 0.250 or 0.375%, in the absence of added mycotoxins, did not alter the performance of the chicks. The sorbent reduced the toxic effects of 5 mg AF/kg of diet on BW gain by 43% but did not significantly diminish the toxic effects of 8 mg T-2 toxin/kg of diet. The decreased efficiency of feed utilization and the increased relative organ weights caused by AF were significantly diminished to differing degrees by the sorbent. Oral lesions caused by T-2 toxin were not affected by the sorbent. In Experiment 2, the sorbent was added at 0.80% to a diet containing 8 mg T-2 toxin/kg of diet. The sorbent did not diminish the toxic effects of T-2 toxin when added at 0.80% of the diet. These data demonstrate that this specific sorbent can provide protection against the toxicity of AF, but not T-2 toxin, in young broiler chicks.

Previous studies have demonstrated that a novel source of ozone gas (O3) maybe used to chemically degrade numerous mycotoxins, including aflatoxin (AF) B1. Subsequent in vitro analyses demonstrated detoxification of AFB1, suggesting a potential method of remediate AF-contaminated grain. The objective of this study was to evaluate the capability of electrochemically produced ozone to degrade AFB1 in naturally contaminated whole kernel corn and confirm detoxification in turkey poults. Corn was procured from the southern coastal areas of Texas and HPLC revealed 1,220 +/- 73.3 ppb AFB1. Control and contaminated corn were treated for 92 h with O3 at 200 mg/min in 30 kg batches; greater than 95% reduction of AFB1 in contaminated corn was achieved. One-day-old female turkey poults were fed 1) control corn, 2) control corn + O3, 3) AFB1 corn, or 4) AFB1 corn + O3 mixed in rations (46% by wt.) and consumed ad libitum for 3 wk. When compared with controls, turkeys fed AFB1 corn had reduced body weight gain and relative liver weight, whereas turkeys fed control corn + O3 or AFB1 corn + O3 did not differ from controls. Furthermore, alterations in the majority of relative organ weight, liver discoloration, serum enzyme activity, hematological parameters, and blood chemistry caused by AFB1 were eliminated (no difference from controls) by treatment with O3. These data demonstrate that treatment of contaminated corn with electrochemically produced O3 provided protection against AFB1 in young turkey poults. It is important to note that treatment of control corn with O3 did not alter the performance of the turkey poults.

The individual and combined effects of feeding diets containing 300 mg fumonisin B1 (FB1), and 5 mg T-2 toxin (T-2)/kg of diet, or 15 mg/kg deoxynivalenol (DON, vomitoxin) from naturally contaminated wheat were evaluated in two studies in male broiler chicks from day of hatch to 19 or 21 d of age in Experiments 1 and 2, respectively. When compared with controls, body weight gains were reduced 18 to 20% by FB1, 18% by T-2, 2% by DON, 32% by the FB1 and T-2 combination, and 19% by the FB1 and DON combination. The efficiency of feed utilization was adversely affected by FB1 with or without T-2 or DON. Mortality ranged from none for the controls to 15% for the FB1 and T-2 combination. Relative weights of the liver and kidney were significantly increased by FB1 with or without T-2 or DON. Serum concentrations of cholesterol were increased in chicks fed FB1 with or without T-2 or DON. Activities of aspartate aminotransferase, lactate dehydrogenase, and gamma glutamyltransferase were increased in chicks fed FB1 at 300 mg/kg alone and in combination with T-2 or DON, indicating possible tissue damage and leakage of the enzymes into the blood. Results indicate additive toxicity when chicks were fed diets containing 300 mg FB1 and 5 mg T-2/kg of diet and less than additive toxicity when chicks were fed 300 mg FB1 and 15 mg DON/kg of diet. Of importance to the poultry industry is the fact that toxic synergy was not observed for either of these toxin combinations and the likelihood of encountering FB1 at this concentration in finished feed is small. However, under field conditions with additional stress factors, the toxicity of these mycotoxins could be altered to adversely affect the health and performance of poultry.

To evaluate the effectiveness of a superactivated charcoal (SAC) in alleviating mycotoxicosis, two experiments were conducted in which 432 male broiler chicks (216 per experiment) were fed diets containing 4 mg aflatoxin (AF) or 6 mg T-2 toxin/kg of diet, with and without 0.5% SAC, from 1 to 21 d of age. Feeding AF and T-2 toxin significantly decreased BW gain over the 21-d experimental period. Inclusion of SAC in the diet containing AF resulted in BW gains that were intermediate between gains of chicks fed AF and those of controls. No benefits were seen in BW gain when SAC + T-2 toxin was fed. Feeding AF increased relative weights of liver, spleen, and kidney; however, only liver weight in Experiment 1 was similar to controls when SAC was included. Of the blood parameters altered by AF (decreased cholesterol, inorganic phosphorus, total protein, and urea nitrogen, and increased mean corpuscular volume and hematocrit in Experiment 1; decreased albumin and total protein, and increased creatine kinase in Experiment 2) only urea nitrogen, hematocrit, and inorganic phosphorus (Experiment 1) and hematocrit (Experiment 2) were comparable to controls when SAC was included in the diet. Feeding T-2 toxin decreased serum cholesterol, total protein, urea nitrogen, and mean corpuscular volume; however, only cholesterol and mean corpuscular volume were improved with the addition of SAC (Experiment 1). Oral lesions were observed in birds fed T-2 toxin with no difference in severity when SAC was added in Experiment 1, however in Experiment 2, birds fed SAC + T-2 had a significantly lower lesion scores than those fed T-2 alone. Mortality was noted in both experiments but was not influenced by SAC treatment. These findings suggest that the addition of dietary SAC is marginally effective in alleviating some of the toxic affects associated with AF, but was of little benefit when T-2 toxin was fed to growing broiler chicks.

Previous studies with cyclopiazonic acid (CPA) have indicated that this mycotoxin strongly adsorbs onto the surface of a naturally acidic phyllosilicate clay (AC). The objective of this study was to determine whether AC (and similar adsorbents) could protect against the toxicity of CPA in vivo. Acidic phyllosilicate clay, neutral phyllosilicate clay (NC, or hydrated sodium calcium aluminosilicate), and a common zeolite (CZ, or clinoptilolite) were evaluated. One-day-old broiler chicks consumed diets containing 0 or 45 mg/kg CPA alone or in combination with 1% AC, NC, or CZ ad libitum from Day 1 to 21. Body weight, feed consumption, feed:gain, hematology, serum biochemical values, and enzyme activities were evaluated. Compared to controls, CPA alone reduced body weight at Day 21 by a total of 26% and resulted in a significantly higher feed:gain ratio. Toxicity of CPA was also expressed through increased relative weights of kidney, proventriculus, and gizzard. Also, there were some alterations in hematology, serum biochemical values, and enzyme activities. Treatment with inorganic adsorbents did not effectively diminish the growth-inhibitory effects of CPA or the increased weights of organs, although there was some protection from hematological, serum biochemical, and enzymatic changes produced by CPA. The results of this study suggest that in vitro binding of CPA to clay does not accurately forecast its efficacy in vivo; the reasons for this discrepancy are not clear, but they may be related to differences in clay binding capacity and ligand selectivity for CPA in vitro vs in vivo. Predictions about the ability of inorganic adsorbents to protect chickens from the adverse effects of mycotoxins should be approached with caution and should be confirmed in vivo, paying particular attention to the potential for nutrient interactions.

The individual and combined effects of feeding diets containing 100 mg moniliformin (M) and 3.5 mg aflatoxins (AF)/kg of diet were evaluated in male broiler chicks from day of hatch to 3 wk of age. When compared with controls, BW gains were reduced 29% by M, 13% by AF, and 33% by the M and AF combination. The efficiency of feed utilization was adversely affected by M independent of AF. Feeding M resulted in decreased relative weights of the bursa of Fabricius and increased relative weights of the heart, increased serum concentrations of creatinine and calcium, increased activities of alkaline phosphatase and alanine aminotransferase, and changes in hematological values. Feeding AF resulted in increased relative weights of the kidney and heart, decreased serum concentrations of total protein, albumin, cholesterol, and calcium, and decreased mean corpuscular volume. Feeding the combination of M and AF resulted in increased relative weights of the heart, decreased serum concentrations of total protein, albumin, and inorganic phosphorus, increased concentrations of creatinine and activity of alanine aminotransferase, and changes in hematological values. Results indicate additive or less than additive toxicity, but not toxic synergy, for most parameters when chicks are fed diets containing the combination of 100 mg M and 3.5 mg AF/kg of diet. The likelihood of encountering these high concentrations of these mycotoxins in finished feed is small; however, additional data on the naturally occurring concentrations of M are necessary before the importance of this mycotoxin to the poultry industry can be assessed.

The individual and combined effects of feeding diets containing 300 mg fumonisin B1 (FB1), and 4 mg diacetoxyscirpenol (DAS) or 3 mg ochratoxin A (OA) were evaluated in two experiments using female turkey poults (Nicholas Large Whites) from day of hatch to 3 wk of age. When compared with controls, body weight gains were reduced 30% (Study 1) and 24% (Study 2) by FB1, 30% by DAS, 8% by OA, 46% by the FB1 and DAS combination, and 37% by the FB1 and OA combination. The efficiency of feed utilization was adversely affected by all treatments except FB1 in Experiment 2. Relative weights of the liver were significantly increased by all treatments except the DAS treatment. Serum concentrations of cholesterol were decreased and activities of aspartate aminotransferase and lactate dehydrogenase were increased and several hematological values were altered in poults fed FB1 alone and in combination with either DAS or OA. Results indicate additive or less than additive toxicity, but not toxic synergy, when poults are fed diets containing 300 mg FB1, and 4 mg DAS or 3 mg OA/kg of diet. The likelihood of encountering FB1, DAS, or OA at these concentrations in finished feed is small. However, under field conditions, other stress factors could alter the impact of these mycotoxins on the health and performance of poultry.

The effects of feeding 6 mg T-2 toxin (T-2) and 34 mg cyclopiazonic acid (CPA)/kg of diet singly and in combination were characterized in male broiler chicks from 1 d to 3 wk of age. Body weights were depressed by T-2, CPA, and the combination of T-2 and CPA. There was a significant synergistic interaction between T-2 and CPA for relative liver and kidney weights and serum cholesterol and triglyceride concentrations and a significant interaction between T-2 and CPA for 3-wk body weights and relative bursa of Fabricius weights, which were less than additive. Neither the efficiency of feed utilization nor mortality was affected by dietary treatments. Oral lesions were present in a majority of the chicks fed diets containing T-2 with or without CPA. When compared with controls, other variables measured exhibited additive or less than additive toxicity. These data demonstrate that T-2 and CPA alone and in combination can cause reduced performance and adversely affect broiler health. The effects of these mycotoxins may be exacerbated by other factors when under field conditions; hence, the potential detrimental effects of these two mycotoxins when present alone or in combination cannot be dismissed.

The effects of feeding 2 mg ochratoxin A (OA) and 6 mg 4,15-diacetoxyscirpenol (DAS)/kg of diet singly and in combination were characterized in male broiler chicks from 1 to 19 d of age. Body weights were depressed by OA, DAS, and the OA-DAS combination. There was a significant antagonistic interaction between OA and DAS for uric acid and cholesterol. The efficiency of feed utilization was reduced by DAS alone and by the OA-DAS combination. When compared with controls, additive toxicity was exhibited for reduced efficiency of feed utilization, increased relative weights of the liver and gizzard, and decreased concentration of serum total protein, mean corpuscular volume, and mean corpuscular hemoglobin. All chicks were scored for oral lesions using a scale of 1 to 4 (0 = no visible lesions; 3 = severe lesions). Oral lesions (average score = 2.6) were present in over 90% of the chicks receiving the DAS diet with or without OA. These data demonstrate that both OA and DAS alone and the OA-DAS combination can adversely affect broiler performance and health.

In three experiments, three different hydrated sodium calcium aluminosilicates (HSCAS) were incorporated into chick diets (.5%) containing either 0 or 5.0 (Experiments 1 and 2) or 0 or 2.5 (Experiment 3) mg/kg aflatoxin (AF). Male broiler chicks consumed their respective diets and water ad libitum from 1 to 21 days of age. When compared with controls, body weights in chicks receiving 5.0 mg AF/kg were reduced by 214 g in Experiment 1 and 220 g in Experiment 2. The addition of .5% of the HSCAS compounds significantly diminished the growth inhibitory effects caused by AF by 39 to 68% in Experiment 1, by 46 to 88% in Experiment 2, and by 38 to 90% in Experiment 3. The increases in relative organ weights and the decreases in serum biochemical values caused by AF were significantly diminished to differing degrees by all three of the HSCAS compounds. These data demonstrate that these specific HSCAS compounds can be protective against the effects of AF in young growing broilers and further emphasizes the fact that all silicate-type sorbents are not equal in their ability to protect against aflatoxicosis. It also seems possible to specially process compounds to increase their efficacy for protection against the toxicity of AF.

The individual and combined effects of aflatoxin (AF) and cyclopiazonic acid (CPA) were evaluated in day-old Petersen x Hubbard broiler chickens to 3 wk of age. Treatments were arranged in a 2 x 2 factorial with levels of 0 and 3.5 mg AF/kg of feed, and 0 and 50 mg CPA/kg of feed. Production performance, serum biochemistry, and gross pathological observations were evaluated. Body weight gain was significantly (P less than .05) reduced by AF, CPA, and the AF-CPA combination at the end of 3 wk. Aflatoxin significantly increased the relative weight of the kidney and serum concentration of blood urea nitrogen and decreased serum concentrations of protein, albumin, cholesterol, phosphorus, and the activity of lactate dehydrogenase. The toxicity of CPA was expressed through increased relative weights of the liver, kidney, and proventriculus, increased levels of uric acid and cholesterol, and decreased serum phosphorus. The activity of AF-CPA combination was characterized by increased relative weight of the liver, kidney, pancreas, and proventriculus, decreased concentrations of serum albumin and phosphorus, increased concentrations of serum glutamic oxalacetic transaminase and blood urea nitrogen, and decreases in the relative weight of the bursa of Fabricius. Post-mortem examination revealed that the chickens fed CPA and the AF-CPA combination had thickened mucosa and dilated proventricular lumens, hard fibrotic spleen, and atrophy of the gizzard. The data from the present study demonstrate that both AF and CPA alone and the AF-CPA combination can limit broiler performance and adversely affect broiler health. In most cases the effects of AF and CPA were additive.

The effect of intracloacal inoculation with anerobic cultures of cecal microflora and addition of lactose to the feed on Salmonella senftenberg cecal colonization was evaluated in turkey poults. One-day-old poults were divided into four groups and provided 1) no anaerobic cultures, no lactose (control), 2) anaerobic cultures, 3) 5% lactose in the feed, or 4) anaerobic cultures and lactose. All groups were challenged orally with 10(6) S. senftenberg at 3 days of age. Salmonella senftenberg growth in the cecal contents was significantly decreased (P less than .05) at 10 and 30 days of age in both trials and at 20 days of age in Trial 1 in each of the three treatment groups as compared with the controls. On Day 30, the number of poults that were positive for Salmonella cecal culture was significantly decreased (P less than .01) in each of the treatment groups compared with the controls. Protection against Salmonella colonization was similar in the treatment groups inoculated with anaerobic cultures or provided dietary lactose. Combined treatment with anaerobic cultures of cecal microflora and provision of dietary lactose resulted in a level of protection against colonization equal to or higher than did either of the two treatments administered separately.

A study was conducted to evaluate the effect of experimental chlorate product (ECP) feed supplementation on Salmonella Typhimurium (ST) in the crop and ceca of market-age broilers. In trial 1, 160 market-age broilers were randomly assigned to 8 treatment groups and replicated twice, with 20 broilers per pen for 1 wk. Trial 2 used the same design, but used 80 market-age broilers with 10 broilers per pen. Treatments were as follows: 1) control feed + double-distilled drinking water (dd H(2)O); 2) control + 18.5% experimental zeolite carrier with dd H(2)O; 3 to 7) control feed supplemented with 0.5, 1.0, 5.0, 10.0, or 18.5% of a feed grade ECP + dd H(2)O; 8) control feed + 1x ECP (0.16% w/v; containing 15 mM chlorate ion equivalent) added to dd H(2)O. Seven-week-old broilers were provided experimental treatments for 7 d, killed, and then ceca and crops were removed and evaluated for ST. Broilers fed 5 to 18.5% ECP or water ECP had a significantly lower (P < 0.05) incidence of ST in the crop (36 to 38% and 14%, respectively) when compared with the control (60%). Broilers fed 10% ECP or water ECP had significantly lower ST crop concentrations (1.03 log(10) and 0.38 log(10) ST/g, respectively) when compared with broilers fed a control diet (1.54 log(10) ST/g). Crop and ceca ST incidence (32 to 48%) and concentration (1.00 to 1.82 log(10) ST/g) were significantly lower in broilers fed 5 to 18.5% ECP as compared with the control (78%; 2.84 log(10) ST/g). Broilers fed 5% or greater ECP had significantly higher water consumption (380 to 580 mL water/d) and litter moisture (31 to 56%) when compared with the control (370 mL water/d; 23% moisture). Only broilers fed 18.5% ECP had significantly lower 7-wk BW (2.77 kg of BW) when compared with the controls (3.09 kg of BW). Average daily gains were significantly depressed in broilers fed 10 or 18.5% ECP compared with the controls. These results indicate broilers supplemented with feed

Molting is a natural process, which birds undergo to rejuvenate their reproductive organs. The US poultry egg production industry has used feed withdrawal to effectively induce molt; however, susceptibility of Salmonella Enteritidis has encouraged the development of alternative methods. Previous research conducted in our laboratory showed that alfalfa is effective at molt induction and provides equivalent postmolt production numbers and quality when compared with feed withdrawal. In the attempt to further increase the efficacy of alfalfa molt diet and decrease the chicken susceptibility to Salmonella Enteritidis during molt, fructooligosaccharide (FOS) was added to a combination of 90% alfalfa and 10% layer ration in 2 levels (0.750 and 0.375%). Ovary and liver colonization by Salmonella Enteritidis in 3 and 2 of the 4 trials, respectively, were reduced (Por= 0.05) in hens fed FOS-containing diets compared with hens subjected to feed withdrawal. Significant decreases in ce-cal Salmonella Enteritidis counts were also observed in 2 of the 4 trials. In 3 of the 4 trials, the same diets did not affect (P0.05) the production of cecal total volatile fatty acids when compared with hens undergoing feed withdrawal. However, in all 3 alfalfa molt diets, the concentrations of lactic acid were greater (Por= 0.05) than hens with feed withdrawal, but no differences (P0.05) were observed among hens fed alfalfa combined with FOS and hens fed alfalfa/layer ration without FOS. Overall, given the similarities between hens fed 0.750% FOS (H) and 0.375% FOS (L), molt diets combined with the lower level of FOS should be sufficient.

Induced molting by feed withdrawal has been a common practice in the commercial layer industry and usually involves the removal of feed for a period of up to 14 d. However, this is a practice that is believed to adversely influence the welfare of the hens and there is a need to examine behavioral responses to alternative molt regimens. The behavioral patterns of hens on 90% alfalfa:10% layer ration, 80% alfalfa:20% layer ration, and 70% alfalfa:30% layer ration molt diets were compared with feed withdrawal (FW) hens, and fully fed (FF) hens. The White Leghorn laying hens were approximately 54 wk old and were placed in 3 identical climate-controlled rooms. The hens were individually housed in 2-tier wire battery cages and provided treatment rations and water ad libitum. Nonnutritive pecking, walking, drinking, feeder activity, preening, aggression, and head movement were quantified during two 10-min periods each day for 6 hens from each treatment. Over the 9-d treatment period, hens in the FW, 70% alfalfa:30% layer ration, and 80% alfalfa:20% layer ration groups spent significantly more time walking than hens in the 90% alfalfa:10% layer ration group. The FF and 70% alfalfa:30% layer ration hens spent half as much time preening, whereas the FW hens displayed nearly twice as much nonnutritive pecking when compared with other treatments. Most differences in head movements occurred at the beginning of the molt period, whereas during the last half of molt, alfalfa-fed hens exhibited feeder activity similar to FF hens, and all were significantly higher than that of FW hens. After some initial adjustment by the hens, consumption of alfalfa molt diets appeared to reduce nonnutritive pecking behavior, which is characteristically associated with FW hens.

An experiment with a completely randomized 2-by-3 factorial design was used to study the effects of ochratoxin A (OA; 0 and 4 mg of OA per kg) and supplemental L-phenylalanine (Phe; .0%, .8%, and 2.4% of Phe) in the diets of 3-wk-old broilers. Diets based on ground yellow corn and dehulled soybean meal were fed from Day 1 to 3 wk of age. A total of 240 male Hubbard-by-Hubbard broilers were randomly placed in battery brooders with 10 birds per pen. Each treatment was replicated 4 times. The parameters measured included mortality, BW, feed conversion, and relative organ weight. Broilers receiving OA weighed less and had poorer feed conversions than birds not receiving OA. For broilers receiving OA, the relative weights (grams of organ weight per 100 g of BW) of the liver, proventriculus, gizzard, and heart increased, while the relative weight of the bursa decreased. Supplemental Phe decreased the relative weight of the liver and increased the relative weight of the gizzard and heart. The regression slopes for Phe at 4 mg of OA per kg of diet were significantly different from 0 for BW, the relative weights of the kidney, spleen, and pancreas and approached significance for mortality (P = .065). In the absence of supplemental Phe, 42.5% of the birds died during the study when the dose level was 4 mg of OA per kg of diet. However, when Phe was supplemented at .8 and 2.4%, only 12.5 and 15.0% of the birds died, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

High fiber and nonstarch polysaccharide-based poultry diets have received more interest recently for retaining or promoting beneficial gastrointestinal microbial populations. The objective of this study was to investigate and compare the in vitro potential fermentability of high-fiber feed substrates (HFFS) by laying hen cecal microflora. Feed sources examined included soybean meal, soybean hull, beet pulp, wheat middlings, ground sorghum, cottonseed meal, 100% alfalfa meal, 90% alfalfa + 10% commercial layer ration, 80% alfalfa + 20% commercial layer ration, and 70% alfalfa + 30% commercial layer ration. Cecal contents and HFFS were incubated anaerobically in serum tubes at 39 degrees C for 24 h. Samples from 2 trials were analyzed at 0 and 24 h for short-chain fatty acids (SCFA). Short-chain fatty acids in samples at 0 h were subtracted from 24-h samples to determine the net production of SCFA. In both trials involving HFFS incubations with cecal inocula, acetate production was highest followed by propionate and butyrate whereas isobutyrate and isovalerate production were in trace amounts. In trial 2, detectable valerate production appeared to consistently occur with alfalfa-based HFFS. It was clear that SCFA production was largely dependent upon HFFS, because cecal inoculum alone yielded little or no detectable SCFA production. For HFFS incubations without cecal inocula, acetate production was highest; propionate and butyrate were similar, and isobutyrate, valerate, and isovalerate production were in trace amounts. Polymerase chain reaction-based denaturing gradient gel electrophoresis results from both trials indicated 69 and 71% similarity for comparison of all feed mixtures in trials 1 and 2, respectively. All alfalfa-based HFFS yielded a higher similarity coefficient in trial 2 than in trial 1 with a band pattern of 90% similarity; diets containing 90% alfalfa + 10% commercial layer ration and 80% alfalfa + 20% commercial layer ration in trial 2 formed a subgroup with a 94% microbial similarity coefficient. These data suggest that high fiber sources may contribute to the fermentation and microbial diversity that occurs in the ceca of laying hens.

A study was conducted to evaluate skeletal quality and eggshell parameters of molted hens at the end of the second laying cycle. Sixty Single Comb White Leghorn hens were used for this study. There were 2 controls and 4 molting treatments: full-fed control 1 (82 wk old; FF1), full-fed control 2 (122 wk old; FF2), feed withdrawal (FW), 100% alfalfa (A100), 90% alfalfa/10% layer ration (A90), and 70% alfalfa/30% layer ration (A70). At the end of the second laying cycle (approximately 122 wk of age), hens were euthanized by CO2. Tibia and femur were collected. There were no differences in bone parameters between FF1 and FF2 (P > 0.05) hens. There were no differences in bone parameters among the different molting dietary treatments (P > 0.05). In the eggshell parameters, the FF2 hens exhibited heavier egg weights than the FF1 (P < 0.05), whereas the percentage shell and egg production of the FF1 birds were significantly higher than those of the FF2 birds. Shell weights of the FW and A90 birds were significantly heavier than that of the A100. The correlation analysis showed that overall bone parameters were negatively correlated with eggshell parameters. Bone parameters were highly correlated with each other. Shell weight, percentage shell, and shell thickness were positively correlated with each other, whereas egg weight was negatively correlated with percentage shell. These results suggest that age of hens and molting dietary treatments influence egg parameters, and eggshell formation is closely related to bone metabolism in laying hens.

Clostridium perfringens (CP) is the etiologic agent of necrotic enteritis (NE). Clinical signs of this disease include depression, decreased appetite, diarrhea, and severe necrosis of the intestinal tract. Understanding the disease progression of NE has been difficult due to its complexity and the involvement of multiple factors (dietary components, immunosuppression, and mechanical irritation of the gut) that appear to contribute to this syndrome. In the present investigation, day-of-hatch broilers were fed a 55% wheat diet and randomly assigned to 1 of 8 groups. Treatments included positive control (CP challenge only), commercial coccidia vaccine (CCV), commercial bursal disease vaccine (CBDV), or the combination of CCV and CBDV, and an appropriate negative control for each (vaccinated and not challenged). Challenged treatment groups received 10(7) cfu of CP twice daily. When compared with controls, broilers in each treatment group had increased (P < or = 0.05) lesion scores, with mean scores of 1.05 and 2.05 in the CP and CBDV + CP treatments, respectively. When compared with controls, the incidence of CP increased (P < or = 0.05) in all treatment groups (73 and 100% in the CCV + CP and CBDV + CP treatment groups, respectively). Compared with controls, percentage mortality increased (P < or = 0.05) from 2% to 26 and 34% in the CP and CBDV + CP treatment groups, respectively. Results of this study indicate that the methodology used provides a good model for studying NE.

Previous reports have shown that some bacteria, including Salmonella, use a dissimilatory nitrate reductase enzyme pathway (NREP) in anaerobic environments. This enzyme reduces nitrate to nitrite and has been shown to cometabolize chlorate to cytotoxic chlorite. The present investigations were performed to evaluate the susceptibility of a competitive exclusion culture (CE) to the experimental chlorate product (ECP). A commercially available CE product was evaluated for its nitrate reductase activity and therefore its chlorate sensitivity. Individual isolates (in triplicate) were cultured in 10 mL of Viande Levure broth containing 5 mM sodium nitrate or 10 mM sodium chlorate. Bacterial growth (optical density at 625 nm) was measured and 1-mL aliquots were removed concurrently for colorimetric determination of nitrate content at 0, 3, 6, and 24 h. Of the 15 different facultative strains, 11 had slight NREP utilization, 3 had moderate NREP utilization, and the remainder were NREP negative (with slight and moderate NREP utilization:0.1 to1.0 mM and1.0 mM nitrate used within 6 h, respectively). Of the obligate anaerobes evaluated, 3 had slight NREP utilization and the remainder were NREP negative. In vivo studies utilizing both products (CE and ECP) in a horizontal transmission challenge model (seeders + contacts) showed significant reductions in Salmonella from 5.37 to 1.76 log10 cfu/g and 3.94 to 0.07 log10 cfu/g, respectively. The combined effect of the CE culture and an ECP are effective in killing these food-borne pathogens.

A study was conducted to evaluate effects of different bone preparation methods on bone parameters and the correlations between bone breaking strength and the other bone parameters. Bone breaking strength is dramatically changed depending on bone preparation methods, whereas other bone parameters such as ash content and ash concentration are not significantly influenced by bone preparation methods. Thus, the objective of this study was to evaluate the effects of 3 bone preparations (fresh, dry, and fat-free dry) on bone parameters and the relationship between bone breaking strength and bone parameters. Sixty Single Comb White Leghorn hens were used for this study. Hens were euthanized by CO2 gas, and the right tibia and femur were collected. The bones were divided into 3 treatment groups: fresh, dry, and fat-free dry. There were no significant differences in fresh weight, bone volume, dried weight, ash weight, and ash concentration of tibia and femur among the treatments. However, fresh tibia (24.13 kg) exhibited more bone breaking strength compared with the dried (9.90 kg) and fat-free dried bones (7.41 kg) (P < 0.05). The bone breaking strength (20.97 kg) of fresh femur was also significantly higher than the dried (9.22 kg) and fat-free dried femurs (6.94 kg). The bone breaking strength of the fresh bone was highly correlated with dried weight, ash weight, and ash concentration, whereas that of the fat-free dried bone was poorly correlated with the other bone parameters. The results indicate that fresh bone gives better bone breaking strength correlated to the other bone parameters than dry or fat-free dry preparation.

Aflatoxin contamination of foods and livestock feeds is an ongoing problem. In this research, NovaSil PLUS (NSP), a calcium montmorillonite clay that is commonly used as an anticaking agent in feeds, was evaluated for its ability to bind aflatoxin B1 (AfB1) in vitro and to prevent the onset of aflatoxicosis and vitamin A depletion in broiler chicks in vivo. Isothermal analyses were conducted with NSP and AfB1 to quantitate and characterize critical sorption parameters at equilibrium, i.e., ligand saturation capacities, affinity constants, and thermodynamics of the sorption process. In vitro results indicated that AfB1 was tightly sorbed onto the surface of NSP, which provided a high capacity and high affinity for the ligand. Thermodynamics favored sorption of AfB1 to NSP. The process was exothermic and spontaneous with a mean heat of sorption equal to approximately -50 kJ/mol, suggesting chemisorption (or tight binding). In addition to the in vitro studies, the effectiveness of NSP as an aflatoxin enterosorbent to attenuate the onset of aflatoxicosis in broiler chicks was determined at 3 different inclusion levels in the diet (0.5, 0.25, and 0.125%). NSP alone was not toxic to chicks at a level as high as 0.5% in the total diets (based on body and organ weights, feed intake, and hepatic vitamin A levels). NSP in the diet significantly protected chicks from the effects of highlevel exposure to aflatoxins (i.e., 5 mg/kg) and preserved hepatic vitamin A levels, even at lower dietary intake of clay.

Young chickens are more susceptible to Salmonella colonization than older chickens that have developed resistance with age as native microflora become established. Elevated concentrations of cecal propionic acid and total volatile fatty acids (VFA) have been observed by many researchers to be indicators of establishment of anaerobic microflora and protection against Salmonella colonization of the ceca. Disruption of the native microflora or competitive exclusion (CE) cultures by components of diets, such as tannic acid (TA), could alter the concentrations of propionic acid and total VFA and possibly affect Salmonella colonization. Two experiments were conducted using day-of-hatch, mixed-sex broiler chicks to evaluate the effects of TA on cecal VFA and the susceptibility to Salmonella colonization. All chicks in both experiments were challenged orally with 10(4) cfu of Salmonella typhimurium (ST) on Day 3 (Experiment 1) or Day 4 (Experiment 2). One-half of the chicks were orally gavaged on the day of hatch with a CE culture (PREEMPT) and were fed diets containing 0, 0.75, or 1.5% TA for up to 12 d of age. Chicks were maintained in batteries in separate rooms for the experimental period. There were some alterations in concentrations of cecal propionic acid or total VFA in chicks fed diets containing 0.75 or 1.5% TA in non CE-treated chicks and in CE-treated chicks. No significant differences were observed for numbers of Salmonella cecal culture-positive chicks or in the numbers of ST in the cecal contents due to dietary content of TA. With minor exceptions, the chicks treated with the CE culture had higher cecal concentrations of propionic acid and were less susceptible to Salmonella colonization than the non CE-treated chicks. Further research is necessary to determine the biological significance of these changes.

A factorial design (2 by 3) was used to evaluate the interaction between aflatoxin (0, 2.5, and 5 mg per kg) and salinomycin [0, 60 g per ton (909 kg)]. There were four replicates of 10 chicks per treatment. The chicks were maintained in batteries from 0 to 3 wk of age, with feed and water available for ad libitum intake. Aflatoxin at both levels (2.5 and 5 mg per kg) with and without salinomycin decreased body weight. The efficiency of feed utilization was affected only at the 5 mg per kg level of aflatoxin. Feeding 5 mg per kg of aflatoxin alone decreased the hemoglobin level. The inclusion of salinomycin (60 g per ton) in the diet with 2.5 or 5 mg per kg of aflatoxin initiated no significant change in body weight or feed efficiency. No significant interaction was observed between aflatoxin and salinomycin on any of the parameters measured.

Diets containing 200 mg fumonisin B1/kg of feed and .75 mg aflatoxin/kg of feed singly or in combination were fed to female turkey poults (Nicholas Large White) from day of hatch to 21 d of age. When compared with controls, 21-d body weight gains were reduced 10% by fumonisin B1, 39% by aflatoxins, and 47% by the combination. Relative weights (grams/100 g body weight) of the kidney and pancreas increased in poults fed the diet containing aflatoxins alone, whereas the relative weight of the liver decreased. Relative weights of the liver and pancreas increased in the poults fed the fumonisin diet. Relative weights of the kidney, pancreas, and gizzard increased in the poults fed the combination diet, whereas the relative weight of the liver decreased. Most serum constituents, hematology values, and activities of enzymes measured were altered in poults receiving the diets containing aflatoxins with or without fumonisin B1. No major histological lesions were observed in tissues from control poults or poults fed the diet containing fumonisin alone. Lesions associated with aflatoxins were only observed in the liver and occasionally in the kidney of poults fed the diets containing aflatoxins with or without fumonisin B1. The primary hepatic change was bile duct hyperplasia with some hepatocellular degeneration and necrosis and megalocytosis. Occasional necrotic and degenerating tubular epithelial cells were observed in the kidneys. The increased toxicity in poults fed the combination diet for most variables can best be described as additive, although some variables showed less than additive toxicity. Although toxicity due to fumonisin B1 was shown, it must be pointed out that these concentrations are not likely to be encountered under field conditions. However, other stress factors may be present that could alter the toxicity observed under these controlled experimental conditions.

Male broiler chicks were fed diets containing 0 or 3.5 mg aflatoxin (AF)/kg from 1 to 28 d of age. The diets were amended with either .5% hydrated sodium calcium aluminosilicate (HSCAS), 16.5 mg virginiamycin (VM)/kg of diet, or .5% HSCAS + 16.5 mg VM/kg of diet to determine the effects of these compounds during aflatoxicosis. When compared with controls (814 g), BW gains were significantly lower for broilers fed the AF (731 g) or AF+VM (716 g) diets. No differences were found between the BW gains of chicks fed diets without aflatoxin (814 g) and those of chicks fed AF+HSCAS (793 g) or AF+HSCAS+VM (803 g), indicating approximately 75% protection against decreased BW gain by HSCAS and 87% protection by the HSCAS+VM combination. Relative weights of the liver and kidney and creatine kinase activity were significantly increased and albumin, total protein, cholesterol, uric acid, and inorganic phosphorus concentrations were decreased in chicks fed the diet containing AF alone. With the exception of albumin, HSCAS was effective in restoring these values to control values. The findings of this research suggest that HSCAS and HSCAS+VM can counteract some of the toxic effects of AF in growing broiler chicks.

Diets containing 300 mg fumonisin B1 (FB1)/kg of feed and 5 mg T-2 toxin/kg of feed singly or in combination were fed to female turkey poults (Nicholas Large White) from day of hatch to 21 d of age. When compared with controls, 21-d body weight gains were reduced 21% by FB1, 26% by T-2, and 47% by the combination. The efficiency of feed utilization was adversely affected by FB1 and the combination of FB1 and T-2. Relative weights (grams/100 g BW) of the liver and gizzard were increased in poults fed the FB1 and the combination diets; whereas, the relative weight of the pancreas was increased in all treated groups. All poults were scored for oral lesions using a scale of 1 to 4 (1 = no visible lesions, 4 = severe lesions). Oral lesions were present in all poults fed the T-2 diet (average score of 3.29) or the combination diet (average score of 3.54). Serum concentration of cholesterol was decreased and lactate dehydrogenase activity was increased in poults fed the FB1 and combination diets. The activity of aspartate aminotransferase and the values for red blood cells, hemoglobin, and hematocrit were increased only in poults fed the combination diet. Inorganic phosphorus concentration was decreased only in poults fed the combination diet. The increased toxicity in poults fed the combination diet for most variables can best be described as additive, although some variables not altered by FB1 or T-2 singly were significantly affected by the combination, indicating that the combination may pose a potentially greater problem to the turkey industry than either of the mycotoxins individually.

Poultry products represent a significant reservoir of Salmonella typhimurium. Ochratoxin A, a mycotoxin and natural contaminant of poultry feedstuffs, produces detrimental effects on the immune and other systems of the broiler chick. Because poultry products are possible sources of S. typhimurium contamination that can potentially infect humans, there is a need to know whether ochratoxin A can alter the growth of Salmonella in poultry. We investigated the pathological alterations of young male broiler chicks by S. typhimurium in the presence (3.0 mg/kg) or absence of ochratoxin A in the diet. Ochratoxin A alone in the diet decreased the body weight and increased the relative organ weights of the liver, kidney, gizzard, spleen, pancreas, and proventriculus. It did not affect the heart and bursa of Fabricius. The mycotoxin altered the serum concentrations of proteins, enzymes, calcium and phosphate salts, normal tissue constituents, and catabolic metabolites in a pattern that would suggest damage to skeletal muscle, liver, kidney, pancreas, and bone. Birds fed diets containing ochratoxin A had microcytic and hypochromic erythrocytes and a decrease in phytohemagglutin- and concanavalin A-stimulated blastogenesis. Salmonella typhimurium alone had no affect on the variables measured except for a decrease in body weight. With the exception of an increase in mortality (13.2%, a significant synergistic interaction) and decrease in body weight, Salmonella in combination with ochratoxin A did not alter the values of the remaining variables measured from those measured in the ochratoxin A diet alone. Cecal colony count of S. typhimurium was not affected by treatment with ochratoxin A.

Volatile fatty acids and lactic acid were products of [14 C]lactose metabolism in 10-day-old broiler chicks. The [14 C]lactose and unlabeled lactose were given to chicks in combination with cultures of cecal anaerobes (direct fed microbials) from adult broiler chickens. Aliquots of these cecal anaerobes had been used previously to reduce Salmonella typhimurium colonization in broiler chicks. In the current study, chicks were treated with anaerobes and anaerobes plus lactose on the day of hatch. Chicks given lactose plus anaerobes also received unlabeled lactose in the drinking water. Chicks in all treatment groups received [14 C]lactose on Day 10 posthatch. After 5 h, most of the radiolabel was detected in the foregut and intestine. Significantly lower concentrations of [14 C]lactic acid were detected in the serum and foregut of chicks given anaerobes and anaerobes plus lactose than in the similar samples from control chicks. Additionally, significantly less [14 C]lactic acid was detected in the feces of chicks treated with anaerobes plus lactose than in feces from control chicks and chicks receiving only anaerobes. Significant differences in the total content of volatile fatty acids and lactic acid were detected in the serum, liver, intestine, and ceca of chicks treated with anaerobes or anaerobes plus lactose. These data indicate that cecal flora utilize lactose to produce volatile fatty acids and lactic acid.

Effects of adding .5% of a hydrated sodium calcium aluminosilicate (HSCAS) to diets containing 1 or .5 mg aflatoxin (AF)/kg were determined in male turkey poults from 1 day to 3 wk of age. Body weight gains were significantly reduced by 51 and 19% in turkey poults fed 1 and .5 mg AF/kg, respectively; efficiency of feed utilization was not affected. There were no deaths in poults fed .5 mg AF/kg; however, the mortality rate was 88% in poults fed 1 mg AF/kg. The addition of .5% dietary HSCAS resulted in a 68% decrease in mortality to 28% for the 3-wk experimental period. Treatment-related changes in relative organ weights, hematological values, serum biochemical values, and enzyme activities were observed. The HSCAS in the absence of AF did not alter any of the parameters measured. The HSCAS diminished the adverse effects of AF on body weight gains, most relative organ weights, hematological values, serum biochemical values, and enzyme activities associated with .5 mg AF/kg, but not 1 mg AF/kg. These findings indicate that HSCAS may diminish many of the adverse effects of AF in an AF-sensitive species, the turkey.

A hydrated sodium calcium aluminosilicate (HSCAS) was incorporated into diets (.5%) containing 3.5 mg of aflatoxin (AF) per kg and 8.0 mg of T-2 toxin (T-2) per kg, singly, and in combination. Male broiler chicks (n = 480) were provided with feed and water for ad libitum consumption from 1 to 21 days of age. Body weight gains were significantly depressed by AF and T-2, singly, and further decreased by the combination of the two toxins. Efficiency of feed utilization was not affected. The AF alone and the AF plus T-2 combination caused increases in relative liver, kidney, proventriculus, gizzard, spleen, and pancreas weights. Treatment-related changes in hematological and serum biochemical values and enzyme activities were observed. Oral lesions were observed only in chicks receiving the T-2 diets. The HSCAS fed singly did not alter any of the parameters measured but it did diminish the toxicity of AF for many parameters but did not appear to alter the toxicity of T-2. Addition of HSCAS to the AF plus T-2 combination diet diminished some of the effects of the toxin combination. These findings indicate that HSCAS can diminish many of the adverse effects of dietary AF in the chicken, but it has no effect on T-2 toxicity.

The amelioration of aflatoxicosis in broiler and Leghorn chickens was examined by feeding a hydrated, sodium calcium aluminosilicate (HSCAS) or activated charcoal. In three experiments, HSCAS or activated charcoal at a concentration of .5% of the total diet were incorporated into diets for broiler and Leghorn chicks containing either no added, purified aflatoxin B1 (AFB1), 7.5 mg of AFB1 per kg, or 5 mg of aflatoxin (AF) per kg (produced by Aspergillus parasiticus on rice). Compared to the controls, the AFB1 reduced BW gains at 0 to 3 wk by 21 to 38% in broilers; and the AF reduced BW gains at 0 to 4 wk in Leghorns by 20 percent. The HSCAS significantly diminished the growth-inhibitory effects of AFB1 or of AF on growing chicks by 50 to 67 percent. Feeding 5 mg of AF per kg of diet with or without charcoal to Leghorn chicks caused a significant increase in the relative weights of the liver, kidney, proventriculus, and gizzard as well as significant increases in activity of serum gamma glutamyltransferase; also, significant decreases in the relative bursa weights as well as the concentrations of serum total protein and albumin. With the exception of the relative bursa weights, the toxic effects caused by aflatoxin were prevented or were reduced by adding hydrated, sodium calcium aluminosilicate. These data suggest that HSCAS can modulate the toxicity of AFB1 and AF in the chicken; however, adding activated charcoal to the diet did not appear to have protective properties against the effects of aflatoxin B1 or of aflatoxin.