Salmonella enterica isolates from pasture-raised poultry exhibit antimicrobial resistance and class I integrons.

AIMS: While considerable foodborne pathogen research has been conducted on conventionally produced broilers and turkeys, few studies have focused on free-range (organic) or pastured poultry. The current surveillance study was designed to isolate, identify and genetically characterize Salmonella from pastured poultry farm environment and from retail samples. METHODS AND RESULTS: In this study, 59 isolates were collected from two pastured poultry farms (n = 164; pens, feed, water and insect traps) and retail carcasses (n = 36) from a local natural foods store and a local processing plant. All isolates were serotyped and analysed phenotypically (antimicrobial resistance profiles) and genotypically (DNA fingerprints, plasmid profiles and integron analysis). Salmonella enterica was detected using standard microbiological methods. Salmonella Kentucky was the most prevalent serotype detected from the sampled sources (53%), followed by Salmonella Enteritidis (24%), Bareilly (10%), Mbandaka (7%), Montevideo (5%) or Newport (2%). All isolates were resistant to sulfisoxazole and novobiocin, and the majority (40/59) possessed class I integrons shown by PCR detection. Each Salmonella serotype elicited a distinct pulsed-field gel electrophoresis fingerprint profile, and unique differences were observed among the serotypes. CONCLUSIONS: The findings of this study show that Salmonella serotypes isolated from pasture-raised poultry exhibit antimicrobial resistance and class I integrons. SIGNIFICANCE AND IMPACT OF THE STUDY: This study demonstrates that despite the cessation of antibiotic usage in poultry production, antibiotic resistant Salmonella may still be recovered from the environment and poultry products.

A broad view of arsenic.

In the mind of the general public, the words "arsenic" and "poison" have become almost synonymous. Yet, As is a natural metallic element found in low concentrations in virtually every part of the environment, including foods. Mining and smelting activities are closely associated with As, and the largest occurrence of As contamination in the United States is near the gold mines of northern Nevada. Inhabitants of Bangladesh and surrounding areas have been exposed to water that is naturally and heavily contaminated with As, causing what the World Health Organization has described as the worst mass poisoning in history. Although readily absorbed by humans, most inorganic As (>90%) is rapidly cleared from the blood with a half-life of 1 to 2 h, and 40 to 70% of the As intake is absorbed, metabolized, and excreted within 48 h. Arsenic does not appreciably bioaccumulate, nor does it biomagnify in the food chain. The United States has for some time purchased more As than any other country in the world, but As usage is waning, and further reductions appear likely. Arsenic is used in a wide variety of industrial applications, from computers to fireworks. All feed additives used in US poultry feeds must meet the strict requirements of the US Food and Drug Administration Center for Veterinary Medicine (Rockville, MD) before use. Although some public health investigators have identified poultry products as a potentially significant source of total As exposure for Americans, studies consistently demonstrate that <1% of samples tested are above the 0.5 ppm limit established by the US Food and Drug Administration Center for Veterinary Medicine. Although laboratory studies have demonstrated the possibility that As in poultry litter could pollute ground waters, million of tons of litter have been applied to the land, and no link has been established between litter application and As contamination of ground water. Yet, the fact that <2% of the United States population is involved in production agriculture and the overtones associated with the word "arsenic" could mean the matter becomes a perception issue.

Cultural and Immunological Detection Methods for Salmonella spp. in Animal Feeds - A Review.

Food-borne salmonellosis continues to be a major public health concern, and contamination with Salmonella spp. in pre-harvest animal production is considered a primary contributor to this problem. Animal feeds can easily become contaminated during primary production, feed mixing and processing as well as during feeding. Consequently, monitoring and surveillance of feeds and feed ingredients for Salmonella spp. contamination may be useful or necessary in the prevention and control of this organism. Cultural and immunological detection methods for salmonellae have been used or suggested as possible approaches for use in animal feeds. Cultural methods remain advantageous owing to their ability to detect viable bacterial cells, while immunological methods have the capability of detecting nonculturable bacterial cells. Advancements and improvements in both methodologies offer opportunities for eventual routine use of these detection technologies in animal feed assays.

Polymerase chain reaction detection of foodborne Salmonella spp. in animal feeds.

Foodborne salmonellosis continues to be a public health issue of considerable concern. Animal feed has been a major link in pre-harvest food animal production. Although monitoring systems and control measures are available to limit Salmonella spp. contamination on animal feeds detection methodology is relatively time consuming in the context of time inputs for feed processing and mixing. Current cultural methods of Salmonella spp. detection in feeds require several days for confirmation. This amount of time represents significant problems if control measures are to be effectively implemented in a fashion that keeps feed processing costs low. Molecular methods offer improved sensitivity and potential reduction in assay time. In particular, several commercial polymerase chain reaction (PCR) assays, and combined PCR-hybridization assays have been suggested as possible means to implement more rapid detection of Salmonella spp. extracted from animal feeds. It has now become possible to rapidly detect and confirm the presence of foodborne Salmonella spp. in feed matrices by commercial amplification detection systems. The primary challenges remaining are to develop more reliable recovery and extraction procedures for routine processing of samples from a wide variety of feed matrices and apply molecular techniques for assessing physiological status of Salmonella spp. contaminants in animal feeds.

Salmonella in commercially manufactured feeds.

We collected 886 samples (68 feed ingredient samples, 189 dust samples, and 629 feed samples) from 3 feed mills each of which produced between 100,000 and 400,000 tons of feed a year. Samples were collected on 3 d (Monday, Wednesday, and Friday), during 2 seasons (early spring and summer), and between 0700 and 1700 h approximately once per hour. Samples were collected from 5 locations within each mill: ingredient receiving, at the mixer, at the pellet mill, from pellet coolers, and at load-out. Temperatures were taken of the samples obtained at the pellet mill immediately following collection. All samples were analyzed for Enterobacteriaceae counts (EC) and Salmonella. The data confirm that feed ingredients and dust can be a major source of Salmonella contamination in feed mills. There were no differences (P < 0.05) in the Salmonella contamination rates of samples collected in spring as compared with samples collected in summer. Salmonella contamination rates were observed to be higher in samples collected on Friday compared with samples collected on Monday or Wednesday, an effect that may be management related. Data collected at the pellet mill clearly illustrate the uneven distribution of Salmonella contamination in feed as well as the need for control of dust around the pellet mill. Feed samples (both mash and pellets) contaminated with Salmonella contained significantly higher EC than samples not contaminated with Salmonella. Thus, EC may provide some indication of the likelihood of Salmonella contamination in feed samples.

Microbial contamination in inoculated shell eggs: II. Effects of layer strain and egg storage.

Three Ottawa control strains and a current commercial laying stock were reared and housed in the same environment. Eggs were collected at 5 different hen ages throughout the 2 production cycles of the flock. The eggs were inoculated with Salmonella Enteritidis (SE), Pseudomonas fluorescens (PF), a combination of the 2, or sterile buffered peptone water and stored up to 5 wk. After storage at room temperature, contamination levels were determined for the exterior surface, air cell, egg contents, and within the shell. Interior, egg contents, and shell contamination levels of SE and PF increased with storage time. There were no apparent increases in the infectivity of SE or PF in the presence of the other organism. PF was a poor survivor on the shell surface under these storage conditions. Throughout the 5-wk storage, eggs from control strain 10 maintained their microbial integrity more effectively. Eggs from control strain 5 and the current commercial stock were more easily contaminated than the other strains. These data suggest that genetic selection has altered microbiological defenses of the eggs produced.

Observations on the history of the development of antimicrobials and their use in poultry feeds.

Antimicrobials are powerful tools, but controversy and conflict often follow power. The development of antimicrobials was marked by personal attacks, political intrigue, internal conflicts, and lawsuits. Such controversy and conflict has continued. The early history of supplementing animal feeds with antimicrobials parallels the isolation and identification of vitamin B12. Vitamin B12 was isolated and characterized in 1948, but further research showed that several feed ingredients, including dried mycelia of certain fungi, were more potent as growth promoters in the diet of chicks than was vitamin B12 alone. The growth-promoting component in fungal mycelia was shown to have antimicrobial activity. A total of 32 antimicrobial compounds are approved for use in broiler feeds in the U.S. without a veterinary prescription. Fifteen compounds are listed for treatment of coccidiosis, 11 are listed as growth promotants, and six are listed for other purposes. Seven compounds are also used in human medicine. These compounds include bacitracin, chlotetracycline, erythromycin, lincomycin, novobiocin, oxytetracycline, and penicillin. No published estimates of antimicrobial use in animals exist at present, and estimates of that use differ markedly. The Union of Concerned Scientists (UCS) estimates usage at 30.6 million pounds, nearly 50% (49.85%) higher than the Animal Health Institute (AHI) estimate of 20.42 million pounds. AHI surveyed their members (the manufacturers of antimicrobials) to obtain their estimates, whereas USC calculated their estimates using published data and the following general formula: antimicrobial use = number of animals treated x average days treated x average dose.

Microbial contamination in inoculated shell eggs: I. Effects of layer strain and hen age.

Three Ottawa control strains and a current commercial laying stock were reared and housed under identical environmental and management conditions. Eggs were collected from each strain when hens were 32, 45, 58, 71, and 84 wk of age. The eggs were inoculated with Salmonella enteritidis (SE), Pseudomonasfluorescens (PF), or a combination of the two. After storage at 26 C, bacterial counts were obtained from the exterior shell surfaces (rinse), air cell, egg contents, and shell structure. SE and PF survived at different rates on the shell surface with as much as a 1 log difference during a given collection period. Egg content counts tended to be higher than eggshell counts in PF, whereas the opposite was true for SE. These data suggest that PF is a primary invader of eggs that is more capable of contaminating egg contents through the shell membranes than SE. The PF and SE data suggest that bacterial contamination of air cells, shells, and egg contents is more easily achieved in eggs from older hens than from younger hens. There were also differences between the strains. Control Strain 10 consistently maintained a lower level of contamination for both organisms in each sampling location. The overall results of this study suggest that genetic selection has altered the ability of eggs to resist microbial contamination and that screening for microbial integrity should be considered in the selection process among the laying egg breeders.

Effects of cryogenic cooling of shell eggs on egg quality.

This study was conducted to investigate the effects of cryogenic cooling on shell egg quality. Gaseous nitrogen (GN), liquid nitrogen (LN), and gaseous carbon dioxide (GC) were utilized to rapidly cool eggs in a commercial egg processing facility and were compared to traditional cooling (TC). A modified food freezer was attached to existing egg processing equipment in order to expose eggs to the selected cryogen. In Experiment 1, eggs were treated with GN, LN, and TC then stored and tested over 10 wk. Experiment 2 eggs were treated (GC and TC) and evaluated for 12 wk. Quality factors that were measured included Haugh units, vitelline membrane strength and deformation at rupture, and USDA shell egg grades for quality defects. Haugh unit values were greater for cryogenically treated eggs as compared to traditionally cooled eggs (Experiment 1: 73.27, GN; 72.03, LN; and 71.4, TC and Experiment 2: 74.42, GC and 70.18, TC). The percentage of loss eggs in the GN treatment was significantly (P < 0.01) greater than those of the LN and TC treatments. Vitelline membrane strength was greater for the cryogenically cooled eggs versus traditional processing. Vitelline membrane breaking strength decreased over storage time. Vitelline membrane deformation at rupture was significantly (P < 0.05) greater for the cryogenically cooled eggs compared to the traditional eggs in each experiment. Use of the technology could allow for egg quality to be maintained for a longer time, which could increase international markets and potentially lead to extended shelf lives.

Effects of hen age, Bio-Mos, and Flavomycin on poult susceptibility to oral Escherichia coli challenge.

The effects of hen age, Escherichia coli, and dietary Bio-Mos and Flavomycin on poult performance from 1 to 21 d were studied. Day-of-hatch BUTA (BIG-6) male poults were gavaged orally (1 mL) with approximately 10(8) cfu/mL E. coli composed of four serotypes or sterile carrier broth. A mixture of the same E. coli cultures was added to the poults' water troughs to attain a concentration of approximately 10(6) cfu/mL on a weekly basis to ensure a continuous bacterial challenge. Within each E. coli split plot treatment group, poults from hens of different ages (33 and 58 wk of age) were fed diets containing Bio-Mos (1 g/kg feed), Flavomycin (2.2 mg active ingredient/kg feed), Bio-Mos plus Flavomycin, or a control diet, in a randomized complete block design. This experiment yielded eight treatments per challenge group. At Weeks 1 and 3, eight birds from each treatment from the E. coli challenged and unchallenged groups were randomly chosen for bacterial sampling of liver and intestinal tissue for coliforms, aerobic bacteria, and Lactobacillus spp. E. coli isolates from tissue samples were O serotyped. During E. coli challenge, dietary Bio-Mos and Flavomycin improved poult BW and BW gains (P < or = 0.05). When poults were not challenged with E. coli, poults from old hens had improved BW and cumulative BW gains over poults from young hens (P < or = 0.05). Cumulative 3-wk BW gains for unchallenged poults from young hens were improved by Bio-Mos and Flavomycin (P < or = 0.05) alone and in combination when compared to the control diet. Two of the four E. coli serotypes administered were recovered. Several serotypes were recovered that were not administered. It may be concluded that dietary Bio-Mos and Flavomycin can improve the overall performance of poults, especially when they are faced with an E. coli challenge.

Comparison of physical quality and composition of eggs from historic strains of single comb White Leghorn chickens.

The effect of long-term genetic selection on physical quality and composition of eggs was determined by analyzing eggs acquired from Agriculture Canada: Ottawa Control Strain 5 (CS5) from a 1950 base population, 7 (CS7) from a 1958 population and 10 (CS10) from a 1972 population. Eggs from the H&N "Nick Chick" current commercial strain (CCS) were also included. Eggs were collected monthly over a 62-wk laying period and analyzed for egg, albumen, shell and yolk weight; albumen protein, solids and pH; percentage yolk solids and fat; Haugh units; and specific gravity. Significant (P < 0.05) differences found between strains included a progressive increase in weight of eggs from the CS5 to CCS. Although the eggs increased in size, no significant differences were found between strains for specific gravity or percentage shell weight. Yolk weights of eggs from the strains examined did not differ. However, the percentage of yolk found in current strain eggs was significantly lower (P < 0.05), with a subsequent higher percentage albumen due to the increase in egg size of the CCS. Haugh units were significantly higher in the CS10 and CCS strains than in the other strains. No significant differences between strains were seen in albumen protein, solids, pH, or yolk solids. Mean percentage yolk fat assay values for eggs from the CS5, CS7, CS10, and CCS strains were 33.08, 32.68, 32.84, and 32.40, respectively. Percentage yolk fat values obtained from CCS were significantly lower (P < 0.05) than those obtained from the other strains. The results from this study indicate that genetic selection has produced larger eggs containing a lower percentage of yolk while overall egg quality has been maintained or improved.

Isolation of Salmonella serotypes from feces of pigs raised in a multiple-site production system.

OBJECTIVE: To determine the prevalence and serotypes of Salmonella organisms in feces of pigs raised in a modern, multiple-site production system. DESIGN: Cross-sectional study of prevalence. SAMPLE POPULATION: Swine housed on 7 farms (1 gilt development farm, 2 breeding farms, 1 nursery farm, and 3 finishing farms) that formed a multiplesite production system. PROCEDURE: Fecal samples were obtained from 792 pigs (96 to 202/farm) and submitted for bacteriolgic culture of Salmonella organisms. RESULTS: Salmonellae were isolated from pigs on all 7 farms and from 95 of 792 (12%) fecal samples. Prevalence ranged from 3.4% at the gilt development farm to 18 and 22% at the breeding farms. Serotypes identified were Salmonella derby, S typhimurium var. copenhagen, S heidelberg, S typhimurium, S mbandaka, S worthington, and S tennessee. No single serotype was not isolated from all the farms of the production system and the most prevalent serotypes at the 3 finishing farms (S typhimurium or S typhimurium var. copenhagen) were not isolated from the breeding or nursery farms. CLINICAL IMPLICATIONS: Upstream infection (pigs infected before arriving at finishing farms) appears to be an unimportant source of Salmonella infection of finished hogs in multiple-site systems. High prevalence of Salmonella shedding in breeding animals suggests that food products derived from culled breeding livestock may be an important source of foodborne disease.

Prevalence of Salmonella in finishing swine raised in different production systems in North Carolina, USA.

We compared the prevalence of salmonella in faecal samples from finishing pigs and in feed samples from swine herds in North Carolina, USA. Farms were either finishing sites using all-in/all-out management of buildings in multiple-site systems (14 farms) or farrow-to-finish systems using continuous flow management of finishing barns (15 farms). The two groups of herds differed with respect to several management variables. Salmonella were isolated from 565 of 2288 (24.6%) faecal samples and from at least 1 faecal sample on 24 of 29 (83%) farms. Predominant serotypes were S. derby, S. typhimurium (including copenhagen), S. heidelberg, S. worthington and S. mbandaka. Fewer farrow-to-finish farms were detected as positive compared with all-in/all-out farms. Prevalence was lower for pigs raised on slotted floors compared with all other floor types, and was highest for pigs raised on dirt lots. Modern methods of raising pigs in multiple-site production systems, using all-in/all-out management of finishing pigs, appear to have no benefit in reducing the prevalence of salmonella compared with conventional farrow-to-finish systems.

Risk of shedding Salmonella organisms by market-age hogs in a barn with open-flush gutters.

OBJECTIVE: To compare prevalence of fecal shedding of Salmonella organisms and serum antibodies to Salmonella sp in market-age pigs housed in barns with partially slotted floors or solid floors with open-flush gutters. DESIGN: Cross-sectional study of prevalence. SAMPLE POPULATION: Finishing-age pigs deemed by the producer to be within 1 month of slaughter. PROCEDURE: Fecal and serum samples were obtained from a group of 121 pigs housed in a barn with solid floors (31 fecal samples, 30 serum samples) and from a group of about 400 pigs housed on partially slotted floors (57 fecal samples, 64 serum samples). Fecal samples were submitted for bacteriologic culture to detect Salmonella organisms, and serum samples were tested for antibodies by use of ELISA. RESULTS: Salmonella agona was isolated from 26 of 31 (84%) fecal samples obtained from pigs housed in the open-flush gutter barn, compared with 5 of 57 (9%) fecal samples from pigs in the barn with slotted floors. Median value for optical density was higher for serum samples from pigs housed in the open-flush gutter barn. CLINICAL IMPLICATIONS: Housing of finishing-age swine in barns with open-flush gutters may contribute to increased shedding of Salmonella sp. Analysis of our observations indicated that repeated exposure to infected feces is important in prolonging fecal shedding by swine.

Degradation of aflatoxin by poultry litter.

Two trials were conducted to determine whether deep stacking of contaminated corn with poultry litter destroys aflatoxin. Contaminated corn was ground and mixed with litter to carbon:nitrogen ratios of 30:1. Moistures were adjusted by adding tap water just prior to incubation or stacking. The initial laboratory trial included only broiler litter at 40% moisture, whereas the subsequent field trial involved a 2 x 2 factorial design with litter type (turkey or broiler) and moisture (20 or 40%) as main effects. Aflatoxin assays were reduced in the laboratory trial from 433 and 402 to 54 and 8 ppb in Containers 1 and 2, respectively, after 35 d of incubation at 28 C. In the field trial, aflatoxin disappeared from broiler and turkey litter mixtures with projected moistures of 20% after 10 and 6 wk of storage, respectively, whereas disappearance in mixtures containing projected moistures of 40% required 5 and 3 wk, respectively. Differences in moisture appear to account for differences in the ability of turkey and broiler litter to detoxify aflatoxin. Hence, turkey and broiler litter would appear equal with respect to the ability to detoxify aflatoxin-contaminated corn. Disappearance of aflatoxin during storage with litter could have occurred as a result of ammonia release during storage or microbial detoxification mechanisms. However, nitrogen values suggest that microbial action was responsible for much of the detoxification, as aflatoxin disappeared from mixtures with little apparent ammonia release.

Salmonella contamination in commercial eggs and an egg production facility.

Egg samples were collected from various stages of an egg processing operation and from the attached production facility. Salmonella was isolated from 72.0% of all samples collected from the laying house environment. Recovery of Salmonella from flush water, ventilation fan, egg belt, and egg collector samples were (positive samples/total samples collected): 2/2, 4/4, 16/22, and 14/22, respectively. Salmonella was found on 7 of the 90 eggshells sampled before processing and 1 of 90 eggshells sampled after processing, but Salmonella was not found in the 180 eggs analyzed for internal contamination following processing. The one eggshell found positive for Salmonella following processing was detected when the pH of wash water samples was lowest (10.19). The 60 isolates from production facilities included the following Salmonella serotypes: S. agona, S. typhimurium, S. infantis, S. derby, S. heidelberg, S. california, S. montevideo, S. mbandaka, and untypable. The 22 isolates obtained from eggshells prior to processing were serotyped as S. heidelberg and S. montevideo. All five isolates obtained from eggshells after processing were serotyped as S. heidelberg. These data suggest that although the shells of about 1% of commercial eggs are contaminated with Salmonella, contamination of the internal contents of eggs with Salmonella is a rare event.

Influence of a novel oxy-halogen compound on early growth and nitrogen retention of broiler chickens challenged with Salmonella.

The potential of a novel oxy-halogen compound (OHC) to alter early growth and nitrogen retention of broiler chickens challenged with Salmonella was evaluated. Three hundred and twenty female broiler chicks (Arbor Acres x Arbor Acres) were weighed and distributed randomly within a 2 x 4 factorial arrangement of treatments. Main effects examined were the presence or absence of Salmonella typhimurium (ST) inoculation and OHC treatment. At hatching, 80 chicks were placed in electrically heated brooder batteries in each of four identical isolation rooms. Chicks designated to receive 100 microL of an oral inoculum containing 10(5) ST cfu at 3 days of age were in two of the rooms, and uninoculated chicks were raised in the other two rooms. Four replicates of 10 chicks each received drinking water containing either 0, .05, .1, or .5% OHC for each level of ST. Chicks administered .05% OHC exhibited enhanced (P < or = .01) growth at 7 and 14 days of age when compared with control values. A significant OHC by ST interaction was observed at 7 (P < or = .0001) and 14 (P < or = .03) days of age. Feed utilization was improved (P < or = .01) by OHC administration (.05 and .1%) from hatching to 7 days of age. The administration of OHC reduced (P < or = .01) nitrogen excretion and enhanced (P < or = .01) nitrogen retention by chicks at Day 7. Cecal ST log10 counts at 7 days of age for chicks given water containing 0, .05, or .1% OHC were 4.72, 3.93, and 3.74, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

A Survey of Salmonella Contamination in Modern Broiler Production.

A survey of contamination with Salmonella was done in the breeder/multiplier and broiler houses, feed mills, hatcheries, and processing plants of two integrated broiler firms. Samples of insects and mice were also collected at each location. Sixty percent (60%) of the meat and bone meal samples collected at feed mills were contaminated. Salmonella was isolated from 35% of the mash feed samples tested. The pelleting process reduced Salmonella isolation rates by 82.0%. Data collected from breeder/multiplier houses suggested that feed was the ultimate source of Salmonella contamination in that environment. Salmonella was found in 9.4% of the yolk sac samples collected from day-old chicks in hatcheries. Fecal dropping samples collected in broiler houses about one week prior to slaughter were contaminated at a rate of 5.2%. Salmonella was found in 33% of the samples collected from live haul trucks and 21.4% of the whole processed broiler carcasses sampled at processing plants. Salmonella typhimurium was the serotype most commonly isolated. The gastrointestinal tract of one of 19 mice sampled was contaminated with Salmonella . Data suggest that insects were primarily mechanical carriers. Results suggest Salmonella contamination in the U.S. broiler production and processing system has changed little since 1969. The data also underline the contention that effective Salmonella control efforts must be comprehensive.

A Survey of Campylobacter jejuni Contamination in Modern Broiler Production and Processing Systems.

Campylobacter jejuni contamination was surveyed in samples collected from the breeder-multiplier houses, broiler houses, feed mills, hatcheries, and processing plants of two integrated broiler firms. Insects and mice were also trapped at each location. C. jejuni was most frequently found in samples collected from processing plants, followed by samples collected from broiler houses, and breeder-multiplier houses. Samples obtained from feed mills and hatcheries were negative, suggesting that the C. jejuni was not transmitted by either feed or eggs. C. jejuni was also not isolated from insect or mouse samples. However, the external surfaces of insects were sanitized with a chlorine solution, prior to analysis. Thus, these data suggest any contamination of insects with C. jejuni is generally external not internal. Contamination in broilers apparently originated from some unknown source(s) in broiler houses. C. jejuni was isolated from 20% of the cloacal swabs taken as birds entered the plant, 52% of the carcasses sampled following immersion chilling, and 31.6% of whole broiler carcasses sampled at retail outlets. While these data suggest that cross-contamination occurred within processing plants, field control methods would appear to be necessary for control of C. jejuni in modern broiler production and processing systems. The frequent C. jejuni isolations from dead birds in broiler houses suggested the regular collection of normal mortality as one farm management procedure that might help reduce Campylobacter contamination in broilers.

Effect of feeding diets containing corn treated with a commercial mold inhibitor (Myco Curb) on broiler-breeder performance.

Corn purchased from commercial sources was split at delivery and was left untreated or treated with a commercial mold inhibitor. Feed was prepared from these two lots of corn from within 1 wk to as much as 20 wk after delivery over the course of two experiments. There was evidence of reduced mold growth due to the mold inhibitor, particularly in the second experiment where initial mold populations were higher. Mycotoxins were evident in feed samples, regardless of the corn treatment. There was no significant effect from the treatment of corn on growth, livability, egg production, feed conversion, egg weight, or the eggshell quality of broiler breeders. Treatment of corn with a mold inhibitor significantly increased hatchability of fertile eggs in both experiments. Fertility was also significantly improved in the second experiment. These data suggest that using corn treated with a mold inhibitor results in significantly better hatchability in broiler breeders than untreated corn, although there were no observed differences in the incidence of mycotoxins in the samples taken.