Evaluating the impact of gypsum as a novel bedding material on broiler performance, foot pad health, and fear response.

Flue Gas Desulfurization (FGD) gypsum is a byproduct of the coal-fired power plant process commonly used to remove sulfur dioxide emissions from the flue gas. FGD gypsum has numerous industrial, agricultural, and environmental applications. This study aimed to explore a novel approach involving the use of FGD gypsum combined with different litter treatments as bedding for broiler production. It focused on performance metrics, including adjusted feed conversion ratio (AFCR) and average body weight (BW), foot pad dermatitis (FPD), and fear response over 5 consecutive flocks. A total of 1,800 one-day-old Ross 708 chicks were randomly assigned to 24 pens (75 birds/pen), divided into 6 treatment groups (4 pens/treatment), with 5 replications and raised until 42 d old (d). Treatments were gypsum that was decaked (D), rotovated (E), and rotovated then windrowed (F) between flocks. Control treatments using pine shavings were decaked (A), rotovated (B), and windrowed postrotovating (C). AFCR, average BW, and mortality were used as a measure of production. Foot pad dermatitis scores were taken on d42 using a scale of 0 (absence), 1 (mild), and 2 (severe). Response to observer and human approach test were used to measure fear response. Data were analyzed as a 2-way ANOVA (Proc Glimmix) for the main effects of bedding type and litter treatment. Means were identified using Tukey's HSD. No effect of bedding type or litter treatment was found for AFCR, BW, or mortality. FPD scores 2 and 1, were higher with pine shavings than gypsum (P = 0.01 and P = 0.01, respectively). While FPD scores 0 were higher for gypsum than the pine shaving (P = 0.01). No difference in fear response was found among birds raised on any of the gypsum litter treatments and any of the pine shaving litter treatments. Overall, the use of gypsum as bedding results in equivalent production and fear response to pine shavings, while increasing FPD quality when compared to pine shaving.

Buffering Capacity Comparison of Tris Phosphate Carbonate and Buffered Peptone Water Salmonella Pre-Enrichments for Manufactured Feed and Feed Ingredients.

Various culture-based methods to detect Salmonella in animal feed have been developed due to the impact of this bacterium on public and animal health. For this project, tris phosphate carbonate (TPC) and buffered peptone water (BPW) buffering capacities were compared as pre-enrichment mediums for the detection of Salmonella in feed ingredients. A total of 269 samples were collected from 6 feed mills and mixed with the pre-enrichments; pH was measured before and after a 24 h incubation. Differences were observed when comparing pH values by sample type; DDGS and poultry by-product meal presented lower initial pH values for TPC and BPW compared to the other samples. For both TPC and BPW, meat and bone meal presented higher final pH values, while soybean meal and peanut meal had lower final pH values. Furthermore, for BPW, post cooling, pellet loadout, and wheat middlings reported lower final pH values. Additionally, most feed ingredients presented significant differences in pH change after 24 h of incubation, except DDGS. From meat and bone meal samples, four Salmonella isolates were recovered and identified: three using BPW and one using TPC. TPC provided greater buffer capacity towards neutral pH compared to BPW, but BPW was more effective at recovering Salmonella.

Effects of dietary yeast cell wall supplementation on growth performance, intestinal Campylobacter jejuni colonization, innate immune response, villus height, crypt depth, and slaughter characteristics of broiler chickens inoculated with Campylobacter jejuni at d 21.

A study was conducted to assess the effects of a dietary yeast cell wall (YCW) with and without a Campylobacter jejuni (CJ) challenge. A total of 2,240-day-old Ross 708 males were randomly assigned within 8 treatments with a 4 × 2 factorial design, with 4 diets (negative control, positive control, YCW constant dose (400 g/ton), and YCW step-down dose (800/400/200 g/ton in the starter/grower/finisher diets, respectively) and with and without d 21 CJ oral gavage challenge at 5.2 × 107 CFU/mL. At d 0, 14, 28, and 41 body weights and feed consumption were measured to determine performance. At d 14, 28, and 42, 8 jejunal and ileal histology samples per treatment were collected for villi morphology measurements. At d 22 and 28 (1- and 7-days postinoculation), 24 ileal tissue samples per treatment were collected for relative gene expression analysis. At d 42, 24 cecal content samples per treatment were collected for CJ enumeration. Finally, on d 44, 96 birds per treatment were processed to determine carcass yield and 16 carcass rinses per treatment were collected to determine CJ prevalence after processing. Diet or inoculation did not impact broiler performance (P > 0.05). Limited differences were observed in intestinal morphology, and villus height and crypt depth were different only in the ileum at d 42 (P = 0.0280 and P = 0.0162, respectively). At d 1 postinoculation, differences between treatments inoculated with CJ and PBS were observed in the expression of avian beta defensin 10 (AvBD10), interleukin 1ß (IL-1ß), and interleukin 10 (IL-10) (P < 0.05). At d 7 postinoculation, expression of AvBD10, IL-1ß, and IL-10 was similar among all treatments (P > 0.05). At d 42, all birds, regardless the inoculation, had similar levels of CJ recovered from cecal contents (P > 0.05). After processing, carcass yield and CJ prevalence postchilling was similar in all treatments (P > 0.05). Overall, under the conditions of this study, the addition of YCW during a CJ challenge did not have an impact in growth performance, innate immune response, cecal colonization, carcass yield, or CJ prevalence after processing.

Effects of Feed-Through Sulfur on Growth Performance, Atmospheric Ammonia Levels, and Footpad Lesions in Broilers Raised Beginning with Built-Up Litter.

To the poultry industry, ammonia accumulation within poultry houses can be a costly issue, as this can lead to problems with bird performance, damage to economically important parts such as paws, and customer disapproval due to animal welfare concerns. Common management practices for ammonia control can be quite effective; however, these methods are used variably from farm to farm, which necessitates ammonia control measures that poultry companies can more uniformly implement across all contract growers. One possible measure is ammonia control through feed additives, which would allow poultry companies more direct control over the treatment. This project explored the efficacy of elemental sulfur added directly to the feed (feed-through sulfur) in controlling litter ammonia levels, live performance, and paw quality of broilers raised on built-up litter over three successive flocks. Feed-through sulfur on its own showed inconsistent effects on performance or footpad lesions after 38 days of production compared to sodium bisulfate or control treatments. However, combination of feed-through sulfur and sodium bisulfate showed a potential synergistic effect on ammonia levels and litter pH, although there were few differences between treatments and controls; therefore, additional research must be explored to confirm these observations.

Effects of Common Litter Management Practices on the Prevalence of Campylobacter jejuni in Broilers.

Campylobacter is an important foodborne pathogen and is naturally found in chickens. During broiler production, litter can become contaminated with Campylobacter when birds defecate, and this litter, in some countries, is typically reused for the next flock, potentially causing cross-contamination. The goal of this experiment was to observe if reusing contaminated litter could spread Campylobacter between flocks and to observe if common litter treatments could prevent this cross-contamination. To determine this, a flock of birds was inoculated with Campylobacter jejuni and allowed to naturally contaminate the litter for 42 days. After grow-out, birds were terminated, and litter was given five treatments: uninoculated fresh litter, untreated re-used litter, composted re-used litter, re-used litter treated with sodium bisulfate (45 kg/305 m2), and re-used litter composted and treated with sodium bisulfate (45 kg/305 m2). A second flock was placed on the litter, grown for 42 days, and tested for C. jejuni prevalence. Following inoculation of the first flock, high prevalence of C. jejuni was observed; however, after a 19-day down-time between flocks, no C. jejuni was detected in any samples from the second flock. These results indicate that re-used litter was not a significant reservoir for cross-contamination of broilers when provided a significant down-time between flocks.

A Comparison of Colonizing Ability Between Salmonella Enteritidis and Salmonella Heidelberg in Broiler Chickens Challenged Through Feed Administration.

With over 1 million estimated cases per year in the United States, foodborne salmonellosis is an important public health issue. Chicken products are frequent sources of foodborne Salmonella infection. These bacteria readily colonize the gastrointestinal tract of broiler chickens, and feed is a known vector. Past research has demonstrated that the survivability of Salmonella in feed is dependent on the serovar and strain. Therefore, the objective of this research was to compare colonization incidence of these two serovars in broiler chicken tissues by administration of feed contaminated with Salmonella enterica serovar Enteritidis (SE) or Salmonella enterica serovar Heidelberg (SH). A comparison was made with equal conditions so that there was no influence of other factors. Birds were inoculated by addition of Salmonella to the feed (1 × 104 colony-forming unit [CFU]/g of feed) at 14 days of age, and the following tissue samples were collected from each bird after grow-out (days 34-41 depending on the trial): abdominal cavity swab, bone marrow swab, cloaca swab, lung swab, breast, bursa and thymus, ceca, crop, kidney, liver and spleen, skin, spinal cord, thigh, and trachea. A higher percentage of birds inoculated with SE were positive in at least one tissue compared with SH (68% and 9%, respectively), and the SE inoculated birds also showed a higher number of positive tissue samples than SH (13.1% and 0.7%, respectively). Recovery of SH was low for all tissue samples. However, recovery of SE was variable between samples, with ceca showing the highest percentage (50%). These results indicate that challenge at day 14 through feed administration results in greater colonization by SE compared with SH, suggesting that monitoring and control methods for Salmonella in feed should focus on SE to have the greatest positive effect.

Impact of poultry litter Salmonella levels and moisture on transfer of Salmonella through associated in vitro generated dust.

Dust present in poultry houses can contain high concentrations of microorganisms and has the potential to include pathogens from the litter. The objective of this study was to examine in vitro the potential for litter to dust transfer of aerobic bacteria, Salmonella, E. coli, and coliforms, and the role of the litter moisture on this process. Poultry litter was inoculated with 102 to 109 CFU/mL of Salmonella Typhimurium to evaluate litter to dust transfer of bacteria (Experiment 1). To evaluate the effect of litter moisture on litter to dust microbial transfer (Experiment 2), litter was inoculated with 109S. Typhimurium with increasing amounts of sterilized water added for moisture adjustment. Dust was generated by blowing air in a direct stream onto inoculated litter while simultaneously collecting dust through impingement. Following litter and dust sample collection, microbial analyses for aerobic plate counts (APC),Salmonella, E. coli, and coliforms were conducted. Both experiments were repeated 5 times and their data analyzed by one-way ANOVA and simple logistic regression. In Experiment 1, APC of litter (log10 CFU/g) and dust samples (log10 CFU/L) were 10.55 and 4.92, respectively. Salmonella ranged from 1.70 to 6.16 log10 CFU/g in litter and only one dust sample had 1.10 log10 CFU/L of Salmonella. As Salmonella levels in litter increased, the probability of obtaining a dust Salmonella positive result also increased. In Experiment 2, attained moisture percentages were 13.0, 18.2, 23.0, 28.2, and 33.3%. Litter recovery for APC, Salmonella, E. coli, and coliforms counts did not differ (P > 0.05) with increasing moisture levels. Dust sample bacterial counts significantly decreased with increasing moisture levels (P < 0.0001). Results from this in vitro study indicate that there is potential for Salmonella to be present in generated dust and the higher levels of Salmonella in litter increase the likelihood of detecting Salmonella in dust. Additionally, with higher litter moisture percentage, prevalence of Salmonella in generated dust was decreased.

Inoculation Route and Serotype Alter Salmonella Recovery in the Broiler's Digestive Tract.

Salmonella enterica serotypes Enteritidis (SE) and Heidelberg (SH) are consistently linked to poultry-related foodborne outbreaks and can be isolated from broiler parts in processing facilities. In order to control this pathogen's establishment in the broiler, entryways at the farm that lead to colonization must be considered. The objective of these trials was to determine if the inoculation route of either SE or SH altered its recovery in a market-age broiler's digestive tract if chicks were dosed on day of hatch. Chicks were given a 104 colony-forming units inoculation of SE or SH on day 0 via one of five inoculation routes (oral, intratracheal, subcutaneous, ocular, or cloacal) and then placed in pens (60-100 chicks/treatment). Broilers were reared for 32-36 days, then euthanatized, and samples of trachea, crop, liver and spleen (pooled), cecum, and a cloacal swab were collected. Samples were enriched and then analyzed on yes/no criteria based on Salmonella growth. Data were analyzed in JMP Pro 14.1 using the GLM procedure with the Student t-test to separate serotype means and a Tukey honestly significant difference test to separate inoculation means (P ≤ 0.05). All samples collected and all inoculation routes resulted in recovery of either serotype. The intratracheal inoculation, mimicking inhaled fomites, resulted in significantly higher recovery of Salmonella serotypes than did the other inoculation routes (P < 0.0001), indicating the importance of controlling respiratory contamination. When comparing serotypes, there was a significantly greater recovery of SH compared to SE based on samples collected (P = 0.001). SH also had significantly greater recovery from the cecum (P < 0.001) and the cloacal swab (P = 0.02). These trials indicate the need for further investigation of the intratracheal route, as well as reinforcing that the potential of systemic infection through grow out with either serotype is highly probable preharvest.

Use of a Multiplex PCR for the Detection of Toxin-Encoding Genes netB and tpeL in Strains of Clostridium perfringens.

Some studies have shown that the NetB toxin may be an important virulence factor of Clostridium perfringens associated necrotic enteritis in poultry. Additionally, research has shown that strains of C. perfringens positive for both the netB gene and a second toxin-encoding gene, tpeL, appear to be more virulent than strains with only netB. In the past, detection of these genes has been performed relatively inefficiently using two single locus PCRs. This report describes a novel multiplex PCR developed to detect netB and tpeL simultaneously in C. perfringens strains isolated from cases of necrotic enteritis in broilers, providing a more efficient diagnostic tool in the screening of strains for these genes.