The correct usage of disinfectants is an important component of a successful biosecurity program. The objective of this study was to determine the effect of time, temperature, and organic matter (OM) on disinfectant efficacy. Staphylococcus aureus and Salmonella Typhimurium were used to represent gram-negative and gram-positive bacteria commonly found in commercial poultry housing. The first study evaluated the effect of temperature (4, 20, 32, or 43 degrees C) and time (1, 2, 3, 4, 6, 8, 12, 16, 20, 24, and 30 wk) on the efficacy of disinfectants diluted to working concentrations. The second study determined the effect of OM on the efficacy of working concentrations of freshly prepared disinfectants against the bacteria. For the third study, we compared the bactericidal properties of freshly prepared disinfectants and 30-wk-old disinfectants in the presence of OM. Quaternary ammonium-, chlorhexidine-, phenolic-, and binary ammonium-based solutions represented disinfectants commonly used within the poultry industry. In the first study, all of the disinfectants were effective against S. aureus and Salmonella Typhimurium regardless of treatment. However, the phenolic compound had reduced (P

Salmonella enterica isolates from turkeys in two commercial processing plants (1 and 2) were characterized for susceptibility to antibiotics, disinfectants, and the organoarsenical growth promoter, 4-hydroxy-3-nitrophenylarsonic acid (3-NHPAA, roxarsone), and it's metabolites, NaAsO(2) (As(III)) and Na(2)HAsO(4) • 7H(2)O (As(V)). The 130 Salmonella serovars tested demonstrated a low incidence of resistance to the antibiotics gentamicin (GEN), kanamycin (KAN), sulfamethoxazole (SMX), streptomycin (STR), and tetracycline (TET). Isolates resistant to antibiotics were most often multidrug resistant. Serovars Hadar and Typhimurium were resistant to KAN, STR, and TET and GEN, SMX, and STR, respectively. All isolated Salmonella serovars were resistant to the disinfectant chlorhexidine with minimum inhibitory concentrations (MICs; 1-8 μg/mL), and they were susceptible to triclosan and benzalkonium chloride. The didecyldimethylammonium chloride component was the most active ammonium chloride tested. No cross-resistance was observed between antibiotics and disinfectants. The MICs for 3-NHPAA (4096 μg/mL) were consistent between processing Plant 1 and Plant 2, but MICs for the 3-NHPAA metabolites (As(III) and As(V)) were higher in Plant 1 than in Plant 2. In Plant 1, 76% of the isolates had MICs >256 μg/mL for As(III) and 92% of the isolates had MICs >1024 μg/mL for As(V). In Plant 2, all of the isolates had MICs ≤256 μg/mL for As(III) and 90% of the isolates had MICs ≤1024 μg/mL for As(V). Only 4 Salmonella serovars were isolated from Plant 1, but 10 serovars were isolated from Plant 2. S. enterica serovar Derby from Plant 1 was highly resistant to As(III) and As(V) with MICs >1024 and >8192 μg/mL, respectively, suggesting previous exposure to high arsenic metabolite concentrations. These levels may have been high enough to kill other Salmonella serovars, thus possibly explaining the lack of serovar diversity observed in Plant 1. The application of a growth promoter may affect the serovar diversity in treated birds.

A series of experiments were conducted to investigate the effect of starter diet protein levels on the performance of broilers vaccinated with a commercially available live oocyst coccidiosis vaccine before subsequent challenge with a mixed-species Eimeria challenge. Data indicated that an increasing protein concentration in the starter diet improved broiler performance during coccidiosis vaccination. Prechallenge performance data indicated that vaccination could decrease BW and increase feed conversion ratio. The time period most important for the observed effects appeared to be between 13 and 17 d of age. This reduction in performance parameters of vaccinated broilers compared with nonvaccinated broilers was eliminated by the conclusion of the experiments (27 d) in the diet groups with higher protein. Vaccination was effective at generating protective immunity against Eimeria challenge, as evidenced by increased (P < 0.05) BW gain, improved feed conversion, reduced postchallenge mortality, and reduced lesion development in vaccinated broilers compared with nonvaccinated broilers. These observations support numerous other reports that confirm live oocyst vaccination can be used effectively as a preventive against avian coccidiosis in commercially reared broilers. More important, these findings suggest that reduced protein concentration of starter diets can lead to significant losses in broiler performance when using a vaccination program to prevent coccidiosis.

Two separate performance trials were conducted to determine the effects of postpelleting feed or drinking water application of a Lactobacillus-based probiotic, alone or in combination with a phytogenic product, on growth parameters of broilers fed medicated or nonmedicated diets. Trial 1 consisted of 1,000 straight-run broilers that were randomized, placed in floor rearing pens, and fed medicated diets. At the conclusion of the experiment, BW of broilers receiving the probiotic were not different (P > 0.05) when compared with control broilers. In trial 2, stocking densities were increased to simulate local industry rearing practices, resulting in a total placement of 1,880 chicks in the same rearing facility. Broilers in trial 2 were fed nonmedicated diets. Broilers administered the probiotic by intermittent drinking water application had increased (P < 0.05) BW and improved FCR (P < 0.05) through d 40 compared with control birds. Similarly, broilers receiving the phytogenic product had reduced (P < 0.05) FCR at d 40 compared with control broilers. We conclude that probiotic administration, alone or in combination with a phytogenic product, has the potential to influence broiler performance during commercial grow-out.