No abstract

In Australia, over 15,000 cases of campylobacteriosis occur annually; however, recent findings from case‐control studies suggest that poultry may not be the primary etiological agent. To determine the incidence of Campylobacter species on Australian poultry, a qualitative and quantitative survey of different poultry products was undertaken. The qualitative study examined 428 poultry carcasses from 42 processors. Overall, 93.7% of the carcasses were found to be positive for Campylobacter species, of which 84.1% were identified as Campylobacter jejuni by hippurate hydrolysis, and 9.6% as other Campylobacter species. A longitudinal study over 6 weeks on 27 broiler carcasses from a single processor found an average Campylobacter species count of 163 cfu/cm2, with a range of 5–1,850 cfu/cm2 excluding one carcass that was negative. The real health risk of this carriage, however, cannot be determined accurately without further investigation of the presence of virulence factors and more accurate species identification. PRACTICAL APPLICATIONS This article identifies that the incidence of Campylobacter species on processed poultry remains at levels recognized to be potentially infectious to humans. This suggests that current changes in processing control in the Australian poultry industry primarily established for Salmonella species may not necessarily reduce all potential human pathogens to safe levels. Using current literature, this article also debates whether the simple identification of presence and absence of a particular pathogen is sufficient for assumptions to be drawn on risk of infection. The discussion questions the real role of poultry in cases of campylobacteriosis, and suggests that based on case‐history data, poultry may be not be the common cause of the disease.

Ruminal acidosis is a prevalent disorder in ruminants such as dairy cows and feedlot beef cattle, caused primarily by the inclusion of a high percentage of readily fermentable concentrates in the diet. The disorder presents as an accumulation of lactic acid, a decrease of pH in the rumen and a subsequent imbalance of the rumen fermentation process with detrimental impacts on the animal's health and productivity. Dairy propionibacteria, a group of bacteria characterised by utilization of lactic acid as the favoured carbon source, with propionic acid produced as a by-product, were evaluated in this study as potential direct-fed microbials for use in controlling ruminal acidosis. Acidosis was simulated by introduction of high concentrations of lactic acid into rumen fluid samples and a multi-strain in vitro analysis was conducted, whereby changes in pH and lactic acid metabolism were compared in identical acidified rumen samples, following inoculation with various propionibacteria. This was followed by a study to evaluate the effect of bacterial inoculation dosage on acid metabolism. The results indicated that lactic acid levels in the rumen fluid were significantly reduced, and propionic acid and acetic acid concentrations both significantly increased, following addition of propionibacteria. Significant 'between strains' differences were observed, with Propionibacterium acidopropionici 341, Propionibacterium freudenreichii CSCC 2207, Propionibacterium jensenii NCFB 572 and P. jensenii 702 each producing more rapid reduction of lactic acid concentration than P. freudenreichii CSCC 2206, P. acidopropionici ATCC 25562 and Propionibacterium thoenii ATCC 4874. Furthermore, the efficacy of this application was dosage related, with the rates of reduction in lactic acid levels and production of propionic acid, both significantly greater for the higher (10 10 cfu mL-1) compared with lower (10 5 cfu mL-1) dosage inoculation. The results confirmed that the introduction of propionibacteria could promote more rapid reduction of lactic acid levels than would occur without their addition, demonstrating their potential in controlling ruminal acidosis.

Aim:  To confirm the reliability and sensitivity of Salmonella testing of processed poultry in Australia. Methods and Results:  The detection of Salmonella in a whole carcass wash of 90 randomly selected processed broilers was compared using the Australian Standard method, an Australian industry method used by a major processor and the United States Department of Agriculture method published in the Federal Register. The sensitivity of each method was determined using a carcass wash containing a known number of Salmonella Typhimurium to determine the minimum concentration to be able to be identified as positive. The two Australian methods were found to be comparable with both the Australian methods detecting more positive carcasses than the United States Department of Agriculture (USDA) method. The Australian methods were sensitive at the level of 1–3 CFU ml−1 and the USDA method was sensitive at 10–30 CFU ml−1. Conclusions:  The Australian Standard method and the Australian industry method were both able to detect Salmonella reliably even at a low level of contamination. Significance and Impact of the Study:  This study gives a high level of confidence both to the operators of poultry‐processing plants and to regulators dependent upon the outcome of Salmonella testing for process control in Australia.

The effects of the probiotic, Propionibacterium jensenii 702 (PJ 702), supplementation on egg productivity, egg shell thickness, fatty acid profile of eggs, and body weight in early layer hens were investigated. Twenty eight twenty-week-old starter pullets were evenly divided into a treatment and a control group for an eight week experiment. Each bird in the treatment group received 107 cfu PJ 702 daily in a total volume of 1 ml by oral administration. No adverse effect was observed due to administration of PJ 702, and successful gastrointestinal transit in the bird was demonstrated by recovery of PJ 702 from faeces of the treatment group. Layer production was significantly improved by the supplementation of PJ 702. Total egg weight in the treatment group was significantly higher than the control (P<0.001). Average egg weight for the treatment group was 55.26 g, 4.2% higher than the control which averaged 53.02 g. Moreover, the fatty acid profile was significantly altered by the supplementation of PJ 702. Myristic acid (P<0.001), palmitoleic acid (P=0.001) and all-cis-11,14-eicosadienoic acid (P=0.02) were significantly lower in the treatment group compared to the control group. No difference in egg shell thickness was observed between the treatment and control group (P=0.23). In conclusion, the application of novel probiotic PJ 702 in the early layer hen is safe and effective to promote production and the quality of products in layer husbandry.