The aim was to assess the onset of brain stem death for two euthanasia methods—manual cervical dislocation (CD) versus the Koechner Euthanizing Device (KED). Over three days broilers of 36 (n = 60), 42 (n = 80), or 43 days old (n = 60) were euthanized. On days 2 and 3, a treatment was added in which the bird’s head was extended at a ~90˚ angle after application of the KED (KED+). On those days, gap size was recorded between the skull and atlas vertebra by 1-cm increments. The onset of brain death was assessed by recording the nictitating membrane reflex, gasping reflex and musculoskeletal movements (sec). Additionally, skin damage and blood loss were recorded (y/n). On all days, CD resulted in quicker loss of reflexes and movements compared to KED or KED+. Reflexes returned in 0–15% of CD birds, 50–55% of KED birds, and 40–60% of KED+ birds, possibly regaining consciousness. Skin damage occurred in 0% of CD birds, 68–95% of KED birds, and 85– 95% of KED+ birds. On day 2 (p = 0.065) and 3 (p = 0.008), KED birds had or tended to have a narrower skull-to-atlas gap compared to CD and KED+ birds. Based on our results, CD would be the recommended method for broilers.

These studies evaluated the bacterial level of unwashed and washed shell eggs from caged and cage-free laying hens. Hy-Line W-36 White and Hy-Line Brown laying hens were housed on all wire slats or all shavings floor systems. On the sampling days for experiments 1, 2, and 3, 20 eggs were collected from each pen for bacterial analyses. Ten of the eggs collected from each pen were washed for 1 min with a commercial egg-washing solution, whereas the remaining 10 eggs were unwashed before sampling the eggshell and shell membranes for aerobic bacteria and coliforms (experiment 1 only). In experiment 1, the aerobic plate counts (APC) of unwashed eggs produced in the shavings, slats, and caged-housing systems were 4.0, 3.6, and 3.1 log(10) cfu/mL of rinsate, respectively. Washing eggs significantly (P < 0.05) reduced APC by 1.6 log(10) cfu/mL and reduced the prevalence of coliforms by 12%. In experiment 2, unwashed eggs produced by hens in triple-deck cages from 57 to 62 wk (previously housed on shavings, slats, and cages) did not differ, with APC ranging from 0.6 to 0.8 log(10) cfu/mL. Washing eggs continued to significantly reduce APC to below 0.2 log(10) cfu/mL. In experiment 3, the APC for unwashed eggs were within 0.4 log below the APC attained for unwashed eggs in experiment 1, although hen density was 28% of that used in experiment 1. Washing eggs further lowered the APC to 0.4 to 0.7 log(10) cfu/mL, a 2.7-log reduction. These results indicate that shell bacterial levels are similar after washing for eggs from hens housed in these caged and cage-free environments. However, housing hens in cages with manure removal belts resulted in lower APC for both unwashed and washed eggs (compared with eggs from hens housed in a room with shavings, slats, and cages).

Three separate broiler Salmonella Typhimurium challenge experiments were conducted evaluating efficacy of formic and propionic acid feed supplements to suppress environmental and cecal Salmonella Typhimurium prevalence. In experiment 1, broilers were provided feed with 1 kg/ton formic acid or 5 kg/ton propionic acid feed additives or a basal control diet. At the day of placement, half of the pens were inoculated with seeder chicks orally challenged with a marker strain of Salmonella Typhimurium and to yield challenged and adjacent nonchallenged pens. No differences in weekly litter samples or cecal Salmonella prevalence at 3 or 6 wk among feeding treatments were detected. In experiment 2, treatments were: 2 kg/ton propionic acid in feed, 1.0 mL/L formic acid in water, both propionic acid in feed and formic acid in water, and a basal control. Every pen was challenged with seeder chicks inoculated with Salmonella Typhimurium. By 6 wk all pens maintained detectable litter Salmonella, and broilers provided both propionic acid in feed and formic acid in water had the lowest cecal recovery (35%), compared to the control (60%). In experiment 3, treatments were: formic acid at 4 or 6 kg/ton from wk 0 to 6 or for only the last wk, propionic acid at 5 or 10 kg/ton for only the last wk, and a basal control. Each pen was challenged with Salmonella Typhimurium inoculated seeder chicks. By 6 wk, broilers fed formic acid (4 kg/ton) for the entire growout had no Salmonella-positive ceca (0/30). All treatments that provided acid supplemented feed for only the last wk had 3-13% Salmonella-positive ceca. These experiments indicate that adding formic acid to broiler feed appears to prevent Salmonella colonization from challenge pens entering into the adjacent nonchallenge pens. Feeding formic acid (4 kg/ton) for 6 wk resulted in no recovery of Salmonella from ceca compared to the control prevalence of 17%.

Numerous antimicrobial chemicals are currently utilized as processing aids with the aim of reducing pathogenic bacteria on processed poultry carcasses. Carryover of active sanitizer to a carcass rinse solution intended for recovery of viable pathogenic bacteria by regulatory agencies may cause false-negative results. This study was conducted to document the potential carryover effect of five sanitizing chemicals commonly used as poultry processing aids for broilers in a postchill dip. The effect of postdip drip time on the volume of sanitizer solution carryover was first determined by regression of data obtained from 10 carcasses. The five sanitizer solutions were diluted with buffered peptone water at 0-, 1-, and 5-min drip time equivalent volumes as determined by the regression analysis. These solutions were then spiked to 10(5) CFU/ml with a mixture of five nalidixic acid-resistant Salmonella enterica serovars, stored at 4°C for 24 h, and finally enumerated by plate count on brilliant green sulfa agar containing nalidixic acid. At the 0- and 1-min drip time equivalents, no Salmonella recovery was observed in three of the five sanitizers studied. At the 5-min drip time equivalent, one of these sanitizers still exhibited significant (P ≤ 0.05) bactericidal activity. These findings potentially indicate that the currently utilized protocol for the recovery of Salmonella bacteria from postchill sanitizer interventions may lead to false-negative results due to sanitizer carryover into the carcass rinsate.