A buffered propionic acid (BPA) was added to broiler diets fed in floor pens with litter. The BPA was fed continuously at 0, .2, .4, and .8% in Trial 1 and at 0 and .4% in Trial 2. The BPA was also fed at .4% for the last 7 days in Trial 2. Natural salmonellae exposure versus periodic dosage with Salmonella typhimurium was compared in Trial 2. In Trial 1, the BPA supplement had no adverse effects on growth, feed utilization, or abdominal fat with a significant (P less than or equal to .05) increase in the female dressing value at .8% of buffered propionic acid. The total number of coliforms and of Escherichia coli in the duodenum were significantly reduced by .4% BPA; in the jejunum, by all levels used in the trials; and in the ileum, by .4% and .8% of buffered propionic acid. The intestinal pH was not influenced by the BPA addition. In Trial 2, the BPA at .4% fed continuously had no adverse effect on growth, feed utilization, the abdominal fat of females, or the dressing percentage of males while significantly reducing the abdominal fat for males and increasing the dressing percentage for females. Feeding .4% BPA for the last 7 days had no effect on any of these parameters. Periodic dosage with S. typhimurium had no effect on body weight, feed utilization, or abdominal fat and significantly increased the dressing percentage. There was a significant interaction between the Salmonella dosage and the time of feeding BPA on dressing percentage.(ABSTRACT TRUNCATED AT 250 WORDS)
The distribution and level of Campylobacter jejuni throughout broiler processing was evaluated. Six trials were conducted at three broiler processing plants to determine the occurrence of C. jejuni on commercial broilers as affected by specific processing functions. Counts were determined at specific sampling stations throughout the plants, and patterns of counts among sampling stations and plants were observed. Between 1,100 and 5,500 C. jejuni/1,000 cm2 skin surface (represents half the skin surface area of one defeathered broiler) were found on birds entering the three plants. Increases in C. jejuni levels were associated with both the picking and evisceration operations. Broiler carcasses ready for packaging contained approximately 50 organisms/1,000 cm2. Campylobacter jejuni was also recovered from gizzard samples, carcass and gizzard chill water, and swab samples taken of selected equipment surfaces.
Two studies were conducted to examine the effects of dietary inclusion of fumaric acid on performance and carcass composition of broiler chickens. Fumaric acid was added to nutritionally complete diets at levels of 0, .125, .25, and .5% and fed from 1 to 49 days under simulated commercial conditions. In one trial, samples of birds were processed to determine dressing percentage and abdominal fat content. In the first trial (mixed sex broilers), the addition of .125% fumaric acid significantly (P less than .05) improved 49-day body weight of females and average weight gain of both sexes with no effect on feed utilization. Feed consumption was significantly increased when diets contained .125 or .50% fumaric acid. In the second trial (male broilers), 49-day body weight was significantly (P less than .05) improved by the addition of .125 and .25% fumaric acid. There were no significant differences in feed consumption; feed utilization was improved by the addition of all levels of fumaric acid. Dietary fumaric acid had no adverse effects on dressing percentage, abdominal fat content, or mortality rate.
Three experiments were conducted to determine the effects of feeding broilers formic acid (FA) or calcium formate (CF) on performance and microbiological characteristics of broilers. Live bird performance was not adversely affected by feeding up to 1.0% FA or 1.45% CF. In Experiment 1, levels of salmonellae in carcass and cecal samples were significantly reduced by feeding birds .36% CF. Salmonellae were not isolated from any of the carcasses of birds fed .36% CF. Similar reductions were not noted for total organisms or presumptive coliforms. In Experiment 2, feeding .36% CF nonsignificantly reduced levels of salmonellae in carcass and cecal samples, but again, levels of total organisms and coliforms were not reduced. In Experiment 3, salmonellae in the ceca or in the carcass rinse fluid were not reduced by feeding .36% CF.
A series of experiments have been conducted at the University of Arkansas over the last two years in efforts to decrease the incidence of salmonellae on commercial broilers. These experiments have concentrated on feeding trials in efforts to alter intestinal microflora, and processing trials in which chemical additives have been evaluated. A buffered propionic acid compound was fed at various concentrations for specific time periods and the cecal tonsils, small intestine, litter, and processed carcasses were tested for salmonellae and other organisms. In a separate series of trials a variety of chemicals were added to the scald, chill, scald and chill, or used as pre- or post-chill dips or sprays in efforts to decrease carcass contamination with salmonellae and extend product shelflife. Feeding trials indicate that the addition of a buffered propionic acid can alter intestinal microflora and decrease contamination of the processed carcass without adversely affecting live bird performance. Processing trials indicate that certain chemicals such as lactic acid can be used in a variety of ways to either decrease or eliminate salmonellae from the carcass and extend shelflife of processed broilers. However, some chemicals at high concentrations may produce undesirable organoleptic characteristics.
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