Effect of bilateral cecal ligation on use of dietary energy in growing chickens

In order to determine the role of the cecum on energy use in growing chickens, metabolizability of the dietary energy and energy expenditure were examined in the week following bilateral ligation and washing out of the cecum. Apparent metabolizable energy (AME) values were 14.30 and 13.69 kJ/g air‐dry matter for sham‐operated and cecally ligated chickens, respectively. These values were found to be significantly different (P < 0.05). Although AME intake and fasting heat production were decreased by cecal ligation, the distribution of AME (measured as fasting and feeding heat production, as well as heat increment and energy retention, as a proportion of AME intake) was not affected. These results suggest that the cecum helps chickens extract AME from corn‐soybean type diets with little, if any, effect on AME use, based on the present study of growing chickens in the week following cecal ligation.     

Campylobacter detection in broiler ceca at processing: A three-year, 211-flock survey

Campylobacter is associated with live broilers and chicken meat products. There is some discussion in the literature about the possibility that Campylobacter prevalence in broilers could be affected by season or weather conditions. The objective of this study was to measure the flock prevalence of Campylobacter by sampling cecal contents from multiple flocks in one commercial slaughter plant over the course of 3 years. Two-hundred-and eleven discrete cecal samples, each from a different flock, were cultured for Campylobacter. Weather data, collected daily at a nearby University of Georgia experiment station, was used for testing for potential relationships between environmental conditions and Campylobacter detection. Fifty-five percent of flocks were found to be Campylobacter-positive. No clear trend was uncovered for Campylobacter prevalence related to mo of yr or daily maximum temperature. Furthermore, no significant relationship was noted between prevalence of Campylobacter and rainfall on the d of slaughter (P = 0.52) or the total rainfall during the grow-out period (P = 0.37).     

Absorption of glucose, amino acids, and dipeptides by the intestines of Atlantic salmon (Salmo salar L.)

Rates of glucose, amino acid and dipeptide absorption by the intestine of Atlantic salmon (Salmo salar L.) were measured in vitro at 10 °C as functions of concentration and region using intact tissues (everted sleeve method). Salmon (weight range 300–1300 g) fed a commercial, extruded salmon feed, were kept at 12–13 °C in freshwater. Maximum rates (V _max) of glucose and dipeptide transport were low compared to most amino acid V _max values. There was a declining proximal-to-distal gradient of absorption along the post-gastric intestinal tract. A saturable component of absorption was not evident for proline and glycyl-proline in the distal intestine, and glycyl-sarcosine in any region. `Apparent diffusion', which may include low affinity, high capacity carrier systems and carrier-independent influx, appears to account for the majority of total uptake at higher concentrations of amino acids and dipeptides. There was competition between the dipeptides for transporter sites in the pyloric ceca and mid intestine, suggesting a common carrier. There was also indication of hydrolysis of these dipeptides by brush border membrane enzymes.     

Recovery of Campylobacter and Salmonella Serovars From the Spleen,Liver and Gallbladder,and Ceca of Six-and Eight-Week-Old Commercial Broilers

Previous studies have demonstrated that when Campylobacter or Salmonella were either orally or intracloacally inoculated into day-old broiler chicks, within 1 h, these bacteria moved rapidly to the lymphoid organs. These bacteria were still present 1 wk after inoculation. Two different market-age (6 and 8 wk old) broilers were obtained from 2 commercial poultry operations and brought to the laboratory for analysis. Necropsy was limited to the removal of the spleen, liver and gallbladder (L-GB), and ceca using aseptic techniques. To reduce the possibility of cross-contamination between samples, the spleen and L-GB were aseptically removed before the ceca. Samples were individually bagged, and standard laboratory procedures for Campylobacter and Salmonella were carried out for all samples. Fifty-two 6-wk-old broilers were analyzed, and Campylobacter were found in 19 of 52 L-GB, 19 of 52 spleens, and 26 of 52 ceca. Salmonella were found in 5 of 52 L-GB, 8 of 52 spleen, and 4 of 52 ceca. Eighty 8-wk-old broilers were analyzed, and Campylobacter were found in 3 of 80 L-GB, 5 of 80 spleens, and 19 of 80 ceca. Salmonella were found in 41 of 80 L-GB, 38 of 80 spleens, and 52 of 80 ceca. The internal organs of the younger birds were more heavily contaminated with Campylobacter, whereas Salmonella was the predominant organism isolated in the older birds. All Campylobacter isolates were found to be Campylobacter jejuni. The predominant Salmonella serotype was Salmonella Typhimurium; however, 7 other serotypes were found. Overall, C. jejuni was found in 22 of 132 L-GB, 24 of 132 spleen, and 45 of 132 ceca, whereas Salmonella serovars were isolated from 46 of 132 L-GB, 46 of 132 spleen, and 56 of 132 ceca. There is no doubt that these bacteria are naturally present in these organs. The significance of these reservoirs in the internal organs of commercial broilers is yet to be determined but could play a role in the microbiology of the intestinal tract and hence the final food product.     

Evaluation of recovery of Salmonella from trachea and ceca in commercial poultry

Unpublished data from our laboratory suggest that the respiratory tract may be a viable portal of entry for Salmonella infection. Further, field reports have indicated that tracheal sampling can be a sensitive tool for monitoring for Salmonella incidence in commercial flocks. In the present study we conducted a series of field trials in North and South America to evaluate the association between cecal and tracheal recovery of Salmonella in chickens and turkeys from commercial flocks. Environmental humidity and temperature were measured to evaluate their effects on frequency of isolation from the organs. Salmonella was recovered from tracheal samples in all trials. In 3 of the 4 trials in which both trachea and ceca were sampled, the incidence of Salmonella recovery was higher in tracheal samples. Though Salmonella was not recovered from ceca in trial 2, 5% of liver and spleen samples indicated infection. Environmental conditions were not associated with incidence of Salmonella recovery. These data suggest that tracheal contamination can be a good indicator of Salmonella infection under commercial poultry conditions.