The effect of dietary poultry litter inclusions on the presence of Salmonella in the hides, carcass, and lymph nodes of beef cattle fed palm kernel meal-based diet during dry and rain seasons in Honduras were evaluated.

Beef cattle (n = 149 and 290 for dry and rain seasons, respectively) from the southeast, northeast, central, and northwest regions of Honduras were studied. Diets contained 0, 8, 10, or 19.9% (DM basis) inclusion of poultry litter, as well as 17, 20, 15, 20.4, and 30.9% of palm kernel meal. Swab samples of hides, carcasses at pre and post-evisceration phase, and subiliac lymph nodes were collected from each of 439 animals at abattoir located in Honduras. Hides and carcasses samples were obtained using pre-hydrated sponges. The lymph nodes were collected by cutting from the flank region. Depending on the type of sample conventional methods (hides), immunomagnetic separation (lymph nodes), and a commercial PCR assay BAX/GeneDisc (carcasses at pre and post- evisceration) were used to detect Salmonella. Procedures of R (v.3.3.2) were used for statistical analyses. Chi-square analysis was used, in which pairwise comparison test assessed the frequency of Salmonella presence among the sampling locations (hides, carcasses at pre and post-evisceration, and lymph nodes). Fisher’s exact test was used when the frequency of Salmonella was studied by country location.

The presence of Salmonella (10.3; 6.4; 0; and 10.9%) was not affected (P = 0.64) by dietary concentration of poultry litter (0, 8, 10, and 19.9%, respectively), or country location (P = 0.42). In addition, a positive association between the presence of Salmonella on hide samples during rainy season was observed (P = 0.016). Hide samples were 5.53 times more likely to result Salmonella-positive in the rainy season than dry season. Frequency of positive samples on hides (5.2% 23/439) was higher (P < 0.05) than pre-evisceration (0.5% 2/439), post-evisceration (1.4% 6/439), and in lymph nodes (2.1% 9/439). The presence of Salmonella in three latter was not significantly different (P = 0.11).

The dietary inclusion of poultry litter did not affect the presence of Salmonella on hides, carcass, or in lymph nodes of beef cattle fed in Honduras. Special measures should be taken during the rainy season to avoid cross contamination from the hides to carcasses at harvest.