PSVII-10 - Effects of Supplementing a Standardized Plant-derived Feed Additive Containing Isoquinoline Alkaloids on Rumen Lesions in Feedlot Cattle

Abstract: Long-term feeding of high grain diets can lead to digestive disorders which can result in inflammation of the digestive tract, poor performance and a negative impact on animal welfare. Plant-derived feed additives are widely used in food producing animals to improve the productivity, digestibility, and health. The objective of the present study was to assess the effects of supplementing a plant-derived feed additive containing standardized concentrations of isoquinoline alkaloids (IQ) on rumen lesions in finishing feedlot cattle. Crossbreed bulls from a commercial feedlot were enrolled in the present study. During the control period (CON; n = 470): from September 1^st to October 12^th cattle were fed the feedlot finishing diet. During the treatment period (TRT; n = 480): from October 13^th to November 23^rd finishing feedlot cattle were fed the same ration plus 600 g/t of a feed additive with standardized concentrations of IQ. Slaughter was performed in 2 abattoirs and the rumen of animals were examined by the same investigator. Rumen health was scored by visual observation of the rumen epithelia: 1) normal rumen; 2) mild rumenitis; 3) moderate rumenitis; 4) diffuse rumenitis 5) ulcerative rumenitis. Statistical analysis was performed with the R software. The Pearson chi-squared statistic was performed to test the independence between the variables. Results showed that TRT had greater and positive association with score 2 (P < 0.05; 3.2), and a negative association (P < 0.05) with scores 4 (-1.1) and 5 (-1.1). The CON presented greater and positive association with score 3 (P < 0.05; 3.3), as well as positive association (P < 0.05) for the scores 4 (1.1) and 5 (1.1). In conclusion, supplementing finishing feedlot cattle with a plant-derived feed additive containing IQ resulted in less severe rumen lesions in feedlot cattle receiving finishing diets indicating that IQ exerted a positive effect on rumen condition.