PSXIII-25 Exploring crude glycerin as an alternative to corn in high-concentrate diets: Effects on performance and ruminal health in feedlot lambs
Authors: Almeida Marco Tulio Costa , de Santos Torres Rodrigo Nazaré S , de Valença Roberta Lima , de Almeida Rafael Assis Torres , Falcão Thainara Tintori , Hemerly Vitor Paolini , de Carvalho Laura Martins Souza 
Published: September 2024

The search for increasingly efficient ruminant production systems has led to the utilization of high-concentration diets, with corn frequently serving as the primary ingredient. However, excessive and inappropriate use of corn can predispose animals to rumen acidosis, resulting in nutritional and metabolic disorders. Given this scenario finding safe and effective alternatives to replace corn has become imperative. Glycerin emerges as a promising substitute. The aim of this study was to evaluate the inclusion of glycerin as a total replacement for corn in high-concentrate diets (80%) for feedlot lambs. Lambs (n = 40) were randomly assigned in a randomized complete block design into two treatments, with one group receiving 30% DM crude glycerin in the total mixed diet and the other serving as the control group. The animals remained confined until they reached 35 kg of body weight (BW), at which point they were slaughtered. Performance and papillae data were collected and analyzed. Principal Component Analysis (PCA) was conducted to assess the relationship between days in the feedlot, average daily gain (ADG), rumenitis score, liver abscess incidence, number of papillae, papillae area (cm2), absorptive surface area (cm2), and papillae area (%). The PCA was performed using R Statistical Software (FactoMiner and Factoextra package). The two principal components (Dim1 and Dim2) accounted for 49% of the data variability. The first component (Dim1 = 30.1%) was positively correlated with treatment, days in the feedlot, number of papillae, papillae area, absorptive surface area, and papillae area. However, it was inversely correlated with ADG, rumenitis score, and liver abscess incidence. Animals that did not receive glycerin had greater ADG during the period (0.316 vs 0.272 kg; P = 0.075), spending less time in the feedlot (56 vs 62 d; P = 0.067), but they exhibited greater ruminitis score and liver abscess incidence values (P &lt; 0.05). On the other hand, animals that received glycerin, despite spending more time confined, showed better values (P &lt; 0.05) for number of papillae (62 vs 59 n/cm2), papillae area (0.07 vs 0.06 cm2), absorptive surface area (4.4 vs 3.91 cm2), and papillae area (90.41 vs 88.60%). In conclusion, the findings of this study highlight the potential of glycerin as a viable alternative to corn in high-concentrate diets for feedlot lambs. While animals receiving glycerin spent more time in feedlot, they exhibited improved ruminal health parameters, such as increased papillae development and surface area, suggesting enhanced nutrient absorption. These results underscore the importance of exploring alternative feed ingredients to mitigate the risk of ruminal acidosis and its associated economic and health implications in ruminant production systems. The inclusion of 30% DM crude glycerin in the total mixed diet is recommended for feedlot lambs, however, further studies must be conducted to confirm its effectiveness and safety of use.