341 Effect of Multispecies Fungal Culture Extract Supplementation on the Growth Performance and Carcass Characteristics of Feedlot Cattle

Abstract

Abstract To evaluate the effect of supplementing feedlot cattle with a multispecies fungal culture extract (MFE; Aspergillus flavus, Aspergillus niger, Aspergillus oryzae, Aspergillus terreus, Phlebia radiata, Pyricularia oryzae, Stropharia coronilla, Thanatephorus cucumeris, Trichoderma longibrachiatum, Trichoderma reesei, Trichoderma viride) in growth performance and carcass characteristics, Angus × SimAngus-crossbred steers (n = 14) and heifers [n = 46; body weight (BW) 344 ± 21 kg] were used in randomized complete block design. Cattle were blocked by BW and housed in 4 feedlot pens (randomly assigned 2 pens per treatment) where a hay-based diet was fed for 84 d (backgrounding), followed by a ground corn-based finishing diet. Subsequently, cattle were harvested upon reaching desired 12th rib fat thickness (2.0 cm). Diets were offered ad libitum and with (MFE) or without (CON) the inclusion of the multispecies fungal culture extract supplement. Steers were weighed at 28-d intervals throughout the experimental period and carcass data were provided by a USDA grader. All data were analyzed using the PROC MIXED procedure of SAS considering the fixed effect of treatment and sex, and the random effect of block and pen (block). During the 84-d period of the backgrounding phase, feeding MFE increased (P = 0.05, Table 1) the average daily gain (ADG) by ~10%, and tended to increase (P = 0.06, Table 1) the dry matter intake (DMI). No differences were observed in the gain to feed ratio (G:F) between treatments (P = 0.67, Table 1). At the conclusion of the 84-d period, cattle fed MFE were heavier (P = 0.04, Table 1) than cattle in the CON treatment. In the finishing phase, no treatment differences were observed (P ≥ 0.36) for the ADG, DMI, and G:F. At the end of the experiment, cattle supplemented with MFE were heavier (P = 0.04, Table 1) than cattle in the CON treatment. The quantity of days on feed in the finishing diet required to reach harvesting target was not different (P = 0.60) among treatments. For the carcass characteristics, dietary inclusion of the MFE tended to increase the hot carcass weight (P = 0.10, Table 2) and increased the marbling score (P = 0.01, Table 2). No treatment effect was detected (P ≥ 0.25, Table 2) for the dressing, longissimus muscle area, 12th rib fat thickness, kidney-pelvic-heart fat content, and yield grade. Results from this study suggest that dietary inclusion of a multispecies fungal culture extract might improve the growth performance of beef cattle fed forage-based diets, as well as their carcass characteristics after conclusion of the feedlot finishing phase.