226 Impact of corn silage level on finishing cattle nutrient digestion, ph characteristics, and feeding behavior

Abstract

Abstract When used as a roughage source in a finishing diet, corn silage can have different effects on digestion compared to hay because of the presence of additional corn grain. The objective of this study was to determine the effects of corn silage inclusion level on cattle digestion and feeding behavior. In a digestion study, 3 ruminally cannulated steers (430 kg ± 0.20 kg) were utilized in a generalized randomized block design with 8 periods. Treatments consisted of 3 levels of corn silage included at 0, 7.5 and 15% of the diet DM and a control treatment with 15% alfalfa. Results showed DMD, OMD, NDF digestibility, and ADF digestibility were greatest for cattle fed CS0 followed by CS7.5, CS15, and Alf (P < 0.01). Average ruminal pH was least for CS0, CS7.5 was intermediate, followed by Alf and CS15 with the greatest pH (P < 0.01). Total VFA production was greatest in cattle fed CS0 followed by CS7.5 and Alf with CS15 having the least. Acetate to propionate ratio was least for cattle fed CS0, intermediate for CS7.5 and CS15 and greatest for Alf. Cattle ate the same number of meals which were similar in size as a % of total DMI (P ≥ 0.60). However, cattle fed Alf and CS0 spent more time eating compared to cattle fed CS7.5 and CS15 (P = 10). The rate of intake (kg/hr) was greatest for CS15 (9.55) and decrease linearly for CS7.5 (9.44), Alf (8.12) and least for CS0 (7.68; P = 0.04). These data suggest that cattle, typically at high risk for reduced performance, are susceptible to negative effects of high grain diets, like acidosis, when fed no or low inclusion of roughage. Feeding silage at 15% was similar to feeding alfalfa at 7.5%.