UTILIZATION OF ENSILED OR ACID-TREATED HIGH-MOISTURE SHELLED CORN BY CATTLE

Abstract

Shelled corn of approximately 25% moisture was artificially dried (DC), ensiled (HMEC), or preserved either with 1.25% of a 60:40 mixture of acetic and propionic acids (HMAP) or with 1.00% propionic acid (HMP), and was examined for chemical and physical differences. Diets consisting of 66% corn (dry matter basis) were fed in a 4 × 4 latin square arrangement of treatments to four rumen and abomasal fistulated yearling heifers. High-moisture (HM) corn diets were more (P < 0.05) digestible in dry matter (77.4 vs. 74.2%) and energy (75.4 vs. 72.4%) than was the DC diet. Acid-treated corn diets had higher (P < 0.05) starch digestibility (95.6 vs. 91.7%) than DC diets. HMP diet was superior (P < 0.05) in starch digestibility to HMEC and significantly (P < 0.05) higher in nitrogen digestibility than was DC. Rumen ammonia nitrogen levels were higher (P < 0.05) on HMEC than on HMAP diet. Significantly (P < 0.05) higher total quantities of propionic and butyric acids in rumen fluid were observed on HMP diet and the quantity of total rumen volatile fatty acids tended to be higher on HMP than on other diets. Results suggest that HM corn diets move through the reticulorumen more slowly and experience greater digestion in this area than does DC diet.