Effects of Lespedeza Condensed Tannins Alone Or with Monensin, Soybean Oil, and Coconut Oil On Feed Intake, Growth, Digestion, Ruminal Methane Emission, and Heat Energy by Yearling Alpine Doelings

Abstract

The primary objective was to determine if greater effects of forage condensed tannins on ruminal emission of the greenhouse gas methane could be achieved by simultaneous use of other rumen modifiers. Yearling Alpine doelings (55) consumed 75% forage diets in a 12-week trial. Alfalfa was the forage in the control (C) diet, and others consisted of Sericea lespedeza resulting in an average dietary condensed tannin level of 8.4%. Lespedeza treatments were no additive (L) and inclusion of monensin (I) at 22 mg/kg (dry matter; L-I), soybean oil (SBO) at 3% (L-S), coconut oil (CCO) at 3% (L-N), I and 3% SBO (L-I-S), I and 3% CCO (L-I-N), 1.5% SBO and 1.5% CCO (L-S-N), and I, 1.5% SBO, and 1.5% CCO (L-I-S-N). Dry matter intake (1.47, 1.27, 1.29, 1.19, 1.33, 1.14, 1.08, 1.14, and 0.98 kg/day), average daily gain (122, 79, 89, 83, 100, 76, 70, 78, and 65 g), and total tract digestibility of organic matter (57.4, 50.9, 51.8, 52.7, 50.3, 52.1, 52.1, 51.9, and 49.8% for C, L, L-I, L-S, L-N, L-I-N, L-S-N, and L-I-S-N, respectively) were greater for C than for lespedeza treatments. Ruminal methane emission was lower for diets with lespedeza relative to intake of gross energy (5.9, 3.3, 3.5, 3.2, 2.8, 2.9, 3.2, 3.2, and 3.3%) and digestible energy (11.2, 7.0, 7.4, 6.4, 5.9, 5.7, 6.4, 6.4, and 6.7% for C, L, L-I, L-S, L-N, L-I-N, L-S-N, and L-I-S-N, respectively). In conclusion, the effect of lespedeza condensed tannins on methane was not influenced by monensin, soybean oil, or coconut oil.