The effect of fibrolytic enzyme, Lactobacillus plantarum and two food antioxidants on the fermentation quality, alpha-tocopherol and beta-carotene of high moisture napier grass silage ensiled at different temperatures

Abstract Alpha-tocopherol and beta-carotene of forage are antioxidants and play important roles in the immune system of ruminants. Fermentation quality, alpha-tocopherol and beta-carotene of high moisture napier grass ( Pennisetum purpureum cv. Mott) ensiled without or with additives (fibrolytic enzyme, EN; Lactobacillus plantarum , LP; tert-butylhydroquinone, TBHQ; tea polyphenols, TP) at 15 °C, 30 °C and 45 °C were examined in the present study. After ensiling for 70 days, untreated silages had lower ( P P P P P P P P P P P P P P P P  99) than at 30 °C (V-score   83), and TP lowered fermentation quality (V-score = 74.5). Silage ensiled at 30 °C increased alpha-tocopherol content and lost beta-carotene slightly. Additives did not reduce alpha-tocopherol and beta-carotene loss at any temperature, except for TBHQ ensiled at 45 °C. The interactions between additives and preservation temperatures indicated that TP ensiled at 30 °C had the poorest fermentation quality, LP and TBHQ ensiled at 30 °C had lower alpha-tocopherol loss, and TBHQ and TP ensiled at 30 °C had lower beta-carotene loss. TBHQ might be a valuable additive to ensile napier grass at 15 °C, 30 °C and 45 °C, and to reduce beta-carotene loss of napier grass silage at 45 °C.