Effect of forage type, harvesting time and exogenous enzyme application on degradation characteristics measured using in vitro technique

Autor: Torben Hvelplund, Martin Riis Weisbjerg, A. Moharrery
Rok vydání: 2009
Předmět:
Zdroj: Moharrery, A, Hvelplund, T & Weisbjerg, M R 2009, ' Effect of forage type, harvesting time and exogenous enzyme application on degradation characteristics measured using in vitro technique ', Animal Feed Science and Technology, vol. 153, no. 3-4, pp. 178-192 . https://doi.org/10.1016/j.anifeedsci.2009.06.001
ISSN: 0377-8401
DOI: 10.1016/j.anifeedsci.2009.06.001
Popis: Five forage species cut at different harvest times were studied for their degradation characteristics using in vitro digestibility technique. The forage species were two grasses and three legumes growing in two seasons (spring growth and second re-growth). Grass and legume forages were harvested at three harvesting times being early (E), middle (M) and late (L), both during the spring growth and the second re-growth. The grasses included perennial ryegrass (Lolium perenne), and festulolium (XFestulolium), and the legumes included white clover (Trifolium repens), red clover (Trifolium pratense) and lucerne (Medicago sativa). The degradation characteristics of the forage species were measured by incubating samples in vitro for up to 96 h in tubes with rumen inoculum. The effect of exogenous enzyme supplementation was studied in a 5 × 6 × 5 factorial design, with five forage species, three harvesting times for both spring growth and second re-growth and 5 enzyme treatments. Both enzyme preparations (E1 and E2) predominantly contained cellulase, and were applied as either a pre-treatment (P) or added at time of in vitro incubation (A). Incubation times were 0, 8, 24 and 96 h. Dry matter (DM) and neutral detergent fibre (aNDFom) degradation profiles were fitted to an exponential equation. The fractional rate of degradation (c) of DM or aNDFom did vary among the forage species and was highest for the legumes. The potential degradability ranged from 580 to 870 g/kg for DM and from 380 to 900 g/kg for aNDFom. For aNDFom, legumes generally had lower potential degradability and longer lag times than grasses. The effective degradability of aNDFom for forage harvested in spring growth was considerably higher than for the same forage harvested in second re-growth. Addition of the E1 and E2 to forage as a form of pre-treatment improved (Pin vitro DM (493 and 484 g/kg vs. 469 g/kg) and aNDFom (182 and 169 g/kg vs. 126 g/kg) digestibility (8 h incubation) compared with control. Data suggest that pre-treatment of forage with fibrolytic enzymes can solubilise some fibre and improve digestibilities at short incubation times. However the fibre which are solubilised by the exogenous enzymes would probably also be easily degraded in vivo, and so in vivo aNDFom digestibility would probably not be affected by a similar treatment as enzyme treatment did not enhance potential degradability of aNDFom.
Databáze: OpenAIRE
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