Effect of ensiling whole crop oat with lucerne in different ratios on fermentation quality, aerobic stability and in vitro digestibility on the Tibetan plateau

Abstract

The objective of this study was to determine the effect of ensiling different ratios of whole crop oat to lucerne on fermentation quality, aerobic stability and in vitro digestibility of silage on the Tibetan plateau. Four experimental treatments were produced varying in the ratio of forages on a fresh matter (FM) basis: 1) 100% oat (control, dry matter (DM) content: 317 g/kg), 2) 90% oat + 10% lucerne (OL10, DM content: 316 g/kg), 3) 80% oat+ 20% lucerne (OL20, DM content: 317 g/kg) and 4) 70% oat+ 30% lucerne (OL30, DM content: 318 g/kg). All treatments were packed into laboratory-scale silos and ensiled for 60 days and then subjected to an aerobic stability test for 15 days. Further, the four experimental treatments were incubated in vitro with buffered rumen fluid to study the nutrient digestibility. All silages were well preserved with low pH and NH -N contents, and high lactic acid contents and V-scores (evaluation of silage quality). Increasing the lucerne proportion increased (p < 0.05) crude protein (CP) content of silage, whereas neutral (NDF) and acid (ADF) detergent fibre contents were not affected. Under aerobic conditions, the control silage showed higher (p < 0.05) yeast counts (>10 cfu/g FM) followed by OL10 silage, and OL10 silage improved aerobic stability for 74 h. OL20 and OL30 silages showed fewer (p < 0.05) yeasts (<10 cfu/g FM) and markedly (p < 0.05) improved the aerobic stability (>360 h). After 48-h incubation, OL30 silage increased (p < 0.05) in vitro dry matter digestibility (IVDMD) and neutral detergent fibre digestibility (IVNDFD) compared with the control silage. These results suggest that replacing oat with lucerne had no unfavourable effects on fermentation quality of silage, but improved CP content, aerobic stability IVDMD and IVNDFD. OL30 silage was the best among the three mixed silages.

Comparative analysis of ensiling characteristics and protein degradation of alfalfa silage prepared with corn or sweet sorghum in semiarid region of Inner Mongolia

“…This may explain the linear decrease ( p < .05) in EE content in alfalfa and SS silages as the proportion of SS increased. Ordinarily, a pH decline accompanies an increase in organic acids during ensiling, with a higher proportion of gramineous plants, such as oats, corn, and SS, in mixed silage resulting in higher lactic acid content (Chen et al, ; Wang, Yu, Wu, & Hannaway, ; Zhang et al, ). However, it was surprising to note that the lactic acid contents in corn or SS pure silage were not higher ( p < .05) than the silages including alfalfa, instead were lower ( p < .05) than some treatments, and this was consistent with the findings of Wang et al (), who found that the inclusion of legumes in silages resulted in higher lactic acid content than that in pure corn silage.…”

“…This may explain the linear decrease (p < .05) in EE content in alfalfa and SS silages as the proportion of SS increased. Ordinarily, a pH decline accompanies an increase in organic acids during ensiling, with a higher proportion of gramineous plants, such as oats, corn, and SS, in mixed silage resulting in higher lactic acid content (Chen et al, 2017;Wang, Yu, Wu, & Hannaway, 2018;Zhang et al, 2015).…”

Ensiling characteristics, in vitro rumen fermentation, microbial communities and aerobic stability of low‐dry matter silages produced with sweet sorghum and alfalfa mixtures

“…The dried pre‐ensiled material and silage samples were analyzed for DM (934.01), CP (984.13), ash (942.05) and ether extract (EE) (920.39) in accordance with the methods of Association of Official Analytical Chemists . The WSC were determined using the method of Chen et al . Ash free neutral detergent fiber (NDF; with heat stable α‐amylase), ash free acid detergent fiber (ADF) and acid detergent lignin (ADL) were sequentially performed in accordance with the procedure of Van Soest et al .…”

“…For the microbial counts, 10 g of the sample was ten‐fold serially diluted with sterilized saline solution (0.85% NaCl). LAB, yeasts and moulds were enumerated using the method of Chen et al . The yeast and mould colonies were enumerated separately, according to their morphological appearance.…”

“…Previous studies reported that high quality silages could be achieved by ensiling mixtures of cereal grains or grasses rich in soluble carbohydrates and AF at proper ratios, whereas Jaurena and Pichard observed a minor effect on fermentation process with adding cereal grains to AF silage. Beyond effects in the silo, there is evidence that associative effects between grasses and legumes at ensiling may enhance animal performance, such as an improvement in milk yield and weight gain, when the mixed silage is fed to ruminants, even in cases where effects on animal performance were not always in accordance with changes in silage fermentation.…”