Laboratory silo type and inoculation effects on nutritional composition, fermentation, and bacterial and fungal communities of oat silage

Abstract

The objectives were to evaluate (1) the use of 2 types of experimental silos (S) to characterize whole-crop oat (Avena sativa L.) silage with or without addition of an inoculant (I), and (2) the effect of inoculation on the microbial community structure of oats ensiled using only plastic bucket silos (BKT). From each of 6 sections in a field, oats were harvested, treated (INO) or not (CON) with inoculant, packed into 19-L BKT or vacuum bags (BG), and ensiled for 217 d. The inoculant added contained Lactobacillus buchneri and Pediococcus pentosaceus (4 × 10 and 1 × 10 cfu/g of fresh oats, respectively). The experimental design was a complete randomized design replicated 6 times. Treatment design was the factorial combination of 2 S × 2 I. Some differences existed between BG versus BKT at silo opening (217 d), including a decreased CP (7.73 vs. 7.04 ± 0.247% of DM) and ethanol (1.93 vs. 1.55 ± 0.155) and increased lactic acid (4.28 vs. 3.65 ± 0.241), respectively. Also, WSC and mold counts were reduced in BG versus BKT for CON (1.78 vs. 2.70 ± 0.162% of DM and 0.8 vs. 2.82 ± 0.409 log cfu/fresh g) but not for INO (∼1.53 and 1.55), respectively. Application of INO increased DM recovery (96.1 vs. 92.9 ± 0.63%), aerobic stability (565 vs. 133 ± 29.2 h), acetic acid (2.38 vs. 1.22 ± 0.116% of DM), and reduced NDF (65.0 vs. 67.0 ± 0.57), ADF (36.7 vs. 38.1 ± 0.60), ethanol (0.63 vs. 2.85 ± 0.155), and yeast counts (1.10 vs. 4.13 ± 0.484 log cfu/fresh g) in INO versus CON, respectively. At d 0, no differences were found for S and I on the nutritional composition and background microbial counts. Leuconostocaceae (82.9 ± 4.27%) and Enterobacteriaceae (15.2 ± 3.52) were the predominant bacterial families and unidentified sequences were predominant for fungi. A higher relative abundance of the Davidiellaceae fungal family (34.3 vs. 19.6 ± 4.47) was observed in INO versus CON. At opening (217 d), INO had a lower relative abundance of Leuconostocaceae (42.3 vs. 95.8 ± 4.64) and higher Lactobacillaceae (57.4 vs. 3.9 ± 4.65) versus CON. Despite several differences were found between BKT and BG, both techniques can be comparable for characterizing effects of INO on the most basic measures used in silage evaluation. The use of inoculant improved oat silage quality partially by a shift in the bacterial community composition during ensiling, which mainly consisted of an increased relative abundance of Lactobacillaceae and reduction of Leuconostocaceae relative to CON.

Quadratic effect of the protein content of a solid state fermented baby banana (<em>Musa acuminata</em> AA) treated with whey

“…. This is due to the favorable temperature and pH conditions of the silage material (Romero et al 2017;Zhou et al (2019). In this regard, Caicedo et al (2019bc) using as taro tubers and baby banana substrates, inoculated with natural yogurt, on day 8 of fermentation, they obtained a significant protein increase, compared to the raw material in its natural state.…”

Effect of maturity stage at harvest on the ensilability of maize hybrids in the early and late FAO classes, grown in areas differing in yield potential

“…This type of ensiling usually leads to high quality silages (Romero et al, 2017), with rather low values of ethanol, acetic, butyric and ammonia, as seen by comparing the attained values with those suggested by Kung et al (2018). For this reason, it was decided to use the above reported FQI to summarize the quality characteristics of fermentation, because it proved to be particularly sensitive in diversifying the quality of fermentation between silages with low, medium and high levels of DM, obtained in laboratory conditions (Andrighetto et al, 2018).…”

Impact of field fungal contamination of barley on ensiling properties, nutritional quality and the microbiome of barley silage

“…It was also reported that the decrease in relative abundance of these fungal orders during ensiling was higher for barley, triticale and intercropped silages, with minimal change for oat silage (Duniere et al, 2017). Duniere et al (2017) and Romero et al (2017) in terminal whole-crop cereal silages.…”

“…Compared to fresh forage, these authors reported that the relative abundance of core microbiome of Hypocreales decreased from 7.0% to 1.0% and Pleosporales from 3.0% to 1.0% in terminal silage. Duniere et al (2017) and Romero et al (2017) in terminal whole-crop cereal silages. Duniere et al (2017) and Romero et al (2017) in terminal whole-crop cereal silages.…”

“…For fungal ITS sequences, the parameters were set as above, and chimeras were also removed. Non-chimeric ITS sequences were clustered into OTUs at 97% similarity with the open reference OTU picking method and the fungal UNITE database (Romero et al, 2017).…”