Microbiological profile and aerobic stability of Tifton 85 bermudagrass silage with or without vacuum and microbial inoculants

Abstract

ABSTRACT:This study aimed to evaluate the microbiological profile and aerobic stability of grass silage Tifton 85, with or without vacuum, and with or without microbial inoculants. The experimental design was completely randomized in a 2 x 2 factorial design, where the treatments included five replicates, with and without vacuum or addition of inoculants. The inoculum consisted of lactic acid bacteria (LAB), specifically Lactobacillus acidophilus, at a concentration of 3 x 10 9 CFU mL -1 per mL. The analyzed variables included the microbiological profile after opening the silage, as well as the aerobic stability at the time of opening on the sixth day of the silage's exposure to oxygen. It was found that no variation occurred in the population of lactic acid bacteria between the applied treatments. The Bacillus population was lower irrespective of the inoculant application, since it was applied in vacuum. When the population of Clostridium was applied, there was a reduction in the inoculant population in the vacuum system compared to that of the non-vacuum system. Without applying the inoculant, there was also a reduction in the population of Clostridium in the non-vacuum system. The yeast population showed linear growth in all of the evaluated treatments from the first to the sixth day of exposure to air, which may have contributed to the high temperatures observed during the air exposure period. There was no growth of fungi in the silage during the period of exposure to oxygen. The breaking of the aerobic stability occurred from the 3rd day after opening the silage. The pH was below the level that is considered to be good for silage preservation at the time of opening. In addition, during the exposure to oxygen, the same phenomenon occurred with the temperature, which demonstrated a quadratic behavior during the study period. Under the conditions evaluated, Tifton 85 bermudagrass silage lost its stability after the third day of exposure to air.

Quality of Tanzania grass (Panicum maximum) haylage in relation to plant dry matter content

“…The pH values observed in the Tanzania grass haylages were higher than those observed by Coblentz et al (2016) in the alfalfa haylage (5.1), which was almost similar to those observed by Nath et al (2018) in the haylage of Tifton 85 grass (5.72) and lower than those obtained by Weirich et al (2018) in the Tifton 85 haylage (7.38). The high pH values observed in the haylage of tropical grasses may be due to the low concentration of organic acids in the masses of these species (3).…”

“…Haylage treated with 600 g/kg DM had the highest surface temperature, probably because of the high amounts of CHO. Better haylage fermentation patterns with higher DM content provide a greater number of available substrates for the consumption of microorganisms in the aerobic phase (61).…”

“…The preservation of grass in the form of haylage is an option for forage grasses with high moisture content because dehydration of the material increases DM content, which reduces proteolysis, secondary fermentation, and pH buffering in the stored material (23). The moisture content of the forage plant is one factor that influences the microbial profile of the forage mass preserved by fermentation (61). When harvested, tropical grasses have a high moisture content accompanied with low levels of soluble carbohydrates (CHO) (49), which favors the occurrence of undesirable fermentation as the grass is preserved.…”

Isolation and identification of lactic acid bacteria in fresh plants and in silage from Opuntia and their effects on the fermentation and aerobic stability of silage

“…Conversely, a fascinating observation was the presence of enterobacteria and Y&M at the end of the fermentative process. These were present despite the final pH being below that recommended for enterobacteria (Weirich et al ., 2018) and despite the amount of acetic fermentation, which would normally inhibit fungi and yeasts. Kung Jr et al .…”