Microbial community dynamics during alfalfa silage with or without clostridial fermentation

Area of Science:

• Agricultural Science
• Microbiology
• Animal Nutrition

Background:

• Clostridial fermentation negatively impacts silage quality and nutrient value.
• Understanding bacterial dynamics in silage is crucial for effective preservation.

Purpose of the Study:

• To investigate the effects of Lactobacillus plantarum (LP) and sucrose (S) on clostridial communities in alfalfa silage.
• To analyze the correlation between clostridia and other bacterial populations during ensiling.

Main Methods:

• Alfalfa was ensiled with or without additives (LP, S, LP+S) for varying durations (7-56 days).
• Bacterial and clostridial communities were analyzed using next-generation sequencing.
• Key fermentation products like butyric acid and ammonia nitrogen were quantified.

Main Results:

• Untreated silage (CK) showed severe clostridial fermentation with high butyric acid and ammonia nitrogen.
• Additives, particularly LP+S, decreased silage pH and inhibited clostridial fermentation.
• Clostridium tyrobutyricum dominated untreated silage but was suppressed by additives.

Conclusions:

• Lactobacillus plantarum and sucrose effectively suppress clostridial fermentation in alfalfa silage.
• Insufficient acidification promotes Clostridium tyrobutyricum growth, leading to poor silage quality.
• Additives improve silage fermentation by inhibiting detrimental clostridial species.