ANSC Feeds Practice Exam

What is a significant outcome of the pH decrease during the ensiling process?

1. Increased protein synthesis

2. Stimulation of aerobic respiration

3. Inhibition of bacterial growth

4. Promotion of mold growth

The correct answer is: Inhibition of bacterial growth

The decrease in pH during the ensiling process is a crucial aspect of food preservation for silage. As the pH lowers, it creates an acidic environment that inhibits the growth of spoilage organisms and pathogenic bacteria. This is significant because it helps maintain the quality of the silage and prevents fermentation from going awry, which can lead to undesirable changes in flavor, texture, and nutritional content. The lower pH supports the growth of lactic acid bacteria, which are beneficial in the fermentation process, while simultaneously suppressing harmful bacteria that could otherwise compromise the silage. In the context of the other options, increased protein synthesis is generally associated with a stable, optimal pH rather than a decrease, as high acidity can sometimes reduce protein availability. Stimulation of aerobic respiration is counterproductive during ensiling, as aerobic conditions would encourage spoilage rather than the preservation process. Lastly, while some molds can thrive in various conditions, a lower pH typically inhibits mold growth, especially in the context of well-fermented silage. Thus, the outcome of pH decrease is fundamentally aimed at preserving and improving the quality of silage by inhibiting unwanted bacterial growth.