PRACTICE QUESTIONS
1. In which of the following respects is fermentative digestion different from glandular digestion?
a. Enzymes are not involved in fermentative digestion.
b. Chemical bonds are not split by hydrolysis in fermentative digestion.
c. Only carbohydrates are digested by fermentative digestion.
d. Substrates are more extensively altered in fermentative digestion than in glandular digestion.
e. Proteins are digested to amino acids by fermentative digestion and to dipeptides by glandular digestion.
2. In a comparison of hindgut fermentation and forestomach fermentation, which of the following statements is true?
a. The microbial populations are considerably different, but the products of digestion are the same.
b. The microbial populations are the same, but the products of digestion are considerably different.
c. Both the microbial populations and the digestion products are similar.
d. Structural carbohydrates of plants are not digested by hindgut fermentation.
e. A nitrogen source is not required by the microbes of the hindgut.
3. The three VFAs—acetate, propionate, and butyrate—are:
a. Net-reaction products of the fermentative action of the entire rumen biomass.
b. The individual products of cellulose, starch, and hemicellulose digestion, respectively.
c. The individual products of bacterial, protozoal, and fungal digestion, respectively.
d. Volatile products that leave the rumen with the gas phase during eructation.
e. Intermediate metabolites that are passed between microbial species.
4. Matching protein and energy availability in the rumen is an important nutritional goal in feeding ruminants. Which of the following completions of this statement concerning protein and energy availability in the rumen is false? Diets well matched in available protein and energy result in:
a. The most efficient use of energy for microbial growth.
b. Maximal delivery of protein to the host.
c. Minimal breakdown of protein in the rumen.
d. Loss of a minimal amount of dietary amino acids due to formation of excess ammonia.
e. Optimal rumen ammonia concentrations.
5. Which of the following statements is true of both methane and propionate?
a. They are waste products of anaerobic fermentation but contain potential energy that is recoverable by the host.
b. They are highly oxidized molecules.
c. They are eructed from the rumen.
d. Their formation results in the generation of NAD from NADH.
e. They are toxic to monogastric animals.