Assistant Laboratory Animal Technician (ALAT) Practice Exam

What physical characteristic do ruminants have that aids in fiber digestion?

1. Single-chambered stomachs

2. Multi-compartmentalized stomachs

3. Fermentation chambers

4. Long intestines

The correct answer is: Multi-compartmentalized stomachs

Ruminants possess a multi-compartmentalized stomach that is specifically adapted to break down fibrous plant materials more efficiently than simpler stomachs found in non-ruminants. This complex digestive system typically consists of four distinct chambers: the rumen, reticulum, omasum, and abomasum. The rumen is the largest compartment and acts as a fermentation vat where microbial activity breaks down cellulose, a major component of plant fiber. This fermentation process allows ruminants to extract nutrients that would otherwise be inaccessible. The multi-chambered structure allows for a specialized environment in each compartment, facilitating efficient digestion and absorption of nutrients from fibrous sources. Ruminants regurgitate and re-chew their food, known as "rumination," which further helps in breaking down fibers and maximizing nutrient absorption. This unique adaptation is fundamental for ruminants, enabling them to thrive on a high-fiber diet primarily consisting of grasses and plants. Other characteristics like long intestines and fermentation chambers are also relevant to digestion but are not as critical as the multi-compartmentalized stomach structure that plays a central role in fiber digestion.