Study Questions - Dr. Grosche (8Q)

Question 1

During the first six months of gestation, the (abomasum/rumen) develops most rapidly, while during the last trimester the (abomasum/rumen) develops most rapidly. After birth, the (abomasum/rumen) continues to grow as a percentage of total GI tract weight, while the growth of the (abomasum/rumen) as a percentage of total GI tract weight remains fairly constant.

Answer 1

abomasum
rumen
rumen
abomasum

Question 2

The main site of microbial digestion in ruminants occurs in these two organs:

Answer 2

rumen, reticulum

Question 3

Briefly describe the role of ruminal papillae.

Answer 3

increase surface area for absorption of VFAs via diffusion to luminal veins > hepatic portal vein > liver

Question 4

Briefly describe the influence of feeding hay and grain on rumen development.

Answer 4

Both promote rumen development. Hay contributes to development of the rumen wall muscle and volume, while grain stimulates microbial fermentation and production of VFAs for development of rumen epithelium and papillae.

Question 5

Briefly describe the feeding disorder that occurs and the physiological mechanisms that take place when ruminants consume too much grain.

Answer 5

Grain is highly fermentable and shifts VFA production to proprionate, so the rumen becomes acidic from the elevated production of VFAs and conversion to lactate leading acute rumen acidosis

• Can lead to rumen distension/bloat, which inhibit rumen motility and can lead to. death
• a highly acidic environment in the rumen will also severely affect the cellulolytic and methanogenic bacteria and Protozoa