VPB 121: Veterinary Physiology - II (2+1)

GASTRIC SECRETION IN RUMINANTS

Gastric secretion

• Abomasum is the only part of the ruminal stomach secreting digestive juices.
• Fundic abomasums is rich in HCl, pepsin and in young ruminant rennin- a milk coagulating enzyme is found.
• pH of abomasal juice is approx 1.0 to 1.3.
• Buffered ingesta with volatile fatty acids entering abomasum increases abomasal secretion.
• Regulation of abomasal secretion is compelx. It involves humoral and neural factors.
• Gastrin, G.I tract hormone is secreted by abomasal mucosa in response to cholinergic stimuli.

Absorption

• Ruminal wall is composed of stratified, squamous, highly vascular which facilitates transport of nutrient and other components from rumen to blood and vice versa.
• Water, electrolytes, volatile fatty acids, alkaloids, iodide, sodium cyanide, potassium ion and are readily absorbed from the rumen.
• 60 to 70% of the digestible organic matter is readily absorbed from the rumen and other two compartments.