Digestive System

Overview

Put a pig and a goat in the same paddock in Jos and feed them nothing but dry maize stover for a week. The goat holds its condition. The pig loses weight fast. Both animals have a mouth, a stomach and intestines, so the difference cannot be that one eats and the other does not. The difference is what happens between the mouth and the intestine, and that is the whole subject of this lesson.

You will trace two digestive tracts organ by organ: the pig's simple, single-chambered system, and the cow or goat's four-compartment ruminant system. You will meet the rumen's population of microbes, the only workforce on the farm that can actually break down cellulose, and see exactly why a compound stomach turns rough, fibrous, cheap feed into meat and milk. Nearly every later topic on nutrition and feeding assumes you already know this system cold, so build it carefully now.

Objectives

  1. Identify the parts of the digestive system of a monogastric animal
  2. Identify the parts of the digestive system of a ruminant animal
  3. Distinguish between the digestive system of a monogastric and a ruminant animal
  4. Explain the process of digestion in farm animals
  5. State the functions of the four compartments of the ruminant stomach

Lesson Note

A feed salesman in Ilorin once sold a smallholder a sack of poultry-style concentrate for her two goats, promising faster gains than grazing. Within a fortnight one goat was bloated and off its feed. The salesman had ignored something a WAEC candidate must know cold: a goat's stomach is not built like a chicken's or a pig's, and feeding it the wrong way disturbs an entire population of living microbes inside it. Knowing how a gut is built, not just that it exists, is what separates sound livestock management from an expensive mistake.

Lesson Evaluation

Congratulations on completing the lesson on Digestive System. Now that youve explored the key concepts and ideas, its time to put your knowledge to the test. This section offers a variety of practice questions designed to reinforce your understanding and help you gauge your grasp of the material.

You will encounter a mix of question types, including multiple-choice questions, short answer questions, and essay questions. Each question is thoughtfully crafted to assess different aspects of your knowledge and critical thinking skills.

Use this evaluation section as an opportunity to reinforce your understanding of the topic and to identify any areas where you may need additional study. Don't be discouraged by any challenges you encounter; instead, view them as opportunities for growth and improvement.

  1. Which of the following is the correct order in which feed passes through the compartments of a ruminant stomach? A. Reticulum, rumen, abomasum, omasum B. Rumen, reticulum, omasum, abomasum C. Omasum, reticulum, rumen, abomasum D. Rumen, omasum, reticulum, abomasum Answer: B
  2. The true, glandular stomach of a ruminant, which secretes hydrochloric acid and pepsin, is the: A. Rumen B. Reticulum C. Omasum D. Abomasum Answer: D
  3. The main compounds absorbed from the rumen as an energy source, produced by microbial fermentation of fibre, are called: A. Amino acids B. Volatile fatty acids C. Simple sugars D. Bile salts Answer: B
  4. Which organ in the pig performs a fermentation role broadly similar to, but much smaller than, the ruminant rumen? A. Duodenum B. Caecum C. Oesophagus D. Reticulum Answer: B
  5. The regurgitation and re-chewing of partly fermented feed by a ruminant is known as: A. Peristalsis B. Egestion C. Rumination D. Mastication Answer: C

Past Questions

Wondering what past questions for this topic looks like? Here are a number of questions about Digestive System from previous years

Question 1 Report

(a) State four ways in which livestock 1s important

(b)i. Mention sIx organs associated with the digestive system in rabbits.

(ii) State two functions of the alimentary canal in livestock

(c)i. State lour functions of the liver in farm animals

(ii) Mention two parasites that could be found in the liver of cattle

(d) State two differences between the digestive s systems of a goat and a rabbit