AGR 1.6 Demonstrate knowledge of livestock management practices External 5 Credits

Topics Feed Management Practices Breeding Management Practices Health Management Practices

Feed Management Practices Digestive Systems – Ruminant vs. non-ruminant Feed Management – the nutritional value of feeds – digestibility – feed requirements of maintenance, growth, pregnancy and lactation

Digestion Farm animals have 2 types of digestion systems – Ruminant (sheep, cattle, goats, deer) – Non-ruminant (horses, pigs and birds) These systems have evolved to digest different types of food

Digestion The digestive system changes food nutrients into compounds that are easily absorbed into the bloodstream and can be used by the body

Ruminants Sheep, cattle, goats and deer Eat mainly plants (herbivores)

Ruminant Digestion Sheep, cattle, goats and deer Eat mainly plants (herbivores) Ruminants have four stomachs – needed to break down the tough cellulose that make up the cell walls of plants Bacteria are present in the first 3 stomachs to help break down cellulose contained in plants Enzymes and stomach acid help to digest food in the fourth stomach video

Ruminant Digestion

Task Read the information sheet and use it to help you complete the table

The digestive system of ruminant animals includes the : Mouth - grasps the food Teeth - grind the food – Ruminants have only one set of teeth in the front of the mouth (incisors), and two sets in the back (molars). Salivary glands - secrete saliva, that moistens food and is mixed with the food material to aid in swallowing. Oesophagus- connects the mouth to the stomach

Ruminant digestive system Rumen- large muscular stomach – Bacteria release digestive enzymes to break down cellulose – Strong muscular walls to mix contents – Lined with papillae which increase the surface area for absorption – Warm (37°C), pH 7, anaerobic conditions assist digestion

Papillae in Rumen

Ruminant digestive system Reticulum- the second stomach – Looks like honey-comb – Food is further broken down by microbes

Reticulum - full

Reticulum - cleaned

Ruminant Digestive Systems Omasum- third stomach – grinds and squeezes feed and removes 60-70% of the water

Omasum - full

Ruminant Digestive Systems Abomasum- forth stomach – It secretes a strong acid and many digestive enzymes – enzymes digest proteins – stomach acid kills the microbes so they can be digested

Abomasum – inside view

Ruminant digestive system Small intestine – Most food nutrients are absorbed from the villi in the small intestine – The food material is continually squeezed as it is moved through the small intestine, becoming more solid

Ruminant digestive system Caecum - microbes digest any remaining cellulose Large intestine- main function is to absorb water before waste material is pass out of the anus animation

Do now 1.Name the order of stomachs involved in ruminant digestion? 2.Why do cows have 4 stomachs? 3.How do bacteria in the first 3 stomachs help to digest grass? 4.Which digestive structures absorb water? 5.What is the function of papillae in the rumen? Rumen, reticulum, omasum, abomasum To break down cellulose Produce digestive enzymes that breakdown cellulose Omasum and large intestine Increase surface area for absorption of broken down food

Ruminant Digestion video

Ruminating Ruminating or ‘chewing the cud’ involves bringing plant material from the rumen back up to the mouth. In the mouth, ‘cud’ is further ground and crushed using the teeth, and re- swallowed down into the rumen. ‘Chewing the cud’ is necessary because coarse plant material must be broken down so that digestion by bacteria can be carried out link

Advantages of Ruminant Digestion It can digest cellulose Micro-organisms make vitamin B, needed by the animal The animal obtains protein when micro- organisms are themselves broken down and their breakdown products absorbed

Disadvantages of Ruminant Digestion Animals must spend a large part of the day eating and ruminating Rapid changes of diet can be harmful, animals need time to build up suitable micro-organism population in the gut Methane gas is given off when food is broken down by microbes in the rumen. Animals may become susceptible to bloat if excess gas builds up which can cause death.

Bloat Gases are produced by bacteria as a by- product during the breakdown of plant material in the rumen.

Questions 1.Describe 3 features of the rumen that help cows digest plant material. 2.a) What does “chewing the cud” mean? b) Describe the process of “chewing the cud” c) Why it is important? 3.Why are bacteria important for digestion in ruminants? 4.a) What causes methane gas to be produced in the rumen? b) Why is it important that the gases are burped out?

Do now The rumen has a neutral pH, is warm, has lots of food and no oxygen. Explain how these conditions help bacteria to break down plant material Bacteria in the rumen are anaerobic, sensitive to pH and require warmth and food for reproduction. This results in greater microbial activity for breaking down plant material.

Non-ruminants Non-ruminant animals (e.g. horses, pigs and birds) Eat small amounts of plant material as well as other types of food Only have 1 stomach (monogastic) Digest food by chemical digestion (enzymes and acids) in the stomach Cannot digest cellulose in the stomach – Bacteria in the caecum digest cellulose

Non-ruminant digestion video

Task Match up the structures that make up the monogastric digestive system with their functions. When you think you have them all correct, check with me and then copy them into your book

Structure and Function Mouth – lips and tongue mix food. Teeth rip, grind and chew food. Enzymes in the saliva begin to digest the starch. Oesophagus – Contractions of the muscles help to carry the food from the mouth into the stomach

Structure and Function Stomach – Food is mixed with gastric juices, which begin to break down protein Small intestine – Enzymes continue chemical breakdown of food. The food is then absorbed through the villi into the bloodstream

Structure and Function Caecum – the caecum holds food while bacteria secrete enzymes that digest some cellulose Large intestine – Absorption of water and some vitamins and minerals. Waste material is stored in the rectum before its excreted through the anus

Task Put the cards under the correct headings – ruminant or non-ruminant

Fast Finisher Questions 1.The digestive systems of cattle and pigs differ from one another in the mouth and stomach. Describe ONE difference between cattle and pigs in these parts of the digestive system. – Difference in the mouth – Difference in the stomach 2.Describe how a horse’s digestive system breaks down lucerne hay plant material and explain why this results in only partial digestion