Concepts In Livestock Production 2022 PDF

CONCEPTS IN LIVESTOCK PRODUCTION Chapter 5 Lecture 2 ANIG1624 Dr R. Grobler Nutrition The process by which an organism obtains food which is used to provide energy and materials for its life sustaining activities The science to study the relationship betw...

CONCEPTS IN LIVESTOCK PRODUCTION Chapter 5 Lecture 2 ANIG1624 Dr R. Grobler Nutrition The process by which an organism obtains food which is used to provide energy and materials for its life sustaining activities The science to study the relationship between nutrient intake and animal life and production Nutrients is converted into various animal products Food production is the main objective Nutrition Nutrient The components of food capable of being utilized by animals for maintenance of life and production purposes Single element (Fe, Cu) or a complex chemical compound composed of different units (starch or protein) E.g. fats, carbohydrates, proteins, vitamins, etc. Also include selected elements that are incorporated into certain molecules synthesized by cells Nutrition Productivity Refers to the ability of an animal to grow, reproduce and produce outputs such as milk, wool, draught power and transport Influenced by various factors Nutrition Two major feed groups in livestock feeding Concentrates Low in fibre High in energy (total digestible nutrients) E.g. grains (e.g. maize), molasses, oil meals Roughage High in fibre Low in energy (total digestible nutrients) E.g. hay, silage, and pasture  Nutrition Digestion Process of breaking down and dissolving feeds so that the body can absorb them Three types of digestion - mechanical, chemical & microbial Mechanical digestion Grinding or chewing food to aid in digestion Muscle contraction of the digestive system to break down food Chemical digestion By enzymes secreted by the digestive system Nutrition Microbial digestion Microbes secretes enzymes to digest compounds that the enzymes secreted by the animal itself cannot digest e.g. cellulose Carbohydrate portion of the cell wall Livestock cannot digest cellulose unless it is first broken down by cellulase that is secreted by microorganisms Bacteria, protozoa and fungi In non-ruminant animals - microbial fermentation occurs mainly in the large intestine Nutrition Digestibility - degree in which nutrient is digested Absorption - passing of nutrients from the digestive system into the body after they are digested and dissolved Absorption Process where nutrients passes into the cell and into fluid surrounding the cell and transported by blood stream to liver and other parts of the body to participate in metabolism  Nutrition Metabolism - sum of all the physical and chemical processes taking place in living organism Anabolism – synthesis of simpler molecules into complex compounds Catabolism – breaking down of complex compounds to simpler molecules Monogastric vs ruminant Livestock can be classified either as non-ruminants (monogastric) or ruminants according to their digestive system Monogastric animals – one stomach Ruminant animals – stomach can be divided into four different parts Monogastric vs ruminant Monogastric Stomach consist of one compartment Nonruminant animals need a high-energy, low-fiber ration, such as grain Monogastric vs ruminant Ruminants Stomach consist of four compartments i. Rumen, ii. reticulum, iii. omasum, iv. abomasum The rumen contains microorganisms (bacteria and protozoa) that allows ruminants to digest many of the feed non-ruminants cannot use effectively i.e. large quantities of roughage Monogastric vs ruminant Ruminants Ruminant animals can digest large quantities of fibrous feeds, such as hay and pasture, via the rumen Ruminants are cud-chewing animals Regurgitate their food (process by which food eaten by a ruminant is carried from the second stomach and the rumen into the gullet, and then forced up to the mouth for chewing) Chewing (mechanical digestion) increases surface area available to bacteria Nutrition Strategic feeding Specific feed fed to animals during different stages based on the requirements needed during that period e.g. during the winter, the protein content of the veld is lower and needs to be supplemented by feed with a higher energy content in order to promote growth, flush feeding, creep feed, etc. Nutrition Flush feeding Common practice in intensive small stock farming operations Feeding the female animal (normally the ewe) extra during mating so she is gaining weight to increase the lambing percentage Extra feed (energy) prior to mating to increase body weight Flush feeding Nutrition Creep feeding The practice of feeding young farm animals with a supplemental feed before they are weaned (especially piglets, calves and lambs) Fed in a sectioned-off part of their indoor environment, in order to prevent the mother from gaining access to the food Creep feeding helps to supplement the milk from the mothers and extend your grazing season Nutrition The most common objective of creep feeding is to increase the growth rate of nursing animals Other benefits include: Producing a more uniform animal crop Reducing weaning stress on young animals Allowing young and/or thin female animals to enter the post nursing period in better condition Nutrition Compensatory growth Ability of an animal to recover growth after periods of underfeeding Nutrition Body condition The condition of an animal is reflected in the proportion of body fat and muscle on its carcass It is generally a more reliable indicator of an animal's nutritional status than body weight since variations in the latter may merely result from changes in gut fill, body water, parturition etc. Nutrition Feed conversion ratio (FCR) The amount of body weight gained for every kilogram of feed consumed Body weight gained/kg feed consumed If an animal gained 1.2 kg after consuming 1 kg of feed, then the FCR is 1.2 Average daily gain (ADG) The average daily liveweight increase of a growing animal, usually expressed in kilograms or grams per day ADG is calculated thus: weight gain / number of days on feed