O level Notes : Agriculture - Animal nutrition

Maintenance and production rations

 In the previous forms, we learnt about livestock nutrients and types of livestock feeds. This was to explain the nutrients that are required by different types of livestock for growth and development. These are, proteins, carbohydrates, minerals, vitamins, water, and fats and oils. Roughage is the last one which is not necessarily a nutrient but an important ingredient of food that aids digestion by preventing constipation.

Roughage also creates a suitable environment for the actions of digestive enzymes. The primary purpose of this section is to train you in the correct way of determining the quantities of food that an individual animal can survive on per day without gaining or losing weight. This section of the chapter shall also discuss how to determine the quantities of food that can enhance production in an animal, depending on the type of animal, age, sex, body mass and purpose for which the animal is kept. In fact, several factors are considered in order to come up with a comprehensive feeding program for a given animal. There are therefore two types of feeds for animals, namely, maintenance and production rations.

 Maintenance rations

 A ration is a specific quantity of food that is given to an animal per day. For maintenance, the quantity is measured so that it is only enough to keep the animal alive and doing only the necessary daily life activities. A critical analysis is done on the given animal so that accurate food quantities are brought about without disadvantaging the concerned animal. The ration in this case does not allow the animal to produce any products such as meat, milk, draught power. Therefore, the ingredients and the feed nutrients should be so balanced in each case that each class of food does not cause unplanned deficiencies or gains but only maintenance.

 The major classes of food for this purpose are carbohydrates, proteins, minerals, fats and oils, as these give an immediate response to production. Depending on the requirement of the animal, each class of food is demanded accordingly for maintaining the life processes at hand. For example, proteins are needed for keeping the body cells in healthy state, repairing those worn out, maintaining blood cells in correct quantity, including the protoplasm, the enzymes, hormones and the critical body fluids.

 The process of keeping all these at the correct levels without decreasing or increasing is called maintenance and the correct amount of food needed for this process is a maintenance ration for protein levels. On the carbohydrates side, all energy required for the daily body movements of the muscles, digestion and locomotion without gaining or losing weight, is supplied from a maintenance ration of carbohydrates including fats and oils. No extra energy is required for doing work if the ration is for maintenance of biological body processes.

 For real maintenance of the animal, the quality of food is very important. Its digestibility plays a big role in the effectiveness of the maintenance process. A feed that requires too much energy to break down will disadvantage the animal when it requires too much energy for breaking it down and absorbing it. Maintenance rations are also critical during times of food scarcity when farmers want to keep animals in good shape, for example, during winter in grazing animals when the grass has lost much on protein levels.

 In indoor livestock, maintenance feeding only occurs when animals are rested from production for a specified period for them to regain production, like layers that are molting, or sows that have been weaned from their piglets. The reason that production is suspended for a given period makes it mandatory to feed the stock concerned with maintenance rations just to keep them in good health. When production is required, an additional amount of food is allowed per individual stock to boost production. That is called a production ration.

 Production ration

 As the term implies, this type of ration is for producing products. If it is a layer, it should produce eggs. A broiler should produce meat; a baconer pig, meat; a dairy cow, milk; and a wool sheep, wool, among others. What is required is that for whatever production, the producing livestock should be compensated for producing that product through production ration. This is calculated by adding a percentage of the maintenance ration to it so that the final ration increases in quantity and it becomes a production ration.

 Calculating production ration

 If the maintenance ration of a non-pregnant sow (pig) is 1.4 kilograms of pig meal (sow and weaner meal) per day and the requirement for a pregnant pig is 25% more, then the production ration should be: (1.4 kg x 0.25) + 1.4 kg = 1.75 kg pig meal per day. This ration is a production ration because it is for the production of a young pig in the uterus. Such requirements vary from animal to animal depending on the nutritional requirements and type of feed.

Other calculations

 As already stated above, the quantity of a ration entirely depends on the following:

•  Type of animal
•  Age of animal
•  Purpose for which animal is kept
•  Type of food
•  Quality of food
•  Nutritional value of the food

 Nevertheless, certain groups of livestock do not need to be fed with maintenance rations at any stages of growth. This is because they have no purpose for maintenance, for example, meat producing broilers. Only production rations are important till slaughter. There is no time or stage in the growth of broilers when maintenance feeding is required because that will compromise meat quality and quantity.

For example, a layer bird is able to maintain its health when fed on 80 grams of layers mash per day without laying an egg. This is its maintenance feed requirement. When another 22grams of layers mash per day is added, the bird starts laying an egg per day. The 22 grams layers mash per day, given above the 80 grams maintenance ration is now the production ration.