Agricultural Science Notes Grade 9-2

]Sources of food

Feed or feedstuff refers to any material fed to livestock, whether natural or artificial.

Feed may be classified according to the predominant nutrient or nutrients they contain. The main groups are:

• Basal feeds

• Supplements

• Concentrates

• Forages

• Additives

Basal feeds: these are energy feeds and are therefore a source of carbohydrates and/or fats. These feeds include molasses, cereal grains such as maize, barley and oats. Basal feeds make up 60% - 90% of livestock ration.

Supplements – these are feeds given to animals in order to supply a deficient nutrient. They are usually rich in protein and may contain vitamins and minerals. Animal products such as fish meal, blood meal, milk and its by-products serve as reliable sources of protein and minerals for livestock. Salt blocks also serve as a source of minerals.

Concentrates – these are feeds which supply primary nutrients such as carbohydrates, proteins and fats. Concentrates are either energy rich e.g. paddy, molasses, coconut meal, rice bran or they are protein rich e.g. soya bean meal, blood meal, meat meal, and groundnut cake.

Forages – are crops grown for the purpose of feeding livestock. These crops include pasture grasses, legumes crops, maize, kale and stem tubers.

Roughages – these have high percentages of fibre and low moisture content. They aid digestion bowel movement. Grass is a good example of roughage. It can be fed green by allowing animals to graze or can be cut and allowed to dry to form hay.

Additives – are synthetic materials that are added to feeds to increase the productivity and efficiency of food conversion in farm animals. Although beneficial from the standpoint of increased production, some of these chemical compounds have been found to have undesirable secondary effects on consumers of the product. Feed additives include vitamins, minerals, electrolytes, antibiotics and hormones.

Livestock Ration

A ration maybe defined as the feed stuff making up a 24-hour diet of any livestock.

Types of rations

Balance ration – this contains all the food nutrients required by the animal, in the right proportion.

The relative proportion of the nutrients will depends upon the age and stage of development of the animal. It is also dependent on whether it is lactating or pregnant.

Maintenance ration – this is a balanced ration. It is needed to supply the energy and protein for the animal’s physiological processes. Such a ration will ensure that there is n o loss or gain in weight.

Production ration – this is a balanced ration that is supplied to the animals to meet both the requirements for production and maintenance of the young, fattening, laying and lactation.

Characteristics of a ration

• Bulk – ruminants need more bulky foods than pigs and poultry. Animals need bulk in order to feel satisfied.

• Palatability – refers to how tasty or appetizing the food is to the animal. This can be determined by how much of the food the animal consumes.

• Familiarity – new foods should always be introduced gradually by mixing them with familiar ones.

• Binding effect – foods that are high in crude fibre has a binding effect e.g. hay, straw.

• Laxative effect – this is the opposite to binding. In the extreme, these rations can lead to diarrhoea, causing dehydration and loss of minerals. Ideally, rations should be somewhere between binding and laxative.

• Flavours and taint – it is possible for some foods to transfer their characteristics, flavours or taint to the fat of the animal being fed.

Pasture grasses

Pastures are areas that are specially cultivated with grass and legumes for the purpose of feeding livestock.

Important pasture grasses

Local names Botanical names

Bermuda or Bahama grass Cynodon dactylon

Guinea grass Panicum maximum

Water grass Paspulum rupers

Razor grass Paspulum virgatum

Sour grass Paspalum conjugatum

Para grass Panicum purpurescens

Antelope grass Echinochloa pyramidalis

Pangola grass Digitaria decumbens

Tanner grass Braccharia regulosa

Elephant grass Pennisetum purpureum

Home work

Describe at least five common grasses and paste pictures of the grasses described.