8.0 GOAT NUTRITION
|At the end of this session farmers should be able to: Understand the digestive system of goats Understand the nutrient and feed requirements of goats Know the sources of the required nutrients for goats Identify suitable fodder crops for semi-arid areas Produce and conserve fodder crops for dry season feeding.|
Goats are natural browsers but they do also graze. They are however selective in their feeding behaviour and they do well where they feed on a variety of feeds. Their main feed is shrubs, bushes (and wild fruit/pods) and grass.
8.1 Digestive system
To understand the feeding of goats one has to know their digestive system. The goat like any other ruminant (cattle, sheep) has four stomachs which are; rumen, reticulum, omasum and abomasums as illustrated in the diagram below.
The quantity of feed consumed by a goat depends on: age; breed; sex, size and physiological status (pregnant /lactating.)
- Goats will consume about 3-5% of their own body weight in dry matter daily
- Young goats will consume relatively more than mature goats
- Pregnant and lactating animals will need more feed to produce milk and to enable the foetus to grow.
Goats need a balanced diet comprising of water, carbohydrates, protein, vitamins, minerals and fibre. The table below shows the nutrients and some of the feeds from which the nutrients can be obtained.
|Protein||Leguminous plants, Poultry litter, Cotton seed cakes,|
|Carbohydrates||Cereals(maize, sorghum, millet, corn),molasses|
|Vitamins||Vegetables, green forage|
|Minerals||Agro-industrial residue, limestone flour|
|Water||Water bodies, succulents(water melons, cacti, etc)|
|Fibre||Crop residues, hay|
Types of feeds:
Problems encountered in feeding
Feeding leguminous feeds which are high in nitrogen content causes bloat, which is the accumulation of gases in the stomach. If animals are not attended to in time they may die. Acidosis
Bladder stones Plant poisoning (Umphaphapha)
8.2 Fodder Production and conservation
- The major constraint to livestock production is the unavailability of sufficient feed, especially in the dry season.
- The rangelands do not provide adequate (quantity and quality) feed throughout the year to support goat production.
- Therefore it is necessary to produce fodder crops for supplementary feeding during the dry season.
These are crops that are grown for livestock feeding. They can be fed while still fresh or preserved. Some examples are given in the table below.
Fodder crops classification
|Grasses||Sorghum||-Sugar drip -Sugar graze||Sow seeds with the first effective rains Spacing-90x20cm||-Harvested at milk dough stage -Make silage. Add legumes to the silage||Refer to the local AREX extension officers.|
|Millet||-Nutrifeed||-Sow seeds with the first effective rains Spacing-90x20cm||-Harvested at milk dough stage -Make silage. Add legumes to the silage||Refer to the local AREX extension officers|
|Bana grass||–||-Planted in furrows/rows with the first effective rains -Rows should be 1m x1m in irrigated lands and 1.5mx1m in dry lands -Use plant cuttings (vegetative propagation)||-Allow the plant to grow for one year before it can be harvested -Thereafter harvest when the plants reach 1m and maintain a height of 10-15cm above the ground. -Continue to harvest for the next 3 years – Make hay or silage||Refer to the local AREX extension officers|
|Legumes||Cowpeas, Dolichos bean, Velvet bean||-Sow seeds with the first effective rains -Spacing-10cmx10cm -For Dolichos the spacing is 75cmx15cm||-harvest after flowering but before hard dough stage before they lose lots of leaves -Mix with cereals for silage making -May harvest them when the seeds have matured. -Crush seeds and mix with cereals.||– Refer to the local AREX extension officers|
Goat farming as a Business 29
MRS, SNV, DLPD
|Forage tree||Leucaena||–Leucacephala -Pallicida||-Scarify the seeds or soften the coat of the seed before planting. -Raise plants in a nursery -Transplant them when they are 20-30cm -Spacing-5mx5m||-Cut, wilt and feed -Cut, dry and feed -Cut, wilt and include in silage mixtures||– Refer to the local AREX extension officers|
|Acacia||–Anguistissma –||-Scarify the seeds or soften the coat of the seed before planting. -Raise plants in a nursery -Transplant them when they are 20-30cm -Spacing-5mx5m||-Cut, wilt and feed -Cut, dry and feed -Cut, wilt and include in silage mixtures||– Refer to the local AREX extension officers|
Goat farming as a Business 30
MRS, SNV, DLPD
Reasons for conserving fodder are:
- To ensure all year round supply of good quality feed for livestock.
- To maintain milk production and fertility in livestock.
- Maintain good body condition and prevent deaths.
- To minimize stress to animals through food search.
The two major fodder conservation methods used in Zimbabwe are silage and hay making. Preservation of crop residues is also a common practice in the smallholder sector.
Silage is material produced by the controlled fermentation of green succulent crop material with a high water and sugar content in a sealed container called silo.
A silo can be:
- a pit covered with plastic
- a drum
- a plastic bag.
The silo has to be sealed completely and the contents should be chopped and well packed together so that all air is driven out and therefore fodder inside will ferment.
- Bacteria convert some of the sugars in the plant into pleasant tasting lactic acid which prevents spoilage bacteria or moulds from making the fodder to rot.
- Wrongly fermented fodder rots, is unpalatable and toxic.
- Properly ensiled fodder has energy and protein in it.
The Plastic Bag Method
- Every year before ensiling begins, the room should be checked.
- 15kg plastic bags are usually used and these should be clean.
- Chop clean material (with no soil) to 15-20mm
- Seal the material completely in the bags so that all the acid is retained.
- Store in a dry, place at room temperature, safe from rodents.
- The silage should be ready after 3 weeks.
The whole bag can be fed completely once opened which reduces chances of spoilage to the remaining fodder. Bags are easily stored and portable. It also reduces the workload in comparison with the pit method.
Storage after preparation
- It is important to store bags of silage in a room safe from rodents and ants.
- Empty bags must be carefully washed, dried and stored in a safe place for use the following year.
The Pit Method
- Dig a pit 2m in depth and 1,5m wide x 3m long with one end sloping to allow easy entry and exit of the water drums
- The pit is dug where the water table is not near the surface e.g. on an upward slope.
- The side walls of the pit should slope slightly inwards at the bottom so that settling of the silage will not produce pockets of air at the sides, which causes spoilage.
- Sides must be completely smooth with no rock outcrops or bumps.
- Trenches should be dug either sides of the pit to facilitate surface drainage / run-off.
- Chopped length of fodder material should be not more than 20cm and compacted as thorough as possible with the use of heavy water drums pulled / rolled over each layer.
- Pit must be filled as quickly as possible and sealed with plastic sheeting well tucked in at the sides
- The silage pit should maintain a doom shape to avoid seepage of water into the pit and allow runoff.
- Leave to ferment for three weeks It is good for mass production.
- Excess grasses and legumes which are in abundance in summer can be conserved and made use of in winter and during dry periods.
- They should be cut during the growing season when they are young and tender, and have sufficient minerals and vitamins.
- The grass should be cut out in dry weather, left to wilt and then heaped in small bunches in order to dry thoroughly.
- The dried hay should then be stored on a properly constructed hay rack to avoid losses.