Production systems
Dairy cattle can be reared in ways that vary depending on the resources available to the farmer. Farmers in East Africa practise three main systems: intensive, extensive and semi- intensive.
Intensive system
In the intensive system, dairy cattle are enclosed in zero-grazing units (see design of zero-grazing unit in Appendix 8), where they are provided with all their requirements for feed and water. This method is mainly practised where grazing land is scarce. In Kenya it is mainly practised in high-potential areas of central Kenya and also by urban and peri- urban farmers; in Tanzania it is practised on the slopes of Mt Kilimanjaro and in Uganda around Kagada. The forage can be grown on farm or purchased.
This system has its advantages and disadvantages.
Advantages
- The cow does not waste energy walking in search of pasture.
- It avoids diseases associated with communal grazing.
- It allows dairy farmers with no grazing land to produce milk and make money.
- The manure can be accumulated for improving soil fertility or used to generate biogas for domestic energy use.
Disadvantages
- The method is labour intensive as feeding and cleaning the unit must be done daily.
- The initial cost of putting up a zero-grazing unit is high.
- It may be difficult to detect when a cow is on heat, especially a singly housed cow. This is because when cows are housed in a group they mount each other and when in the open they show signs of restlessness by moving around.
Extensive system
In the extensive system, the cattle are reared on pasture. It is practised where grazing land is available. In East Africa the grazing land mainly comprises natural unimproved grass. In Kenya it is practised in most parts of the Rift Valley, where farmers own large tracts of land.
Advantages
- It is cheaper than the intensive system.
- It is not labour intensive.
Disadvantages
- It requires dedicating much more land to grazing.
- Cows waste a lot of energy by walking while grazing in the field.
- It is difficult to accumulate manure for improving soil fertility in crop fields.
Natural grasses can be improved by oversowing with herbaceous legumes (e.g. Trifolium)
or planting grasses (e.g. Rhodes grass). Oversowing is the method of choice.
Semi-intensive system
In the semi-intensive system, the cattle graze for some time during the day and in the afternoon or evening they are supplemented with other forages like Napier grass. This method is a compromise between intensive and extensive systems, whereby land is not limiting as in the intensive system but on the other hand is not enough to allow free grazing throughout the day.
Due to population pressure leading to subdivision of land, this system tends towards the intensive system.
Other systems
Other methods include ‘roadside grazing’ and ‘tethering’. Roadside grazing involves herding cattle on the roadside where they graze on natural unimproved pastures. It is popular in areas with land shortage. Tethering restricts the cow to a grazing area by tying it with a rope to a peg. This can also be done on the roadside or any other public land. However, in either of these systems the animals may not get enough to satisfy their requirements.
Pasture management
Efficient pasture management results in high yields of good-quality pasture that can be fed to dairy cattle for high milk production. Key activities to be considered include weed control, grazing management and fertility management.
Weed control
Weeds can reduce the productivity of the sown pastures, particularly during the establishment year, and should be controlled during the first year by either hand weeding or using herbicide (2-4D amine at the rate of 2.5 litres per hectare [ha]). In subsequent years fields are kept clean by slashing, hand pulling or mowing the weeds.
Grazing management
The following should be observed:
- In the establishment year grasses reach the early flowering stage 3–4 months after planting. At this stage the plant is not firmly anchored in the soil and therefore it is usually advisable to make hay rather than graze the pastures to avoid the risk of the cattle pulling out the young shoots.
- If the pasture must be grazed during the establishment year, grazing should be light enough (use calves) to allow the plants to establish firmly in the soil.
- For maximum benefit, use the pasture not later than the start of the flowering stage. Graze or cut at intervals of 4 to 6 weeks, leaving stubble at 5 cm height.
- Graze animals when the grass is at the early flowering stage by moving animals from paddock to paddock.
- One animal will need 1–2 acres of improved pasture per year in areas receiving over 900 mm rainfall.
- Conserve excess pasture in the form of hay for dry-season feeding.
Fertility management
To attain maximum production from pasture, the grass requires additional nutrients from inorganic fertilizer or farmyard manure.
- During the establishment year, soil nitrogen is adequate for grass productivity.
- In subsequent seasons, topdress grass with 5–7 bags of calcium ammonium nitrate (CAN) or ammonium sulphate nitrate (ASN) per hectare per year in three splits during the rainy season or 5–10 tonnes of farmyard manure.
- In areas with phosphate deficiencies topdress with 2 bags of single superphosphate (SSP) or 1 bag of triple superphosphate (TSP) per hectare per year after the establishment year. This is in addition to nitrogen fertilizer.
- Nitrogen fertilizer may be applied on 1 or 2 months before the dry season to increase yields during the dry season.
Stocking rates for different grasses
Stocking rate is the number of animals (animal unit) for which a grassland unit (hectare) can provide adequate dry-matter forage for a specified length of time. Stocking rate influences animal performance, pasture recovery, long-term pasture production and long-term pasture species composition.
Stocking rates should represent a balance between grazing pressure (pasture demand) and carrying capacity (pasture supply). The ultimate goal should be to optimize both animal and pasture production over the long term, as opposed to maximizing only one or the other. In general, improved pastures can support higher stocking rates than native
or unimproved pastures. Table 3.1 gives examples of recommended stocking rates for different improved pastures. Yields of commonly used grasses and legumes are in Table 3.2.
Table 3.1. Recommended stocking rates
| Grass type | Stocking rate (MLU/acre per year) |
| Cenchrus ciliaris (blue buffalo grass) | 0.4–1.2 |
| Panicum maximum (white buffalo grass) | 1.2–2.4 |
| Chloris gayana (Rhodes grass) | 1.6 |
| Pennisetum clandestinum (Kikuyu grass) | 1.2–3.2 |
MLU – matured livestock unit, equivalent to 500 kg non-lactating bovine
Table 3.2. Yields of different types of fodder at different agroecological zones (AEZs)
| Fodder type | AEZ | Dry matter yield (kg/acre per year) | Mature dairy cow supported (no. days)* |
| FODDER GRASSES | |||
| Napier grass | LH1, LH2 | 4000–12,000 | 333–1000 |
| Fodder sorghum (E6518) | LH 3 | 6800–8800 | 567–733 |
| Boma Rhodes | LH 3, LH 4 | 4868 | 406 |
| Elmba Rhodes | LH 3, LH 4 | 3944 | 329 |
| Star grass | LH 3, LH 4 | 2988 | 249 |
| Guinea grass | LH 3, LH 4 | 2564 | 214 |
| Masaba Rhodes | LH4 | 4560 | 380 |
| Guatemala grass | LH4 | 4080 | 340 |
| Mbarara Rhodes | UM1 | 5640 | 470 |
| Giant setaria | UH2–3 | 4000 | 333 |
| Giant panicum | UM4 | 4720 | 393 |
| Oat | UM4 | 2680 | 223 |
| FODDER LEGUMES | |||
| Silverleaf desmodium | LH2 | 3448 | |
| Greenleaf desmodium | LH2 | 3060 | |
| Sesbania sesban | LH4 | 10880 | |
| Leucaena | LH4 | 5300 | |
| Starleafed sweet potato | LH4 | 3868 | |
| Purple-leafed sweet potato | LH4 | 3116 | |
| Broadleafed sweet potato | LH4 | 2880 | |
| Vetch | LH4 | 1480 | |
LH – lower highland, UH – upper highland, UM – upper midland
* A mature dairy cow weighing about 400 kg consumes about 12 kg dry matter per day