www.infonet-biovision.org - Fodder production

Fodder production

Fodder and pasture production (for ruminants)				Upper Highland Zones
Assessment of feed quality for dairy production				Information Source Links

Fodder and pasture production (for ruminants)

Pasture leys and fodder (forage) crops are either annuals, perennials, or permanent crops. They are cultivated on arable land and are grazed or cut and fed to the livestock either green or conserved in the form of hay or silage. They are usually grown in rotation with cultivated cash crops. Their high productivity and quality per unit area makes them appropriate for small-scale farmers because they provide them with:

(a) Immediate feeding material for the livestock especially in a zero-grazing system.
(b) Surplus material which can be conserved in form of hay or silage for dry season feeding

The role played by pasture legumes as a feed should also be emphasized because of their high protein content and the fact that they fix atmospheric nitrogen into the soil. Table 2 shows major pasture leys and fodder crops suitable for different Kenyan Agro-ecological zones.
It is advisable to make a feeding plan which covers the whole year with allowances for missed rainy seasons. This means storing hay, straw, silage whenever it can be available. Good quality and well stored feed always comes in handy when the rains delay or fail. Such feeding plans will depend on the agro-ecological zone where animals are kept. Below some examples:

Table 2. Suitable forages in Kenyan Agro-ecological Zones

back to Index

Assessment of feed quality for dairy production

At farm level, dairy cattle are exposed to many feeds, with diets varying in different regions and farming systems. The productivity of a dairy system is highly dependent on the quality of feeds. This is because the feed quality determines the intake and availability of ingested nutrients for utilization by the dairy cattle. Consequently, farmers are not only faced with the problem of knowing the quality of the feeds but also the factors that influence the quality. The objective of this chapter is to provide highlights of information about quality indicators of cattle feeds and backgrounds of some measurements of feed quality often encountered in dairy industry. These include physical indicators to determine feed quality.

Physical indicators of feed quality

The physical nature of the feeds can pose serious limitations to efficient utilization of a feed or a ration comprised of several feed resources. However, the influence of physical attributes of feeds on quality is often ignored. Some of the physical aspects that can limit the quality and utilization of feeds in dairy production are briefly discussed:

1. Stage of growth

Vetch (Vicia villosis) harvesting at the right stage of growth

The nutritive quality of forages varies as they grow towards maturity. Consideration of the stage at which both biomass yield and nutrient content are optimal is therefore important. After attainment of maturity, the forages generally depreciate in nutritive value. This is mostly due to increase fibrous material, particularly lignin. For many forages, the leaves die off systemically after attainment of maturity, and this reduces photosynthetic activities. As a result, there will be reduced accumulation of nutrients. These factors are important to be considered e.g. when harvesting forage for conservation as hay. For instance, when making hay from grass (e.g. Rhodes grass) and legumes (e.g. Lucerne ) it is generally advisable that cutting be done at the onset of flowering upto the time of 50% flowering. For a vegetatively propagated forage such napier grass, cutting height is the most important physical consideration for quality. Studies have shown that optimum harvesting height for Napier grass range between 50-60 cm (dry season) and 130-140 (rainy season).

2. Texture

Grass exhibiting difference in quality due to the impact of texture

The physical/textural changes which occur as forages grow can impact on palatability, intake and animal digestive physiology. For instance, high intake of succulent young forages (e.g. Lucerne, vetch and Comelina spp) may cause bloat. At young stage the dry matter (DM) content of some forages can be very low (e.g. sweet-potato vines and napier grass), and this can limit the adequate intake of dry matter to support the desired level of production. The palatability can be compromised as the forages age because of increase in toughness. This can further complicate issues if some species and classes of livestock e.g. young ones are unable to consume old and tough forages or parts of.

3. Ratio of stem and foliage

It is important to have knowledge of the nutritive attributes of the various morphological components of the individual forages. The leaf is in most cases the most nutritive component, hence the need to consider the utilization of a forage when the biomass yield and leaf:stem ratio are optimal.

4. Processing

Where the cattle are stall fed, the particle size may play an important role in selection, intake and digestibility. For instance, the chop length of ensiled maize stovers have been shown to influence the selection where leafy parts are consumed more and the overall intake is reduced with increase in chop length. Also, where different feed resources are to be mixed, the particle size must be considered to enable homogeneity in mixing. Some ingredients necessary in the diets may not be in appropriate physical/textural form for cattle intake. Generally, cattle do not prefer powdery or finely processed feeds. Also, feed resources like molasses (semi-liquid) need to be mixed appropriately with a carrier feed. Some feed additives or supplements are better provided in pellet or lick block forms e.g. calf pellets and mineral licks.

5. Appearance and colour

Generally, feeds have typical appearance, which the farmers are or should be familiar with. The appearance can be an important attraction to both farmers and animals. Deviation from the typical appearance should be taken seriously as this may have implication on quality. The colour of specific feed resources can be good indicators quality. Thus feed users need to know the typical colour of feeds so that when there is deviation from the norm, precaution can be observed. For most forages, green colour is a good indicator of quality. For instance, greenness may depict good growing conditions, hence abundance of nutrients. It may also indicate absence of diseases, pests and parasites. Appropriate colour can be used by farmers to judge the stage of harvesting.

6. Freshness

Dairy meal contaminated with foreign objects

Freshness of the feeds can be indicated by e.g. colour, smell and/or presence of mould. Generally, the cattle intake will be negatively affected as the feed deteriorates in freshness. Consumption of stale feed can harm the cattle due to toxicity.

7. Presence of foreign objects

Mould infested maize stovers as a result of poor conservation practice

Presence of visible undesirable objects is also a good pointer to a compromised quality. The foreign bodies may include pieces of glass, polythene, nails and metals and wood particles. Detection of foreign or non-conventional elements in a feed should not be taken for granted because this can lead to harmful or at worse fatal consequences.

8. Acceptability

Cattle, like most animals have natural instinct of preference. It is therefore possible that a good feed may be rejected because it unfamiliar. On other hand, rejection of certain feeds can be a good indicator of hidden factors which should be identified and eliminated to improve the intake. In this regard, it may be dangerous and unethical to provide such a feed in mixtures where the cattle are forced to consume it. It is therefore necessary to ascertain the factors causing rejection and the benefits of such a feed before its use.

9. Negative symptoms after feeding

Cattle may consume feeds normally, but there can be negative symptoms shown as result of the consumption of certain feeds. These may include diaorrhea, abnormal water intake, bloat, poor appetite, non-typical or unpleasant smells in products (e.g. milk) and excreta and of discomfort. Appropriate action must be to ascertain the quality aspects of the feed concerned when such negative effects are noted.

back to Index

Upper Highland Zones

UPPER HIGHLAND ZONES (norm. above 2300 m a.s.l.) - Central and Eastern provinces in Kenya

This zone is cool and usually has reasonable amount of rainfall - at least where the forests have been preserved to a certain extent. There is risk of frost at times so sensitive crops like maize are usually not attempted on a large scale. Good fodder production plans include grasses and legumes as listed below, which can be either cut and carried, grazed (Lucerne does not like being grazed by animals) or made into hay or silage. For grass pastures it is usually a good idea to fence off part of the grazing area early in the rainy season, and let the grass in fenced in plots grow tall for hay making, while the cows graze the rest. After making hay, the fenced off grass is left to grow again and if the other part of the pasture is by now grazed low, the animals can be let onto the regrowth of second pasture, while the first sector gets a chance to recover

Short season grain crops like barley and oats make excellent silage either alone or intercropped with purple vetch or peas/beans. Seed of peas and beans are expensive, but purple vetch can be grown on the farm for seed production. The addition of legumes in the fodder crops will boost milk and meat production and save on expensive feed concentrates.

Also a few fodder trees can be grown in highland areas as Hedges or borders between other crop sections. It is advisable to ask your nearest forestry officer which varieties are more productive in your area.

Grasses:

Kikuyu grass (Pennisetum clandestinum) UH 1,(2)

Rye grass (Lolium perenne) UH 1,2,3,(4)

Cereals:

Oats (Avena sativa) UH 1,(2)
Fodder barley (Hordeum vulgare)/m.mat. var.B 106 UH 2
Fodder barley (Hordeum vulgare)/e.mat. var.Amani UH 3,4

Legumes:

Lucerne (Medicago sativa)
Kenya white clover (Trifolium semipilosum) cv. Safari UH 1,2,3
Purple vetch (Vicia benghalensis) UH 1,2,3

Trees and Shrubs:

Calliandra (Calliandra calothyrsus) UH 2,3
Leucaena (Leucaena leucocephala)

1. Oats (Avena sativa)

Oats are recommended as a fodder crop for high altitude areas of Kenya (over 2100m above sea level) and may be grown in pure stand or in mixture with vetch.

Planting

o Drill oat seeds in rows of 30-40cm
oWhen oat is being grown as purestand 70 - 80 kg of seed per hectare is recommended. When
grown as a mixture with vetch 30 - 40 kg per
hectare of oats and 20 kg per hectare vetch seed is recommended
oApply 2-3 bags TSP fertilizer per hectare at planting.

Management

oHand-weed or spray with herbicide 2, 4-D Amine 72% at the rate of 2.5 litre per hectare.
Spraying is only done when oat is grown as a mono
crop but not when grown with vetch.
oCut at milk stage (4-6 weeks) leaving a stubble height of 5cm (2in) from ground level
oTop-dress with 3 bags of C.A.N./ha to enhance growth and subsequent fodder yield.

Feeding

o Oats is cut at milk stage and wilted before feeding to prevent incidence of bloat
o An average dairy cow needs 70-80kg of fresh oats to produce 12kg of milk per day.
o Oats can also be cut and conserved as hay or silage.
o When conserving as silage, oats should be cut when the grain is at milk or dough stage.
o For hay making the oat should be cut when the grain is in the milk stage.

2. Lucerne (Medicago sativa)

Uses/applications

Lucerne was one of the first forage crops to be domesticated. It is used as multi-purpose forage, able to be used for both grazing and conservation (hay, silage, meal and forage dehydration). It can be sown as a pure stand or in mixtures with both temperate and tropical grasses. The seed can also be used for human consumption as sprouts.

Moisture

Lucerne is a crop, which is relatively drought tolerant and will produce yields about in proportion to the water supply. In periods of drought, it will adjust plant density to cope with the availability of water supply. Its taproot is capable of following water supply to considerable depths (up to 8 m, but more commonly 2-3 m). It is well suited to growing under irrigation.

Companion species

Grasses: Panicum maximum , Cenchrus ciliaris , Chloris gayana , prairie grass (Bromus spp.).

Legumes: Clitoria ternatea, Macroptilium bracteatum, M. lathyroides, M. atropurpureum.

Feeding value

Nutritive value

It is usually considered the 'King of Fodders' because it grows throughout the year if soil moisture is available. Protein and calcium levels are high, relative to other fodders, but metabolizable energy (ME) and phosphorus levels are low. ME and phosphorus levels are good in young growth but drop rapidly as the foliage matures. Intake of digestible nutrients by livestock is higher than for most other forages. Level of fibrous tissue is low and this allows rapid passage through the rumen . Lucerne foliage is highly digestible
Palatability/acceptability

Lucerne is highly palatable. There are some cultivar differences in palatability and this is thought to be the result of different protein fractionations.
Toxicity

Bloat is the major limitation to grazing lucerne. A combination of management and control measures can be used to reduce the risk of animals bloating on lucerne. Hungry animals are more at risk of bloat so provide animals with access to a source of roughage before or during grazing. There is usually reduced risk of bloat in mixed stands under rain grown conditions. Access to anti-bloating agents (drenching, in their water supply, rumen capsules or sprayed on foliage) is essential in intensively grazed situations. Enterotoxaemia can be a problem with sheep. This can be controlled by injections.

Production potential

Dry matter
Under irrigation, lucerne is capable of producing 25-27 t/ha dry matter in the first year of a stand and this can fall to as little as 8-15 t/ha by the third year. Production can be related to plant density, level of disease and pest resistance and winter activity level of the cultivar. Under rain-grown situations it is also determined by availability of soil moisture. Good irrigated stands can produce 20 t/ha of hay per year (allowing for at least one spoiled cut per year). A utilisation figure of 50% is expected under grazed conditions.
Animal production
When green feed is available, daily liveweight gains for beef cattle will be around 0.7 kg/head/day compared with 1 kg/head/day on oats, improved tropical pasture and native pasture. This reduced weight gain is a result of the lower energy availability. However lucerne grows throughout the year so, over the full year, supplementing native pasture with lucerne can increase gains from 0.5 to 0.7 kg/head/day at double the stocking rate. Irrigated lucerne can carry a beef cow and a calf on 0.5 to 1 ha on a year-round basis. Supplementing dairy cows grazing tropical grasses with lucerne can raise milk production from 10-12 to 14-15 L/cow/day. This can increase to 20 L/cow/day if the cows are further supplemented with grain to combat the energy deficiency. Sheep numbers can be increased from 6 to 15/ha by supplementing native pasture with lucerne. Irrigated lucerne can carry more than 80 dry sheep equivalents/ha from October to May.

Strengths

Year-round production.
High quality.
Dual purpose (grazing or conservation ).
Ability to extract water from deep soil layers.
Persistent.
Wide range of climatic adaptation
Responsive to irrigation.

Limitations

Low energy levels.
Restricted soil adaptation (fertile, well-drained).
Cannot stand continuous grazing.
Causes bloat.
Susceptible to waterlogging .

3. Kikuyu grass (Pennisetum clandestinum)

Suitable Agro-ecological zones: UH 1 (2); LH 1,2
Kikuyu grass (Kikuyu) originates from areas with rainfall of 1,000?1,600 mm. Although this native environment mostly does not have a pronounced dry season, the grass has become naturalised in areas with a distinct 5 month dry season. Where soils are suitable, it has become naturalised in areas with rainfall up to 3000 mm and down to 800 mm/yr, and performing well under irrigation in lower rainfall areas. It is moderately drought tolerant, because of deep root system (to >3 m. Most active growth occurs during periods of high humidity.

Regular cutting or grazing is necessary to maintain forage quality and palatability of the stand. Management should aim to maximise the amount of leaf, and minimise the amount of stem. Accordingly, stands should be grazed to about 5 cm in height and allowed to regrow to about 15 cm. If pasture height exceeds 15 cm, it is best to mow the sward back to 5 cm to remove stems and mature growth. If well fertilised, kikuyu is very tolerant of constant heavy grazing, although productivity is reduced under such management.

Establishment:Kikuyu is readily established vegetatively or from seed. Harvested pieces of stolon or rhizome can be planted on a regular grid, or broadcast and cultivated into the soil surface. Subsequent rolling ensures better establishment. Seed is sown at 1 to 2 kg/ha when soil temperature reaches 20°C. Good moisture conditions for several days after sowing are essential for effective establishment.

Yield and utilization: DM yields are only limited by soil fertility and moisture availability. Under optimum conditions, it is capable of producing 30 t/ha/yr, but is unproductive if not fertilised. Responses of the order of 15 to 30 kg DM per kg N applied are reported. Kikuyu is particularly demanding for N and P. While other nutrients are also essential, historically it has been decline in soil N and P levels that has led to decline in formerly productive stands. Renovation of 'run-down' kikuyu grass should include incorporation of a legume or the use N and P fertiliser.

Young growth is very soft and palatable, but older growth is not relished by most animals. The presence of a legume in the sward increases utilisation of the kikuyu. Well-fertilised kikuyu produces very high quality feed with over 25% CP and over 70% digestibility in young leaf. CP levels tend to stay high for 1 or 2 weeks and then decline rapidly, to below 10% within 12 weeks. Digestibility also falls to <50% in the same period. For good silage fermentation, kikuyu needs to be wilted first or have extra sugar added because of its low DM and low water soluble carbohydrate content.

Well fertilised pastures are capable of carrying 1.5?3.0 adult cattle/ha. Dairy cows can produce over 15 L milk/day, and beef animals over 400 kg/ha/yr weight gain from vigorous kikuyu pastures.

Strengths

Productive under heavy grazing.
Good ground cover.
Responsive to good fertility.
Suited to high altitude tropics.

Limitations

Requires fertile soils for persistence and production.
Competitive against many legumes
Rhizomes can create weed problem.
Susceptible to 'kikuyu yellows'

back to Index

Information Source Links

Ashiono GB, Ouda JO, Akuja TE, Kitilit JK, Irungu RG and Gatwiku S (2006). Effect of Potato Vines and Sorghum Silage on Cattle Milk Productivity. Asian Journal of Plant Science 5 (1) 81-84.
Dijkstra, J., Kebreab, E., Bannink, A., France, J., Lopez, S., 2005. Application of the gas production technique to feed evaluation systems for ruminants. Anim. Feed Sci. Technol. 123, 561-578.
McDonald, P., Edwards, A.R., Greenhalgh, J.F.D., Morgan, C.A., 2002. Animal nutrition (6th Ed.). Pearson Education Ltd., Edinburgh Gate, Harlow, UK.
Mugo BJ and Gatwiku SW (undated). Livestock fodder from sorghum and sweet potato vines. Kenya Agricultural Research Institute (KARI). Extension brochure, KARI Publications
Ouda JO (2001). Feeding and care of livestock In: Managing dryland resources. A manual for Eastern and Southern Africa. International Institute for Rural Reconstruction (IIRR). ISBN 9966-9705-2-5.

back to Index