| FEEDS AND FORAGES IN PACIFIC ISLANDS
FARMING SYSTEMS |
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| 1. Introduction 2. Livestock numbers and distribution in the Pacific Islands 3. Production systems 4. Some cattle production systems in six countries Fiji Samoa Village beef production Large-farm production system Papua New Guinea Tonga Solomon Islands Smallholder sub-sector Intermediate communal sub-sector Large scale commercial sub-sector Vanuatu Smallholder sector Estate plantation sector 5. Feeding systems Cut and carry Grazing systems Rotational or paddock grazing Strip grazing Cattle grazing open pastures Integrated animal and tree cropping systems Crop/livestock systems Cattle under coconuts Role of forage and feed in the systems Crop residues and agro-industrial by- products Legumes and trees 6. Descriptive and analytical data on some
forages (grasses and browses) |
Some common browse plants of the region Calliandra(Calliandra calothyrsus) Erythrina spp. Gliricidia (Gliricidia sepium) Leucaena (Leucaena leucocephala) Cassava leaves (Manihot esculenta) Sweet Potato leaves (Ipomoea batatas) Vi or Vie plant (Spondias mombin) Flemingia macrophylla Moringa oleifera Mulberry (Morus alba) Sesbania grandiflora Legumes as feed 7. Descriptive and analytical data of some feed resources Crop residues Agro-industrial by-products Cocoa by-products (Theobroma cacao) Noni juice extract waste (Morinda citrifolia) Coffee pulp meal (Coffea arabica) Copra cake/meal (Cocos nucifera) Brewers’ grains Palm kernel meal Molasses Cereal by-products Rice bran, pollard and polishing 8. Impact of the use of the feeds/forages Some economic data Country studies Feeds and forages likely to increase in use and why 9. Conclusion 10. References |
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There are many grazing systems in the Pacific Island countries (PICs) – see map; for a target level of animal performance from forage, daily ingested young forage leaf and stem dry matter should possess specified levels of protein (nitrogen), metabolisable energy, phosphorus, calcium, potassium, magnesium, sulphur, sodium and trace elements. The quantity and quality of pasture available to different classes of ruminants in the region varies considerably. Besides environmental factors, others such as inherent nutritive (and sometimes anti-nutritive) characteristics of selected pasture plants, quality of management, weeds and grazing systems and animals contribute to affect pasture quantity and quality.
Ruminant livestock can subsist on forage alone but, to achieve this, available forage for year round feeding should be of good quality to meet the nutritional requirements of grazing animals so as to attain their genetic potential. With good management quality forage could be available year-round, where this is lacking alternative feed should be provided. Ruminant livestock rely mostly on native and some introduced grasses along with crop residues in the PICs (Macfarlane, 1998). Maximum animal production from an environment or farming system is based on a mix of the best-adapted legumes and one or more grasses while the primary factors which maximize digestible nutrient intake and hence, animal performance (growth, lactation, reproduction and work) are: (i) the quantity of feed; (ii) its nutrient content, and (iii) digestibility. Most pastures in the PICs are characterized by large fluctuations in quantity and quality of herbage available to free-ranging ruminants. Such fluctuations influence intake and production, thus animal performance in terms of reproduction, growth, traction, milk and meat in the region is generally less than half their genetic potential due to poor quality forage. 2. Livestock numbers and distribution in the Pacific Islands The Pacific island countries have no long history of grazing livestock management and production. Despite this, there are now substantial numbers of ruminants (Table 1) in the region. Ruminant production is promoted by all governments for import substitution, self-sufficiency in meat and a source of income for farmers. Ruminant livestock form an integral part of the rural life of the PICs because, at village level, raising cattle, goats and sheep provide many benefits. They are assets that are readily saleable and relied on for income and for meeting large payments such as school fees. In countries which have suffered cyclone disasters, such as Samoa and Vanuatu, smallholders increasingly view cattle as more important than tree crops and relatively cyclone-proof. Smallholders are involved with several species (Macfarlane, 1998). Ruminant livestock are numerically less significant than non-ruminants but they have the potential to increase smallholder incomes. The countries in the region currently graze 664,900 beef cattle, 30,100 dairy cattle, 24,900 sheep, 258,000 goats, 12,000 farmed deer and 110,000 feral deer (in New Caledonia) (Macfarlane, 1998). Beef cattle, the predominant ruminants, are raised mainly for meat and secondarily for draught, especially by the Indo-Fijians in Fiji. There are dairies in Fiji, Tonga and Papua New Guinea; sheep in Fiji and Papua New Guinea and an important goat industry in Fiji and Vanuatu (Macfarlane, 1998). Vanuatu has the highest number of cattle per person amongst countries in the Pacific Islands.
Land mass, pressure on land for other activities; culture and tradition, size and number of livestock and feed availability determine the type of production system (Aregheore, 2004a). Ruminant livestock in greater or lesser numbers are associated with production systems which differ from one country to another. The smallholder unit (tethering and free range) is common in all countries, always relying on pasture. Foliage of shrubs is used to supplement low quality forage to meet requirements for maintenance, fattening and other physiological processes. Livestock production systems can be classified as free range, tethering, fenced and penned. Free range – The simplest system where animals roam freely finding their feed and are thought of having no production cost because they exist and reproduce without contribution or inputs from the owner. This system requires little or no skill and involves minimal labour (Ramsay, 1999). Animals are very hardy and are products of their own environment (Aregheore, 2002a). Tethering – Animals are tied to a tree or stake but have to be moved often to ensure that they can reach feed. This system requires more input than free range but does not guarantee a greater output; it is very common among the Indo-Fijians and in the Cook Islands (Figure 1). It has advantages and disadvantages (Ramsey, 1999). The advantages are:
The disadvantages are:
Fencing - Fences such as permanent post, wire or electric are used to control stock. Fenced animals require a regular supply of clean, fresh water and sufficient feed of good quality. When animals are kept in paddocks, their entire feed requirement should be met by the development and maintenance of available pasture or through supplementation. Penning or confinement - Animals are confined at all times so this system requires much higher levels of husbandry than the other systems, since all inputs must be provided; this increases production costs. This system is not very common in the PICs. Farmers prefer a semi-intensive system where animals graze during the day and are housed at night or during adverse weather. Figure 2 shows a make-shift housing or shelter for goats under semi-intensive system at Siusega, Samoa.
These are the general production systems, however countries have modified them to suit conditions peculiar to their environment. 4. Some cattle production systems in six countries Production systems for cattle in some Pacific Island countries (Aregheore, 2004a) are described below.
Beef production systems in Fiji can be classified as: -
Small arable farms - under 10 ha. These own up to 75 % of the beef cattle. Beef is a sideline to sugar cane or rice production. Most cattle are in the sugar and rice areas of Viti Levu and Vanua Levu. Farmers tether animals along roadsides and field fringes. Bullocks are kept for draught. Fencing is not used and in some situations animals are allowed to roam and fend for themselves. Commercial farms of 10 – 50 ha. This involves the breeding and/or fattening of animals under extensive grazing. Owners and family members manage the farms, but contract labour is hired from time to time for fencing and daily routine tasks. Ranching operations of 50 – 2000 ha or more. These are based on intensive cattle systems for breeding and provision of stock to smallholders. Ranches in Fiji are found in Uluisaivou and Yaqara and also in Cakauudrove and Taveuni and are large estates with full time managers, stockmen and labourers. The Yaqara Pastoral Company, Fiji's largest single operation, covers over 4,000 hectares and maintains 7,000 head of cattle. This includes the recent acquisition of the famous French Limousin breed, purchased from New Caledonia. Cattle under coconuts. This is concentrated in Northern and Eastern Fiji. Cattle are kept to control weeds and provide income. Grazing is continuous. This system requires large areas. Sixty percent of beef farmers in the northern division produce under coconuts and of these 40 % are indigenous Fijians. This system is also found in some bigger outer islands including Rotuma (Vulaono, 2004). Cattle under pines. This system which is mainly used in the dry, western part of Fiji, involves a small herd maintained by the Fiji Pine Commission. Cattle graze under pine plantations and are used as weeders; grazing is continuous on an extensive area of land. There are 1,825 beef producers with 30.5 animals per farm and three large properties with more than 1,000 cattle each. The commercial beef herd is distributed by region as 27 % Central, 56.9 % Western, 14.1 % Northern and 2 % Eastern Division. Commercial beef farmers have about 1,100 work oxen (Macfarlane, 2000a). Poor nutrition leads to low weaning percentages and daily liveweight gains. The Ministry of Agriculture, Fisheries and Forests assists farmers in access to beef cattle in Fiji through a breeding programme that aims at improving the genetic composition of local beef herds and involves the importation of high quality semen. Fiji is well endowed with pasture resources. The potential role of pastures as cheap and available feed has been well documented by Macfarlane (1998) and Kumar et al., (2001). Beef production systems rely on tethering and enclosed grazing with some cut-and-carry feeding. Natural and improved pastures are used. The national cattle herd grazes 125,000 hectares of unimproved Mission grass (Pennisetum polystachyon), 43,000 hectares of naturalized/native pastures including Nadi blue grass (Dichanthium caricosum); Batiki grass (Ischaemum aristatum var. indicum); carpet grass (Axonopous compressus) T-grass (Paspalum conjugatum) and an unquantified area of roadsides and harvested cane fields (Macfarlane, 2000a). Mission grass (Pennisetum polystachyon) is extensive low cost feeding. But limitations to its use are low productivity, low digestibility and inadequate protein and mineral levels; its quality and quantity can be improved by adding legumes with appropriate fertilization. Improvement of Mission grass by sowing Siratro (Macroptilium atropurpurenum) or Stylo (Stylosanthes guianensis) and broadcasting single-superphosphate at 440 kg/ha into burnt grassland resulted in a three-fold increase in dry matter from 6.0 tons/ha/yr to 18.0 tons/ha/yr. Maximum liveweight gain of 520 kg/ha was recorded from improved Mission grass leading to reduced gains in later years when Mission grass and legumes rapidly disappeared. There is a need for more stable grasses and legumes. Nadi blue (Dichanthium caricosum) and Hetero (Desmodiun heterophyllum) have these attributes and were actively promoted.
In 1995 the cattle population of Samoa was split among sectors in the following proportions:- Government (3 %), Western Samoa Trust Estates Corporation (WSTEC) (12 %), NGOs (17 %), and private (68 %) (Lee, 1999a), thus breaking the early monopoly of WSTEC. At present beef cattle are raised in Samoa under two systems: village production, and large-farm production (Tevita (2001), personal communication). (a) Village beef cattle production is divided into two types:
Village beef production The subsistence system is a very significant in Samoa’s beef industry and plays an important role in increasing the number of animals in the country. There are 46 registered cattle farmers’ association or village groups. The formation of the Village Cattle Farmers’ Association, a self-help group activity to improve and draw more farmers to develop interest in beef cattle production, has motivated farmers’ interest in the keeping of cattle. Cattle ownership by small farmers is increasing and development of the beef industry has received government support through importation of cattle, development of breeding farms, distribution of cattle to farmers at subsidized prices and training in pasture development and maintenance (Ramsay, 1999). Smallholders cum commercial systems. Farmers in this group usually have five – fifty cattle on properties where both subsistence and commercial production are carried out. A farmer will produce livestock, root crops, coconut and bananas for home use. Today, the strength and growth in the beef cattle industry is in the emerging commercial smallholders sector. Large-farm production system Government/WSTEC Estates. Two government farms at Togitogiga, Le Mafa and Tanumalala were established under Asian Development Bank funding during 1972 – 1979 to provide demonstration and training, conduct research and provide improved breeding stock for distribution to WSTEC estates and to farmers. WSTEC estates is government owned and has about 3,000 cattle grazing 2,400 ha under coconuts at Mulifanua. WSTEC once controlled most of the cattle in Samoa, but the number of animals and the land area of WSTEC properties have fallen drastically. Government farms sell some of their breeding animals to the other sectors under the village level beef system. Samoa has identified cattle development as an important strategy for import substitution. Beef stock is based on Braham-Hereford mix which seems adapted to the environment. In 1989, Droughtmaster cattle were introduced from Australia with additional shipments in 1993 and 1995. The beef farms at Togitogiga, Lamefa and Tanumalala breed and distribute calves at subsidized rate. Bulls are imported periodically to prevent inbreeding. Droughtmaster cattle have adapted very well to Samoan conditions and have become a breed of choice (Tevita, 1995). Samoa’s climate favours the growth of forage all year round. Batiki grass (Ischaemum aristatum var. indicum) is the predominant pasture grass, either under coconuts or in open fields. Other grasses such as signal (Brachiaria decumbens), Guinea (Panicum maximum), carpet (Axonopous compressus) and elephant (Pennisetum purpureum) grasses contribute to the nutrition of ruminants. Signal, Guinea and elephant grasses are mostly used in cut-and-carry feeding. Browse plants including Leucaena leucocephala, Gliricidia sepium, Erythrina spp., Spondias mombin, Calliandra calothyrsus, Morus alba and Sesbania grandiflora are available to supplement batiki grass during the dry season (Aregheore, 2003). Some agro-industrial by-products, especially brewer's grains, noni (Morinda citrifolia) juice extract waste, desiccated coconut waste meal and copra cake are available year-round and are used to supplement grazing animals during adverse weather. The use of brewer's grains is widespread.
The cattle industry expanded rapidly from the early nineteen-sixties and numbers peaked in 1976 at around 153,000 head (although current estimates suggest a national herd of only 82,000 cattle). Numbers have declined sharply in both large and smallholder sectors. Two production systems are identified (Benjamin, 2001) and these are:
Smallholder projects. Based on earlier data over 1,000 smallholder projects run a total of 50,000 cattle. The remainder is on 550 smallholder farms on 78,000 hectares of grazing land. Cattle graze native, semi-improved or fully improved pastures. Tethering is growing rapidly in mid-altitude zones and areas of high land pressure where smallholders use forage along roadsides and around tree crops. This system is associated with cut-and-carry (Macfarlane, 2000b). Improvements in smallholder projects are limited (Benjamin, 2001, Personal communication). Large properties/commercial/ranching. Based on earlier data there were 30 ranches with 103,000 head. About 80% of the cattle are on large properties that occupy 113,000 hectares. This system is integrated with about 100 km2 of coconuts. Ramu Beef’s feedlot bales green cane tops and helps Ramu sugar by reducing the wastage of crop residues during ploughing. There are 203,000 ha of extensive natural grasslands in PNG most of which are maintained by regular burning. These grasslands have been recognized as an important resource (Falvey, 1981, Smith and Whiteman, 1985) and have been successfully improved, usually by over-sowing with Stylosanthes spp. following burning and application of appropriate fertilizer (Partridge, 1977). Shelton et al., (2002) stressed the importance of pasture as a cheap feed in PNG. All beef production systems in PNG rely on natural or improved pasture. The beef industry has developed the supplementary paddock feeding systems with locally-produced by-products. Copra meal, palm kernel meal and molasses are used to supplement pasture (Bubar, 2000). This is a major step through improved growth rates and animal handling. Smallholders can benefit from technologies developed and introduced by ranches. Besides the above mentioned, a number of crop residues such as sugar cane tops, rice straw and bran, cocoa husk, coffee hulls and pulp, palm fibre press and oil palm sludge are available as possible supplementary feed for grazing beef cattle (Moat, 2002).
Beef cattle in Tonga are held under two systems (Lee, 1999b); these are:- smallholders, and large commercial properties: Smallholders. Beef animals are raised in small numbers. Crop production is the farmers’ priority and livestock are integrated into this system. Their purpose is to supply animals for traditional and social obligations such as funerals, wedding and church functions. Animals are tethered and graze along roadsides, fallow land or under-utilized bushland. Forty percent of beef herds of 10 or fewer animals are under the smallholder system. Large commercial style properties. Nobles, entrepreneurs who sub-lease land and the churches operate commercial properties involving beef cattle. These properties are now few, but they are very important because of their ability to produce surplus meat for local markets and breeding stock for the beef industry. They specialize in both milk and beef, often with separate herds. They have some developed, fenced long-term pastures and land is generally cropped only during pasture renewal (Lee, 1999b).
In the Solomon Islands over 56 % of the cattle are in the Central district, 20 % in Western district, 16 % in Malaita and 8 % in the Eastern district, (Wahananiu et al., 1993). However, the 1998-2000 civil war or disturbance in the Solomon Islands affected commercial beef production and it declined to less than 78 % of the previous level. Three beef production systems are recognized (Kama, 1994):- small holder; intermediate communal, and large-scale commercial-government. Smallholder sub-sector Intermediate communal sub-sector: Large scale commercial sub-sector: A national cattle development plan was initiated some years ago for the rehabilitation of the beef cattle industry. The Solomon Islands government is keen to rebuild the cattle industry in commercially viable areas that have access to established markets. Government policy goals and objectives are to sustain self-sufficiency in all livestock sectors with exports where possible (Wate, 1995). The cattle development strategies of the Solomon Islands included the continued provision of breeding animals for smallholder expansion and restocking. In 1996 the impact of genetic improvement from imported bulls and semen came to fruition. There was a strong interest on Malita and Santa Cruz for breeding stock. The Mamara breeding unit set up by the Livestock Development Authority (LDA) provided vigorous replace ment stock to farmers. Beef cattle have access to both natural and improved pastures. Grazing areas range from open pastures under extensive grazing under plantations to those in the smallholder sector (Wahananiu et al., 1993). The Livestock Development Authority (LDA) operated five farms on Guadalcanal and four in the Western Province and owned most of the large open pasture. It has been estimated that only 4,000 ha of pasture might be left for grazing. As a consequence of the different holding systems, land for pasture development was allocated in the sixth Development Plan (1970 – 1984) as follows; smallholder (6,441 hectares); LUD projects (3,943 hectares); holding grounds (442 hectares); LDA fattening (760 hectares) and Government (2,060 hectares). By 1991, it was estimated that 9,000 hectares would revert to bush while in some areas pastures will be under-grazed. There is still scope for targeted pasture development in Gizo, Kolombangara, North New Georgia, Rendova areas of western Province, Santa Isabel, Makira; and accessible and adequately fertile areas on Maliata and Guadalcanal (Wate, 1995). Commercial pasture development in the Solomon Islands was based on the replacement of Themeda australis/Pennisetum polystachyon natural grassland with a minor contribution of Gleichenia linearis and Cyperus spp. by cultivation and planting of grasses such as Para (Brachiaria mutica); signal (Brachiaria decumbens cv. Basilisk); green panic (Panicum maximum var. trichoglume cv. Petrie); batiki grass (Ischaemum aristatum); koronivia (Brahciaria humidicola) and Nadi blue (Steel and Whiteman, 1980; Watson and Whiteman, 1981). The nutrient content and palatability of the grasses would be improved by legumes as mixtures. Legumes used in the Solomon Islands are Centrosema pubescens cv. Common (Centro); Pueraria phaseoloides (Puero), Stylosanthes guianensis cv. Endeavour (Stylo); Vigna luteola (Vigna); Desmodium uncinatum (Silverleaf); D. heterophyllum (Hetero); Macroptilium atropurpureum cv. Sirato (Sirato) and Glycine wightii cv. Tinaroo (Glycine). Macfarlane (1996) reported that the pasture resources for ruminant livestock production in the Solomon Islands could be categorized into open pastures, pastures under coconuts and pastures under trees.
The production systems in Vanuatu are:- Smallholder sector Estate plantation sector Other plantations owned by the private sectors are Mon-beef Tech on the Island of Santo which supply beef solely to the abattoir in Santo; Din van Tan which owns one of the biggest beef cattle holdings, supplies beef mainly to its own SAEF cannery. Michelle (a French lady) owns a plantation that also supplies beef to her small abattoir which, in turn supplies beef to wholesalers and retailers. Another worth mentioning is the French Plantation known as Roche and Madam Coshe. These plantations contribute to the export market through their abattoirs and they have assisted to improve the economy of Vanuatu (Otto, 2001). Cut-and-carry Cut-and-carry is an indicator of pressure on land for crops and the application of local laws to regulate the exploitation of communal and on-farm resources. The present trend of population growth and land ownership in the Pacific Islands has resulted in an increase in its use and competition for feed. This system gives lower production levels and even changes to lower production objectives (milk, traction, reproduction and growth) and in herd size and composition (fewer large ruminants and more small ruminants). The general rule in cut-and-carry is to give freshly cut forage equivalent to about 10 % of an animal’s body weight daily. Ideally half of the cut forage should be given in the morning and the rest in the evening so that the animal can make more efficient use of it and reduce waste. The quality and the year-round availability of feed are good because farmers look for the best forage to harvest. However, the constraints are mainly availability of forage especially during adverse conditions and household labour, distance of feed from the farm, means of transport and access rights to feed on private and or communal or public land. Cut-and-carry is very common in Fiji, Samoa, Tonga, the Cook Islands, Vanuatu, the Solomon Islands and Papua New Guinea; the farmers involved are those with small farms, cultivating as shareholders, farmer labourers and landless households. The land these farmers have access to is often intensively cultivated, the households are poor and a major share of their income is derived from casual labour and/or employment. The livestock they keep are their main assets and savings. Fiji – Feeding systems rely on tethering and enclosed grazing, with some cut-and-carry. There are no feedlots. Dairy cattle receive a lot of supplementary feed (Macfarlane 2000a). PNG – Feeding systems are based on grazing. Some estates are interested in time controlled rotational grazing or cell grazing. Tethering is growing rapidly in mid-altitudes and areas of higher land use pressure where smallholders use forage along roadsides and around tree crops. It may be associated with cut and carry. Some estates feed copra meal, palm kernel cake and molasses with mineral supplementation (Macfarlane, 2000b). Tonga – Cut and carry feeding of elephant grass, pasture, supplements such as copra meal, crop by-products for feeding, urea supplementation (Lee, 1999) Samoa – Cut and carry is now practiced by farmers who tether their animals around Apia. Also Sunny Island Dairy farm at Lalom auga uses cut-and carry Napier and Guatemala grass (the latter on the wetter soils) to satisfy part of the feed requirements of the herd of 15 milking cows. Vanuatu – Both smallholder and plantation graziers predominantly use free grazing. Tethering occurs occasionally but stall feeding is not practiced. The feeding system in both sectors is pasture based and no supplements or conserved feeds are used (Mullen, 1999).
Ruminants digest cellulosic substances and convert them to produce milk, meat, wool, hides for leather and draught power. A well managed pasture is therefore critical to the survival of ruminants and the products they provide. To obtain maximum profits from grazing, farmers must manage the land for high production and manage the animals to minimize forage waste and ensure that they are growing sufficiently. Grazing systems employ the basics of rational management to help producers accomplish their goals. Depending on what system farmers choose, they may improve pasture conditions, increase forage use, or enhance livestock production. Pasture-based livestock systems appeal to farmers seeking lower feed and labour costs and to consumers who want alternatives to grain-fed meat and dairy products. The choice of grazing system is the key to an economically viable pasture-based operation. Grazing systems vary widely in the degree of control which the farmer has in the management of grassland, but all are designed to help match the nutritional demands of animals to the forage supply. There are three main types of grazing system in the Pacific Island countries: (i) continuous grazing or set stocking, (ii) rotational or paddock grazing and (iii) strip grazing. Continuous grazing or set stocking
Figures 9 – 13 show photographs of pasture for continuous grazing in some PICs. This results in selective grazing and under such grazing regime it is hard for nutritious and palatable legumes to survive. This type of grazing frequently results in higher per-animal gains than other systems, so long as adequate forage is available to maintain high growth rates. Where continuous grazing is used the number of animals in the paddock must be adjusted from time to time to allow for seasonal pasture production. As animals grow, some animals have to be taken out of the grazing area to maintain a correct stocking rate. If pastures are overstocked, growth rates usually dwindle. Continuous grazing often results in poor forage utilization in the rainy season when re-growth is rapid. A high stocking rate should be used in the rainy season when forage production is high and decreased during the dry season. This system is of value on farms where pasture is plentiful and the farmer does not intend to increase stock numbers. In some countries such as Samoa and Vanuatu grazing cattle under coconut and on open pasture centre around continuous grazing.
Rotational or paddock grazing Advantages –
Disadvantages –
Strip grazing with electric fencing involves giving animals a fresh allocation of pasture each day. It is usually organized within a paddock system or where there are no paddocks at all and the animals are controlled solely by the use of electric fences (Figures 25 -26). In the Pacific Island countries strip grazing systems are often employed where a farmer uses communal land with significant excess of forage when providing animals with access to a larger area would result in waste through trampling or spoiling by dung. The temporary fencing gives the farmer the versatility to strip graze. Generally the fence is moved daily and the distance it is moved is based upon the number of animals being grazed and the quality and quantity of pasture available. A back fence should used to stop animals from returning to land already grazed. Sheep and goats require three wires instead of a single wire. Strip grazing has a number of benefits, such as:
If properly managed, constructed and serviced electrical fences can increase the efficiency and profitability of cattle, sheep, or goat enterprises through better management of animals and forage resources.
The bulk of cattle production occurs on open pastures in the Pacific Island countries (Figure 32); in well managed operations cattle are grazed at 1.5-3.0 AU/ha, depending on agro-ecological region and turn off slaughter weight cattle (280-300 kg carcass) at 24-36 months. Over the past 20 years an increasing number of commercial smallholder graziers have developed open improved pastures. For example in Vanuatu, the rapid increase in stockyard infrastructures on smallholder farms over the past 10 years has improved stock management and production per hectare from the best smallholder farms so that it is now close to some commercial farms. Integrated animal and tree cropping systems Crop/livestock systems The potential for animal production is one of the advantages of grazing livestock under plantation crops; they can be integrated with coconuts, oil palm, rubber, cocoa, and noni (Morinda citrifolia). Coconut and oil palm are significant and grazing under them is becoming increasingly important. In Fiji, cattle graze 27,000 ha under coconuts while sheep grazed puero (Pueraria phaseoloides) based pasture under coconuts on Taveuni. With the population of goats relatively constant and the development of sheep farming in Fiji, integration with tree crops is likely to increase (Macfarlane, 2000a). In Papua New Guinea cattle are integrated with approximately 100 km2 of coconuts (Macfarlane, 2000b), oil palm and rubber. In Vanuatu the preferred pasture plant under coconuts for cattle is buffel grass because it is extremely tolerant of high grazing pressure and the lower rainfall coastal environment where coconuts grow (Mullen and Shelton, 1996; Mullen, 1999). It is envisaged that in the Solomon Islands cattle will run under oil palm plantations as well as coconuts. In Samoa pasture-cattle-coconut systems are very common. Figures 27 – 30 contain photographs to illustrate crop/livestock systems in the PICs. The main objectives of integration of animals with coconut and oil palm are:
The cattle industry in most of the Pacific Island countries is associated with coconut plantations. In Papua New Guinea cattle are integrated with 100 km2 of coconuts (Macfarlane, 1999) which could increase to 250 km2; the potential is 600 – 700 km2. There is a potential to expand cattle under coconuts in New Ireland to supply the Lihir gold mine, rising to 200 tons/meat/year. Today nearly all smallholder and plantation graziers have at least part of their herds under coconuts. As copra prices continue to decline in real terms, the importance of cattle in the cattle-coconut farming system has increased. Daily liveweight gain of steers grazing under coconuts is below that of animals on open pastures due to the reduced quality of shaded herbage (Macfarlane 1993). Reduction in liveweight gains are exacerbated by dense plantings of coconuts (>150 palms/ha) on some smallholder farms. However, high quality veal is produced by specialist graziers who graze cows and calves under coconuts (Figures 28, 29 and 31). A unique quality of coconuts compared to most other plantation crops is that they can be intercropped on a semi-permanent basis. Unlike rubber and oil palm, the light environment under coconut is relatively constant and bright over the life of the crop which can be as long as 60 – 80 years (Shelton et al., 2002), although in the period 5-20 years light levels at ground level may be somewhat reduced (Reynolds, 1995).
Role of forage and feed in the systems Tropical pasture technology aims to improve animal production through the judicious use of inputs according to prevailing economic and social conditions (t'Mannetje, 1993). Nutritional research has demonstrated that very large increases in ruminant production can be achieved by small alterations to the feed base (Leng, 1993). In most tropical countries, including those in the South Pacific region, ruminant production is based on grazing pasture. Most tropical pastures are low in nutritive value due to their rapid growth and early lignification. Feed availability is more critical during the dry season. To improve the nutrition of ruminant livestock it is recommended that cheap sources of protein should be used as supplements. Aregheore (2000a) suggested the inclusion of foliage of browse plants and multipurpose trees; the use of urea/mineral lick blocks to supplement grazing animals for correcting protein, energy and mineral deficiencies is highly advocated. In Fiji, the production of urea molasses blocks is common (Manueli and Mohammed, 2002). There are several possibilities for improving forage production, and several options are open to smallholders. They can improve forage production by establishing:
Thus the reasons for improving forage production are to supplement the forage resources available with more and/or better quality feed for purposes such as:
This system advocates the adoption of cheap forage improvement based on legumes with minimum fertilizer use and the supplementation of low quality forage with the leaves of browses, legumes and multipurpose trees. Crop residues and agro-industrial by-products Animal production does not depend on pastures and forages alone. Crop residues and agro-industrial by-products make a substantial contribution in integrated crop-forage production systems. Aregheore (2000a) reported that they complement each other in ruminant nutrition and this is widely recognized by farmers. However, the feeding of livestock solely on poor quality forage, crop residues and agro-industrial by-products leads to low liveweight gains and low animal productivity. Inadequate nutrition of animals in the tropics is associated with delayed age at puberty or maturity; age at first conception and parturition; prolonged parturition interval, prolonged non-productive life and high mortality (Devendra and Li Pun, 1993). In the South Pacific region quantity and quality of forage, particularly in the dry season, are major constraints to livestock production from pastures. Therefore, there is the need to supplement fodder then. Strategic supplementation for energy, proteins, and minerals that might be deficient in low quality forage or crop residues offer an important means to ensure that animal performance is maintained during periods when feed shortage is imminent. Low quality forages can be improved in several ways. The use of foliage of browse plants and multipurpose trees is a cheap way of supplementing animals on poor pasture. The use of foliage of forage legumes and multipurpose trees is underestimated but these can improve the quality and utilization of roughages. Several browses and multipurpose trees are used in the South Pacific region including: Leucaena leucocephala, Erythrina spp. (dadap), Calliandra calothyrsus, Sesbania grandiflora, Gliricidia sepium, Spondias mombin (Vi or Vie) breadfruit, bananas/plantain and mango. Advantages of using these forages especially in mixed farms in the humid tropics are as follow:-
Devendra (1990) reviewed the potential value of these forage and observed that, with ruminant livestock, the use of supplements consistently increased liveweight gain or milk production. In many instances the beneficial response was associated with reduced production costs of the forage supplements used. Legumes have been particularly advantageous and in a majority of situations stall-feeding or cut-and-carry systems are commoner than grazing. The leaves of these plants are cheap sources of protein, energy and sulphur for the rumen bacteria. They have great potential to be exploited for the benefit of ruminant livestock production. 6. Descriptive and analytical data on some
forages (grasses and browses) Some common grasses found in the Pacific Islands Batiki grass (Ischaemum aristatum) This is a creeping, stoloniferous, perennial with ascending culms and conspicuously red-coloured stolons rooting at hairy nodes (Figure 33). It is propagated by stem cuttings. Once established it spreads quickly. It is shade tolerant and therefore found in most coconut plantations in the Pacific Island countries. Batiki is very suitable for open pastures and performs well on acid soils at high altitudes. It is very competitive, therefore it is difficult to use in mixtures. Compared to most grasses it has low protein content (Aregheore, 2003).
Guinea grass (Panicum maximum) Guinea is an erect tufted, perennial which can grow up to two metres if not grazed; there are many cultivars. Examples are Tall Guinea (a tall, robust variety that is well accepted by cattle) (Figure 34); Creeping Guinea (very well adapted for coconut plantations) and Common Guinea (not as high as Tall Guinea, but tall enough to interfere with coconut harvest). Guinea grass may be propagated by seed or vegetatively using splits. Seed propagation can be unreliable due to poor seed viability. Creeping Guinea is exceptionally shade tolerant and therefore suitable under plantations. Guinea grass can be used in open pastures where it could be combined with legumes in such a way that the legume can grow in the open spaces between bunches to prevent weed growth as well as fix nitrogen. It is a grass that cannot stand waterlogging, therefore a well-drained soil is required for its growth.
Signal grass (Brachiaria decumbens) This is a coarse perennial with erect, ascending stems up to one metre high. The nodes are usually smooth but sometimes slightly hairy (Figure 35). It is propagated by stem cuttings or seeds. It is aggressive, smothers weeds easily and covers the ground rapidly. It could be used in grass/legume mixtures. It is shade tolerant, so can be recommended under coconuts and it produces good quality, palatable forage. It is well established on different soils but requires well-drained soil although it has been shown to be resistant to flooding.
Para grass (Brachiaria mutica) Para is commonly used in rotational grazing and can be cut for green fodder or used for hay. It is a perennial that is widely distributed in the tropics and sub-tropics especially in areas with high rainfall. It is unproductive in the dry season because of its high water requirement. It is well suited to very wet, even waterlogged soils where it maintains a high dry matter content. It can be cut at intervals of 4-6 weeks and compares well in quality with most tropical fodders. Para grass combines well with creeping legumes, but is easily grazed out unless well-managed. Nadi blue (Dichanthium caricosum). Nadi blue is a tall robust perennial grass and has broad leaves which can be up to 40 cm long and 8-20 mm wide (Reynolds, 1995). It originated in tropical East and South Africa and grows well in areas with rainfall between 900 – 1,825 mm. Nadi blue spreads by short rhizomes. It combines well with legumes such as Sirato, Glycine and Greenleaf desmodium. It has a high digestibility and palatability and is usually established by seed in a well-prepared seedbed. It can also be established from cuttings or divided rootstocks. Nadi blue has been very effective in competing with Navua Sedge (Cyperus aromaticus) in low-lying (wet) areas in Fiji. Setaria grass (Setaria sphacelata) Setaria is a long-lived, caespitose perennial which generally forms dense tussocks and spreads by short rhizomes. Leaves can be up to 40 cm long and 8 – 20 mm wide, but considerable variations in the leaf width and plant height occur. It has a well-developed root system. The leaf blade is widely lanceolate, long acuminate, dense scabrous, and may have a brightly coloured midrib; leaf edges serrate. Leaf sheaths longer than the nodes; collar indistinct, ligule, short and thick. Inflorescence has a main stalk with shortened branches bearing spikes and bristles. Flower has two spikelets and the upper is bisexual (Ranacou, 1985). Elephant or Napier grass (Pennisetum purpureum) It is a tall deep-rooted perennial (Figure 36), widely found the Pacific Island countries and is more suited to cutting for fodder than grazing, but under rotational grazing a satisfactory stand can be maintained for many years. Elephant grass is normally established from stem cuttings that are planted similarly to sugar cane in rows of 60 – 90 cm apart. The yield of green forage depends on soil fertility and on how much fertilizer is applied. Compared to other tropical pasture grasses it has a high yield (120 tons per acre are not uncommon). Young leafy grass has low dry matter content (10-15 %).
Guatemala grass (Tripsacum laxum or T. andersonii) An alternative grass for the dry season. It is a tall leafy perennial (Figure 37) and spreads by short stout rhizomes to form large clumps or stools (Whyte et al., 1959, Reynolds, 1995). The leaves are hairy and large. The grass is propagated by stem cuttings or pieces of root-stock (Reynolds, 1995). It is used as a cut-and-carry fodder because it is shallow rooted and can easily be uprooted by grazing stock. It is persistent in both dry and rainy season. In the dry season it is chopped with a manual chaff-cutter to about 8-10 cm and mixed with other feeds for ruminant livestock. It has a reasonable content of nutrients, especially protein, in both dry and rainy seasons. It is more persistent than elephant grass, but less productive and lower in nutritive value. It tolerates acidity.
Tables 2 – 3 present the proximate chemical composition and macro mineral contents of some common grasses found in the Pacific Island countries.
- indicates no data available; Source of data: Aregheore, E.M. (2004d) Some common creeping legumes found in the Pacific Islands Centro (Centrosema pubescens) This is a perennial twinning and climbing legume with long, smooth stems which often root at the nodes. The trifoliate leaves are slightly hairy. Although centro roots at the nodes it is propagated by seeds which need to be inoculated with the right Rhizobium strain. Centro is slow to establish, however, once established it tolerates higher stocking rates than most legumes (VPIP, 1990). Centro mixes well with both creeping and tufted grasses and is regarded as the most persistent of the introduced legumes to the Pacific (Figure 38). It is well adapted to a wide range of soil but does not grow well on coral soils. It can tolerate heavy grazing better than puero but less than hetero (Pottier, 1983).
Hetero (Desmodium heterophyllum) It is a small strongly stoloniferous plant with trifoliate leaves of which the central leaflet is the largest. This legume is usually propagated by cutting because the seeds are difficult to harvest. It spreads quickly with runners on a really wet soil which is the prerequisite for its successful establishment. It is adapted to a wide range of soils. It is a native legume in the Pacific (Figure 39) and it is well represented in open pasture and coconut areas. It may be shaded by tall grasses, however it mixes well with stoloniferous grasses and is very persistent under heavy grazing situations (Pottier, 1983).
Mimosa (Mimosa pudica) Commonly called small mimosa or sensitive grass is a creeping plant with thorny stems (Figure 40)and many lobed leaves. It is very common in the Pacific. The leaves are sensitive and fold-up quickly when touched. Although it has proven to be able to produce liveweight gains, it is however, considered a weed and a volunteer pasture legume. It tolerates heavy grazing and does well with low growing stoloniferous grasses. It is not recommended for planting, but should be accepted where it grows. Small mimosa should be grazed back by continuous grazing rather than rotational grazing as cattle will eat the young tender shoots, but not the older woody thorny material (Pottier, 1983; Reynolds, 1995).
Puero (Pureraria phaseoloides) Commonly called Puero or tropical kudzu It is a perennial creeping legume, vigorously climbing or twining legume with large hairy leaves and hairy stem. The leaves are made up of three round large leaflets. Puero is cylindrical shaped but sometimes somewhat flattened, hairy and turns black in maturity. It can be established from cuttings or seed. It is a legume that is adapted to high rainfall tropical areas and is moderately drought tolerant because of its deep root system. It is fairly tolerant of waterlogging and shading. It also tolerates acid conditions and prefers heavy soils (Vanuatu Pasture Improvement Project (VPIP, 1990). It is commonly found on a wide range of soils. It shows seasonal variation in its palatability to cattle, being more palatable after flowering. It cannot tolerate heavy grazing, therefore it is advisable that farmers should be more cautious with early grazing as this may cause it to disappear from the pastures. Puero is the most important cover crop (Figure 41)for plantation crops such as coconuts, cocoa, rubber, citrus, oil palm and mango. It is best used in open pastures and it mixes well with improved grasses. It may be sown with a persistent legume such as centro (Pottier, 1983).
Siratro (Macroptilium atropurpureum) Is a pioneer legume that is under-rated in the Pacific. Siratro along with leucaena and glycine is the best adapted to coastal soil fertility conditions. It is a deep rooted, creeping and twinning perennial with stems that root readily at the nodes (Figure 42). Leaves are trifoliate, dark green and slightly hairy with a characteristic lobe on one side of the leaf. It is not persistent at stocking rates in excess of 1.8 Animal unit (AU)/ha. It has proven more productive than legumes such as centro or verano stylo (VPIP, 1990). However, it is more susceptible to leaf and stem damage from fungus Rhizoctonia solani than other legumes and can be devastated during extended periods of high humidity. It combine well with a range of grasses and is more drought tolerant than glycine.
For details of other creeping and non-creeping legumes such as: Alysicarpus vaginalis, Calopogonium mucunoides, Desmodium heterophyllum, Desmodium canum, Desmodium intortum, Desmodium ovalifolium, Neonotonia wightii, Stylosanthes guianensis etc. refer to Reynolds (1995). Some common browse plants of the region Calliandra (Calliandra calothyrsus) Calliandra (Figure 43) has been introduced in Pacific Island countries but has acclimatized and is found growing luxuriantly wild or semi-cultivated in most countries where it is used as a hedge. It is a woody, perennial legume that is well adapted, productive and has some degree of resistance to pests and diseases. The high production potential and high protein content of Calliandra make it promising as a supplementary feed. However, owing to its high tannin content, its palatability is less than that of Leucaena and Gliricidia. Like most tree legumes it remains green throughout the year and produces a lot of leaf biomass. The leaves are used to supplement low quality roughage diets because of its potential as a high protein source (Aregheore, 2005a). The constraint to the feeding of Calliandra is its low digestibility in the rumen when it is dried or wilted. It has a high content of phenolic compounds that are responsible for the protection of the protein against degradation in the rumen by microflora. For highly productive dairy cows that need some by-pass prote in, Calliandra is a good dietary ingredient (Paterson et al., 1999).
The genus Erythrina (Figure 44) contains several species widely distributed throughout the tropics and subtropics. In the Pacific Island countries two are known, Erythrina indica and Erythrina variegeta var. orientale which occur throughout the sub-region and are generally called ‘dadap’. They are widely distributed in a wild or semi-cultivated state, especially as fencing and as hedges in compounds. It is a potentially valuable feed supplement (Aregheore, 2004a). Erythrina is high in crude protein (20.6 %), comparable with Leucaena and Gliricidia (Aregheore, 2004a). The season of the year and varietal differences affects its protein content. Aregheore, (2004b) reported a crude protein content of 32.6 %. Despite the high protein content, anti-nutritive factors in the form of soluble phenolic and condensed tannin compounds in the leaves may affect its full utilization in livestock nutrition. Another important anti-nutritional substance in foliage is the alkaloid betaerythroidine but some metabolism occurs in the rumen (Erythrina Production and Use, 1993). Erythrina spp. however, have high forage quality and could effectively serve as cheap protein supplements for low-quality diets during the dry season (Aregheore, 2004b, Aregheore and Pereira, 2004).
Gliricidia (Gliricidia sepium) Gliricidia sepium (Figure 45) is a deep rooted, fast growing, medium sized leguminous tree, common in many tropical countries. It was introduced into Pacific Island country animal agro- forestry systems some years ago. The tree has no thorns and a smooth whitish-grey bark. Gliricidia is generally deciduous and grows in a wide range of climates and soil types. As it matures, crude protein levels decrease slightly while crude fibre increases. Palatability or acceptability of Gliricidia forage can be a problem. The presence of inhibiting substances such as coumarin and flavanol has been suggested to cause low palatability. Gliricidia also contains high tannins and total phenols. With ruminants an adjustment period is needed if they have not been fed Gliricidia from birth. Animals will lose weight for the first 4-6 weeks after the introduction of Gliricidia to their diets. Once animals are adjusted its feed value is well utilized for maintenance and production. However, farmers have developed various means to improve the intake of Gliricidia. Wilting, drying or sprinkling of salt or diluted molasses on leaves apparently hastens acceptance (Aregheore and Yahaya, 2002; and Aregheore and Pereira, 2004). Drying and wilting may influence chemical composition, digestibility and voluntary dry matter intake. However, palatability is increased when mixed wit h grass, straw or other roughages.
Leucaena (Leucaena leucocephala) Leucaena leucocephala (Figure 46) is a shrub or tree which can grow up to 20 metres. The leaves are bipinnate, 15 – 20 cm long, with 4-10 pairs of pinnae, each with 5-20 but mostly 10-15 pairs of leaflets; leaflets 7-15 mm long and 2-4 mm wide. The plant is valued for its ability to withstand repeated defoliation, high yields of foliage and tolerance to low soil fertility and relatively low rainfall (Bogdan, 1977). It is remarkably tolerant to adverse moisture conditions, apparently because of its deep roots, and can grow at annual rainfalls of 500 to 5,000 mm; at low rainfall it responds well to irrigation. It is more tolerant of low soil phosphorus status than many other tropical legumes which may be due to the presence of endotrophic mycorrhizae in the roots (Possingham, et al. 1971). Leucaena is highly productive and palatable (Morris and Du Toit, 1998). It is one of the most widely used forage trees in agro-pastoral enterprises as it provides a number of other products apart from protein rich forage (Brewbaker et al., 1985) and serves as a source of energy and sulphur for rumen bacteria. Like Gliricidia it was introduced to Pacific Island country animal agro-forestry systems some years ago. Leucaena is one of the most productive fodders an | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||