Potential of pasture and forage for ruminant production in Eastern zone of Tanzania

P Y Kavana, J B Kizima, Y N Msanga, N B Kilongozi^*, B S J Msangi^**, L A Kadeng'uka***, S Mngulu and P K Shimba

Livestock Research Institute, P.O. Box 5016, Tanga, Tanzania
lrc@kaributanga.com   ;   pkavana2001@yahoo.com
^* Department of Livestock Production, Ministry of Water and Livestock Development, P.O. Box 9152, Dar es Salaam, Tanzania
nelkilongozi@yahoo.co.uk
^** Department of Livestock Research, Ministry of Water and Livestock Development, P.O. Box 2066, Dar es Salaam, Tanzania
bakarimsangi@yahoo.co.uk
^*** Agricultural Research Institute Ilonga, P.O Box 33, Kilosa, Morogoro, Tanzania.
arii@iwayafrica.com   ;   ilonga@iwayafrica.com

Abstract

Evaluations of pasture and forage species available in potential areas for ruminant production were conducted in eastern zone of Tanzania from year 2000 to 2004. Observational visits were conducted in different agro-ecological zones that have potential for livestock production.

Herbaceous legumes were not commonly found in grazing areas in most of the agro-ecological zones visited. This observation implies the need for protein supplementation strategies to improve ruminant production in different locations. Gliricidia sepium and Leucaena leucocephala had high coppicing ability among the multipurpose trees evaluated. Stylosanthes guianensis and Calopogonia muconoides had the higher perpetuation ability among herbaceous legumes evaluated. This observation suggests that smallholder farmers could establish these legumes without practicing yearly reseeding. Compatibility study between Pennisetum purpureum (Napier grass) and herbaceous legumes indicated that highest dry matter yield could be obtained by intercropping Clitoria ternatea with Pennisetum purpureum. However stable dry matter production in different weather conditions encountered among different years could be attained through intercropping of Macroptilium atropurpureum (Siratro) with Napier grass.

It was concluded that protein availability in basal diets of most ruminants kept in eastern zone of Tanzania is limited. Endeavours to supplement basal diets with protein sources to improve ruminant production are a prerequisite.

Keywords: forage production, herbaceous legumes, legume trees, pasture, protein sources, ruminant production

Introduction

The expansion of rural population with limited arable land units will inevitably lead to an increase in need of land for cultivation. This tendency would lead to either intensification of livestock production or exacerbated conflicts between crop and livestock farmers. High yielding feed resources are the bases for intensive ruminants' production in any livestock production system. However, quality of most of natural pasture that form a basal diet for ruminants during the dry season declines drastically. Feed resources are diverse depending on weather and environmental conditions in different agro-ecological zones. This situation entails a need to identify pasture species that would support ruminants' production during adverse conditions in different localities. Successful development of sustainable feed resource base relies upon availability and diversification of native and exotic pasture and forage germplasm available within isotherms. Seldom do smallholder farmers in eastern zone of Tanzania grow the crops for use as livestock feed. A similar situation exists with respect to establishment of pasture for grazing. Many cattle and other ruminants are grazed on unimproved communal lands or roadsides. As advances in agricultural practices are adopted, food production can be substantially increased over the low levels of production (Poehlman and Borthakur 1972). This change would permit land to be used for forage or fodder production that consequently improves livestock production. Improved cultural practices, improved varieties of forages and improved livestock will mean greater returns to smallholder farmers as well as improvement in nutritional status of the people who will consume animal proteins. Current changes in land tenure policy are not in favour of shifting pastoralism. For this reason it is reasonable to establish the potential of different agro-ecological zones that are suitable for livestock production. Productivity of dairy animal depends on quality and quantity of feed supplied. Proteins available in the feed are generally converted to micro-organic protein in the rumen. Microorganisms are digested in small intestine to render micro-organic protein available for metabolic processes of the animal. However, when the ruminant productivity increases, micro-organic protein alone would not suffice the protein requirement of the animal. In such condition protein deficiency occurs that leads to the decline of productivity. Protein that escapes microbial digestion in the rumen (bypass protein) is essential to counteract the deficit (Preston and Leng 1987). It is therefore important to establish protein profiles of locally available feed resources so as to ascertain development of supplementation strategies.

Smallholder dairy production in eastern zone of Tanzania is constrained by inadequacy of feed resources on farm to meet the animals' requirement. Among the contributing factors is the land shortage for pasture production and seasonal variation in terms of quantity and quality of forages, with scarcity being intensified in the dry season. These factors lead to recommendation of Pennisetum purpureum as a pre-requisite fodder to establish in zero grazing systems. However, sole feeding of Pennisetum purpureum requires protein supplementation for better performance of the animals. Protein supplementation through concentrate feeding in the smallholder dairying has been limited due to high costs of industrial by products and low prices of milk and milk products. Alternative recommendation has been integration of forage legumes through intercropping. This study therefore intended to elucidate the potential of feed resources that are available for ruminants' production in different agro-ecological zones in eastern zone of Tanzania.

Materials and Methods

Study area

The study was conducted in different agro-ecological zones of eastern zone of Tanzania for three years from 2000 to 2004. The study area was located between 36.5° - 39 °E and 36.5° - 7.5 °S. The eastern zone of Tanzania comprises 4 regions namely Tanga, Morogoro, Coast and Dar-es-Salaam with a total of 20 administrative districts, and occupying a total land area of 13.1 million hectares. The zone is divided into six major farming systems that include coastal (0 - 500 m above sea level) with 500 - 1000 mm of rainfall, lowland wet (0-900 m above sea level) with 1,200 mm of rainfall, lowland dry (0 - 900 m above sea level with 500 - 800 mm of rainfall, intermediate dry (900 - 1500 m above sea level) with 500 - 800 mm of rainfall, highlands (over 1500 m above sea level) with over 1000 mm of rainfall and Peri-urban suitable for livestock, mainly dairy and poultry keeping (Moshi et al 1997).

Methodology

Transect walk was conducted in 6 agro-ecological zones for in situ determination of potential pasture and forage species. On station evaluation of potential pasture and forage species were conducted at the Livestock Research Centre in Tanga municipality, Vikuge Pasture Seed farm in Kibaha and Matombo Agricultural Secondary School in Morogoro. Coppicing ability of multipurpose trees was determined by cutting trees at 20 cm above the ground. Number of branches that sprout on each stump after cutting were counted and recorded. Perpetuation ability of herbaceous legumes was assessed after removal of old plants in randomly selected plots. The numbers of seedlings that germinate after initial rainfall were counted in each plot. Descriptive statistics were used to describe the differences among plant species. Bypass protein was determined as the protein solubilised in acid detergent extraction (Elizalde et al 1999). Proteins soluble in acid detergent are more slowly degraded in the rumen than proteins soluble in buffer solutions. Thus a large proportion of acid detergent soluble crude protein escapes the rumen and is degraded in the lower gut 

Animal unit requirement was calculated according to Maule (1990). Carrying capacity was calculated by assuming a use factor of 50% and that forage requirements were 3 kg DM per 100 kg live weight.  Stability of Napier grass intercropped with different herbaceous legumes was assessed by intercrop performance in different locations and years.

Results and Discussion

Herbaceous legumes were not commonly available in many locations visited (Table 1). Legumes are important in swards for improvement of animal production in terms of productivity per unit area. Animal production is normally greater from grass-legume mixtures than pure grass stands (Mannetje 1984; Walker 1987). Observations made in this study necessitate development of supplementation strategies for grazing animals especially during the dry season. The carrying capacity of different agro-ecological zones ranged from 0.05 to 0.4 Tropical Livestock Units (TLU)/ha/year. This indicates the necessity of improving pasture production in different areas so as to increase carrying capacity beyond 0.5 TLU/ha/year.

On station results indicated that Stylosanthes guianensis and Centrosema puberscens thrive well during the dry season. These species have well-developed tap root system that could penetrate deeper in the soil to draw moisture. For grass species Panicum maximum and Pennisetum purpureum performed better than other grass species. Calopogonia muconoides and Clitoria ternatea dropped most of their leaves during the dry season while other species shaded their leaves moderately. Multipurpose trees such as Albizia lebbeck, Leucaena leucocephala, Gliricidia sepium, Tamarindus indica and Sesbania sesban were leafy throughout the year. After two years of establishment, Albizia lebbeck had the highest forage dry matter production followed by Leucaena leucocephala while Tamarindus indica had the lowest dry matter yield. This is in agreement with Calub (1990) who reported that poor total herbage production and high tannin content in Tamarindus indica may limit its use as fodder tree.

Results shown in figure 1 indicate that Gliricidia sepium had the highest coppicing ability followed by Leucaena leucocephala. Differences in coppicing ability of multipurpose trees observed in this study could be caused by species difference. Differences between species in relation to effects of harvest damage may be due to location of the sprout producing buds (Nurmi and Hytönen 1994). Many external factors and practical management measures such as cutting season, stump diameter, stump height, cutting method, fertilization, site quality, rotation length and spacing have influence on coppicing vigour of trees (Sennerby-Forsse et al 1992). Knowledge of the influence of factors affecting the coppicing ability of different multipurpose trees is therefore important to enable cutting schedule and harvesting techniques for sustainable utilization of these feed resources.

The legume species had higher contents of crude protein in the DM and a higher proportion of the crude protein that was estimated (Elizalde et al 1999) to have bypass characteristics (Preston and Leng 1987) (Table 2 and Figure 2).  The reason for the high proportion of bypass protein in legumes could be the content of tannins that bind some of the proteins to render them unavailable for rumen microbes.

Perpetuation ability of herbaceous legumes was assessed by removing old plants during the dry season with expectation that dropped seeds could germinate after rainfall.  Stylosanthes guianensis and Calopogonia muconoides appeared to have higher perpetuation ability than the other forage legumes (Figure 3). This implies that livestock farmers who wish to establish herbaceous legumes without reseeding every year are advised to establish either of the these two species. Tropical kudzu (Pueraria phaseoloides) had the lowest perpetuation ability. This could be attributed to lower viability of tropical kudzu seed than that of other legumes evaluated.

Tropical kudzu (Pueraria phaseoloides) had  higher dry matter yield than the other legumes evaluated (Figure 4).  Panicum maximum had the highest dry matter yield of the grass pastures evaluated. This suggests that Panicum maximum could be a potential grass for hay making in eastern zone.

Intercropping of Napier grass with either Calopogonia muconoides or Neonotonia weightii (Glycine weightii) resulted in the production of total dry matter that was lower than that for the pure stand of Napier grass (Figure 5). This indicates that these two legumes were not compatible with Napier grass within the Eastern zone environment. However, total dry matter yields obtained from intercropping Napier grass with Siratro (Macroptilium atropurpureum), Centrosema (Centrosema puberscens) and Clitoria  (Clitoria ternatea) were higher than for Napier grass alone.

Conclusions

• Herbaceous legumes were rarely found in different agro-ecological zones of eastern zone of Tanzania.

• Stylosanthes guianensis, Centrosema puberscens and Calopogonia muconoides appear to have potential for development of  grass-legume pasture.

• Intercropping of Napier grass with Siratro (Macroptilium atropurpureum), Centrosema (Centrosema puberscens) and Clitoria  (Clitoria ternatea)appears to be a suitable way to ensure availability of dry matter regardless of environmental variation among consecutive years.

• Green panic (Panicum maximum) is one of the most outstanding grass species for hay making in the eastern zone of Tanzania due to its high biomass production.

• Albizia lebbeck and Leucaena leucocephala are potential multipurpose trees well adapted to environmental conditions in the Eastern zone

Acknowledgement

The authors wish to acknowledge financial support obtained through Tanzania Agricultural Research phase II (TARP II) that enabled execution of this study. Special thanks to Farm Manager and Headmaster of Vikuge Pasture Seed Farm and Matombo Agricultural Secondary School in Morogoro respectively. Lastly but not least, we thank all colleagues who participated in one way or another to support this study.

Reference

Calub B M 1990 Evaluation of local multipurpose trees for fodder production. In: Research on multipurpose tree species in Asia [D A Taylor and K G MacDicken, editors.] Proceedings of an international workshop held November 19 - 23, 1990 in Los Banos, Philippines, pp 24-33.

Elizalde J C, Merchen N R and Faulkner D B 1999 Fractionation of fibre and crude protein in fresh forages during the spring growth. Journal of Animal Science, 77: 476 - 484.

Mannetje L't 1984 Nutritive value of tropical and subtropical pastures with special reference to protein and energy deficiency in relation to animal production. In: Herbivore Nutrition in the Tropics and Subtropics [ F C M Gilchrist and R I Mackie, eds]. The Science Press, South Africa, pp 51 - 66.

Maule J P 1990 The cattle of the Tropics. Redwood press Ltd, Mellesham, Wilts, pp 189.

Moshi A, Anandajayasekeram P, Kaliba A, Mantella D, Mwangi W and Shao F 1997 Economic impact of maize research in Tanzania. Southern Africa Centre for Cooperation in Agricultural and Natural Resources Research and Training (SACCAR), Gaborone, Botswana.

Nurmi J and J Hytönen 1994 The effect of whole tree harvesting on fuel quality and coppicing ability of SRIC willow crops. Paper presented at the Mechanization in Short rotation, Intensive Culture Forestry Conference, Mobile, AL, March 1 - 3, 1994.

Poehlman J M and Borthakur D 1972 Breeding Asian Field Crops. Oxford and IBH Publishing Co., New Delhi, pp 385.

PrestonT R and L A Leng 1987 Matching ruminant production system with available resources in the tropics and sub tropics. Penambul Books, New South Wales pp 1 - 200.

Sennerby-Forse L, Ferm A and Kauppi A 1992 Coppicing ability and sustainability. In: Ecophysiology of short rotating coppice [C P Mitchell J B, Ford-Robertson, T Hicklye and L Senerby-Forse, eds]. Elsevier Applied Science, 146 - 184.

Walker B 1987 Animal production from pasture and forages in the tropics. In: The proceedings of the 4^th AAAP Annual Science Congress [T F Reardon, J L Adam, A G Campbell and R M W Sumner, editors]. Hamilton New Zealand, pp 5 - 8.