C.R. Field
UNESCO Kenya Arid Lands Research Station
P.O. Box 147 Marsabit Kenya
Introduction
Material and methods
Results and discussion
Conclusions
Acknowledgements
Summary
Milk and meat production by sheep and goats was monitored under traditional Rendille management and also with a veterinary input. The nutritional value of these products to a typical Rendille household was estimated in terms of protein and energy. The contribution of smallstock to the nutritional requirements of the household is compared with that of camels and cattle under the two regimes. It is concluded that smallstock supply from 22-26 per cent of energy requirements and 55 per cent of protein requirements under the traditional system: with the health programme these proportions increase to 25-31 per cent and 65 per cent. The contribution of smallstock is greater than that of cattle and under the health programme their production is only exceeded in protein by camels. Smallstock are an important source of meat in dry seasons in particular. Milk contributes little to the Rendille diet. Male animals are sold and the proceeds used to purchase cereals which help reduce the energy deficit in the human diet.
It has been estimated that at the present rate of growth (four per cent per annum) the human population of Kenya will have doubled by the turn of the century and at that time will be increasing at the rate of one million per annum. In fact, in less than half a century there may be five people for every one living in Kenya today (Field & Simpkin, 1984).
Recently, it was stated that the number of people living in the dry areas of Kenya, which cover 80 per cent of its surface, is expected to increase from the current 6 million to 11 million in the next decade and a half (Muturi, 1985).
The national economy is growing at a much slower rate than this and more people will be forced back to the land and subsistence agriculture. As the remaining high- and medium-potential land is settled and cultivated there will be intensification of the use of semi-arid lands of marginal agricultural potential. There is little hope for the survival of forests and woodlands, water conservation will be forfeited and there will be accelerated erosion and desiccation of the land.
In northern Kenya, nevertheless, extensive rangelands which cannot be cultivated because of the low and unreliable rainfall will remain. Attempts to transpose the existing beef economy from the Kenya highlands to these rangelands should be resisted since in the arid zone, where water is at a premium, water-dependent cattle are a major factor in the elimination of the herbaceous layer over large areas of annual vegetation around permanent water points (Field & Simpkin, 1984). Greatest emphasis should be placed on improving the productivity of camels, sheep and goats which are better adapted to arid conditions.
This paper is a synthesis of several simultaneous studies on the productivity of camels, cattle and small ruminants under traditional management and with a veterinary health programme. The data are combined with information on household stock ownership to determine the relative importance of the different livestock species in fulfilling the nutritional requirements of the Rendille pastoralists in Marsabit district. They also show the relative advantages of a strategic health programme in raising the productivity of the different species of livestock.
STUDY AREA
The study area covered 11,300 km² of the Rendille home range in Western Marsabit district.
LIVESTOCK NUMBERS AND HOUSEHOLD OWNERSHIP
Methods used involved aerial survey and household questionnaires.
Aerial Survey
Results from 11 systematic reconnaisance flights over a six per cent sample of the study area are used. The method is described in Norton-Griffiths (1975) and Field et al (1981). Data from the 1979 national census of the human population were used to determine average household ownership (Government of Kenya, 1981).
Household Questionnaires
In the household survey separate questions were asked of the men and women. Data were collected on family size and food consumption. Measurements were taken, on site, of: livestock numbers and flock compositions; animal weights; age; and milk production. Data are from 150 household surveys among Rendille, Ariaal and Samburu.
PRODUCTIVITY EXPERIMENTS
Measurements were taken of the main production parameters (milk, liveweight gain, recruitment and mortality) of herds of all four species of livestock. The minimum size of the herds was 100 animals and the composition approximated to that of traditional Rendille herds. The herds were monitored between 1979 and 1982, the minimum period being 18 months for cattle while the other three species were monitored for two to three years. Monitoring was on a monthly basis for camels and cattle and every two weeks for smallstock.
The health programme was introduced after a period of observation of six to twelve months during which all main diseases were identified. The herds were then divided, one half receiving a comprehensive veterinary input known as the health programme while the other half was maintained under a husbandry regime which permitted treatment of disease on traditional lines.
Further details are given for sheep and goats in Carles (1985) and Simpkin (1985) and for cattle in Field (1981).
HOUSEHOLD OWNERSHIP OF LIVESTOCK
Results calculated from aerial and household surveys are presented in Tables 1 and 2 respectively.
In Table 2 the age-specific composition of the herds of each species, together with data on weights-for-age, have been used to calculate mean liveweight. In Marsabit district these are quite low where a cow is equivalent to 0.66 TLU, a camel 1.2 TLU, a sheep 0.09 TLU and a goat 0.10 TLU.
From these two tables it can be seen that from 31 to 36 TLU are owned per household and smallstock comprise from 17 to 31 per cent of the total depending on the method of calculation.
MINIMUM REQUIREMENTS OF LIVESTOCK
An average family of eight persons is estimated to have dietary needs equivalent to 6.5 adults (Brown, 1971). Daily energy requirements for pastoralists have been estimated to range from 2000 Kcal. for a woman to 2800 Kcal for a man (Dahl & Hjort, 1976). However, a pastoralist has been described as "an active individual doing no heavy work" needing 2300 Kcal per day (Brown, 1971). Thus, family requirements are calculated to range from 15 000 Kcal (Brown, 1971) to 18 300 Kcal per day (Dahl & Hjort, 1976) after adjusting for a family of eight. Protein requirements are about 422 g per family per day.
Table 1. Average stock ownership per family in Western Marsabit district (from aerial survey data)
|
Species |
Number |
Density N°/km² |
Percent of TLUa) |
Number owned |
TLU per family |
|
|
Per personb) |
Per familyc) |
|||||
|
Camels |
18 643 |
1.65 |
40.3 |
1.4 |
11.6 |
14.5 |
|
Cattle |
24 552 |
2.17 |
42.4 |
1.9 |
15.2 |
15.2 |
|
Smallstock |
107 547 |
9.52 |
16.9 |
8.3 |
66.7 |
6.1 |
|
Donkeys |
235 |
0.02 |
0.4 |
0.02 |
0.1 |
0.1 |
|
Total |
150 977 |
13.36 |
100.0 |
11.62 |
93.6 |
35.9 |
Notes:a) One Tropical Livestock Unit (TLU) is equivalent to a 250 kg cow or 0.8 of a camel or 11 smallstock.b) Assumes a population of 12 900 Rendille people.
c) Assumes eight people per family.
Table 2. Average stock ownership per family in Western Marsabit district (from household surveys)
|
Species |
Number per family |
Tropical Livestock Units (TLU) |
||
|
Per family % of total |
Adjusted for area |
|||
|
Camels |
12 |
15 |
42.6 |
14.4 |
|
Cattle |
11 |
11 |
31.3 |
7.3 |
|
Smallstock |
101 |
9.2 |
26.1 |
9.6 |
|
Total |
124 |
35.2 |
100.0 |
31.3 |
Brown (1971) suggested that in most African pastoral societies a standard family consumes a diet of 75 per cent milk and 25 per cent meat over a year: this amounts to 16 litres of milk and 2.41 kg of meat per day. Today however, many families have access to cereals with which they supplement their diet.
Daily milk requirements of a family can be supplied by about seven cows or four camels in milk on any and every day of the year (Brown, 1971). A pastoralist must keep 35 to 40 cattle but only half this number of camels in order to maintain this level of production (Lamprey, 1983). Brown (1971) concluded that in whatever manner this figure is calculated a family of eight must maintain 27 to 31 TLU's and if these figures are adjusted to the smaller size of animals in our area, equivalents lie within the following ranges for each species: camels 23 to 26; cattle 41 to 47; sheep 278 to 326; goats 275 to 311.
Tables 1 and 2 show that average Rendille stock ownership should provide at least these minimum requirements. In practice pastoralists try to keep more animals to provide for disasters such as drought, disease and theft and also for social reasons. Clearly there is considerable variation in stock ownership in terms of numbers, species and productivity and this may determine whether or not a household will be dependent on food aid.
ESTIMATED YIELDS OF SHEEP AND GOATS
Milk Yields
Under the two management regimes the year round average daily yields of milk have been estimated per adult female. The calorific values of sheep and goat milk are taken as 1114 and 700 Kcal/kg and the protein values as 63 and 36 g/kg, respectively. From Table 3 it can be seen that the health programme did not lead to an increase in milk production or in energy and protein in sheep.
Meat Production
Growth rates of small ruminants have been converted into daily gains in carcass weights. With an energy of 2.36 Kcal and a protein value of 0.145 g/g of carcass, the energy and protein available per day has been calculated in Table 4.
The normal ratio of sheep and goats in Rendille flocks is 1.0:1.5. Therefore household ownership of goats ranges from 40 to 61 and sheep from 27 to 40 depending on whether data are used from Table 1 or 2. A survey of flock compositions showed that 40 per cent of sheep and goats are adult females while the remainder can be considered to be meat producers.
In the final analysis, the flock size from the household surveys has been taken to be more accurate as the aerial surveys yield one-third less small ruminants. This is understandable as the noise from an aircraft causes goats and sheep to aggregate and makes counting from oblique photographs difficult.
Table 3. Milk, energy and protein yields from small ruminants in Western Marsabit district
|
Species |
Management regime |
|||||
|
Traditional |
Health programme |
|||||
|
Milk (ml/d) |
Energy (Kcal) |
Protein (g) |
Milk (ml/d) |
Energy (Kcal) |
Protein (g) |
|
|
Sheep |
17.5 |
19.5 |
1.10 |
17.5 |
19.5 |
1.10 |
|
Goats |
35.1 |
24.6 |
1.26 |
35.1 |
27.4 |
1.41 |
Table 4. Daily production of meat and energy and protein yield for small ruminants in Western Marsabit district
|
Species |
Management regime |
|||||
|
Traditional |
Health programme |
|||||
|
Carcass yield (ml/d) |
Energy (Kcal) |
Protein (g) |
Carcass yield (ml/d) |
Energy (Kcal) |
Protein (g) |
|
|
Sheep |
23 |
54 |
3.3 |
27 |
64 |
3.9 |
|
Goats |
20 |
47 |
2.9 |
24 |
57 |
5.5 |
For the estimation of overall yields the assumption is that in an average flock of 101 animals, 24 goats and 16 sheep are milk producers and 37 goats and 24 sheep are meat producers.
OVERALL YIELDS OF THE FAMILY HERDS
Similar estimates have been made of milk and meat production for camels and cattle. Details of the procedures followed for each species are given in Field & Simpkin (1984).
Results are presented in Table 5 and 6 for a typical family herd. Information is also presented to show the extent to which each livestock category fulfills the needs of the owners.
From Table 5 it is apparent that under traditional management there is adequate protein available from the family herds but there is a shortfall in energy requirements ranging from 39 to 50 per cent. Small ruminants may supply from 22 to 26 per cent of energy requirements and 55 per cent of protein needs.
Under the health programme protein is in surplus while there is still a shortfall of 26-39 per cent in energy. Clearly the purchase of cereals, sugar and fat will remain a necessity for some time.
Goats and sheep have an important function as a source of meat which may, under the health programme, supply about a quarter of the energy needs and over a half of the protein needs in dry seasons. Their milk contributes little to the diet.
Table 5. Estimated mean daily yields from all livestock under traditional management in Western Marsabit district
|
|
Species |
Total |
|||
|
Sheep |
Goats |
Camels |
Cattle |
||
|
Mean number owned |
40 |
61 |
12 |
11 |
124 |
|
Energy from milk (Kcal) |
312 |
590 |
2 541 |
940 |
4 383 |
|
Energy from meat (Kcal) |
1 296 |
1 739 |
327 |
1 478 |
4 840 |
|
% of required minimum |
11 |
15 |
19 |
16 |
61 |
|
% of required maximum |
9 |
13 |
16 |
13 |
50 |
|
Protein from milk (g) |
18 |
30 |
142 |
47 |
237 |
|
Protein from meat (g) |
80 |
107 |
69 |
91 |
347 |
|
% of required diet |
23 |
32 |
50 |
33 |
138 |
Sheep and goats are also a convenient size for minor trade negotiations and to meet social obligations. By selling a castrated goat or sheep, a pastoralist may obtain about US$10 with which he may then purchase 32 kg of maize meal or 16 kg of sugar. These rich sources of energy go a long way to filling the shortfall in energy in the diet: they also remove the reliance of the pastoralist on milk in an environment which is hostile for milk production.
Table 6. Estimated mean daily yields from all livestock under the health programme in Western Marsabit district
|
|
Species |
Total |
|||
|
Sheep |
Goats |
Camels |
Cattle |
||
|
Mean number owned |
40 |
61 |
12 |
11 |
124 |
|
Energy from milk (Kcal) |
312 |
658 |
3 581 |
1 040 |
5 591 |
|
Energy from meat (Kcal) |
1 536 |
2 109 |
519 |
1 404 |
5 568 |
|
% of required minimum |
12 |
18 |
27 |
16 |
74 |
|
% of required maximum |
10 |
15 |
22 |
13 |
61 |
|
Protein from milk (g) |
18 |
34 |
199 |
52 |
303 |
|
Protein from meat (g) |
94 |
129 |
110 |
86 |
419 |
|
% of required diet |
26 |
39 |
73 |
33 |
171 |
In this simultaneous survey of all four major livestock species in northern Kenya, we conclude that the camel is the most important source of food to the pastoral herd owner. However, when sheep and goat production is combined, which we consider legitimate as they are always run as a mixed species flock, we find that their production of energy is the greatest while protein production is only exceeded by camels under the health programme.
Evidence that even higher productivities may be possible from small ruminants has recently been obtained from the Project's experimental flock which increased by 64 per cent over a one-year period, one-third of which was extreme drought.
I wish to thank H. Blackburn of Texas A and M University and A. Carles of the University of Nairobi for information on small ruminants. T. Rutagwenda and P. Simpkin both completed their theses with the Project on different aspects of camel productivity. Research could not have been completed without the dedicated contribution of our Field Support Staff. They are too many to mention individually, but I am sincerely grateful for their work which was carried out under continual threat from either predators, theft or personal injury. Finally I wish to thank the livestock owners who cooperated with us, in particular Councillor Hassan Mussa and Messrs Lengima and Lenangaya.
