Botswana occupies 572 000 km2 of raised plateau at a mean elevation of 1 000 m; 450 000 km2 of this area is rangeland, supporting a cattle population of around 3 million and a sheep and goat population of approximately 1.5 million. Mean annual rainfall varies from 700 mm in the north-east, dropping to 400 mm in the east and 200 mm in the southwest. The rain falls in the summer months from October to April and fluctuates widely between and within seasons. The beef cattle industry is based on the use of the natural pasture produced by this environment.Botswana has a human population of about 800 000, giving the high ratio of cattle to human population of 3.75:1 which is unique in Africa. Exports of animal products from Botswana, mainly in the form of fresh meat, account for 17 percent of the gross domestic product (GDP) and almost one half of the value of exports. Before the recent expansion in the mining industry, the livestock sector was even more important to the economy.
The success which has been achieved in beef marketing is due largely to a history of effective disease control, particularly foot and mouth disease, and the absence of rinderpest and pleuropneumonia. Tsetse flies carrying trypanosomiasis are limited to part of the Okavango swamp area, and there is no limiting tick-borne disease such as East Coast fever (theileriosis).
Two broad cattle production systems are practiced. The first is the traditional cattle post system where cattle are grazed on unenclosed, tribally administered land with no individual security of land tenure and a traditional right to grazing of unlimited cattle numbers. The second is a freehold farming system with fenced ranching. The traditional system has changed through time; undoubtedly there have been radical changes in the comparatively recent past, particularly due to the opportunity to exploit groundwater resources by mechanical bore-hole drilling and consequent extension of the grazing area. This process has been accelerated since the Second World War and has been responsible in part for the increase in the cattle population. The extension of grazing areas and the widely held fear of degradation of the range resources from overgrazing has led to the introduction of the national tribal grazing land policy (TGLP). The aims of tribal grazing land development are to stop overgrazing and degradation of the rangeland, to promote greater equality of incomes in the rural area, and to encourage growth and commercialization of the livestock industry on a sustained basis (Botswana, 1975).
Grazing in the tribal cattle post areas is communal, but some farmers have drilled their own boreholes and have acquired an individual right to the borehole water. Cattle are penned at night when they are near cultivated areas and when there is danger of stock losses from predators. Stock theft is rare in Botswana, hence herding is rarely practiced during the daytime. Animal management standards are low, and it is difficult to introduce innovations such as the weaning of calves or the controlled use of improved bulls. On the ranches, fences are used to control breeding herds, to separate young stock and to retain standing hay for the dry season. Disease control measures are applied, and mineral supplementation is provided to combat phosphorus deficiency. The ranch cattle also have perennial, adequate water supplies available within a reasonable distance.
The history of animal production research in Botswana is similar to that of many former colonial territories. Government farms were established during the colonial area to investigate and demonstrate improved methods of husbandry. These were run by the Veterinary Department as the government agency responsible for animal husbandry. Much of this past research was carried out in isolation, or in separate operations which were not part of any particular production systems. Not only were the research results not adopted by cattle producers, but the research failed to provide many aspects of basic production data. In animal breeding, for example, the paucity of information on the performance of indigenous cattle throughout southern Africa has been noted even up to the present time (Maule, 1972). Experimental design was frequently deficient, which made comparisons of the performance of different breed types impossible. In 1970, the few breeds of cattle maintained on 12 government ranches were each isolated on a different station under different conditions, rendering comparisons of breed performance impossible (Trail and Fisher, 1971).Range research was initiated in Botswana in 1936 at Morale. However, when this long-term research was reviewed there was found to be insufficient conclusive evidence to permit the formulation of management recommendations (McKay, 1968). The only other range research results available are surveys of the grazing resources (Blair Rains and Yalala, 1972; 1973). As a result of this pattern of research, there was little concrete information available to extension advisers or economic planners when Botswana achieved independence in 1966. The advice given was essentially of an ad hoc nature, based on results and experience from other countries and from casual observations in Botswana. Much of this advice was undoubtedly sound, and the development of the cattle industry in the country is indebted to these workers, but it has been seriously hampered by the lack of more comprehensive research results.
In 1970, the Ministry of Agriculture formed an Animal Production Research Unit (APRU). Although one of the preliminary objectives was to evaluate beef cattle breeds and crosses, it was quickly realized that a multi-disciplinary approach would be necessary to cover the many aspects of beef production. The programme which has developed covers three broad areas:-
The objectives of this integrated programme in Botswana are to provide reliable data on which politicians, economists and planners can assess the potential value of development proposals, and to provide reliable information to extension workers and producers, demonstrated in an acceptable ongoing production system.
To these ends, the APRU plans and supervises all technical aspects of a network of 17 ranches, totalling 40 000 hectares and carrying over 5 500 cattle. It also co-operates with commercial ranches and other organizations, involving a further 10 000 cattle. As positive research results must be fed continuously into the production system for demonstration to extension workers and producers, extensive data handling facilities have been set up for rapid collection, analysis and use of beef cattle performance records (Trail and Rennie, 1974; McNamara et al., 1975).
The detailed research programmes being undertaken and the results to date can best be summarized under four main headings. These are animal productivity results from the two beef cattle production systems; range productivity and improvements; nutrition and animal productivity; and breeding and animal productivity.
Studies on the two main beef cattle production systems in Botswana—traditional cattle posts and improved ranches—begun in 1970 (Rennie et al., 1977). At that time, 92 percent of the cattle were maintained under a traditional management system on unenclosed grazing (on cattle posts). These herds produced approximately 85 percent of the cattle slaughtered for export. The remaining 8 percent of the cattle were maintained under a fenced system and produced 15 percent of the slaughtered animals (Botswana, Ministry of Agriculture, 1970).In productivity studies, reproductive performance, growth and viability have been compared under the two systems over a four-year period. Calving percentages average 46.4 percent, average weight of 7-month-old calves is 122.5 kg, calf mortality averages 10. 2 percent and post-weaning growth to 18 months averages 88. 5 kg under cattle post conditions. Corresponding figures for cattle on the fenced ranches are 74. 0 percent for calving percentage, a 7-month calf weight of 177.4 kg, 8.5 percent calf mortality and a 105.8 kg post-weaning growth to 18 months. These results indicate annual overall productivity estimates of weaner calf weight per cow at 51 kg on the cattle posts and 120 kg on the fenced ranches, and annual estimates of 18-month-old calf weight per cow of 86 kg and 188 kg respectively.
The major objective in these studies has been to determine productivity constraints and opportunities on which future work could most profitably concentrate. The increase of over 100 percent in productivity obtained under the fenced ranch conditions illustrates the great potential for increased productivity, even without employing more sophisticated techniques of range management, animal nutrition and breeding.
The composition of the natural grasslands of Botswana varies considerably throughout the country, due to variations in soil type and rainfall distribution. Under highly variable rainfall conditions, efficient pasture management and utilization are difficult. In 1972, initial research objectives were to evaluate the usefulness of different range parameters for establishing limiting factors in animal production, and to indicate promising future lines of research. An initial survey has been conducted to determine the principal questions toward which future research should be aimed (Pratchett et al., 1977). Six range parameters measured monthly over an eleven-month period on nine ranches distributed throughout the main ecological zones have been related to the monthly liveweight changes of growing cattle. Clipped and oesophageal fistula samples provide estimates of crude protein (CP) content and dry matter (DM) digestibility, while available DM and grazing indices provide estimates of available herbage. Statistical analyses indicate that liveweight change is influenced primarily by the CP content of the herbage selected. The CP content of fistula samples accounts for 54 percent of the variation in liveweight, while digestibility of the same samples accounts for 32 percent. Thus, under the natural range conditions of Botswana, crude protein is the major limiting factor. Following this finding, research has been conducted to identify and encourage grasses having above-average levels of crude protein. Since April 1974, 30 different species of grass have been collected monthly over 13 ranches throughout the country's major ecological zones and screened for CP content and digestibility. The results to date indicate that certain species are superior in both CP content and digestibility (Botswana, Ministry of Agriculture, 1978).Large-scale grazing trials were then initiated in 1974 in an attempt to encourage the better species and to determine if improved cattle performance would follow. Four grazing treatments were examined; continuous; one-herd three-paddock; four-day grazing, 32-day resting rotation; and seven-day grazing, 56-day resting rotation. Stocking rates of 1 LSU : 10 ha and 1 LSU : 8 ha were adopted in the first and second years of the trials respectively. After two years, no significant differences have been detected among treatments in terms of total yield of dry matter, dry matter of good species, botanical composition or cattle performance.1
Factors of considerable economic importance in any beef production system are the reproductive performance of breeding cows and the length of time taken by growing animals to reach slaughter weight. In semi-arid areas such as Botswana, with variable summer rainfall and a prolonged winter dry season, nutritional deficiencies in the natural pasture limit both reproductive performance and liveweight gain. Deficiencies of phosphorus, crude protein and energy in the natural pastures of southern Africa have long been recognized, and the beneficial effects of phosphorus supplementation have been demonstrated repeatedly. For phosphorus supplementation, the basic recommended policy is to allow cattle access to a 1 : 1 mixture of bonemeal and salt at all times.As mentioned earlier, the range research programme in Botswana. has determined that under natural grazing conditions crude protein rather than energy is the major limiting factor. Several supplementary protein feeds containing non-protein nitrogen (NPN), often referred to as rumen stimulatory licks, are available commercially to offset the deficiencies in the natural pasture. A series of trials has been carried out to investigate the effects of these licks on the reproductive performance of breeding cows and the liveweight gain of growing cattle (Capper et al., 1977). The trials involved 1 375 breeding cows at five artificial insemination centres, and 360 breeding cows and 269 growing stock under ranch conditions. The licks increase the percentage of pregnancies in cows under lactation stress by up to 20 percent, but have no effect on the reproductive performance of dry cows or cows with a calf older than five months. In growing animals, the provision of rumen stimulatory licks increases live-weight gain by an average of 12 percent.
In Botswana there are three locally available breeds, all members of the stabilized Sanga grouping. About 80 percent are indigenous Tswana, 15 percent are Africander, mainly originating from South African imports, and a small proportion are Tuli. The Tuli breed has been developed since 1946 in the southwest of Rhodesia from Tswana types. The use of Africander, Tuli, Brahman and Simmental bulls on Tsawana cows has been recommended for a number of years.Since 1970, performance tests have been carried out on all male and female stock on a network of 13 government ranches. Superior performance-tested males are thus available as artificial insemination (AI) sires or as bull replacements for the government ranches. The remaining superior males are sold to farmers, while inferior males are castrated and eventually slaughtered. Superior females are selected for herd replacements.
The breeding programme was planned to cover three main areas:-
The ongoing breed studies are carried out mainly under fenced ranch conditions, but evaluations of crossbred cattle under traditional management conditions in the communal grazing areas have also been made. Production is entirely from natural pasture with the exception of phosphate supplementation. Sufficient standing hay is retained for dry season grazing. The traits examined are calving percentages, weights at birth, weaning and 18 months, and calf mortality.
Over a three-year period, the calving percentages of Africanders, Tswanas and Tulis were 64. 5, 70.6 and 85 percent respectively (Trail et al., 1977). Mortality was higher among the Africander calves up to two years of age, at 11 percent compared to 7.5 percent for Tswana calves and 7.4 percent for Tulis. The 18-month weight of Tuli cattle was 284 kg, and of Tswanas 279 kg, both higher than the 270 kg for the Africanders. In terms of annual weight of weaner calf per cow, the Tuli is 16 percent more productive than the Tswana, which in turn is 18 percent more productive than the Africander. In terms of annual weight of 18-month-old calf per cow, the Tuli is 22 percent superior to the Tswana, which is in turn 17 percent superior to the Africander.
The results of this evaluation of the three local breeds support the use of the Tuli breed in Botswana. These findings are contrary to previous extension policy which advocated the use of the Africander. As a result the Tuli herds on government ranches for demonstration and production of breeding stock are now being expanded. Comparisons of crossbreds produced by the use of Simmental, Brahman, Bonsmara and Tuli sires on Tswana cows show an advantage in growth to 18 months through crossbreeding. The average 18-month weight of Simmental crosses is 324 kg and of Brahman crosses 304 kg. Both are significantly higher than the average weight of pure Tswana at 279 kg. Bonsmara and Tuli crosses at 294 and 290 kg also show a significant increase over the pure Tswana. The use of Tuli sires on Tswana cows is therefore now recommended for all management conditions. The use of Brahman and Simmental sires on Tswana cows also produces superior growth under both ranch and cattle post conditions. An evaluation of mothering ability and reproductive performance of first cross females is now needed. The indications are that a criss-cross breeding system for Brahman and Tswana will be valuable, with the Simmental breed substituted for Brahman under improved management conditions.
Cattle productivity levels are lower in the traditional system than on ranches, but it is still not possible to quantify the incremental advantages of adopting different components of the ranch management package. To date this problem has not been studied, as it has been assumed that piece-meal adoption of individual components of the package will have little effect. Examples are improving water supplies in the absence of grazing control, urea supplementation when forage is severely limited, and early weaning without adoption of a breeding season. However, the need to study these questions is now urgent in Botswana with the introduction of the tribal grazing land policy (TGLP) and the implementation of the Second Livestock Development Project (Botswana, Ministry of Agriculture, 1976a). This project meets the aims of the TGLP in that it seeks to create the infrastructure needed for the development of sustained profitable production systems suitable to communal and commercial grazing areas, and for the marketing of livestock products. The development of improved management at cattle posts will, in most cases, be a gradual process, and producers will require sound advice from the extension services on the best development sequence to be followed.The difficulties in this situation of formulating sound extension proposals for animal management on the basis of formal research are almost insurmountable. Research work on privately owned cattle posts is difficult to conduct, and research on a sufficient number of representative cattle posts to cover all environmental areas would be very expensive. Individual situations are likely to need individual evaluations and the optimal sequence of development could differ markedly among locations. Investigation of all possible combinations would require resources far beyond the value of the results which might be obtained.
Once phosphate requirements have been satisfied, protein deficiency in pastures is the major limitation on cattle productivity. Nutrition work has therefore concentrated on the use of protein supplements in the form of NPN. The question of when and to which stock category this supplementary feed should be given, and whether this should be combined with some other management intervention such as weaning age, is indicative of the many alternatives confronting livestock producers.In 1974, when prices were favourable, feedlot finishing of cattle appeared attractive and feedlot performance trials were conducted. Supplying sufficient cattle to the feedlots would involve the removal of significant numbers of animals from the herds. This would have an important effect on grazing pressures and would increase the grazing available to the remainder of the herds. Such effects are difficult to measure but must be estimated before the overall effect on the production system can be evaluated. This problem will assume importance if price ratios again become favourable to feedlot operations.
Sound information on the value of the major indigenous breeds is now available. The advantages to be obtained from crossbreeding have been demonstrated in terms of growth, and there is widespread interest in its adoption. The question of the optimum size of the crossbred cow for a specific environment, and the possibility that selection for maximum growth may in some cases be counter-productive, is of concern. Similarly, crossbreeding under the more rigorous environment of the cattle post may have different requirements than in the ranch situation. The optimum choice of breeding programmes in the transition from the Tswana, through Tuli-crosses and Brahman-crosses up to Simmental-crosses cannot be determined from field experimental work covering all situations.
There is a total gap in research knowledge in this area. Experience suggests that milking low-yielding cows detracts significantly from beef production. However, opportunities exist for dual-purpose production which may be commercially attractive in certain localities. A research question in Botswana is whether the Tswana cow is suitable for this purpose or whether a cross with a breed such as Simmental would be more appropriate.
Seasonal rains rarely fail completely in Botswana. More commonly, minor seasonal differences occur in the total rainfall and in its distribution within the season and these have marked effects on forage and cattle production. The best tactical responses of producers to such situations, which are in essence droughts of various severities and durations, have not been investigated in Botswana. Formal research programmes cannot be designed to include drought situations, so research results do not lend themselves readily to the formulation of extension recommendations for times of drought. Ongoing research in Botswana will identify possible improvements in the existing systems, and the value of these improvements are related in varying degrees to their performance in drought situations. Despite the methodological difficulties involved, research must be capable of estimating this performance.