Aspects of productivity of traditionally managed Barotse cattle in the Western Province of Zambia

In sub-Saharan Africa, traditionally managed livestock is important because of the provision of draught power and manure, the provision of security and investment possibilities, for the provision of meat and milk, and for social purposes (eg. brideprice, gifts). In the Western Province of Zambia, cattle are the only livestock of significance. The soils of the province virtually entirely consist of Kalahari sands, that are not very suitable for crop production, but with a good suitability for extensive cattle keeping. Cattle in the province belong to the Barotse breed. This is a Sanga breed, with a moderate to reasonable potential for meat and milk production, when compared with other local breeds, and if maintained under improved range conditions.A livestock development project in the Western Province (Prov. Vet. officer (1987), Livestock Development Project Western Province, Project Document) operates within the Department of Veterinary and Tsetse Control Services. It is aimed at providing a sustainable infrastructure for disease control, at assisting in the formulation of a cattle development policy, and at developing an integrated animal husbandry and animal health extension package for the traditional farmer. In order to establish its goals, the project has engaged in a programme of research activities. In this research, animal husbandry and animal health, but also grassland expertise, sociology and economy were involved. Part of the research programme was the herd monitoring programme.The aim of this thesis is, to evaluate the use of longitudinal physical monitoring of herds of cattle under traditional management for the description of productive performance and identification of factors that influence productivity. This evaluation should provide insight in the suitability of herd monitoring for the provision of basic information for extension and solutions for constraints to productivity.The herd monitoring programme is aimed at collecting quantitative information on the productivity of cattle in the province. Knowledge of these aspects was needed for the identification of constraints to productivity, for the assessment of the need for specific veterinary measures, and in order to give indications on the structure and development of the provincial herd.A total of 52 herds was involved in the first phase of the research (Chapter 2.1.). These herds were based in four of the six districts of the province. Herds were based in each of four Grazing Management Systems (GMS). The Grazing Management Systems differed in terms of grazing area and its, use, vegetation, main water resources, and largely in the practice of transhumance (periodically moving herds to other grazing grounds) or sedentarism (herding the animals from one permanent basis). All animals in the herds were individually identified through eartags, and the records were taken at the level of the individual animal.Deaths and slaughters were evaluated together, because slaughters should generally be considered emergency slaughters (Chapter 2.2.). Statisticaly significant effects on the combined death and slaughter figures were found of sex, age and the herd. Sales figures were also significantly influenced by Grazing Management System and husbandry system. Significant seasonal influences on death and slaughter figures, as well as on sales figures, could also be identified. The overall sales figures were smaller than the death and slaughter figures. Deaths and emergency slaughters must be seen as absolute losses, even though the meat of these animals is often still eaten or sold. The revenue this generates is, however, far less than that generated by sales of animals.The percentage of cows that calve differs considerably between Grazing Management Systems (Chapter 2.3.). This figure is, however, influenced by the proportion of animals that move into and out of the herds, and that spend less than a year in the herd. This proportion also differs considerably between herds.Significant influences on the mean lengths of calving intervals were found of the Grazing Management System (GMS) and the parity. Cows of which the calf died, or was not weaned, and which were not milked also showed a longer calving interval. The calving intervals are longest in GMS 1. Also seasonality in calving seems to be most clear in this GMS. In GMS 2, the interval between the birth of a calf and the moment the farmer starts milking the cow is significantly shorter than in most of the other GMS. At the same time the length of the period that the cows are milked is longest, and the interval between weaning of the calf and the birth of the next calf is shortest.The season in which the calf was born also significantly influenced the interval between calving and the moment the cow was milked for the first time, the length of the milking period and the age of the calf at weaning. The girth was generally influenced by GMS, sex and season. In GMS 1 the negative influence of environmental circumstances on productivity seemed biggest, in GMS 2 smallest.The number of owners involved in the herds that were included in the programme varied considerably (Chapter 2.4.). Most owners in a herd belonged to the family or relatives of the herd owner. The majority of cattle owners are men, and the average number of animals owned by men is twice as big as that owned by women. The number of owners in a herd was positively related to the size of the herd. One third of all removals from, and entries into the herds consisted of transfers from one herd to another, mostly because of herding arrangements. Also brideprice payments are an important reason for transfers of animals. The ownership and the transfers between herds are likely to influence decision-making processes in the herds. Transfers may pose risks of infection, but may also be aimed at reducing risks because of disease outbreaks.Diseases, in particular those caused by helminth parasites, are considered important constraints to productivity in the tropics (Chapter 3). Livestock owners also often consider parasitic diseases as a major reason for depressed body condition and consequently for depressed productivity. In the Western Province, the liverfluke Fasciola gigantica has a high prevalence. As in many other areas of Africa, floodplain grazing is an important factor in the epidemiology of this parasite. A seasonal influence is also present in many areas in Africa.A distinct seasonal influence is identified in many areas in Africa on the epidemiology of intestinal helminths. This is importantly related to the survival chances of the larval stages outside the vertebrate host. In the dry season no larval activity on pasture is found. The lack of moisture, rather than the temperature, seems to be the major determinant.The extent to which animals suffer from infections with intestinal helminths and liverflukes is partly determined by previous exposure. After previous exposure the animals develop resistance against re-infection, as a result of which the number of helminths that mature, as well as the adverse effects of infection are reduced. This is the result of development of immunity, and also, specifically in liverfluke, of fibrosis and calcification of liver tissue.The influence of infections with liverflukes and intestinal helminths on productivity is often evaluated through measuring the effects on growth or weight. In the Western Province, however, animals being sold for slaughter are normally selected from older animals. Therefore reproductive performance and parameters such as mortality and slaughter figures would be more important.In the second phase of the research, the intervention programme, two routine treatments against liverfukes (either Rafoxanide or Triclabendazole) were included, as well as two routine treatments against intestinal helminths (either Avermectine or Thiabendazole), and one combined routine treatment against both groups of parasites (both Rafoxanide and Thiabendazole). A total of 20 herds was involved in the intervention trials.Hardly any significant differences could be identified for the influence of treatment against liverflukes (Chapter 4.1.). In the Rafoxanide group, part of the treated animals had a slightly larger girth. Also a significantly shorter interval between weaning and the next delivery was found for treated animals in this group. In both girth and the intervals related to reproduction and lactation differences were found for other factors than the treatment, such as season, herd and sex. Deaths and slaughters for emergency were not significantly influenced by treatment against liverflukes. Significant differences could be identified for the herd in this analysis.The intervention, involving treatments against intestinal parasites and a combined treatment against intestinal helminths and liverflukes, also showed significant influences of season, sex and herd in several of the parameters, but hardly any of treatment (Chapter 4.2.). In the Avermectine trial, the girth of treated animals was larger. A significant effect of treatment on deaths and slaughters, at a confidence level of .90, was found in the Thiabendazole group. It is likely, that a clinical problem of gastro-intestinal parasitism was present in these herds. Analysis of faecal samples showed, that the largest percentage positive samples was found in the second half of the wet season.The intervention trials seemed to produce little or no favourable effects of treatment against either liverflukes or intestinal helminths (Chapter 4.3.). It is possible, that part of these results can be explained by the circumstances under which the trials were carried out and the trial design. More importantly, it is likely, that both liverflukes and intestinal helminths, though present, are in general not a serious problem. The low numbers of eggs found in faecal samples suggest this. Individual cases do occur, and large percentages of animals are likely to be infected, but the physical damage done by these infections is either small, masked by other factors, or is a far less influencial factor than factors such as nutrition, management or grazingenvironment.Even small differences between treated and untreated animals could economically justify the use of routine treatments, even if the schedules are relatively intensive, if the cost of application is not included. However, management of the herd andmanagement ofenvironmental factors are more important elements in improvement of productivity.Several aspects of the herdmanagement can be mentioned asinfluences on the productivity of the herds (Chapter 5). These include collection of manure, causing pressure on grazing time, the frequency of kraal shifting, especially for calves, day-to-day choice of pastures to graze, the quality of herdsmen, and uncontrolled burning of grassland. Competition between calf and man for the milk of the cows is not likely to be an important negative influence in calf health.Further research into day-to-day management factors in relation to the productive performance of animals and herds is necessary to provide the basis for extension. ownership division, the number of owners and their relation to the herd owner and, if possible, environmental factors should be included in this research.Economic and socio-economic factors are determinant factors in livestock development. Customs concerning animal husbandry, trade conditions and communal land use management are of importance.