General consideration on the local livestock population, census and

Table 6.4.: Overall strata sample size requirements for different expected relative errors in ward no. 4, Mbashe Local Municipality, Eastern Cape South Africa. Two strata were built by grouping villag-es based on (1) -cattle stratum, average cattle herd size and (2) -sheep stratum, average sheep flock size.

It was observed that the variation on sample size (n and %) is small regardless if the cattle or the sheep stratification was used, being the maximum variation observed less than 4%. Fur-thermore the variation between both strata for goats (not a target species for any of both strati-fications) is low. A preliminary conclusion is that although livestock populations in the area are statistically heterogeneous, the difference does not produce considerable differences if a pre defined strata is constructed based on one livestock species only. This could be also true if other criteria are used to generate the strata. In the alternative presented here, the stratified random sample is conceptually simple although in general the construction of the strata can be a difficult task (Levy and Lemeshow, 1999).

6.4.3. General consideration on the local livestock population, census and sampling strategies

In general FAO recommends the use of complete enumeration census strategy for agricultural census, but local conditions should be a key determinant in selecting the ideal strategy and therefore sampling procedures may used to avoid logistic errors (FAO, 1995, 2005). In re-gards to the livestock population in this study the findings are that in one area animal popula-tions are homogeneous (ward no. 3) and within a second area livestock populapopula-tions are hete-rogeneous (ward no. 4). Thus calls for a need for different strategies to address various needs when setting up census activities.

Since the Eastern Cape communal area is composed of livestock owners that are not nomads, traditional census and sampling strategies could be employed in this case. The limited re-sources in the province and the complexity of any census calls for consideration of different strategies dictated upon by the local conditions (Cochran, 1977; Levy and Lemeshow, 1999).

Depending on the area and its livestock population characteristics (homogeneity or hetero-geneity) census / sampling strategies will differ. In homogeneous areas, depending on the scale of the census or survey, random livestock owners within villages or even random villag-es within wards could be sampled, decision supported by the low animal population variation.

Further evaluation of the livestock population in a broader area is required to test the extent of the livestock homogeneity observed.

For heterogeneous areas like ward no. 4, the creation of strata is of critical importance to al-low reliable strategies (Levy and Lemeshow, 1999; Dohoo et al., 2010). The information col-lected could be then extrapolated to a larger scale with the approximated farmers / household numbers in a broader area and generate estimates. This methodology would save time and resources by reducing the census visits only to some farmers and or villages. Alternately the organization of a complete enumeration census when confronted to heterogeneous livestock populations could be a preferred situation to avoid complicated strata construction and the application of complex sampling methodologies that require difficult planning and special data analyses.

It is desirable to determine to which extent the status quo observed (homogeneity in one area, heterogeneity in other) applies to other regions of the Eastern Cape. Agro ecological factors areas determine the animal density to a big extend as described by McDermott and Arimi (2002). Further studies are required to evaluate the influence of these or other factors on ani-mal ownership (multi species ownership, aniani-mal numbers, etc.). The results of this study are to be considered as a tool for decision takers and as a way to provide further information re-garding alternative methods to estimate the livestock population in the Eastern Cape Province.

References

Altman, D.G., 1991. Practical Statistics for Medical Research. Chapman and Hall, Cornwall.

Anonymous, 2006. Livestock Development Strategy for South Africa, 2007. Department of Agriculture of the Republic of South Africa, Pretoria, p. 56.

Anonymous, 2007a. Community Survey 2007: Municipal data on household services. In: Le-hohla, P. (Ed.) Statistics South Africa, Pretoria, p. 336.

Anonymous, 2007b. Department of Agriculture Annual Performance Plan. Department of Agriculture of the Eastern Cape, p. 75.

Anonymous, 2008. Department of Agriculture Strategic Plan 2006-2009. Department of Agriculture of the Eastern Cape, p. 90.

Bennett, S., Woods, T., Liyanage, W.M., Smith, D.L., 1991. A simplified general method for cluster-sample surveys of health in developing countries. World Health Stat Q 44, 98-106.

Cochran, W.G., 1977. Sampling Techniques. Wiley New York.

Colwell, J., Som, H., 2004. The World Census of Agriculture 2010 Programme: A Modular Approach. 3rd. International Conference on Agricultural Statistics (ICAS III). FAO, Cancún, Mexico.

Dohoo, I., Martin, W., Stryhn, H., 2010. Veterinary Epidemiologic Research. AVC Inc. Uni-versity of Prince Edward Island, Charlottetown.

FAO, 1995. Programme for the World Census of Agriculture 2000. FAO Statistical Devel-opment Series N°5. Food and Agriculture Organization of the United Nations.

FAO, 2005. A System of Agricultural Censuses and Surveys. FAO Rome.

Kiguli, L.N., Palmer, A.M., Avis, A.M., 1999. A description of rangeland on commercial and communal land, Peddie diustrict, South Africa. African Journal of Range & Forage Science 16, 89-95.

Kirkwood, T., 1979. Geometric Means and Measures of Dispersion. Biometrics 35, 908-909.

Levene, H., 1960. Robust tests for equality of variances Stanford University Press Standford.

Levy, P., Lemeshow, S., 1999. Sampling of Populations, Methods and Applications. John Wiley & Sons, Inc. New York.

Mapekula, M., Chimonyo, M., Mapiye, C., Dzama, K., 2009. Milk production and calf rear-ing practices in the smallholder areas in the Eastern Cape Province of South Africa. Tropical animal health and production 41, 1475-1485.

Marufu, M.C., Chimonyo, M., Dzama, K., Mapiye, C., 2010. Seroprevalence of tick-borne diseases in communal cattle reared on sweet and sour rangelands in a semi-arid area of South Africa. The Veterinary Journal 184, 71-76.

Masika, P.J., Mafu, J.V., 2004. Aspects of goat farming in the communal farming systems of the central Eastern Cape, South Africa. Small Ruminant Research 52, 161-164.

McDermott, J.J., Arimi, S.M., 2002. Brucellosis in sub-Saharan Africa: epidemiology, control and impact. Veterinary Microbiology 90, 111-134.

Milligan, P., Njie, A., Bennett, S., 2004. Comparison of two cluster sampling methods for health surveys in developing countries. Int. J. Epidemiol. 33, 469-476.

Nqeno, N., Chimonyo, M., Mapiye, C., Marufu, M.C., 2010. Ovarian activity, conception and pregnancy patterns of cows in the semiarid communal rangelands in the Eastern Cape Prov-ince of South Africa. Animal Reproduction Science 118, 140-147.

Palmer, A., Ainslie, A., Hoffman, M., 1999. Sustainability of commercial and communal ran-geland systems in southern africa. In, VIth International Ranran-geland Congress Proceedings Townsville, Australia, pp. 1020-1022.

Palmer, T., Ainslie, A., 2002. Country Pasture/Forage Resource Profiles; South Africa. Coun-try Pasture/Forage Resource Profiles; FAO. p. 21.

Rumosa Gwaze, F., Chimonyo, M., Dzama, K., 2009a. Communal goat production in South-ern Africa: a review. Tropical animal health and production 41, 1157-1168.

Rumosa Gwaze, F., Chimonyo, M., Dzama, K., 2009b. Variation in the functions of village goats in Zimbabwe and South Africa. Tropical animal health and production 41, 1381-1391.

Searle, S.R., 1971. Linear Models. Wiley & Sons. New York.

Acknowledgements

We thank all the State Veterinary Services of the Eastern Cape personnel for their help during the organization and field operations during the pilot census study. Furthermore we thank the Lower Saxony Ministry of Food, Agriculture, Consumer Protection and Regional Develop-ment and the Ministry of Agriculture of the Eastern Cape for funding this study.