Spatiosurvival analysis of mortality on smallholder dairy farms in Tanga and Iringa regions of Tanzania

A combination of survival and spatial analyses was applied to a dataset containing cattle mortalities on smallholder dairy farms in two separate regions (Tanga and Iringa) of Tanzania. Cattle mortality data for the year 1998 were collected retrospectively during the period January to April 1999. The objectives of the current study were, firstly, to quantify the hazard of mortality and, secondly, to investigate whether there was a spatial pattern in the variation that was unaccounted for in the hazard of mortality. A Cox regression model with farm as a frailty term was used to quantify the hazard of mortality. Geostatistical techniques were used to explore the first- and second-order spatial distribution of the farm frailty term. A total of 1,790 cattle from 400 randomly sampled smallholder dairy farms were included in the study. The overall mortality incidence rate for the study was 11.8 per 100 animal years (95% CI 10.0–13.8). The hazard of mortality for male cattle was 2.4 (95% CI 1.7–3.4) times higher than that of female cattle. There was evidence of a first-order spatial pattern, i.e., a tendency for farms with higher frailty to aggregate.     

The effect of feeding maize husk and leucaena as mixture on the voluntary intake of the husk

The effect of feeding maize husk and leucaena as a mixture on voluntary intake of maize husk was studied over a 40-day period. Ten male goats with an average weight of 15 kg were used. The treatments were: (a) maize husk fed in a mixture with leucaena and (b) maize husk plus leucaena offered in separate troughs but at the same time. The maize husk intake and total dry matter intake for the two feeding methods were about the same. Thus total dry matter intake was not affected (P<0.05) by the method of feeding. There was also no significant difference (P<0.05) between the two methods of feeding in the digestibility values. The data were considered to indicate that there were no significant differences in the intake of maize husk when fed in a mixture withLeucaena leucocephala or when offered separately but at the same time.     

The effect of browse supplementation on maize husk utilization by goats

The effect of browse supplementation on maize husk (Zea mays) utilization by goats was studied in a 12 week feeding and 2 week digestibility trial. Twenty-four goats were stratified according to their weight, and then randomly allocated to four treatments. Browse supplementation significantly increased (P < 0.05) the total dry matter intake, diet dry matter digestibility and diet organic matter digestibility (P < 0.05) but did not have any significant effect on acid detergent fibre digestibility (P > 0.05). The browse supplemented goats gained more weight than the non browse supplemented goats.     

The comparative role of cattle, goats and pigs in the epidemiology of livestock trypanosomiasis on the plateau of eastern Zambia

To determine and compare the prevalence of trypanosome infections in different livestock species (cattle, pigs and goats) in areas where game animals are scarce and livestock constitute the main food source of tsetse, a survey was conducted on the plateau of the Eastern Province of Zambia in Katete and Petauke districts where Glossina morsitans morsitans is the only tsetse species present. Blood was collected from a total of 734 cattle, 333 goats and 324 pigs originating from 59 villages in both districts and was examined using the buffy coat method and the PCR-RFLP as diagnostic tools. The prevalence of trypanosome infections differed substantially between livestock species. Using microscopic diagnostic methods, trypanosome infections were detected in 13.5% of the cattle and 0.9% of the pigs. All goats were parasitologically negative. The PCR-RFLP analyses increased the trypanosomiasis prevalence to 33.5, 6.5 and 3.3% in cattle, pigs and goats respectively. The majority of the infections (91.2%) were due to Trypanosoma congolense. The presence of a trypanosome infection in cattle and pigs resulted in a significant decline in the packed cell volume. The outcome of the study clearly shows that despite the availability of goats and pigs, cattle seem to be the major livestock species affected by the disease in trypanosomiasis endemic areas. The high proportion of infections in cattle could be partly attributed to their higher availability and attractiveness to tsetse.     

Dissimilar effects of human and elephant disturbance on woodland structure and functional bird diversity in the mopane woodlands of Zambia

Landscape Ecology - Humans and elephants are major disturbance agents in the African savanna woodlands. While both species remove trees, humans selectively harvest larger stems, which are less...     

Biomass equations for selected drought-tolerant eucalypts in South Africa

In the water-scarce environment of South Africa, drought-tolerant eucalypt species have the potential to contribute to the timber and biomass resource. Biomass functions are a necessary prerequisite to predict yield and carbon sequestration. In this study preliminary biomass models for Eucalyptus cladocalyx, E. gomphocephala and E. grandis · E. camaldulensis from the dry West Coast of South Africa were developed. The study was based on 33 trees, which were destructively sampled for biomass components (branchwood, stems, bark and foliage). Simultaneous regression equations based on seemingly unrelated regression were fitted to estimate biomass while ensuring additivity. Models were of the classical allometric form, ln(Y) = a+x₁ln(dbh)+x₂ln(h), of which the best models explained between 70% and 98% of the variation of the predicted biomass quantities. A general model for the pooled data of all species showed a good fit as well as robust model behaviour. The average biomass proportions of the stemwood, bark, branches and foliage were 60%, 6%, 29% and 5%, respectively.     

Common conditions leading to cattle carcass and offal condemnations at 3 abattoirs in the Western Province of Zambia and their zoonotic implications to consumers

From a total of 32 717 cattle slaughtered, 183 whole carcass condemnations were attributable to 9 diseases and conditions, namely, tuberculosis (TB), cysticercosis, emaciation, generalised lymphadenitis, jaundice, abscesses, moribund, sarcosporidiosis and odour. Bovine TB was the most important cause of condemnations (152/183, 83.1%). Bovine cysticercosis and sarcosporidiosis accounted for 5/183 (2.7%) and 8/183 (4.4%), respectively, while each of the remaining conditions contributed less. Among the many conditions responsible for offal/organ condemnations were fascioliasis, contagious bovine pleuropneumonia, hydatidosis and TB. In terms of number and weight, Fasciola gigantica infections made livers and lungs the most condemned offals (20.1% and 0.7%, respectively). Hydatidosis was the cause of 0.9% lung and 0.1% liver losses. Cysticercus bovis contributed to only 0.05% of all inspected tongues, hearts, and heads. TB was very rare in heads (0.01%). The financial impact of whole carcasses and offals condemned during the study period was enormous and deprived livestock farmers of the much needed revenue and consumers of protein sources. Much or all of the condemned material that could have been useful was wasted by not being retrieved for conversion to processed meat, bone meal or pet food. Failure to detect lesions of potential zoonotic diseases at slaughter poses a health risk to consumers especially when meat is eaten undercooked.     

Prevalence of fasciolosis in Zambian cattle observed at selected abattoirs with emphasis on age, sex and origin

The aim of this study was to determine the prevalence and some factors influencing occurrence of fasciolosis in cattle, carried out at selected major abattoirs in Zambia. Of 841 cattle livers inspected and 677 faecal samples analysed, prevalence rates of 53.9% and 48.9%, respectively, were found. Cumulative prevalence of 60.9% (n = 677) was recorded. According to age, no significant difference of infection was found. Female cattle on liver inspection (59.3%) and coprological examination (65.2%) had significantly higher (P < 0.001) rates than males (44.5% and 36.3% respectively). Origin of cattle had a significant influence (P < 0.001) on the prevalence rate. According to fluke egg count classification, 68.5% of cattle had light infection, 20.9% moderate, 4.4% heavy and 6.2% severe. These results indicate that Fasciola gigantica infection is an important condition that leads to high liver condemnations and/or trimmings in cattle tendered for slaughter.     

Seasonal pattern of bovine amphistomosis in traditionally reared cattle in the Kafue and Zambezi catchment areas of Zambia

Seasonality of bovine amphistomosis in the Southern province of Zambia was established after examining 268 faecal samples from cattle presented for slaughter at Turnpike slaughter slab, Mazabuka. Amphistomosis was found present throughout the year but the highest abundance rate was found during the post-rainy season (47.8%) and the lowest during the cold dry season (24.8%). In the rainy and post-rainy seasons, higher mean egg counts and cattle found positive were recorded than in any other season. The distribution of amphistome eggs was significantly different (p < 0.001) among the four seasons, with the rainy season having higher median egg counts than others. There were no significant differences in abundance rates between sexes or between ages of cattle. A similar seasonality to that of fasciolosis exists and may help in strategic management of Fasciola and amphistomes.