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Efficacy of Strychnos spinosa (Lam.) and Solanum incanum L. aqueous fruit extracts against cattle ticks.Tropical Animal Health Production,45(6), 1341-1347.

2026-01-06T01:02:45Z

Title: Efficacy of Strychnos spinosa (Lam.) and Solanum incanum L. aqueous fruit extracts against cattle ticks.Tropical Animal Health Production,45(6), 1341-1347. Authors: Madzimure, James; Nyahangare, Emmanuel T.; Hamudikuwanda, Humphrey; Hove, Thokozani; Belmain, Steve R.; Stevenson, Philip C.; Mvumi, Brighton M. Abstract: The efficacy of Solanum incanum and Strychnos spinosa aqueous fruit extracts was evaluated against cattle ticks in on-station experiments and laboratory tick bioassays. In the on-station experiment using cattle, fruit extracts were applied at three concentrations 5, 10, and 20%(w/v) and compared with a commercial acaricide, Tickbuster® (amitraz) spray (positive control) and no treatment (negative control). The treatments were applied at weekly intervals for 6 weeks as surface sprays on 32 Mashona cattle in a completely randomized design experiment. Ticks on individual cattle were identified, counted, and recorded daily. Peripheral blood samples were collected for parasite screening. In the laboratory, tick bioassays were conducted at four concentrations, 5, 10, 20, and 40 % (w/v) fruit extracts compared to Tickbuster® (amitraz) spray (positive control) and distilled water (negative control). The extracts were incubated with Rhipicephalus (Boophilus) decoloratus tick larvae and mortalities for each treatment level recorded after 24 and 48 h. The 5 % Solanum incanum treatment had higher efficacy ratio (P<0.05) than the other fruit extract concentrations of the same plant species. Efficacy ratio was higher (P<0.05) in the 5 % S. spinosa-treated cattle than in the untreated control but lower (P<0.05) than that for the amitraz treatment. The bioassays indicated that there was a high efficacy ratio for the lowest fruit extract concentrations when ticks were exposed to acaricidal treatments for 48 h compared to 24 h. Overall, the results indicate that Solanum incanum and Strychnos spinosa individually have some acaricidal effect.

Some insights into the phenotypic and genetic diversity of indigenous pigs in Southern Africa

2026-01-06T01:06:49Z

Title: Some insights into the phenotypic and genetic diversity of indigenous pigs in Southern Africa Authors: Halimani, T. E.; Muchadeyi, F. C.; Chimonyo, M; Dzama, K. Abstract: Indigenous pigs in southern Africa are mainly owned by economically vulnerable groups in marginal areas where they are used as a source food, income and security. A study was carried out to achieve three objectives: to describe pig production systems, get a phenotypic description of the pigs and to characterize them genetically. A survey of 199 farmers in three districts in South Africa, (Vhembe, OR Tambo and Alfred Nzo) and one district in Zimbabwe (Chirumhnazu) was carried out. Additional farmers in Malawi (Dedza, Mchinji and Salima) and Zimbabwe (Mutoko) were sampled in order to meet the other two objectives. Most of the pigs (69.7%) were owned by women, with men owning 20.5% and children the remainder. Production of the pigs was constrained by several factors including disease, inadequate feeds, poor housing and lack of knowledge. The majority of the pigs were small and black with characteristics that are probably suited for thermoregulation in arid environments. The third objective was achieved through genotyping 111 pigs using 22 microsatellites. Preliminary results indicate very little differences across populations with an overall inbreeding coefficient of the subpopulation relative to the total population (FST) of 0.071. The results indicate that the indigenous pigs in southern Africa are relatively homogenous.

Genetic prediction models and heritability estimates for functional longevity in dairy cattle

2026-01-06T01:00:52Z

Title: Genetic prediction models and heritability estimates for functional longevity in dairy cattle Authors: Imbayarwo-Chikosi, V. E.; Dzama, K.; Halimani, T. E.; van Wyk, J. B.; Maiwashe, A.; Banga, C. B. Abstract: Longevity is a major component of the breeding objective for dairy cattle in many countries because of its high economic value. The trait has been recommended for inclusion in the breeding objective for dairy cattle in South Africa. Linear models, random regression (RR) models, threshold models (TMs) and proportional hazard models (PH) have been used to evaluate longevity. This paper discusses these methodologies and their advantages and disadvantages. Heritability estimates obtained from these models are also reviewed. Linear methodologies can model binary and actual longevity, while RR and TM methodologies model binary survival. PH procedures model the hazard function of a cow at time t derived from survival from first calving to culling, death or censoring. It is difficult to compare methodologies for sire evaluation and ranking across countries because of the variation in the definition of longevity and the choice of model. Sire estimated breeding values (EBVs) are derived differently for the models. Sire EBVs from PH models are expressed as deviations of the culling risk from the mean of the base sires, expected percentage of daughters still alive after a given number of lactations, expected length of productive life in absolute terms or as standard deviation units. In linear, TM and RR modelling, sire EBVs for longevity have been expressed as deviations of survival from the mean estimated with Best Linear Unbiased Prediction (BLUP). Appropriate models should thus be developed to evaluate functional longevity for possible inclusion in the overall breeding objective for South African dairy cattle.

Mortality and Diseases of Goats in Wedza Communal Areas of Zimbabwe

2025-11-15T02:56:21Z

Title: Mortality and Diseases of Goats in Wedza Communal Areas of Zimbabwe Authors: Kusina, N.T; Chikura, S; Sibanda, S Abstract: A study was conducted to evaluate the extent and causes of mortality and diseases affecting goats in Wedza Communal Area. Mortality ranged from 16% in adult stock to 40% in pre-weaned kids. Kid mortality was higher during the rainy season than the dry season, but this pattern was not evident in adult animals. Mortality was from unknown causes (47.4%), infectious diseases (17.1%), predation (17.1 OlD), diarrhoea (5.2%), starvation (3.4%), and other causes (9.8%). Diseases identified included pneumonia, ort, pulpy kidney, heartwater and foot rot. Infection by helminths showed a distinct seasonal pattern. It was high during the rainy season and low during the dry season. The main ectoparasites found were Rhipicephalus evertsi, Amblyomma hebraeum, Demodex caprae, Sarcoptes scabiei and Ctenocephalides felis. It is inferred that poor health management of goats in Wedza Communal Area negatively affects productivity because of high kid mortality. It is concluded that pre-weaned kids need more veterinary attention during the rainy season than the dry season.