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The effects of supplementing crossbred cows with non-conventional protein sources on dry matter intake, milk yield parameters and economic returns were investigated. Twenty-five lactating F1 Holstein-Mashona crossbreds averaging 115 ± 24 days in milk were used. Five treatments, total mixed ration (TMR), urea-treated maize stover, untreated maize stover, Macroptilium atropurpureum (Siratro) hay and veld hay, were randomly assigned to cows and replicated five times in a completely randomised design. Nutrient composition, intake, milk yield and economic returns were determined. M. atropurpureum hay, urea-treated maize stover and TMR had equal crude protein content. Daily dry matter intake and yield differed significantly among the treatment diets (P < 0.05). Cows on TMR, urea-treated maize stover and M. atropurpureum consumed more (P < 0.05) than cows on untreated maize stover and veld hay. Supplementing with TMR, urea-treated maize stover and M. atropurpureum hay increased (P < 0.05) milk yields. Mean daily milk yield was highest for cows supplemented with urea-treated maize stover. Percent fat, protein and total solids in milk from cows fed urea-treated stover compared favourably to that of milk for cows supplemented with TMR. Income over supplement cost was highest for cows supplemented with M. atropurpureum hay and urea-treated maize stover. Urea-treated maize stover and M. atropurpureum can therefore be used as a replacer protein supplements for dairy cattle in Zimbabwe.

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Nutrition is a major constraint in smallholder livestock production; hence, the use of alternative sources which are adaptive to long dry seasons is imperative. The study was conducted to establish options of improving nutrition and palatability and also to determine the performance of goats fed on cactus-browse hay as dry season supplements. Palatability and adequacy of nutrition was investigated using 32 castrated male goat kids. The kids were housed in individual metabolism cages for 84 days in a complete randomised design (CRD) with eight replicates for the four treatment diets. Daily experimental diet, basal diet and water intake were measured, and live mass was measured at weekly intervals. Daily diet intake was significantly different (P < 0.05) among treatments. Kids that were supplemented with cactus-Leucaena leucocephala meal (CLLM) consumed more than those on cactus-Acacia angustissima meal (CAAM), cactus-Gliricidia sepium meal (CGSM) and cactus-Pennisetum purpureum meal (CPPM) in that order. CGSM was not readily palatable as goat kids refused to take it when mixed with fresh cactus. Animals that were not supplemented with a source of nitrogen together with those that were supplemented with less palatable diet of CGSM lost weight significantly (P < 0.05) initially but gained weight slightly towards the end of the study. Significantly higher weight gains (P < 0.05) were observed in animals in CLLM and CAAM treatment. It was concluded that fresh cactus could be used to improve poor quality roughage intakes in goats, and therefore, there is need to promote its use in periods of feed deficit especially in smallholder sector.

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The influence of different land tenure and rangeland management systems on rangeland condition and livestock grazing capacity in African rangelands is not well documented. A rangeland condition assessment was carried out at 15 sites located in the communal grazing system, small-scale commercial grazing system and the large-scale commercial grazing system in Zimbabwe. Rangeland indicators assessed were: floristic composition, herbaceous biomass yield, shrub stem density and grazing capacity. Grass species composition and forage value were analysed using PROC FREQ procedure of SAS 9.3. Fisher’s exact test was performed to test for independence of the grass variables between grazing systems. A one-way ANOVA was used to test for significant differences (P < 0.05) in floristic composition, shrub stem density, herbaceous biomass yield and grazing capacity among the three grazing systems. It was observed that communal rangelands had significantly high levels of woody species, unpalatable wiry grass species, low biomass yield and were dominated by the invading shrub Helichyrsum kraussii compared with the other rangeland management systems. These results suggest that if control measures are not put in place, livestock production may not be feasible in communal rangelands in the near future because of high levels of rangeland deterioration when compared with the commercially managed rangelands. Furthermore, the observed high stem density of unpalatable woody species and the low grazing capacity of communal rangelands affect livestock production, a primary source of livelihood. This warrants a change in rangeland management system in favour of the rest-rotation grazing system, which is beneficial to both livestock and the range.

Introduction: There is high malaria related morbidity and mortality amongst infants and children in malaria endemic areas. An In-depth understanding of protective immunity correlates enables the long due necessary development of an effective malaria vaccine. This study aimed at evaluating antibody responses to apical membrane antigen 1 (AMA 1) that helps P falciparum entry into red blood cells, Glutamate rich protein (GLURP), an antigen expressed in the whole life cycle of the malaria causing pathogen, merozoite surface protein-1 (MSP 1) coding for a major antigen in the asexual stage of P falciparum and merozoite surface protein 3 (MSP 3), a polymorphic blood stage malaria antigen in Zimbabwean children living in malaria endemic areas. Methods: We characterized humoral immune responses to malaria vaccine candidates in a two year longitudinal survey among 136 children (6-16 years) from Burma and Kariba in Zimbabwe. Blood samples were collected and analyzed for malaria parasites, plasma and antibody titers against malaria vaccine candidates [MSP1, MSP3, GLURP, AMA] by ELISA technique. The blood samples were also checked for potential confounders like anemia, bilharzia and HIV sero-status using the ELISA technique. Results: Ig levels were significantly different (p < .0001) across the three time points, and against the different candidates (p < .0001). MSP3 had the highest (13,552.2) and GLURP the least (4,741.6) IgM titers. However, IgG, IgG1, IgG3 and IgG4 levels were highest against AMA compared to other vaccine candidates, 3) and anti-GLURP IgG4 (58.7)]. Anemia burden was about 44% at baseline with a threefold decrease (-16%) over the 12 month follow up. Conclusions: This study highlights the need for robust evaluation of several malaria vaccine candidates in combination to understand correlates of protective immunity as suggested by the significant antibody levels against the four vaccine candidates. Longer follow up periods are needed to assess the impact of continuous malaria exposure on host immune responses. Multivalent malaria vaccine development offer a better chance towards an efficacious malaria vaccine compared to monovalent vaccine. Antibody levels against the four vaccine candidates were significant suggesting that an ideal malaria vaccine should target more than one antigen.