A Comparative Evaluation of Carcass Quality, Nutritional Value, and Consumer Preference of Oreochromis niloticus from Two Impoundments with Different Pollution Levels in Zimbabwe

The objective of the study was to determine the quality and consumer preferences of Nile tilapia (Oreochromis niloticus) from two water bodies with different pollution levels and trophic states. Water quality assessment of the two impoundments was carried out. Fish were sampled from hypereutrophic Lake Chivero and oligomesotrophic Lake Kariba for proximate analysis, carcass quality, and sensory evaluation. Conductivity, dissolved oxygen, transparency, ammonia, total phosphates, reactive phosphates, and chlorophyll a were significantly different (P<0.05). Fish from Lake Kariba had significantly higher condition factors and lower fillet yields, while fish of length 10-20 cm, from Lake Chivero had significantly more fat. Lake Chivero fish were darker, greener, and less red while Lake Kariba fish were lighter, less green, and less red. Raw fish from Lake Kariba were significantly firmer, were less green and redder, had a stronger typical fish odour, and were more acceptable than Lake Chivero fish. Lake Chivero fish had a stronger foreign fish odour than their counterparts. No statistical differences were observed on fillet cooking losses, cooked fish sensory parameters, and acceptability. The fish could, however, not be safe due to possibility of toxins in water and feed (algae) which may bioaccumulate and ultimately affect other attributes of fish quality

Interventions privilégiées en matière d'élevage pour les petits éleveurs dans la zone de conservation transfrontalière du Grand Limpopo : une approche systémique axée sur la demande

International audienceIn southern Africa, residents of Transfrontier Conservation Areas practice small-scale farming in semi-arid environments constrained by the presence of protected areas and extensive wildlife/livestock/human interfaces that come with conflicts and opportunities. Under these contexts, livestock production aims at supporting local livelihoods despite the harsh semi-arid environment and conflicts with wildlife. In order to promote local development and the well-being of TFCA residents, prioritization of livestock interventions adapted to the local context is needed. The objective of this study was to explore a methodology to list demand-driven interventions for livestock production (cattle, small ruminants and chicken) in a communal land in Zimbabwe. This study used the outputs of an anticipatory scenario-building workshop and individual questionnaires to establish possible and desired livestock interventions by local stakeholders. Results from both the co-elaborative scenario building workshops and the questionnaire survey had participants preferring almost the same interventions that were: restocking herds with breeds adapted to local production; training in livestock practices and production; support to marketing; feed development and value addition; loan schemes to invest in livestock housing and stockfeeds; and finally, animal health interventions to reduce the heavy disease burden. The individual questionnaire data specified preferred interventions for each domestic species. These demand-driven interventions provide a basis for future development projects in the area and avoid top-down approaches by development agencies that fail to address local needs and lack appropriation by local stakeholders necessary for the sustainability of the interventions.En Afrique australe, les habitants des zones de conservation transfrontalières (TFCA) pratiquent une agriculture à petite échelle dans des environnements semi-arides contrainte par la présence de zones protégées et de vastes interfaces faune/bétail/homme qui s'accompagnent de conflits et d'opportunités. Dans ces contextes, l'élevage vise à soutenir les moyens de subsistance locaux. Afin de promouvoir le bien-être des résidents des TFCAs, il est nécessaire de prioriser des interventions en matière d'élevage adaptées au contexte local. L'objectif de cette étude était d'explorer une méthodologie permettant de dresser une liste d’interventions pour la production animale (bovins, petits ruminants et poulets) dans une zone communale du Zimbabwe. Cette étude s'est appuyée sur les résultats d'un atelier d'élaboration de scénarios et sur des questionnaires individuels pour établir les interventions possibles et souhaitées en matière d'élevage par les parties prenantes locales. Les résultats desateliers de construction de scénarios et de l'enquête par questionnaire ont montré que les mêmes interventions étaient identifiées par les deux approches, à savoir : le repeuplement des troupeaux avec des races adaptées à la production locale ; la formation aux pratiques d'élevage et à la production ; le soutien à la commercialisation ; le développement des aliments pour animaux et la création de valeur ajoutée ; les programmes de prêts financiers pour investir dans les bâtiments d'élevage et les aliments pour animaux ; et enfin, les interventions en matière de santé animale pour réduire la lourde charge de morbidité. Les données du questionnaire individuel ont spécifié les interventions préférées pour chaque espèce domestique. Ces interventions axées sur la demande fournissent une base pour les futurs projets de développement dans la région et évitent des approches descendantes des agences de développement qui ne répondent pas aux besoins locaux et manquent d'appropriation par les parties prenantes locales, nécessaires à la durabilité des interventions

Storage quality and marketability potential of bagged silage for smallholder dairy farmers in Zimbabwe

Bagged sole maize and maize–cowpea silages in three bag sizes were assessed at 42 and 282 d post-ensiling for sensory and chemical quality. A survey of dairy farmers on silage use and preferences was conducted in the Chikwaka communal area and Marirangwe small-scale commercial farming area. Only silage dryness changed with time. Percentage neutral detergent fibre significantly changed in 20 kg bags from 58.1 ± 0.75% at 42 d to 52.3 ± 0.86% at 282 d and in 10 kg maize–cowpea bags from 48.6 ± 0.75% to 56.0 ± 0.86%. Percentage crude protein significantly decreased (P < 0.05) for 15 kg (11.8 ± 0.30% to 9.4 ± 0.35%) and 20 kg bags (11.4 ± 0.30% to 8.9 ± 0.35%) for maize– cowpea. All 45 farmers surveyed knew about silage and 90% were feeding it to cows, 53% were making their own and 37% purchased silage. Challenges in making silage included unavailability of forage choppers, lack of requisite resources and inadequate knowledge. Silage unavailability and difficulties in transportation and storage resulted in a low frequency of silage purchases. There was no association (χ2 = 0.18; P > 0.05) between farming system and farmers’ willingness to buy or sell silage, and larger bags were preferred (χ2 = 78.96; P < 0.05). Computed silage costs per tonne were farm-produced sole maize US$57.54, maize–cowpea US$58.59 and bought-in sole maize US$89.80.Keywords: bag silage, dairy, marketing, nutrition, qualit