20 research outputs found
Influence of Prices on Market Participation Decisions of Indigenous Poultry Farmers in Four Districts of Eastern Province, Kenya
Over 70% of the domesticated birds in Kenya are indigenous chicken (IC) providing meat and table eggs. They are frequently raised through the free range, backyard production system. Small flock sizes are characteristic of this production system and often, sales are mainly at the farmgate. Although IC production possesses enormous potential at livelihood improvement, marketing systems are undefined and variable. The influence of prices on market engagement has frequently been assumed. A study of 68 farmers conducted in Machakos, Kibwezi, Nzaui and Mwala District in 2008 revealed that 70% of all IC sales were conducted at the farmgate while only 19% of the sales were at the local market. This study also investigates the probability of market participation by employing a binary logistic regression model. The results suggests that while farmers complain of poor farm gate prices for indigenous chicken offered by middlemen, low volumes are an important drawback to market participation
Studies on the Interaction of Schistosoma Mansoni and Leishmania Major in Experimentally Infected Balb/c Mice
Schistosoma mansoni and Leishmania major are important tropical human
parasites. It is crucial to know the effect of the two infecting man
concurrently. Two groups of BALB/c mice were infected with each of the
parasites separately; another group was co-infected with both parasites
and there was a na\uefve control. Draining lymph node and spleen
cells from mice infected with either of the parasites showed high
proliferative responses to their specific parasite antigen. However,
crossreactivity occurred between S. mansoni and L. major. Spleen and
Lymph node cells from co-infected group demonstrated high and sustained
proliferative responses to schistosome soluble worm antigen preparation
and killed Leishmania major antigen, respectively. There was high and
sustained IgG levels for both the single and coinfected groups. At 10
weeks post-infection, co-infected mice had significantly larger nodules
than mice with L. major infection alone. However, co-infected animals
had less severe liver pathology and less enlarged mesenteric lymph
nodes than those infected with S. mansoni only. This work shows that
co-infection results in two different outcomes: protection against S.
mansoni and exacerbated pathogy in L. major. We suggest that cellular
responses possibly protect against S. mansoni, while high IgG levels
lead to exacerbated L. major response
Mitigação das emissões de amônia por zeólitas naturais durante a compostagem de dejetos de suínos
Effect of natural zeolite (clinoptilolite) on microbial decomposition processes in stored pig-slurry solids
Dry matter production and nutrient accumulation after successive crops of lettuce, tomato, rice, and andropogongrass in a substrate with zeolite Produção de matéria seca e acúmulo de nutrientes após cultivos sucessivos com alface, tomate, arroz e capim andropogon em substrato com zeólita
Zeolites are hydrated crystalline aluminosilicate minerals of natural occurrence, structured in rigid third dimension net that can be used as slow release plant-nutrient source. The main objective of this study was to evaluate the effects of plant growth substrate under zeolite application, enriched with N, P and K, on dry matter yield and on nutrient contents in consecutive crops of lettuce, tomato, rice, and andropogon grass. The experiment was carried out in a greenhouse, with 3 kg pots with an inert substrate, evaluated in a randomized block design with three replications. Treatments consisted of four types of enrichment of concentrated natural zeolite: concentrated zeolite (Z) only, zeolite + KNO3 (ZNK), zeolite + K2HPO4 (ZPK) and zeolite + H3PO4 + apatite (ZP), and a control grown in substrate fertilized with a zeolite-free nutrient solution. Four levels of enriched zeolite were tested: 20, 40, 80, and 160 g/pot. Four successive crops were grown on the same substrate in each pot: lettuce, tomato, rice, and andropogon grass. Results indicated that N, P and K enriched zeolite was an adequate slow-release nutrient source for plants. The total dry matter production of above-ground biomass of four successive crops followed a descending order: ZP > ZPK > ZNK > Z.<br>Zeólitas são minerais aluminossilicatos cristalinos hidratados de ocorrência natural, estruturados em redes cristalinas tridimensionais rígidas que podem ser usados como fonte de liberação lenta de nutrientes para as plantas. O objetivo deste trabalho foi avaliar o efeito da adição de zeólita enriquecida com N, P e K ao substrato de cultivo sobre a produção de matéria seca e o acúmulo de nutrientes pelas culturas sucessivas de alface, de tomate, de arroz e de capim-andropogon. O experimento foi conduzido em vasos em casa de vegetação, em vasos contendo 3 kg de substrato inerte. O delineamento experimental foi o de blocos ao acaso, com três repetições. A zeólita natural estilbita foi concentrada e enriquecida com nutrientes N, P e K obtendo-se os seguintes tratamentos: zeólita concentrada (Z), zeólita + KNO3 (ZNK), zeólita + K2HPO4 (ZPK) e zeólita + H3PO4 + apatita (ZP), além de um tratamento testemunha sem adição de zeólita, mas com solução nutritiva. Utilizaram-se quatro doses de zeólita enriquecida: 20, 40, 80 e 160 g/vaso. Foram realizados quatro cultivos sucessivos no mesmo substrato de cada vaso: alface, tomate, arroz e capim-andropogon. Os resultados indicaram que a zeólita enriquecida com N, P e K funcionou como fonte de nutrientes de liberação lenta. A produção de matéria seca total da parte aérea dos quatro cultivos sucessivos seguiu a seguinte ordem decrescente: ZP > ZPK > ZNK > Z
Produção e qualidade de frutos de tomateiro cultivado em substrato com zeólita Yield and fruit quality of tomato grown in substrate with zeolite
Avaliou-se a produção e a qualidade dos frutos de tomateiro cv. Finestra, cultivado em substrato com zeólita enriquecida com N, P e K. Os tratamentos utilizados foram quatro doses (20; 40; 80 e 160 g por vaso) de zeólitas enriquecidas com H3PO4/apatita, KNO3 e KH2PO4, além de uma testemunha cultivada em solução nutritiva. Foram avaliados a produção de frutos por vaso, firmeza, sólidos totais, pH, acidez titulável e ácido ascórbico dos frutos, dos 80 aos 90 dias de cultivo. O fornecimento de nutrientes através do mineral zeólita enriquecido com N, P e K comprovou ser uma alternativa para o aumento da produção. As maiores produções foram obtidas nos tratamentos com adição de P e K e nas maiores doses de zeólita (160 e 80 g por vaso). A produção de frutos foi 11 a 17% maior em relação à testemunha cultivada com solução nutritiva. Houve efeitos positivos das zeólitas enriquecidas com fontes de fósforo sobre a firmeza e efeito negativo sobre o pH. A firmeza dos frutos variou 104% entre tratamentos, de 7,06 N (ZNK 160) a 14,38 (ZPK 40). O aumento da disponibilidade de potássio contribuiu para o aumento do teor de ácido ascórbico dos frutos.<br>We evaluated yield and quality of tomato fruits, cv. Finestra, grown in a zeolite substrate enriched with N, P and K. Treatments comprised four levels (20; 40; 80 and 160 g per pot) of zeolite enriched with H3PO4/apatite, KNO3 and KH2PO4, and a control grown in a nutrient solution. Fruit production, firmness, total soluble solids, pH, titratable acidity and ascorbic acid were evaluated from 80 to 90 days of plant cultivation. Nutrients supplied through the mineral zeolite enriched with N, P and K was an adequate alternative to increase the production. Higher fruit production was obtained with addition of P and K and higher zeolite dosis (160 and 80 g per pot). Fruit production was 11% and 17% higher when compared to the plants grown in nutritive solution (check treatment). Positive effects were observed in P-enriched zeolites in relation to fruit firmness, and negative effects over fruit pH. Fruit firmness varied 104% among treatments, from 7.06N (ZNK 160) to 14.38N (ZPK 40). The increase of potassium availablity increased the ascorbic acid levels of the fruits