Altrop, un calculateur des rations des bovins pour l’accompagnement des projets d’élevage familiaux

Au Burkina Faso, les producteurs ont des difficultés à satisfaire les besoins alimentaires de leurs bovins (boeufs de trait, vaches laitières, bovins à l’engraissement) en fonction de leur niveau de production et à certaines saisons. L’étude avait pour but de présenter un outil permettant de mieux gérer l’alimentation de lots de bovins, en prenant en compte la logique des pratiques d’alimentation des producteurs, tout en intégrant les références zootechniques permettant d’ajuster l’offre aux besoins alimentaires des animaux. Altrop est un calculateur permettant d’ajuster l’offre alimentaire proposée à un lot de bovins affectés à une production particulière aux besoins de ces derniers. Il permet de simuler des scénarios d’amélioration des stratégies d’alimentation, de voir rapidement les effets sur l’ajustement de l’offre aux besoins, et de calculer les stocks de fourrages et d’aliments nécessaires à la réalisation de ces scénarios. En réduisant les déséquilibres des pratiques d’alimentation, souvent observées chez les producteurs, Altrop permet d’améliorer la rentabilité des projets d’élevage familiaux.Mots clés : Besoin alimentaire, bovin, calculateur Altrop, offre, simulation, stratégies d'alimentation

Prodlait : un outil permettant d’ajuster l’alimentation des vaches pour atteindre un objectif de production fixe par l’eleveur

Avec l’essor des mini laiteries en Afrique de l’Ouest, de nombreux producteurs s’intéressent à la production laitière. Mais, les pratiques d’alimentation des vaches ne permettent pas d’atteindre leurs objectifs de production. Cet article présente l’outil Prodlait, conçu sur le tableur Excel, pour simuler l’effet des pratiques d’alimentation sur l’évolution du poids vif des vaches au cours de la lactation en fonction de l’objectif de production de lait de l’éleveur. Prodlait, utilise six courbes de lactation théoriques, représentant des objectifs de production croissants, calcule au quotidien sur 12 mois, les besoins des vaches, la couverture des besoins et l’évolution quotidienne du poids vif. Prodlait, propose deux indicateurs de poids vif des vaches : le poids vif à 90 jours après mise-bas comparé au poids vif de forme, pour apprécier la capacité des vaches à recevoir une saillie fécondante à cette période et le poids vif à 365 jours après mise-bas comparé au poids vif de mise-bas, pour apprécier la capacité de l’éleveur à reconstituer l’état corporel des vaches au bout d’une année. Deux cas d’utilisation montrent comment les indicateurs de Prodlait permettent aux producteurs de raisonner les apports alimentaires aux périodes cruciales de la gestion de la reproduction des vaches.Mots clés : Intervalle entre mise-bas, lactation, modèle de simulation, poids vif, pratique d’alimentation

Characterisation of the opposing effects of G6PD deficiency on cerebral malaria and severe malarial anaemia.

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is believed to confer protection against Plasmodium falciparum malaria, but the precise nature of the protective effecthas proved difficult to define as G6PD deficiency has multiple allelic variants with different effects in males and females, and it has heterogeneous effects on the clinical outcome of P. falciparum infection. Here we report an analysis of multiple allelic forms of G6PD deficiency in a large multi-centre case-control study of severe malaria, using the WHO classification of G6PD mutations to estimate each individual's level of enzyme activity from their genotype. Aggregated across all genotypes, we find that increasing levels of G6PD deficiency are associated with decreasing risk of cerebral malaria, but with increased risk of severe malarial anaemia. Models of balancing selection based on these findings indicate that an evolutionary trade-off between different clinical outcomes of P. falciparum infection could have been a major cause of the high levels of G6PD polymorphism seen in human populations

Insights into malaria susceptibility using genome-wide data on 17,000 individuals from Africa, Asia and Oceania

The human genetic factors that affect resistance to infectious disease are poorly understood. Here we report a genome-wide association study in 17,000 severe malaria cases and population controls from 11 countries, informed by sequencing of family trios and by direct typing of candidate loci in an additional 15,000 samples. We identify five replicable associations with genome-wide levels of evidence including a newly implicated variant on chromosome 6. Jointly, these variants account for around one-tenth of the heritability of severe malaria, which we estimate as -23% using genome-wide genotypes. We interrogate available functional data and discover an erythroid-specific transcription start site underlying the known association in ATP2B4, but are unable to identify a likely causal mechanism at the chromosome 6 locus. Previously reported HLA associations do not replicate in these samples. This large dataset will provide a foundation for further research on thegenetic determinants of malaria resistance in diverse populations.Peer reviewe

Safety of single low-dose primaquine in glucose-6-phosphate dehydrogenase deficient falciparum-infected African males: Two open-label, randomized, safety trials.

BACKGROUND: Primaquine (PQ) actively clears mature Plasmodium falciparum gametocytes but in glucose-6-phosphate dehydrogenase deficient (G6PDd) individuals can cause hemolysis. We assessed the safety of low-dose PQ in combination with artemether-lumefantrine (AL) or dihydroartemisinin-piperaquine (DP) in G6PDd African males with asymptomatic P. falciparum malaria. METHODS AND FINDINGS: In Burkina Faso, G6PDd adult males were randomized to treatment with AL alone (n = 10) or with PQ at 0.25 (n = 20) or 0.40 mg/kg (n = 20) dosage; G6PD-normal males received AL plus 0.25 (n = 10) or 0.40 mg/kg (n = 10) PQ. In The Gambia, G6PDd adult males and boys received DP alone (n = 10) or with 0.25 mg/kg PQ (n = 20); G6PD-normal males received DP plus 0.25 (n = 10) or 0.40 mg/kg (n = 10) PQ. The primary study endpoint was change in hemoglobin concentration during the 28-day follow-up. Cytochrome P-450 isoenzyme 2D6 (CYP2D6) metabolizer status, gametocyte carriage, haptoglobin, lactate dehydrogenase levels and reticulocyte counts were also determined. In Burkina Faso, the mean maximum absolute change in hemoglobin was -2.13 g/dL (95% confidence interval [CI], -2.78, -1.49) in G6PDd individuals randomized to 0.25 PQ mg/kg and -2.29 g/dL (95% CI, -2.79, -1.79) in those receiving 0.40 PQ mg/kg. In The Gambia, the mean maximum absolute change in hemoglobin concentration was -1.83 g/dL (95% CI, -2.19, -1.47) in G6PDd individuals receiving 0.25 PQ mg/kg. After adjustment for baseline concentrations, hemoglobin reductions in G6PDd individuals in Burkina Faso were more pronounced compared to those in G6PD-normal individuals receiving the same PQ doses (P = 0.062 and P = 0.022, respectively). Hemoglobin levels normalized during follow-up. Abnormal haptoglobin and lactate dehydrogenase levels provided additional evidence of mild transient hemolysis post-PQ. CONCLUSIONS: Single low-dose PQ in combination with AL and DP was associated with mild and transient reductions in hemoglobin. None of the study participants developed moderate or severe anemia; there were no severe adverse events. This indicates that single low-dose PQ is safe in G6PDd African males when used with artemisinin-based combination therapy. TRIAL REGISTRATION: Clinicaltrials.gov NCT02174900 Clinicaltrials.gov NCT02654730

Deep Eutectic Solvents (DESs) and their applications [forthcoming]

Deep Eutectic Solvents (DESs) and Their Application

A phase 2b randomized, controlled trial of the efficacy of the GMZ2 malaria vaccine in African children.

: GMZ2 is a recombinant protein malaria vaccine, comprising two blood-stage antigens of Plasmodium falciparum, glutamate-rich protein and merozoite surface protein 3. We assessed efficacy of GMZ2 in children in Burkina Faso, Gabon, Ghana and Uganda. : Children 12-60months old were randomized to receive three injections of either 100μg GMZ2 adjuvanted with aluminum hydroxide or a control vaccine (rabies) four weeks apart and were followed up for six months to measure the incidence of malaria defined as fever or history of fever and a parasite density ⩾5000/μL. : A cohort of 1849 children were randomized, 1735 received three doses of vaccine (868 GMZ2, 867 control-vaccine). There were 641 malaria episodes in the GMZ2/Alum group and 720 in the control group. In the ATP analysis, vaccine efficacy (VE), adjusted for age and site was 14% (95% confidence interval [CI]: 3.6%, 23%, p-value=0.009). In the ITT analysis, age-adjusted VE was 11.3% (95% CI 2.5%, 19%, p-value=0.013). VE was higher in older children. In GMZ2-vaccinated children, the incidence of malaria decreased with increasing vaccine-induced anti-GMZ2 IgG concentration. There were 32 cases of severe malaria (18 in the rabies vaccine group and 14 in the GMZ2 group), VE 27% (95% CI -44%, 63%). : GMZ2 is the first blood-stage malaria vaccine to be evaluated in a large multicenter trial. GMZ2 was well tolerated and immunogenic, and reduced the incidence of malaria, but efficacy would need to be substantially improved, using a more immunogenic formulation, for the vaccine to have a public health role.<br/

Dairy production in Western Burkina Faso in a context of emergence of dairies: Diversity of breeding practices and proposals for improvement

In Western Burkina Faso, dairies are facing a local milk supply problem because production is low, seasonal, fragmented and expensive to collect. This study aimed to identify levers to increase production and reduce seasonality. It was carried out at 18 multicultivator-breeder farms of the Hauts-Bassins region involved in milk production. A multivariate analysis based on variables of farm structure, operation and performance identified five types of polyculture-livestock farms involved in this production: Low-input, pasture-oriented suckling cows with a large number of cows (T1), with a medium number of cows (T2); agropastoral-oriented suckling cows (T3); commercially-oriented, specialized dairy farms with little use of green fodder (T4), or with high use of green fodder (T5). T1 and T2 were characterized by grazing almost exclusively in all seasons and milk production levels of less than two liters per cow per day at lactation peak. Milk from these farms was poorly marketed and seldom sold to dairies. T3 made greater use of dry fodder and feed, allowing to improve milk production, which was frequently marketed in dairies (about 2 L/cow/d at lactation peak). T4 and T5 were characterized by the use of improved breeds, and the extensive use of forage and feed purchased year-round, ensuring higher milk yields (5–13 L/cow/d at lactation peak). These farms sold all of their milk to dairies. Our results highlight the fact that production was severely penalized by a diet that was too poor in quality feed and fodder, and that the seasonality of calving worsened the drop in production at the end of the dry season

Participatory innovation design, and support of family livestock projects in Burkina Faso: explore, experiment, evaluate

In mixed farming systems in Western Burkina Faso, a large majority of farmers have a family livestock project (FLP) in mind. However, more than half of these projects do not even get started. Among those implemented, major flaws have been observed in livestock feed management, jeopardizing their profitability. This article presents an approach to design and support family livestock projects (DSFLP) conducted in part­nership between the farmers and a consultant. This approach helps to assist farmers in preparing, implementing and assess­ing their projects. It was developed with 10 farmers whose projects concerned draft, fattening, or dairy cattle production. DSFLP involves four steps: i) diagnosis, ii) measurement and research on improvement options, iii) implementation and adjustment, and iv) assessment. In this approach, the farmers had gradually developed FLP, while learning to manage it, by reorganizing their work and means of production. DSFLP has enhanced their learning on i) the control of feeding practices and ii) developing livestock project strategies, to promote suc­cess. For the researcher, it helped to understand the rationality of farmers by participating in the construction and implemen­tation of their projects

Heamoglobin S protects against symptomless Plasmodium falciparum patent parasitaemia in two populations from Burkina Faso

HbS protects against clinical Plasmodium falciparum malaria and is associated with lower parasite densities in symptomatic subjects. Conclusive evidence of a protective role of HbS against symptomless P. falciparum infection has not been obtained so far. Here we show, in a large-scale epidemiological survey involving 2200 subjects studied during five cross-sectional surveys across two consecutive years in Burkina Faso, West Africa, that HbS is associated with a 70% reduction of harbouring a P. falciparum infection (OR=0.26 [0.11-0.60], P=0.002). This observation outlines a scenario made of consistent experimental and epidemiological observations. The abnormal display of parasite adhesive molecules on the surface of the HbS and HbC infected erythrocytes, disrupting the pathogenic process of sequestration, might displace the parasite from the deep to the peripheral circulation hence promoting its elimination at the spleen level