How to use the world's scarce selenium resources efficiently to increase the selenium concentration in food

The world's rare selenium resources need to be managed carefully. Selenium is extracted as a by-product of copper mining and there are no deposits that can be mined for selenium alone. Selenium has unique properties as a semi-conductor, making it of special value to industry, but it is also an essential nutrient for humans and animals and may promote plant growth and quality. Selenium deficiency is regarded as a major health problem for 0.5 to 1 billion people worldwide, while an even larger number may consume less selenium than required for optimal protection against cancer, cardiovascular diseases and severe infectious diseases including HIV disease. Efficient recycling of selenium is difficult. Selenium is added in some commercial fertilizers, but only a small proportion is taken up by plants and much of the remainder is lost for future utilization. Large biofortification programmes with selenium added to commercial fertilizers may therefore be a fortification method that is too wasteful to be applied to large areas of our planet. Direct addition of selenium compounds to food (process fortification) can be undertaken by the food industry. If selenomethionine is added directly to food, however, oxidation due to heat processing needs to be avoided. New ways to biofortify food products are needed, and it is generally observed that there is less wastage if selenium is added late in the production chain rather than early. On these bases we have proposed adding selenium-enriched, sprouted cereal grain during food processing as an efficient way to introduce this nutrient into deficient diets. Selenium is a non-renewable resource. There is now an enormous wastage of selenium associated with large-scale mining and industrial processing. We recommend that this must be changed and that much of the selenium that is extracted should be stockpiled for use as a nutrient by future generations

Wealth, household heterogeneity and livelihood diversification of Fulani pastoralists in the Kachia Grazing Reserve, northern Nigeria, during a period of social transition

A mixed methods study was undertaken in the Kachia Grazing Reserve of northern Nigeria. Surveys in March, June and October 2011 included focus group discussions, key informant and in-depth household interviews, concerning livelihood practices, animal health, ownership, and productivity. In May 2011, 249 Fulani families fleeing post-election violence entered the reserve with their livestock, increasing the number of households by one third.Despite being settled within a grazing reserve, over half of households sent all their cattle away on seasonal transhumance and another third sent some away. Cattle accounted for 96% of total tropical livestock units (TLU), of which 26% were cattle kept permanently outside the reserve. While all households cited livestock as their main source of income, 90% grew crops and 55% derived income from off-farm activities. A multiple correspondence analysis showed that for each extra member of a household its TLU value increased by 2.0 [95% CI, 1.4-2.7], while for each additional marriage its TLU increased by 15.7 [95% CI, 7.1-24.3]. A strong association was also observed between small herds, small households with only one wife, alongside marked geographical wealth differences within the reserve. New immigrant families had larger household sizes (33) and livestock holdings (122 TLU) than old settlers (22 people and 67 TLU). Prior to the mass immigration, the distribution of TLU per person was unimodal: 41% of households were classified as 'poor' and 27% as 'medium', whereas post-immigration it was bi-modal, with 26% classified as 'very poor' and 28% as 'medium'.While cattle remain the principal source of Fulani income and wealth, the inhabitants of Kachia Grazing Reserve have diversified their livelihood strategies to respond to changing circumstances and stress, especially the limited availability of grazing within the reserve and political insecurity outside, resulting in continued transhumance, the maintenance of smaller livestock holdings and pushing households into poverty

Serum biochemical parameters and cytokine profiles associated with natural African trypanosome infections in cattle.

BACKGROUND: Animal African trypanosomiasis (AAT) greatly affects livestock production in sub-Saharan Africa. In Ghana prevalence of AAT is estimated to range between 5 and 50%. Studies have reported serum biochemical aberrations and variability in cytokine profiles in animals during infection. However, information regarding the biochemical parameters and cytokine profiles associated with natural infections are limited. This study was therefore aimed at investigating changes in the levels of serum biochemical parameters and inflammatory cytokines during a natural infection. METHODS: Nested internal transcribed spacer (ITS)-based PCR and sequencing were used to characterise trypanosome infection in cattle at two areas in Ghana (Adidome and Accra) of different endemicities. The cattle were sampled at four to five-week intervals over a period of six months. Levels of serum biochemical parameters, including creatinine, cholesterol, alkaline phosphatase (ALP), alanine aminotransferase (ALT), total bilirubin and total protein and cytokines (interleukin 10, interleukin 4, interleukin 12, interferon gamma and tumor necrosis factor alpha) were measured in serum samples and then compared between infected cattle and uninfected controls. RESULTS: The predominant trypanosome species detected in Accra (non-endemic) and Adidome (endemic) were Trypanosoma theileri and Trypanosoma vivax, respectively. Serum biochemical parameters were similar between infected and uninfected cattle in Accra. Infected cattle at Adidome however, had significantly higher levels of ALP, creatinine, total protein and total bilirubin (P < 0.05) and significantly lower levels of cholesterol (P < 0.05) at specific time points. At basal levels and during infection, significantly higher pro-inflammatory to anti-inflammatory (Th1/Th2) cytokine ratios were observed in cattle at Adidome compared to Accra (P < 0.05), indicating a shift towards Th1 immune response in Adidome. Levels of IL-10 were, however, significantly elevated in infected cattle in Accra (P < 0.05), suggesting high anti-inflammatory cytokine response in Accra. CONCLUSION: These results suggests that cattle in an endemic area repeatedly infected with trypanosomes of different species or different antigenic types demonstrate high pro-inflammatory (Th1) immune response and biochemical alterations whereas cattle in a non-endemic area with predominantly chronic T. theileri infections demonstrate high anti-inflammatory response and no biochemical alterations

EFFECT OF Dactyladenia barteri (Hook. f. ex Oliv.), Leucaena leucocephala (Lam.) de Wit, Gliricidia sepium (Jacq.), and Senna siamea (Lam.) MULCHES ON EARTHWORM ACTIVITY AND NUTRIENT TURNOVER IN CASTS

A two year field study was conducted to investigate the effects of prunings of Dactyladenia barteri (Hook. f. ex Oliv.), Leucaena leucocephala (Lam.) de Wit, Gliricidia sepium (Jacq.), and Senna siamea (Lam.) on the activity of earthworms and soil and worm cast properties. Earthworm activity was measured by quantifying worm casts deposited at the soil surface. Results of the study showed that the effect of the different mulches on earthworm activity was similar. The cumulative trend in surface cast production was also similar under the different mulches. Irrespective of the type of mulch and the year of sampling, the concentration of nutrient elements were significantly (P = 0.05) higher in worm casts relative to uningested soil. Worm casts contain 2 – 3 times more Ca, 2 – 3 times more Mg, 3 – 4 times more K, 5 – 6 times more N and 2 – 5 times more organic C than the top 5 cm of the soil. [Niger Agric. J. 34 (2003): 27-35

MULCHING EFFECT OF Dactyladenia barteri (Hook. f. ex Oliv.), Leucaena leucocephala (Lam.) de Wit, Gliricidia sepium (Jacq.), and Senna siamea (Lam.) LEAVES ON SOIL TEMPERATURE, MOISTURE REGIME AND YIELD OF MAIZE

A two-year field study was conducted to investigate the effects of mulches of multipurpose trees on soil properties and yield of maize. The field layout was a randomized complete block design with five replicates. Results of the study showed that the mulching effect of the prunings was highest with Dactyladenia barteri and lowest with Leucaena leucocephala. Moisture tension less than 50 hPa were more frequent under Dactyladenia barteri at 10cm and Senna siamea at 30cm soil depth. There were significant increases in maize grain yield over the control in both years. Mulching effect on grain yield was higher in the second season cropping than in the first season cropping. The effect of mulch applied at the start of the first season cropping on second season grain yield was highest under mulches of Leucaena leucocephala and Dactyladenia barteri. [Niger Agric. J. 34 (2003): 36-43