Dairy production systems of Colombia: challenges and opportunities

Colombia has opened its markets to international competition by signing several free trade agreements. This condition has generated great pressure on the dairy sector, which must be competitive in a globalized market. In the year 2014, Colombia produced 6.717 million L of milk and per capita milk consumption was 143 L. There are an estimated 99,000 dairy producers in specialized systems and 250,000 in dual-purpose systems. Specialized dairy production is found mainly in pastoral systems in the highland tropics (>2000 m elevation) with pastures of Kikuyu grass (Pennisetum clandestinum Hoschst ex Chiov) and the predominant dairy breed is Holstein Friesian. Average milk production is 12 to 14 kg/d with a stocking rate between 1 and 2 cows/ha. Dual-purpose dairying under grazing systems occurs mainly in the low (<1200 m) and medium-high (1200 to 2000 m) tropics, and uses crossbreed cows (Bos indicus × Bos taurus), with once a day milking with the calf present. The calf sucks residual milk and grazes with the mother until midday or mid-afternoon. Milk production is low (3 to 5 L/d) and lactation length is short (<280 d). Lowest unit costs of milk production (<U$ 0. 27/L) is obtained in low input systems and low productivity. These systems account for more than 66% of the producers and 54% of the milk produced nationally. The concentrations of milk fat and protein and standard plate count (SPC) are higher for dual-purpose systems (3.7%, 3.3%, and 884.993/mL) than for specialized dairies (3.5%, 3.1%, and 395.551 SPC/mL). Milk somatic cell count (SCC) is between 400,000 and 600,000 cells/mL nationally. Milk transportation costs are high due to the geographical dispersion of dairy producers and the low volumes they deliver (<200 L/d). Although Colombia has been declared free of foot and mouth disease with vaccination, its admissibility to international markets may be limited by other diseases such as brucellosis (prevalence >4%) or tuberculosis. To compete in international markets Colombia should consolidate milk production systems, improve milk quality (solids content, hygiene), increase volumes of delivery by the supplier and achieve zones of sanitary excellence

Estudio quimico preliminar de los fenoles y polifenoles de dos accesiones de calliandra calothyrsus (mimosaceae)

El objetivo de este estudio comparativo es conocer la composición química cualitativa y la concentración relativa de los fenoles y de los taninos condensados en dos accesiones de la especie forrajera Calliandra calothyrsus (Fabaceae Mimosaceae) cultivada y clasificada por el CIAT. El análisis por técnicas cromatográficas y métodos espectroscópicos permitió establecer claras diferencias en las dos muestras, no solo en cantidades sino en el número de derivados fenólicos observados. Entre los componentes fenólicos de bajo peso molecular identificados en las dos muestras sobresalen las isoflavonas: genisteína, prunetina y 7-O-glucosil-genisteína; catequinas, quercetina, miricetina y sus dihidroderivados, epigaloilcatequina, y galatos de epigaloilcatequinas. Entre los oligómeros, por MALDI-TOF y ESI en modo negativo se detectaron hasta pentámeros de catequinas en series de distintas combinaciones de monómeros según la regla Krueger

Transethnic meta-analysis of rare coding variants in PLCG2, ABI3, and TREM2 supports their general contribution to Alzheimer’s disease

Rare coding variants in TREM2, PLCG2, and ABI3 were recently associated with the susceptibility to Alzheimer’s disease (AD) in Caucasians. Frequencies and AD-associated effects of variants differ across ethnicities. To start filling the gap on AD genetics in South America and assess the impact of these variants across ethnicity, we studied these variants in Argentinian population in association with ancestry. TREM2 (rs143332484 and rs75932628), PLCG2 (rs72824905), and ABI3 (rs616338) were genotyped in 419 AD cases and 486 controls. Meta-analysis with European population was performed. Ancestry was estimated from genome-wide genotyping results. All variants show similar frequencies and odds ratios to those previously reported. Their association with AD reach statistical significance by meta-analysis. Although the Argentinian population is an admixture, variant carriers presented mainly Caucasian ancestry. Rare coding variants in TREM2, PLCG2, and ABI3 also modulate susceptibility to AD in populations from Argentina, and they may have a European heritage.International Society for Neurochemistry (ISN) and Alexander von Humboldt Foundation (to M.C.D.); Agencia Nacional de Promoción Científica y Tecnológica (PBIT/09 2013, PICT2015-0285 and PICT-2016-4647 to L.M.; PICT-2014-1537 to M.C.D.

Transethnic meta-analysis of rare coding variants in PLCG2, ABI3, and TREM2 supports their general contribution to Alzheimer's disease

Rare coding variants in TREM2, PLCG2, and ABI3 were recently associated with the susceptibility to Alzheimer's disease (AD) in Caucasians. Frequencies and AD-associated effects of variants differ across ethnicities. To start filling the gap on AD genetics in South America and assess the impact of these variants across ethnicity, we studied these variants in Argentinian population in association with ancestry. TREM2 (rs143332484 and rs75932628), PLCG2 (rs72824905), and ABI3 (rs616338) were genotyped in 419 AD cases and 486 controls. Meta-analysis with European population was performed. Ancestry was estimated from genome-wide genotyping results. All variants show similar frequencies and odds ratios to those previously reported. Their association with AD reach statistical significance by meta-analysis. Although the Argentinian population is an admixture, variant carriers presented mainly Caucasian ancestry. Rare coding variants in TREM2, PLCG2, and ABI3 also modulate susceptibility to AD in populations from Argentina, and they may have a European heritage.Acknowledgements: This work was supported by grants from the International Society for Neurochemistry (ISN) and Alexander von Humboldt Foundation (to M.C.D.); Agencia Nacional de Promoción Científica y Tecnológica (PBIT/09 2013, PICT-2015-0285 and PICT-2016-4647 to L.M.; PICT-2014-1537 to M.C.D.); GENMED Labex and JPND PERADES grant; and JPND EADB grant (German Federal Ministry of Education and Research, BMBF: 01ED1619A)