Review: Strategies for enteric methane mitigation in cattle fed tropical forages.

Methane (CH4) is a greenhouse gas (GHG) produced and released by eructation to the atmosphere in large volumes by ruminants. Enteric CH4 contributes significantly to global GHG emissions arising from animal agriculture. It has been contended that tropical grasses produce higher emissions of enteric CH4 than temperate grasses, when they are fed to ruminants. A number of experiments have been performed in respiration chambers and head-boxes to assess the enteric CH4 mitigation potential of foliage and pods of tropical plants, as well as nitrates (NO3-) and vegetable oils in practical rations for cattle. On the basis of individual determinations of enteric CH4 carried out in respiration chambers, the average CH4 yield for cattle fed low-quality tropical grasses (>70% ration DM) was 17.0 g CH4/kg DM intake. Results showed that when foliage and ground pods of tropical trees and shrubs were incorporated in cattle rations, methane yield (g CH4/kg DM intake) was decreased by 10% to 25%, depending on plant species and level of intake of the ration. Incorporation of nitrates and vegetable oils in the ration decreased enteric CH4 yield by ∼6% to ∼20%, respectively. Condensed tannins, saponins and starch contained in foliages, pods and seeds of tropical trees and shrubs, as well as nitrates and vegetable oils, can be fed to cattle to mitigate enteric CH4 emissions under smallholder conditions. Strategies for enteric CH4 mitigation in cattle grazing low-quality tropical forages can effectively increase productivity while decreasing enteric CH4 emissions in absolute terms and per unit of product (e.g. meat, milk), thus reducing the contribution of ruminants to GHG emissions and therefore to climate change.

Reduction capacity on nitroblue tetrazolium (NBT) of the normal human spermatozoa.

Experimental conditions were determined to find out if washed spermatozoids from fertile, health donors are capable of nitroblue tetrazolium (NBT) reduction in a similar way (although in the absence of a substrate) to that of leukocytes. Formazan blue formation obtained suggest the participation of the NADH oxidoreductase mitochondrial enzyme. The sperm capacity for NBT reduction might be take as a reflection of human sperm metabolic capacity. Our results seem to be useful for comparison of reduction (metabolic) capacity of normal sperms with that of individuals with fertility problems.

[Evaluation of the use of sodium bicarbonate in a group of children with diarrhea, 10 per cent dehydration and metabolic acidosis]. / Evaluación del uso del bicarbonato de sodio en un grupo de niños con diarrea, deshidratación del 10% y acidosis metabólica

Considering the disparity of criteria regarding the use of sodium bicarbonate in the management of infants with diarrhea, dehydration and metabolic acidosis, a prospective study was done in 25 infants (13 managed without and 12 with bicarbonate) where it was demonstrated; a) The use of bicarbonate does not lead to a more rapid correction of the metabolic acidosis. b) Bicarbonate should not be used in patients with serum bicarbonate levels of 5 mEq/1. or over. c) Patients with dehydration and metabolic acidosis show hyperglycemia that returns to normal when the dehydration is corrected. This fact is of great interest because these children should not be considered nor managed as diabetics.