Evaluation of fecal recovering and long term bias of internal and external markers in a digestion assay with cattle

The objective of this work was to estimate the total recovering and the long term bias of the estimates of fecal excretion using the external markers chromic oxide and titanium dioxide and internal markers indigestible dry matter (iDM), indigestible neutral detergent fiber (iNDF) and indigestible acid detergent fiber (iADF) in a digestion assay with cattle fed different diets. Fourteen F1 Red Angus x Nellore averaging 12 months and 287 kg were used. The animals were fed with elephant grass silage, corn silage or signal grass hay and supplemented or not with 20% of concentrate. The experiment consisted of two 13-days experimental periods according to a 2 x 2 Latin square design with seven squares. The animals received 10 g/d of chromic oxide and titanium dioxide through esophageal sounder. There was no effect of forage, concentrate or their interaction on fecal recovering of external and internal markers. The average fecal recovering of chromic oxide and titanium dioxide were 99.50% and 101.95%, respectively. iDM, iNDF and iADF presented average fecal recovering of 99.02%, 98.87% and 102.07%, respectively. For all markers the fecal recovering was found to be 100% and all of them presented no long term bias. However, higher precision was observed for fecal excretion estimates obtained with internal markers.Objetivou-se estimar a recuperação total e o vício de tempo longo das estimativas de excreção fecal obtidas com os indicadores externos óxido crômico e dióxido de titânio e com os indicadores internos matéria seca indigestível (MSi), fibra em detergente neutro indigestível (FDNi) e fibra em detergente ácido indigestível (FDAi) em ensaio de digestão com bovinos alimentados com diferentes dietas. Foram utilizados 14 novilhos F1 Red Angus x Nelore, não-castrados, com idade e peso médios de 12 meses e 287 kg. Os animais foram alimentados com silagem de capim-elefante, silagem de milho ou feno de capim-braquiária, suplementados ou não com 20% de mistura concentrada. O experimento foi constituído de dois períodos de 13 dias cada, segundo delineamento em quadrado latino 2 x 2, com agrupamento de sete quadrados. Os animais receberam diariamente 10 g de óxido crômico e 10 g de dióxido de titânio através de sonda esofágica. Não foram observados efeitos de forragem, nível de concentrado ou de sua interação sobre as estimativas de recuperação fecal, tanto dos indicadores internos quanto dos indicadores externos. As estimativas de recuperação fecal média para o óxido crômico e para o dióxido de titânio foram de 99,50% e 101, 95%, respectivamente. Para os indicadores internos, observou-se recuperação fecal média de 99,02; 98,87 e 102,07% para MSi, FDNi e FDAi, respectivamente. Em todos os casos, as recuperações fecais foram iguais a 100%. Todos os indicadores avaliados podem ser considerados isentos de vício de tempo longo. Contudo, maior precisão é verificada para as estimativas de excreção fecal obtidas com indicadores internos

The pivotal role of biochar in enhancement soil properties, morphophysiological and yield characters of barley plants under drought stress

Drought is one of the most harmful abiotic stresses in arid and semiarid regions, so, field experiments were performed to examine biochar impact (15 or 20 t ha−1) on soil properties, physiological, morphological, and yield of barley under drought conditions. Our results displayed that drought caused a remarkable decrease in stem height and leaf area. Additionally, relative water contents (RWC%), chlorophyll a and b concentrations, as well as yield parameters were significantly reduced under drought. Conversely, lipid peroxidation (MDA), electrolyte leakage (EL%), and enzymatic activity were significantly augmented in the stressed plants during both seasons. Application of biochar led to improve leaves number (15.3), stem height (57%) and leaf area. Also, physiological characters like chlorophyll (72%) and RWC (33%), as well as yield, were increased considerably. Contrariwise, MDA and EL were reduced significantly (47 and 54%) under biochar application; furthermore, biochar led to regulate peroxidase and catalase activity in the stressed plants. It is concluded that biochar treatment can significantly improve soil properties, particularly soil EC (dSm-1), soil organic matter % and soil pH as well as increase yield characters via improving stress tolerance of barley under drought conditions; the best treatment was 20 t biochar ha−1 in the plants irrigated twice

The pivotal role of biochar in enhancement soil properties, morphophysiological and yield characters of barley plants under drought stress

Drought is one of the most harmful abiotic stresses in arid and semiarid regions, so, field experiments were performed to examine biochar impact (15 or 20 t ha−1) on soil properties, physiological, morphological, and yield of barley under drought conditions. Our results displayed that drought caused a remarkable decrease in stem height and leaf area. Additionally, relative water contents (RWC%), chlorophyll a and b concentrations, as well as yield parameters were significantly reduced under drought. Conversely, lipid peroxidation (MDA), electrolyte leakage (EL%), and enzymatic activity were significantly augmented in the stressed plants during both seasons. Application of biochar led to improve leaves number (15.3), stem height (57%) and leaf area. Also, physiological characters like chlorophyll (72%) and RWC (33%), as well as yield, were increased considerably. Contrariwise, MDA and EL were reduced significantly (47 and 54%) under biochar application; furthermore, biochar led to regulate peroxidase and catalase activity in the stressed plants. It is concluded that biochar treatment can significantly improve soil properties, particularly soil EC (dSm-1), soil organic matter % and soil pH as well as increase yield characters via improving stress tolerance of barley under drought conditions; the best treatment was 20 t biochar ha−1 in the plants irrigated twice.</jats:p

Glycine N-methyltransferase deficiency: a novel inborn error causing persistent isolated hypermethioninaemia.

This paper reports clinical and metabolic studies of two Italian siblings with a novel form of persistent isolated hypermethioninaemia, i.e. abnormally elevated plasma methionine that lasted beyond the first months of life and is not due to cystathionine beta-synthase deficiency, tyrosinaemia I or liver disease. Abnormal elevations of their plasma S-adenosylmethionine (AdoMet) concentrations proved they do not have deficient activity of methionine adenosyltransferase I/III. A variety of studies provided evidence that the elevations of methionine and AdoMet are not caused by defects in the methionine transamination pathway, deficient activity of methionine adenosyltransferase II, a mutation in methylenetetrahydrofolate reductase rendering this activity resistant to inhibition by AdoMet, or deficient activity of guanidinoacetate methyltransferase. Plasma sarcosine (N-methylglycine) is elevated, together with elevated plasma AdoMet in normal subjects following oral methionine loads and in association with increased plasma levels of both methionine and AdoMet in cystathionine beta-synthase-deficient individuals. However, plasma sarcosine is not elevated in these siblings. The latter result provides evidence they are deficient in activity of glycine N-methyltransferase (GNMT). The only clinical abnormalities in these siblings are mild hepatomegaly and chronic elevation of serum transaminases not attributable to conventional causes of liver disease. A possible causative connection between GNMT deficiency and these hepatitis-like manifestations is discussed. Further studies are required to evaluate whether dietary methionine restriction will be useful in this situation

Determinação de rotina do crômio em fezes, como marcador biológico, pelo método espectrofotométrico ajustado da 1,5-difenilcarbazida The spectrophotometric method on the routine of 1,5-diphenylcarbazide was adjusted on chromium determination in feces, after its utilization as a biological marker as chromium (III) oxide

O objetivo deste estudo foi ajustar o método espectrofotométrico da 1,5-difenilcarbazida à determinação do crômio em fezes, como marcador biológico, adequando-o à rotina laboratorial. Fatores que poderiam exercer interferência na transformação do crômio (III) à crômio (VI) foram testados, como a recuperação do metal, quantidade de amostra, quantidade e ordem de emprego dos ácidos oxidantes da digestão úmida, temperatura e tempo de digestão e perda por volatilização do crômio como cloreto de cromila, porém não se determinou estatisticamente interferência destes fatores. No método ajustado, a amostra é digerida pela clássica mistura ácida nítrica/perclórica, levando a oxidação do crômio (III) a crômio (VI), e alíquota do extrato diluído é usado para reação com 1,5-difenilcarbazida; as absorbâncias são medidas a 550nm, utilizando-se de cubetas de um centímetro de caminho óptico, contra prova em branco conduzida simultaneamente. Dicromato de potássio foi empregado como substância de referência para obtenção da curva padrão na faixa de 0,25 - 2,5mg.mL-1 de Cr2O3 (1mg Cr2O3 &ordm; 1,9355mg K2Cr2O7).<br>This work aims at adjusting the spectrophotometric method of 1,5-diphenylcarbazide for the determination of chromium in feces, as a biological marker. Factors that could interfere with the transformation of chromium (III) into chromium (VI) were tested, as the metal recovery, the sample amount, the amount and the order of use of the oxidant acids of the wet digestion, digestion temperature and digestion time, loss of chromium by volatilization as chromyl chlorid. However the interference of these factors were not statistically determined. In the adjusted method, the sample is classically digested by nitric/perchloric acid mixture leading to the oxidation of chromium (III) to chromium (VI), and an aliquot of the diluted extract is used for reaction with 1,5-diphenylcarbazide; absorbance was measured at 550nm, using 1cm path length optical cuvettes. Potassium dichromate was used as a standard substance to obtain the standard curve ranging from 0.25mg.mL-1 to 2.5mg.mL-1 of Cr2O3 (1mg Cr2O3 &ordm; 1.9355mg K2Cr2O7)