Studies on mushroom flavours 2. Flavour compounds in coprinus comatus

Within 3 hours, 10 healthy male volunteers were infused 500 ml of a 5 percent emulsion in which 25 percent of the fat proportion had been replaced by MCT-fats. As expected, the ketone body concentration in the blood rose, while pyruvate remained constant and lactate dropped. The results show that, basically, a MCT-containing fat infusion is suited for parenteral nutrition and, because of their specific properties, medium chain triglycerides may be used as rapid energy donators.     

Study of the lactation curve in dairy cattle on farms in central Mexico

Accurate knowledge of lactation curves has an important relevance to management and research of dairy production systems. A number of equations have been proposed to describe the lactation curve, the most widely applied being the gamma equation. The objective of this work was to compare and evaluate candidate functions for their predictive ability in describing lactation curves from central Mexican dairy cows reared under 2 contrasting management systems. Five equations were considered: Gaines (exponential decay), Wood (gamma equation), Rook (Michaelis-Menten ×exponential), and 2 more mechanistic ones (Dijkstra and Pollott). A database consisting of 701 and 1283 records of cows in small-scale and intensive systems, respectively, was used in the analysis. Before analysis, the database was divided into 6 groups representing first, second, and third and higher parity cows in both systems. In all cases except second and above parity cows in small-scale systems, all models improved on the Gaines equation. The Wood equation explained much of the variation, but its parameters do not have direct biological interpretation. Although the Rook equation fitted the data well, some of the parameter estimates were not significant. The Dijkstra equation consistently gave better predictions, and its parameters were usually statistically significant and lend themselves to physiological interpretation. As such, the differences between systems and parity could be explained due to variations in theoretical initial milk production at parturition, specific rates of secretory cell proliferation and death, and rate of decay, all of which are parameters in the model. The Pollott equation, although containing the most biology, was found to be over-parameterized and resulted in nonsignificant parameter estimates. For central Mexican dairy cows, the Dijkstra equation was the best option to use in describing the lactation curve.     

On-line identification method in column liquid chromatography: UV resonance Raman spectroscopy.

Ultraviolet resonance Raman spectroscopy (RRS) is presented as a novel identification tool for conventional-size column liquid chromatography (LC). The on-line coupling was made using a standard Z-shaped flow cell. A continuous-wave frequency-doubled argon ion laser operating at a wavelength of 244 nm was used for excitation. "On-the-fly" resonance Raman spectra of four model compounds, fluorene, phenanthrene, fluoranthene, and pyrene, were recorded after a standard acetonitrile/water reversed-phase LC separation. When applying a large-volume-injection procedure (32 mL), detection limits were at the nanogram per milliliter level. The results indicate that UV-RRS gives detailed spectral information at an appropriate sensitivity level so that coupling with LC becomes feasible.     

One-Sided Chronic Intervillositis of Unknown Etiology in Dizygotic Twins: A Description of 3 Cases

Chronic intervillositis of unknown etiology (CIUE) is a rare, poorly understood, histopathological diagnosis of the placenta that is frequently accompanied by adverse pregnancy outcomes including miscarriage, fetal growth restriction, and intrauterine fetal death. CIUE is thought to have an immunologically driven pathophysiology and may be related to human leukocyte antigen mismatches between the mother and the fetus. Dizygotic twins with one-sided CIUE provide an interesting context to study the influence of immunogenetic differences in such cases. The main immune-cell subsets were investigated using immunohistochemistry. We identified three dizygotic twin pregnancies in which CIUE was present in only one of the two placentas. Two of the pregnancies ended in term delivery and one ended in preterm delivery. Presence of CIUE was correlated with lower placental weight and lower birthweight. Relative number of CD68, CD56, CD20, and CD3 positive cells were comparable between co-twins. The presence of one-sided CIUE in dizygotic twin pregnancy was associated with selective growth restriction in the affected twin. This suggests a unique fetal immunogenetic contribution to the pathogenesis of CIUE. Further study of dizygotic and monozygotic placentas affected by CIUE could identify new insights into its pathophysiology and into the field of reproductive immunology.     

A multi-level hierarchic Markov process with Bayesian updating for herd optimization and simulation in dairy cattle

Herd optimization models that determine economically optimal insemination and replacement decisions are valuable research tools to study various aspects of farming systems. The aim of this study was to develop a herd optimization and simulation model for dairy cattle. The model determines economically optimal insemination and replacement decisions for individual cows and simulates whole-herd results that follow from optimal decisions. The optimization problem was formulated as a multi-level hierarchic Markov process, and a state space model with Bayesian updating was applied to model variation in milk yield. Methodological developments were incorporated in 2 main aspects. First, we introduced an additional level to the model hierarchy to obtain a more tractable and efficient structure. Second, we included a recently developed cattle feed intake model. In addition to methodological developments, new parameters were used in the state space model and other biological functions. Results were generated for Dutch farming conditions, and outcomes were in line with actual herd performance in the Netherlands. Optimal culling decisions were sensitive to variation in milk yield but insensitive to energy requirements for maintenance and feed intake capacity. We anticipate that the model will be applied in research and extension.     

The effect of high-sugar grass on predicted nitrogen excretion and milk yield simulated using a dynamic model

High-sugar grass varieties have received considerable attention for their potential to reduce nitrogen (N) excretion and increase milk yield in cattle. However, considerable variation exists in the magnitude of response in published results. The purpose of this study is to explain the variation in response using a dynamic mechanistic model to predict observed N and milk yield results from the literature, and from simulated data. Examined effects were (1) water-soluble carbohydrate [WSC; g/kg of dry matter (DM)] increase; (2) change in crude protein (CP) and neutral detergent fiber (NDF) content of the plant with WSC increase; and (3) the level of N fertilization. The database for evaluation of model N and milk yield predictions consisted of 4 published studies with 28 treatment means for which high-sugar grasses were being evaluated. Water-soluble carbohydrate content of the diets ranged from 95 to 248 g/kg of DM, CP content ranged from 115 to 263 g/kg of DM, and the NDF content ranged from 400 to 568 g/kg of DM. Urine N, milk N, and total N excretion were predicted well by the model and followed the directional pattern of observed values within each study. Simulation results showed that the N utilization ratio increased as the WSC content of the diet increased, but to varying degrees depending on the grass scenario examined. The greatest benefit in terms of N utilization ratio and urine N levels were seen when the WSC content of grass increased at the expense of CP, followed by a 50:50 CP and NDF mix, followed by a trade for NDF. Simulated milk yield decreased slightly when WSC increased at the expense of CP, increased slightly when it increased at the expense of a CP and NDF mix, and increased most when WSC increased at the expense of NDF. Results were amplified slightly under conditions of low-N fertilization and in the absence of grain feeding. Overall, modeling is useful as an explanatory tool. The variation from results in the literature with high-WSC grass feeding may be, at least in part, the result of the level of WSC (g/kg of DM) increase, concurrent changes occurring within the CP and NDF fractions of the plant, and the plane of nutrition of the diet (grain feeding and N fertilization levels).     

Studies on mushroom flavours 3. Some flavour compounds in fresh, canned and dried edible mushrooms

Summary The concentrations of 1-octen-3-ol, 5-GMP and glutamic acid were compared in 8 fresh, 3 canned and 5 dried mushroom species. The highest amounts of 1-octen-3-ol and 5-GMP were found in the fresh mushrooms.Agaricus bitorquis, Pleurotus ostreatus andPholiota squarrosa contained 5–7 times as much 1-octen-3-ol asAgaricus bisporus andCalvatia gigantea 58 times as much.Coprinus comatus andPleurotus ostreatus contained much 5-GMP. Little 1-octen-3-ol and 5'-GMP were found in most dried and canned mushrooms. Potatoes and tomatoes were analyzed for comparison. Little or no 1-octen-3-ol and 5-GMP were observed. Glutamic acid was present in most samples in sufficient quantities to have an important influence on the flavour.

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Studien über Pillzaromastoffe 3. Einige Aromastoffe in frischen, naßkonservierten and getrockneten Speisepilzen

Zusammenfassung Die Konzentrationen von 1-Octen-3-ol, 5-GMP and Glutaminsäure wurden in 8 frischen, 5 getrockneten and 3 in Dosen konservierten Pilzarten verglichen. Die höchsten Konzentrationen von 1-Octen-3-ol and 5-GMP wurden in den frischen Pilzen beobachtet.Agaricus bitorquis, Pleurotus ostreatus undPholiota squarrosa enthielten 5–7mal undCalvatia gigantea 58 mal so viel 1-Octen-3-ol wieAgaricus bisporus.Coprinus comatus undPleurotus ostreatus enthielten beträchtliche Mengen 5-GMP. Wenig 1-Octen-3-ol und 5-GMP warden in den meisten getrockneten and naßkonservierten Pilzen gefunden. Kartoffeln and Tomaten zum Vergleich enthielten wenig oder kein 1-Octen-3-ol and 5-GMP. Glutaminsäure lag in den meisten Proben in genügenden Konzentrationen vor, um einen wichtigen Einfluß auf das Aroma auszuüben.