Exchanging physically effective neutral detergent fiber does not affect chewing activity and performance of late-lactation dairy cows fed corn and sugarcane silages

The objective of this study was to determine whether replacing the physically effective neutral detergent fiber (peNDF) of corn silage with sugarcane silage peNDF would affect performance in dairy cows. Twenty-four late-lactation Holstein cows were assigned to eight 3 × 3 Latin squares with 21-d periods. The dietary treatments were (1) 25% peNDF of corn silage, (2) 25% peNDF of sugarcane silage, and (3) 12.5% peNDF of corn silage + 12.5% peNDF of sugarcane silage. The physical effectiveness factors (pef) were assumed to be 1 for corn silage and 1.2 for sugarcane silage, as measured previously by bioassay. Thus, peNDF was calculated as neutral detergent fiber (NDF) × pef. The concentrate ingredients were finely ground corn, soybean meal, pelleted citrus pulp, and mineral-vitamin premix. Dry matter intake (22.5 ± 0.63 kg/d), 3.5% fat-corrected milk yield (28.8 ± 1.13 kg/d), milk composition (fat, protein, lactose, urea, casein, free fatty acids, and somatic cell count), and blood metabolites (glucose, insulin, and nonesterified fatty acids) were unaffected by the treatments. The time spent eating, ruminating, or chewing was also similar among the diets, as was particle-sorting behavior. By contrast, chewing per kilogram of forage NDF intake was higher for the sugarcane silage (137 min/kg) than the corn silage diet (116 min/kg), indicating the greater physical effectiveness of sugarcane fiber. Based on chewing behavior (min/d), the estimated pef of sugarcane silage NDF were 1.28 in the corn silage plus sugarcane silage diet and 1.29 in the sugarcane silage diet. Formulating dairy rations of equal peNDF content allows similar performance if corn and sugarcane silages are exchanged.     

Investigation of the Structure of the Biochar Obtained by Slow Pyrolysis of Elephant Grass during Its Steam Gasification

A detailed evaluation of the structure of biochar from slow pyrolysis of elephant grass during its steam gasification was performed. The effects of surface area and inherent alkali and alkaline earth metal (AAEM) species on the reactivity of the biochar were investigated. Drastic changes in biochar structure occurred throughout the reaction, especially for low degrees of conversion. The BET surface area of the biochar increased significantly until the conversion reached 0.49, and there was a steep decrease at high degrees of conversion. The biochar showed a high AAEM concentration. The aromaticity of the biochar suggested an ordered carbon structure that can lower the reaction rate. The high syngas yield makes the process attractive for generation of renewable energy.     

Impact of human aging and modern lifestyle on gut microbiota

Human evolution and lifestyle changes caused by the agricultural and industrial revolutions have led to great advances in medicine and increased life expectancy, whilst also profoundly altering the ecological relationships and disease patterns of populations. Studies involving populations that still enjoy a rural way of life and with traits similar to the Paleolithic period reveal them to present a more robust, resistant and diverse gut microbiota, in comparison to highly industrialized civilizations. The human diet has expanded and broadened to include the consumption of high-calorie foods, particularly from animal sources such as game meat and eggs. For some time, authors have been alert to the fact that a modern lifestyle leads to reduced intake of beneficial bacteria, suggesting that nonpathogenic bacteria are being eradicated. Furthermore, therapeutic procedures, including the use of probiotics and prebiotics, have been proposed to lead to recovery of this microbiota, which is altered due to both the ageing process and lifestyle related aspects. Accordingly, this article aims to review the impact of human aging and modern lifestyle on gut microbiota, within an evolutionary, ecological, epidemiological and therapeutic context.     

Scenario-based verification of uncertain parametric MDPs

We consider parametric Markov decision processes (pMDPs) that are augmented with unknown probability distributions over parameter values. The problem is to compute the probability to satisfy a temporal logic specification with any concrete MDP that corresponds to a sample from these distributions. As solving this problem precisely is infeasible, we resort to sampling techniques that exploit the so-called scenario approach. Based on a finite number of samples of the parameters, the proposed method yields high-confidence bounds on the probability of satisfying the specification. The number of samples required to obtain a high confidence on these bounds is independent of the number of states and the number of random parameters. Experiments on a large set of benchmarks show that several thousand samples suffice to obtain tight and high-confidence lower and upper bounds on the satisfaction probability.

     

Short communication: Influence of various proteolytic sources during fermentation of reconstituted corn grain silages

The objective of this study was to determine the contribution of corn kernel enzymes, bacteria, fungi, and fermentation end-products (main acids and ethanol) to protein solubilization during fermentation of reconstituted corn grain silage. Flint corn kernels were ground (5-mm sieve), rehydrated to 32% of moisture, and treated with no additives (control), gamma irradiation (32 kGy), gamma irradiation + fermentation end-products (1% of lactic acid, 0.3% of acetic acid, and 0.7% of ethanol, as fed), and natamycin (1% as fed). Treated grains were ensiled in nylon-polyethylene bags and stored for 90 d. Protein solubilization was calculated for each treatment and the contributions of proteolytic sources were determined. Bacterial activity was the main contributor to proteolysis (60%) followed by corn kernel enzymes (30%), whereas fungi and fermentation end-products had only minor contributions (～5% each).     

Steam Gasification of Biochar Derived from the Pyrolysis of Chrome‐Tanned Leather Shavings

Chromium‐treated leather shavings are generated in large quantities by the leather industry. The biochar gasification from leather shavings leads to two main products, a hydrogen‐rich syngas and a chromium‐rich ash. Syngas has found different applications such as electricity generation and chemical manufacturing. The remaining ash potentially can be utilized, e.g., in stainless‐steel production processes. The thermochemical conversion of biochar from chromium‐tanned leather shavings via steam gasification was investigated. The cumulative gas yield and cumulative H₂ yield were determined as well as the total chromium as Cr₂O₃ in the remaining ash.     

Ethylene Polymerization using Combined Ni and Ti Catalysts Supported in situ on MAO‐Modified Silica

Summary: Branched polyethylene/linear polyethylene blends (BPE/LPE) were prepared using the combined Ni(α‐diimine)Cl₂ ( 1 ) (α‐diimine = 1,4‐bis(2,6‐diisopropylphenyl)acenaphthenediimine) and {Tp^Ms*}TiCl₃ ( 2 ) (Tp^Ms* = hydridobis(3‐mesitylpyrazol‐1‐yl)(5‐mesitylpyrazol‐1‐yl)) catalysts supported in situ on methylaluminoxane (MAO)‐modified silica (4.0 wt.‐% Al/SiO₂). The polymerization reactions were performed in toluene at two different polymerization temperatures (0 and 30 °C) and several nickel molar fractions (x_Ni), using MAO as external cocatalyst. At all temperatures, the activities show an approximate linear correlation with x_Ni, indicating a non‐synergistic effect between the nickel and the titanium species. Higher activities were found at 0 °C. The melting temperatures for the polyethylene blends produced at 0 °C decrease as x_Ni increases in the medium, indicating good compatibility between the polyethylene phases made by both catalysts. The melting temperature (T_m) of the polyethylene blends was shown to depend on the order in which the catalysts were immobilized on the MAO‐modified silica support. The initial immobilization of 1 on the support ( 2 / 1 /SMAO‐4) affords polymers with a lower T_m than those produced with 1 / 2 /SMAO‐4. In addition, scanning electron microscopy (SEM) studies revealed that the spherical morphology of the supported catalyst is replicated in the polyethylene particles.

Influence of polymerization temperature on the activity of 1 / 2 /SMAO‐4 with varying x_Ni.