BACKGROUND Cellulose as a renewable biomaterial has forced attention on the use of cellulose‐hydrolyzing enzymes for industrial bioconversion of lignocellulosic materials to glucose. This paper reports immobilization of cross‐linked cellulase aggregates (CLEA) on the amine‐functionalized Fe3O4@silica core‐shell magnetic nanoparticles (MNPs). RESULTS The optimum pH of the cellulase cocktail upon immobilization (cellulase CLEA–MNP) shifted a little to the acidic side whereas the optimum temperature did not change significantly. The behavior of CMCase activity in the cellulase CLEA–MNP at pH and temperature values higher than the optimum was significantly different compared with free cellulase. Cellulase CLEA–MNP retained about 45% of its maximum activity at pH values higher than 4.8, while free cellulase lost its activity sharply. Immobilized cellulase in contrast to the free form retained about 65% of its maximum activity at 80°C. Cellulase CLEA–MNP had improved thermal stability at 65°C. Operational stability of the immobilized cellulase was also noticeable. After a sharp decrease during two cycles of CMC hydrolysis, cellulase CLEA–MNP retained 30% of its initial activity through six cycles of reuse. CONCLUSION Simple separation of MNPs from reaction medium and durability of CLEA–MNP composite during repeated use may overcome the major bottleneck against comprehensive applications of cellulase enzymes in industry. © 2014 Society of Chemical Industry

The study investigated the effects of replacing soybean meal (SBM) with slow-release urea (SRU) on milk production, milk composition, and rumen fermentation of Holstein dairy cows. Sixteen Holstein cows weighing between 550 and 680 kg in mid lactation were randomly assigned to four dietary treatments in a 12-week study. The treatments consisted of T1: a diet containing 16.7% crude protein (CP), T2: T1 with 0.5% SRU replacing plant protein, T3: T1 with 0.75% SRU replacing plant protein, and T4: T1 with 1.00% SRU replacing plant protein. Animals were fed three times a day with feed being offered ad libitum. Dry matter intake (DMI) and average daily gain (ADG) were not affected by the level of SRU. Feeding SRU did not affect milk production and milk composition significantly, but milk fat and milk urea nitrogen (MUN) levels were increased. Significant differences were observed in ruminal volatile fatty acid (VFA) concentration. Feeding SRU increased butyrate concentration with no significant effects on concentrations of acetate or propionate. Significant differences were observed in cholesterol, triglyceride, high-density lipoprotein (HDL), low-density lipoprotein (LDL), and nonesterified fatty acid (NEFA) concentrations, but glucose, very-low-density lipoprotein (VLDL) and β-hydroxybutyrate (BHB) levels were not affected significantly by the treatments. Thus, feeding SRU altered the release rate of ammonia and provided more ammonia nitrogen (NH3-N) for microbial protein synthesis in the rumen.

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The present study investigated the effects of different feed additives on growth performance, carcass characteristics, gut microbial population, intestinal morphology, and blood metabolites of broiler chickens. A total of 540, day-old Ross 308 male chicks were randomly distributed into 6 dietary treatments with 6 replicate pens per treatment for 35 days. The birds fed on a basal diet without feed additive (CON) or the basal diet supplemented with 0.25 g/kg antibiotic as growth promoter (AGP), 1 g/kg essential oils (EO), 1.7 g/kg synbiotic (SYN), 3 g/kg medium-chain fatty acids (MCFA), and 1 mL/L essential oils in drinking water (EOW). The additives improved the body weight gain (p ¼ .004) and feed conversion ratio (p ¼ .02) compared to the CON group during the whole trial. The serum concentration of cholesterol was lower in the birds fed the MCFA diet and serum concentration of low-density lipoprotein cholesterol (LDL) decreased in MCFA and SYN groups. The relative weight of spleen was the greatest in MCFA group (p ¼ .01). Feeding birds diets containing different additives decreased the population of coliform (p ¼ .002) and Clostridium perfringens (p ¼ .01) while Lactobacillus population was greater in broilers offered EOW, SYN, and MCFA supplements (p ¼ .02). The jejunal villus height enhanced in the broiler chickens which received AGP and MCFA additives (p ¼ .008). It is concluded that EOW, SYN, MCFA, and EO as alternatives for AGP improved the growth performance and intestinal morphometric indices and reduced the caecal pathogenic bacteria in broiler chickens. HIGHLIGHTSAdding MCFA to diet and EO to the drinking water improved BWG and FCR in broiler chickens. Dietary supplementation of MCFA decreased serum total cholesterol, increased caecal LAB population, and improved intestinal villus height. All supplements as AGP alternatives had beneficial effects on suppressing the pathogenic bacteria.

This research was conducted in order to investigate rumen degradability of some factors includes; Dray Matter (DM), Organic Matter (OM), Crude Protein (CP), Acid Detergent Fiber (ADF) in three different plant protein supplements includes; soybean, canola and cottonseed meal. The experiment was carried out using in three castrated and fistulated male Zel sheep. Each feedstuff was weighed into duplicate nylon bags and incubated in each of the three rumen fistulated sheep for 0, 2, 4, 8, 16, 24 and 48 h. Results revealed that effective degradability of DM of soybean, canola and cottonseed meal were 55.8, 73.8 and 48.5%, respectively. Effective degradabilities of the CP in feedstuffs were 55.8, 62 and 48.3% for the respective feedstuffs. Effective degradabilities of the OM were 55.7, 56.4 and 47.4%, respectively. Results also showed that effective degradabilities of the ADF were 55, 56.4 and 37.6, respectively. According to the results the researchers concluded that canola and soybean were more degradable in the rumen of the sheep while cottonseed meal were less degradable and, hence resulted in higher rumen undegradable protein.