Bioefficacy of a mono-component protease in the diets of pigs and poultry: a meta-analysis of effect on ileal amino acid digestibility

A meta-analysis of the effect of a mono-component bacterial protease (RONOZYME® ProAct) on the apparent ileal digestibility of amino acids in poultry and swine diets was conducted to examine functional patterns, mean effects and variability of response. A total of 25 independently-conducted experiments were included comprising a total of 804 datapoints. The mean response to protease was +3.74% (SE 1.1%, P0.05). However, the inherent digestibility of amino acids in the control diet as a single explanatory term explained around 47% of the variance (P<0.001) in effect. When the inherent digestibility of amino acids in the control diet was less than 70% protease addition improved amino acid digestibility in 90% of cases with a mean improvement of around 10%. When the inherent digestibility of amino acids in the control diet was more than 90% there was a protease-mediated improvement in digestibility in only 60% of cases with a mean improvement of around 2%. It can be concluded that the inherent digestibility of amino acids in the diet without protease supplementation is the primary explanatory term for the efficacy of this exogenous protease, demonstrating that it is highly effective in improving the digestibility of amino acids across a wide range of feed ingredients. Benchmarking diets or feed ingredients as to their relative nutritional value would enhance the ability of nutritionists to determine the likely return on investment on use of bacterial proteases in their operatio

Controlling the properties of the micellar and gel phase by varying the counterion in functionalised-dipeptide systems

The micellar aggregates formed at high pH for dipeptide-based gelators can be varied by using different alkali metal salts to prepare the solutions. The nature of the micellar aggregates directly affects the properties of the resulting gels

Possible role of available phosphorus in potentiating the use of low-protein diets for broiler chicken production

A total of 945 male Ross 308 broiler chicks were used in a growth study to explore the interaction between dietary crude protein concentration and available phosphorus. Nine experimental treatments were constructed factorially by offering low, medium, or standard protein concentrations without or with low, standard, or high available phosphorus. Diets were based on corn, wheat, and soybean meal and all nutrients other than protein/amino acids and available phosphorus were maintained at or above breeder guidelines. Additional synthetic amino acids were used in the diets with low protein concentration in attempt to maintain digestible amino acid supply. Diets were offered to 7 replicate pens of 15 chicks per pen from day 8 to 35. Growth performance was measured during the grower (day 8–24) and finisher (day 25–35) periods. On day 35 carcass composition was determined, blood was drawn for various biochemical measurements and the tibia was excised for mechanical and compositional analyses. Birds that received the low-protein diet had lower terminal body weight and higher feed conversion ratio compared with those that received diets with adequate crude protein content. However, addition of available phosphorus to the low-protein diet resulted in significant reductions in weight-corrected feed conversion that were not evident in the diet with adequate protein content. Bone architecture was only moderately influenced by dietary treatment but birds that ingested the diets containing low and medium protein concentrations had relatively heavier abdominal fat pad weight. Blood biochemistry, especially ammonia, uric acid, and phosphorus, was influenced by both dietary protein and available phosphorus and trends suggested that both axes are involved in protein accretion and catabolism. It can be concluded that performance losses associated with feeding low protein diets to broiler chickens may be partially restored by additional available phosphorus. The implications for use of exogenous enzymes such as protease and phytase and protein nutrition per se warrants further examination

Isotopic control over self-assembly in supramolecular gels

It is common to switch between H2O and D2O when examining peptide-based systems with the assumption being that there are no effects from this change. Here, we describe the effect of changing from H2O to D2O in a number of low molecular weight dipeptide-based gels. Gels are formed by decreasing the pH. In most cases, there is little dif-ference in the structures formed at high pH, but this is not universally true. On lowering the pH, the ki-netics of gelation are affected and, in some cases, the structures underpinning the gel network are dif-ferent. Where there are differences in the self-assembled structures, the resulting gel properties are different. We therefore show isotopic control over gel properties is possible

The Efficacy of Avizyme 1500 for Improving Performance of Laying Hens

Suatu percobaan telah dilakukan untuk menguji manfaat penambahan enzim-Avizyme 1500® (Danisco Animal Nutrition, Marlborough, UK) terhadap performan ayam petelur selama periode satu tahun produksi. Ransum kontrol disusun dengan bahan utama terdiri dari jagung dan bungkil kedelai untuk memenuhi kebutuhan gizi ayam petelur strain ISA Brown. Dua perlakuan yang diuji adalah ransum kontrol (C) dan ransum yang diberi enzim (C + 1000 g Avizyme/ton ransum. Setiap jenis ransum diberikan pada 80 ekor ayam petelur (20 ulangan dan 4 ekor/ulangan) mulai umur 20 hingga 72 minggu. Selama percobaan tersebut dilakukan pengamatan terhadap performan ayam petelur (konsumsi pakan, produksi telur, bobot telur, total berat produksi telur atau egg mass, konfersi pakan atau FCR, mortalitas, perubahan bobot badan dan kualitas telur). Perbedaan perlakuan dianalisis dengan menggunakan t-test. Hasil penelitian menunjukkan bahwa penambahan Avizyme 1500 kedalam pakan dapat menurunkan konsumsi pakan 4% (P &lt; 0,01), mengurangi mortalitas dari 15% menjadi 3,75% (P &lt; 0.01) serta memperbaiki efisiensi penggunaan pakan (FCR) sebanyak 3% (P &lt; 0,05). Mortalitas yang tinggi pada ayam kontrol (15%) terjadi karena adanya infeksi E.coli, sesuai uji post-mortem yang dilakukan. Akan tetapi, produksi telur (HD and HH), bobot telur dan massa telur tidak nyata dipengaruhi oleh penambahan Avizyme didalam pakan. Kualitas telur (HU, indeks kuning telur, bobot kuning telur dan tebal kerabang tidak nyata dipengaruhi oleh penambahan Avizyme dalam ransum. Oleh karena itu disimpulkan bahwa penambahan 1000 g Avizyme /ton ransum dapat memperbaiki efisiensi penggunaan pakan (FCR) sebagai akibat penurunan konsumsi pakan, tanpa merubah produktifitasnya. A trial was conducted in order to study the effect of the supplementation of Avizyme 1500® (Danisco Animal Nutrition, Marlborough, UK) on the performance of laying hens for one year. A control diet based on corn -soybean meal was formulated to meet nutrient requirement of ISA Brown laying hens. Two treatments, the control diet (C) and C + 1000 g Avizyme/tonne diet were tested. Each diet was fed to 80 birds (20 replicates of 4 birds) from 20 to 72 weeks of age, and performances of birds (feed intake, egg production, egg size, egg mass, feed conversion ratio, and egg quality) were measured. All data were subject to analyses of variance following the t-test. Results showed that the addition of Avizyme 1500 to the feed reduced feed intake by 4% (P &lt; 0.01), mortality by 75 % or from 15% to 3.75% (P &lt; 0.01) and improved the feed conversion ratio by 3 % (P &lt; 0.05). The high mortality of the control treatment (15%) is explained by an E.coli infection that was observed following the postmortem examination of dead birds. The egg production (HD and HH), egg size and egg mass however were not significantly affected by the Avizyme supplementation. Egg quality (HU, yolk colour score, yolk weight and shell thickness) was not significantly affected by Avizyme supplementation. It can be concluded that the supplementation of 1000 g Avizyme /tonne of diet improved feed efficiency and this was mediated via a reduction in feed intake

Controlling photocatalytic activity by self-assembly – Tuning perylene bisimide photocatalysts for the hydrogen evolution reaction

Amino acid functionalized perylene bisimides (PBIs) form self-assembled structures in solution, the nature of which depends on the local environment. Using a high-throughput photocatalysis setup, five PBIs are studied for the hydrogen evolution reaction (HER) under a range of conditions (pH and hole scavenger concentration) across 350 experiments to explore the relationship between supramolecular structure and photocatalytic activity. Using small angle X-ray scattering (SAXS), NMR spectroscopy and ultraviolet-visible (UV-vis) absorption spectroscopy, it is shown that photocatalytic activity is determined by the nature of the self-assembled aggregate that is formed, demonstrating the potential of self-assembly to tune activity. There is a clear correlation between the presence of charged flexible cylindrical aggregates and the occurrence of photocatalytic H2 production, with UV–vis spectroscopy indicating that the most active structure type has a distinctive form of π-aggregation which is proposed to enable efficient charge separation across multiple PBI units

Stochastic stability at the boundary of expanding maps

We consider endomorphisms of a compact manifold which are expanding except for a finite number of points and prove the existence and uniqueness of a physical measure and its stochastical stability. We also characterize the zero-noise limit measures for a model of the intermittent map and obtain stochastic stability for some values of the parameter. The physical measures are obtained as zero-noise limits which are shown to satisfy Pesin?s Entropy Formula