Effects of a starch binding agent on in vitro rumen degradability of maize and sorghum starch

The objective of the study was to quantify the potential of a starch binding agent (BioProtectTM) to reduce in vitro rumen starch degradation of maize and sorghum particles that varied in size. Maize and sorghum grain samples were ground through 2-mm sieves with a Wiley mill and subsequently sieved to obtain these sizes: less than 250, 250 - 500, 500 - 1180, and 1180 - 2000 μm (i.e., very fine to coarse). All fractions were analysed separately for starch content. Samples were treated 24 hours before fermentation by spraying BioProtect onto the substrate. Both treated and untreated samples were fermented in vitro for 0, 6, 12 and 24 hours to quantify starch degradability. Rates of degradability (kd) were calculated with a first-order decay model. BioProtect was effective in decreasing starch degradability and rates of degradability for both grains (P <0.0001). The product was more effective with smaller particle size, by reducing starch degradability 17% for the smallest particles as opposed to 7% for the largest particles. A time interaction was observed (P <0.0001), which showed that the highest impact of BioProtect occurred after 12 hours of fermentation for both grains. The starch binding agent resulted in an effective decrease of in vitro starch degradation, but results were affected by particle size and fermentation time. Starch digestion could possibly be shifted to the small intestine with BioProtect

Partial differential equations for self-organization in cellular and developmental biology

Understanding the mechanisms governing and regulating the emergence of structure and heterogeneity within cellular systems, such as the developing embryo, represents a multiscale challenge typifying current integrative biology research, namely, explaining the macroscale behaviour of a system from microscale dynamics. This review will focus upon modelling how cell-based dynamics orchestrate the emergence of higher level structure. After surveying representative biological examples and the models used to describe them, we will assess how developments at the scale of molecular biology have impacted on current theoretical frameworks, and the new modelling opportunities that are emerging as a result. We shall restrict our survey of mathematical approaches to partial differential equations and the tools required for their analysis. We will discuss the gap between the modelling abstraction and biological reality, the challenges this presents and highlight some open problems in the field

From segment to somite: segmentation to epithelialization analyzed within quantitative frameworks

One of the most visually striking patterns in the early developing embryo is somite segmentation. Somites form as repeated, periodic structures in pairs along nearly the entire caudal vertebrate axis. The morphological process involves short- and long-range signals that drive cell rearrangements and cell shaping to create discrete, epithelialized segments. Key to developing novel strategies to prevent somite birth defects that involve axial bone and skeletal muscle development is understanding how the molecular choreography is coordinated across multiple spatial scales and in a repeating temporal manner. Mathematical models have emerged as useful tools to integrate spatiotemporal data and simulate model mechanisms to provide unique insights into somite pattern formation. In this short review, we present two quantitative frameworks that address the morphogenesis from segment to somite and discuss recent data of segmentation and epithelialization

Evolutionary Epidemiology of Drug-Resistance in Space

The spread of drug-resistant parasites erodes the efficacy of therapeutic treatments against many infectious diseases and is a major threat of the 21st century. The evolution of drug-resistance depends, among other things, on how the treatments are administered at the population level. “Resistance management” consists of finding optimal treatment strategies that both reduce the consequence of an infection at the individual host level, and limit the spread of drug-resistance in the pathogen population. Several studies have focused on the effect of mixing different treatments, or of alternating them in time. Here, we analyze another strategy, where the use of the drug varies spatially: there are places where no one receives any treatment. We find that such a spatial heterogeneity can totally prevent the rise of drug-resistance, provided that the size of treated patches is below a critical threshold. The range of parasite dispersal, the relative costs and benefits of being drug-resistant compared to being drug-sensitive, and the duration of an infection with drug-resistant parasites are the main factors determining the value of this threshold. Our analysis thus provides some general guidance regarding the optimal spatial use of drugs to prevent or limit the evolution of drug-resistance

Fungal Planet description sheets: 154–213

Novel species of microfungi described in the present study include the following from South Africa: Camarosporium aloes, Phaeococcomyces aloes and Phoma aloes from Aloe, C. psoraleae, Diaporthe psoraleae and D. psoraleae-pinnatae from Psoralea, Colletotrichum euphorbiae from Euphorbia, Coniothyrium prosopidis and Peyronellaea prosopidis from Prosopis, Diaporthe cassines from Cassine, D. diospyricola from Diospyros, Diaporthe maytenicola from Maytenus, Harknessia proteae from Protea, Neofusicoccum ursorum and N. cryptoaustrale from Eucalyptus, Ochrocladosporium adansoniae from Adansonia, Pilidium pseudoconcavum from Greyia radlkoferi, Stagonospora pseudopaludosa from Phragmites and Toxicocladosporium ficiniae from Ficinia. Several species were also described from Thailand, namely: Chaetopsina pini and C. pinicola from Pinus spp., Myrmecridium thailandicum from reed litter, Passalora pseudotithoniae from Tithonia, Pallidocercospora ventilago from Ventilago, Pyricularia bothriochloae from Bothriochloa and Sphaerulina rhododendricola from Rhododendron. Novelties from Spain include Cladophialophora multiseptata, Knufia tsunedae and Pleuroascus rectipilus from soil and Cyphellophora catalaunica from river sediments. Species from the USA include Bipolaris drechsleri from Microstegium, Calonectria blephiliae from Blephilia, Kellermania macrospora (epitype) and K. pseudoyuccigena from Yucca. Three new species are described from Mexico, namely Neophaeosphaeria agaves and K. agaves from Agave and Phytophthora ipomoeae from Ipomoea. Other African species include Calonectria mossambicensis from Eucalyptus (Mozambique), Harzia cameroonensis from an unknown creeper (Cameroon), Mastigosporella anisophylleae from Anisophyllea (Zambia) and Teratosphaeria terminaliae from Terminalia (Zimbabwe). Species from Europe include Auxarthron longisporum from forest soil (Portugal), Discosia pseudoartocreas from Tilia (Austria), Paraconiothyrium polonense and P. lycopodinum from Lycopodium (Poland) and Stachybotrys oleronensis from Iris (France). Two species of Chrysosporium are described from Antarctica, namely C. magnasporum and C. oceanitesii. Finally, Licea xanthospora is described from Australia, Hypochnicium huinayensis from Chile and Custingophora blanchettei from Uruguay. Novel genera of Ascomycetes include Neomycosphaerella from Pseudopentameris macrantha (South Africa), and Paramycosphaerella from Brachystegia sp. (Zimbabwe). Novel hyphomycete genera include Pseudocatenomycopsis from Rothmannia (Zambia), Neopseudocercospora from Terminalia (Zambia) and Neodeightoniella from Phragmites (South Africa), while Dimorphiopsis from Brachystegia (Zambia) represents a novel coelomycetous genus. Furthermore, Alanphillipsia is introduced as a new genus in the Botryosphaeriaceae with four species, A. aloes, A. aloeigena and A. aloetica from Aloe spp. and A. euphorbiae from Euphorbia sp. (South Africa). A new combination is also proposed for Brachysporium torulosum (Deightoniella black tip of banana) as Corynespora torulosa. Morphological and culture characteristics along with ITS DNA barcodes are provided for all taxa

The effect of rumen inert fat supplementation and protein degradability in starter and finishing diets on veal calf performance

The original publication is available at http://www.sasas.co.za/Thirty six Holstein bull calves were divided into six groups to determine the effect of protein degradability and rumen inert fat supplementation in starter and finishing diets on nutrient digestibility and veal production. Calves received low (LD) or high (HD) degradable protein diets, with or without rumen inert fat supplementation. Two commercial fat sources were used, Morlac (mlc) and Golden Flake (gf), included in the experimental diets at 2.5% of dry matter (DM). A commercial milk replacer was fed to all calves at 4 L/day for 42 days, followed by 2 L/day until weaning at 49 days of age. Starter diets were offered ad lib. from day 14 to 10 weeks of age and finishing diets ad lib. from 11 to 20 weeks of age. All calves were slaughtered at 20 weeks to determine carcass weight and dressing percentage. There were no significant differences in body weight gain or dry matter intake over the entire 20 week period. Feed conversion ratio (FCR) was improved when fat was supplemented to LD, but not to HD diets. The FCR (DM intake/kg gain) of LD, HD, LDmlc, HDmlc, LDgf and HDgf diets was 3.45, 3.44, 3.07, 3.81, 3.02 and 3.43, respectively. All 36 calves were used in a digestibility trial during week 18 of the study, using chromium oxide as a marker. Apparent digestibility values (%) for LD, HD, LDmlc, HDmlc, LDgf and HDgf, respectively, were 61.7, 65.9, 75.4, 69.0, 75.5 and 67.2 for DM, 61.4, 61.6, 71.3, 68.2, 75.4 and 66.1 for crude protein and 58.6, 66.5, 76.0, 70.9, 78.4 and 70.8 for fat. Dry matter and fat digestibilities were significantly higher when fat was added to LD diets, but not to HD diets. The CP digestibility was significantly higher when fat was added to either the LD or the HD diets. It was concluded that rumen inert fat supplementation to calf diets appears to improve feed conversion ratio and DM and fat digestibilities, but only when added to low degradable protein diets and only after 10 weeks of age. Crude protein digestibility appears to improve with fat supplementation to either high or low degradable protein diets.Publishers' versio

The effect of rumen inert fat supplementation and protein degradability in starter and finishing diets on veal calf performance

AgriwetenskappeVeekundige WetenskappePlease help us populate SUNScholar with the post print version of this article. It can be e-mailed to: [email protected]

The effect of dietary protein degradability and rumen inert fat supplementation on calf performance and veal production

AgriwetenskappeVeekundige WetenskappePlease help us populate SUNScholar with the post print version of this article. It can be e-mailed to: [email protected]

The effect of rumen inert fat supplementation and protein degradability in starter and finishing diets on veal calf performance

Thirty six Holstein bull calves were divided into six groups to determine the effect of protein degradability and rumen inert fat supplementation in starter and finishing diets on nutrient digestibility and veal production. Calves received low (LD) or high (HD) degradable protein diets, with or without rumen inert fat supplementation. Two commercial fat sources were used, Morlac (mlc) and Golden Flake (gf), included in the experimental diets at 2.5% of dry matter (DM). A commercial milk replacer was fed to all calves at 4 L/day for 42 days, followed by 2 L/day until weaning at 49 days of age. Starter diets were offered ad lib. from day 14 to 10 weeks of age and finishing diets ad lib. from 11 to 20 weeks of age. All calves were slaughtered at 20 weeks to determine carcass weight and dressing percentage. There were no significant differences in body weight gain or dry matter intake over the entire 20 week period. Feed conversion ratio (FCR) was improved when fat was supplemented to LD, but not to HD diets. The FCR (DM intake/kg gain) of LD, HD, LDmlc, HDmlc, LDgf and HDgf diets was 3.45, 3.44, 3.07, 3.81, 3.02 and 3.43, respectively. All 36 calves were used in a digestibility trial during week 18 of the study, using chromium oxide as a marker. Apparent digestibility values (%) for LD, HD, LDmlc, HDmlc, LDgf and HDgf, respectively, were 61.7, 65.9, 75.4, 69.0, 75.5 and 67.2 for DM, 61.4, 61.6, 71.3, 68.2, 75.4 and 66.1 for crude protein and 58.6, 66.5, 76.0, 70.9, 78.4 and 70.8 for fat. Dry matter and fat digestibilities were significantly higher when fat was added to LD diets, but not to HD diets. The CP digestibility was significantly higher when fat was added to either the LD or the HD diets. It was concluded that rumen inert fat supplementation to calf diets appears to improve feed conversion ratio and DM and fat digestibilities, but only when added to low degradable protein diets and only after 10 weeks of age. Crude protein digestibility appears to improve with fat supplementation to either high or low degradable protein diets