A forage-only diet alters the metabolic response of horses in training

Most athletic horses are fed a high-starch diet despite the risk of health problems. Replacing starch concentrate with high-energy forage would alleviate these health problems, but could result in a shift in major substrates for muscle energy supply from glucose to short-chain fatty acids (SCFA) due to more hindgut fermentation of fibre. Dietary fat inclusion has previously been shown to promote aerobic energy supply during exercise, but the contribution of SCFA to exercise metabolism has received little attention. This study compared metabolic response with exercise and lactate threshold (VLa4) in horses fed a forage-only diet (F) and a more traditional high-starch, low-energy forage diet (forage–concentrate diet - FC). The hypothesis was that diet F would increase plasma acetate concentration and increase VLa4 compared with diet FC. Six Standardbred geldings in race training were used in a 29-day change-over experiment. Plasma acetate, non-esterified fatty acids (NEFA), lactate, glucose and insulin concentrations and venous pH were measured in samples collected before, during and after a treadmill exercise test (ET, day 25) and muscle glycogen concentrations before and after ET. Plasma acetate concentration was higher before and after exercise in horses on diet F compared with diet FC, and there was a tendency ( P50.09) for increased VLa4 on diet F. Venous pH and plasma glucose concentrations during exercise were higher in horses on diet F than diet FC, as was plasma NEFA on the day after ET. Plasma insulin and muscle glycogen concentrations were lower for diet F, but glycogen utilisation was similar for the two diets. The results show that a high-energy, forage-only diet alters the metabolic response to exercise and, with the exception of lowered glycogen stores, appears to have positive rather than negative effects on performance traits

Survival and Phenology of \u3ci\u3eAgrilus Planipennis\u3c/i\u3e (Coleoptera: Buprestidae) Reared on a Newly Developed Artificial Diet Free of Host Material

The final phase in the development of an artificial diet that contains no ash host material and the phenology of the emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Bupresidae) on that diet are documented. A diet containing powdered ash phloem exists, but host material introduces potential variability and contamination, and the cost and effort needed to collect and process it can be high. The post-embryonic development of A. planipennis was evaluated on four artificial diets lacking host material, and effects of variations in diet layer thickness and moisture content were also investigated. The best diet and rearing method resulted in 67.8% survival to pupation and 51% to adult. Larval size and development rate were comparable to published accounts for emerald ash borer larvae developing on susceptible host plants. Important advances include reduction of antimicrobial components to the lowest functional level; change of protein sources from wheat germ, brewer’s yeast, and casein to soy flour and casein; reduction of diet moisture content to 50%; and adding a fresh layer of diet to spent diet half-way through larval development. The artificial diet represents a step toward the development of a standardized mass- production system for A. planipennis

Effect of plant-based feed ingredients on osmoregulation in the Atlantic salmon lens

Lenses of adult Atlantic salmon fed with a plant oil and plant protein-based diet (plant diet) were compared to lenses of fish fed a diet based on traditional marine ingredients (marine diet) with respect to biochemical composition and functionality ex vivo. After 12 months of feeding, plant diet-fed fish had smaller lenses with higher water contents and lower concentrations of histidine (His) and N-acetylhistidine (NAH) than fish fed with the marine diet. Cataract development in both dietary groups was minimal and no differences between the groups were observed. Lens fatty acid and lipid class composition differed minimally, although a significant increase in linoleic acid was observed. The lenses were examined for their ability to withstand osmotic disturbances ex vivo. Culture in hypoosmotic and hyperosmotic media led to increase and decrease of lens volume, respectively. Lenses from plant diet-fed fish were less resistant to swelling and shrinking, released less NAH into the culture medium, and accumulated His and NAH at higher rates than lenses from marine diet-fed fish. Culture in hypoosmotic medium resulted in higher cataract scores than in control and hyperosmotic medium. mRNA expression of selected genes, including glutathione peroxidase 4 and SPARC (secreted protein acidic and rich in cysteine), was affected by diet and osmotic treatment. It can be concluded that lenses of farmed Atlantic salmon are affected by the diet composition, both in biochemical composition and physiological functionality in relation to osmoregulation

Establishing macroecological trait datasets: digitalization, extrapolation, and validation of diet preferences in terrestrial mammals worldwide

Ecological trait data are essential for understanding the broad-scale distribution of biodiversity and its response to global change. For animals, diet represents a fundamental aspect of species’ evolutionary adaptations, ecological and functional roles, and trophic interactions. However, the importance of diet for macroevolutionary and macroecological dynamics remains little explored, partly because of the lack of comprehensive trait datasets. We compiled and evaluated a comprehensive global dataset of diet preferences of mammals (“MammalDIET”). Diet information was digitized from two global and cladewide data sources and errors of data entry by multiple data recorders were assessed. We then developed a hierarchical extrapolation procedure to fill-in diet information for species with missing information. Missing data were extrapolated with information from other taxonomic levels (genus, other species within the same genus, or family) and this extrapolation was subsequently validated both internally (with a jack-knife approach applied to the compiled species-level diet data) and externally (using independent species-level diet information from a comprehensive continentwide data source). Finally, we grouped mammal species into trophic levels and dietary guilds, and their species richness as well as their proportion of total richness were mapped at a global scale for those diet categories with good validation results. The success rate of correctly digitizing data was 94%, indicating that the consistency in data entry among multiple recorders was high. Data sources provided species-level diet information for a total of 2033 species (38% of all 5364 terrestrial mammal species, based on the IUCN taxonomy). For the remaining 3331 species, diet information was mostly extrapolated from genus-level diet information (48% of all terrestrial mammal species), and only rarely from other species within the same genus (6%) or from family level (8%). Internal and external validation showed that: (1) extrapolations were most reliable for primary food items; (2) several diet categories (“Animal”, “Mammal”, “Invertebrate”, “Plant”, “Seed”, “Fruit”, and “Leaf”) had high proportions of correctly predicted diet ranks; and (3) the potential of correctly extrapolating specific diet categories varied both within and among clades. Global maps of species richness and proportion showed congruence among trophic levels, but also substantial discrepancies between dietary guilds. MammalDIET provides a comprehensive, unique and freely available dataset on diet preferences for all terrestrial mammals worldwide. It enables broad-scale analyses for specific trophic levels and dietary guilds, and a first assessment of trait conservatism in mammalian diet preferences at a global scale. The digitalization, extrapolation and validation procedures could be transferable to other trait data and taxa

Is a healthy diet an environmentally sustainable diet?

Peer reviewedPublisher PD

Effect of fumaric acid, calcium formate and mineral levels in diets on the intake and growth performance of newly weaned pigs

peer-reviewedThe weaned pig has limited ability to acidify its stomach contents. The objective of this study (comprising three experiments) was to examine the effect of feeding diets containing fumaric acid (FA), calcium formate (CF) or diets of low acid binding capacity (ABC) on post-weaning pig performance. In all three experiments, pigs (10 per treatment) were weaned at 19 to 24 days, blocked on sex and weight and assigned at random to one of six treatments. In Experiment 1, treatments were: (1) control diet, (2) control 20 g/kg FA, (3) control 15 g/kg CF, (4) low Ca (2.8 g/kg) and P (5.1 g/kg) (LCaP) diet for seven days followed by the control diet, (5) LCaP diet for seven days followed by control 20 g/kg FA, and (6) LCaP diet for seven days followed by control 15 g/kg CF. In Experiment 2, treatments were: (1) control diet, (2) control 20 g/kg FA, (3) control 15 g/kg CF, (4) LCaP diet for 14 days followed by the control diet, (5) LCaP diet for 14 days followed by control 20 g/kg FA, and (6) LCaP diet for seven days followed by control diet. In Experiment 3, treatments were: (1) high Ca (HC) diet (12 g/kg), (2) medium Ca (MC) diet (9 g/kg), (3) low Ca (LC) diet (6 g/kg), (4) HC 20 g/kg FA, (5) MC 20 g/kg FA, and (6) LC 20 g/kg FA. Pigs were individually fed for 26 days. In Experiment 1, CF tended to depress daily feed intake (DFI) in the final two weeks (691 v. 759 and 749, (s.e. 19) g/day, P = 0.07) and overall average daily gain (322 v. 343 and 361 (s.e. 11) g/day, P = 0.09) compared with the control and FA supplemented diets, respectively. Feeding diets with LCaP for seven days post weaning increased DFI (208 v. 178, (s.e. 8) g/day, P < 0.01) in week 1 and tended to improve feed conversion rate in the first two weeks (1.65 v. 1.85, s.e. 0.10, P = 0.09). In Experiment 2, treatment had no significant effect on pig performance but feed conversion rate in weeks three and four was improved for Treatment 5 compared with Treatment 4 (1.30 v. 1.39 (s.e. 0.06) g/g, P < 0.01). In experiment 3, FA increased (P < 0.05) pig weight at day 14 (8.4 v. 7.7 (s.e. 0.2) kg) and feed intake in weeks one and two (223 v. 251, (s.e. 9) g/day). It is concluded that CF did not improve performance but reducing diet ABC or including FA in the diet did improve performance

Envelope Factorization with Partial Elimination and Recombination, EF-PER, a New Linear RF Architecture

In this paper, a new architecture for efficient linear radio frequency transmitters is proposed; it includes envelope-tracking (ET) and envelope-elimination-and-restoration (EER) architectures as special instances. The proposed technique is referred to as Envelope Factorization with Partial Elimination and Recombination (EF-PER). It relies on a decomposition of the RF signal before power amplification as a product of two signals, one of them being the envelope signal elevated to an exponent “α”. Compared to ET or EER architectures, the parameter “α” constitutes a new degree of freedom. This allows one to realize good tradeoffs between different performance criteria such as spectrum use, power efficiency, and transmitter linearity. An intuitive aggregate cost function is introduced to capture the desired tradeoff and turns out to be maximized in α=0.5. The full relevance of EF-PER is sustained both by analytical results and realistic simulations performed for OFDM signals. The EF-PER architecture (with α=0.5) has been simulated under Agilent-ADS with a non-linear transistor model from Avago (E-PHEMT) and compared with ET and EER

Variation in the apparent faecal digestibility of macronutrients and urinary energy excretion for three diets varying in fat and fibre content-- assessment of the Atwater factors and related energy conversion factors : a thesis presented in partial fulfillment of the requirements for the degree of Master of Science in Nutritional Science at Massey University, Palmerston North, New Zealand

Background: Current systems to estimate dietary metabolisable energy (ME), often based on Atwater factors, assume that diet ME can be accurately predicted based on a few chemical components and that the ME of components is constant across foods. Objective: Our aim was to investigate variation in apparent faecal nutrient digestibility and urinary energy excretion on different diets, and evaluate the accuracy of current systems for predicting dietary ME. Design: The ME contents of a refined (high fat, low fibre) diet and two high fibre low fat diets were determined in balance experiments on human subjects and calculated using factorial and empirical models. Apparent faecal nutrient digestibilities and urinary energy excretions were also determined. Results: The difference between calculated (Atwater factors) and determined ME values was up to 4% for the refined diet and 11% for the high fibre diets. The empirical models were generally no more accurate than the modified Atwater factorial model. Apparent faecal nutrient digestibility varied considerably among the three diets, as did urinary energy per unit urinary nitrogen. Mean digestibilities ranged from 81.4 (fruit and vegetable diet) to 90.0% (refined diet) for crude protein; 87.0 (fruit and vegetable diet) to 95.7% (refined diet) for fat; 91.1 (cereal diet) to 95.5% (fruit and vegetable diet) for total carbohydrate. Mean urinary energy per unit urinary nitrogen ranged from 33.9 (refined diet) to 44.1 KJ/gN (fruit and vegetable diet). Conclusion: Modified Atwater factors and some of the empirical models evaluated here may be suitably accurate (±5%) for use for general food labelling purposes and for determining dietary ME intakes of groups and populations, but may be inadequate for application to specialised weight-loss diets and ingredients. KEY WORDS Atwater factors, Digestibility, Energy, Metabolisable Energy, Urinary Energy Excretion

Effects of Diet Composition and Insulin Resistance Status on Plasma Lipid Levels in a Weight Loss Intervention in Women.

BackgroundOptimal macronutrient distribution of weight loss diets has not been established. The distribution of energy from carbohydrate and fat has been observed to promote differential plasma lipid responses in previous weight loss studies, and insulin resistance status may interact with diet composition and affect weight loss and lipid responses.Methods and resultsOverweight and obese women (n=245) were enrolled in a 1-year behavioral weight loss intervention and randomly assigned to 1 of 3 study groups: a lower fat (20% energy), higher carbohydrate (65% energy) diet; a lower carbohydrate (45% energy), higher fat (35% energy) diet; or a walnut-rich, higher fat (35% energy), lower carbohydrate (45% energy) diet. Blood samples and data available from 213 women at baseline and at 6 months were the focus of this analysis. Triglycerides, total cholesterol, and high- and low-density lipoprotein cholesterol were quantified and compared between and within groups. Triglycerides decreased in all study arms at 6 months (P&lt;0.05). The walnut-rich diet increased high-density lipoprotein cholesterol more than either the lower fat or lower carbohydrate diet (P&lt;0.05). The walnut-rich diet also reduced low-density lipoprotein cholesterol in insulin-sensitive women, whereas the lower fat diet reduced both total cholesterol and high-density lipoprotein cholesterol in insulin-sensitive women (P&lt;0.05). Insulin sensitivity and C-reactive protein levels also improved.ConclusionsWeight loss was similar across the diet groups, although insulin-sensitive women lost more weight with a lower fat, higher carbohydrate diet versus a higher fat, lower carbohydrate diet. The walnut-rich, higher fat diet resulted in the most favorable changes in lipid levels.Clinical trial registrationURL: http://www.clinicaltrials.gov. Unique identifier: NCT01424007

Chemoprevention of aberrant crypt foci in the colon of rats by dietary onion

Onion intake might reduce the risk of colorectal cancer, according to epidemiology. However, Femia showed in 2003 that diets with a 20% onion intake increase carcinogenesis in rats. We speculated this dose was too high. Prevention of initiation was thus tested in 60 rats given a 5% dried onion diet or AIN76 diet, and initiated 12 days later with azoxymethane (AOM, 1 × 20 mg/kg i.p.), 2-amino-3-methylimidazo[4,5-f]quinoline (IQ, 2 × 200 mg/kg p.o.), or N-nitroso–N–methylurea (2 × 50 mg/kg p.o.). Prevention of promotion was tested in 38 rats given AOM, then randomised to: AIN76 diet; 5% onion diet; phytochemicals diet (supplemented with propyl-disulfide, quercetine-glycosides and oligofructose); 1% pluronic F68 diet (a potent chemopreventive PEG-like block-polymer, used as a positive control). Aberrant crypt foci (ACF) were scored 30 days (initiation) or 100 days (promotion) after carcinogen injection. The onion diet given during initiation reduced the number of AOM-induced ACF (60 versus 86, p = 0.03), and the size of IQ-induced ACF (1.33 versus 1.97, p = 0.02). Given post-initiation, the onion diet reduced the number of ACF (34 versus 59, p = 0.008) and of large ACF (6 versus 15, p = 0.02). Phytochemicals diet and pluronic diet reduced ACF growth similarly. Data show that a 5% onion diet reduced carcinogenesis during initiation and promotion stages, and suggest this chemoprevention is due to known phytochemicals