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Marlborough, United Kingdom

Adeola O.,Purdue University | Walkf C.L.,AB Vista Feed Ingredients
Poultry Science | Year: 2013

The objectives of this study were to determine the ileal digestibility of P in potassium phosphate, phytase-related ileal digestible P release, bone-mineralization-based ileal digestible P equivalency of phytase, and phytase-related efficiency of ileal digestible P utilization for bone mineralization in broiler chickens at 2 dietary concentrations of highly soluble Ca (HSC). Birds were sorted by BW at d 15 posthatch and assigned to 8 cages per diet with 8 birds per cage. Twelve diets were arranged in a 2 × 6 factorial of HSC at 5 or 6 g/kg and P supply treatment at 6 levels consisting of 4 added P levels (P from KH2PO4 added at 0, 0.7, 1.4, or 2.1 g/kg of diet) or 2 added phytase levels (500 or 1,000 phytase units). On d 24 posthatch, ileal digesta were collected for ileal P digestibility (IPD) determination and the left tibia was collected from the 4 heaviest birds in each cage for bone ash determination. Weight gain, G:F, and tibia ash were higher (P < 0.05) at 5 than at 6 g of HSC/kg. Added P from KH2PO4 or added phytase linearly increased (P < 0.001) weight gain, G:F, tibia ash, and IPD. The IPD of KH2PO4 derived from multiple linear regressions of digestible on total P intake for the diets without added phytase showed a reduction (P < 0.05) from 89.5 to 84.5% with increased HSC from 5 to 6 g/kg. Polynomial regressions of digestible P intake on phytase intake indicated that 1,000 units of added phytase released 1.701 or 1.561 g of digestible P in diets containing 5 or 6 g of added HSC/ kg, respectively. Polynomial regressions of tibia ash on digestible P or phytase intake in diets containing 5 or 6 g of added HSC/kg at 1,000 phytase units gave digestible P equivalency of 1.487 or 1.448 g, respectively. Thus, phytase-related efficiency of ileal digestible P utilization for bone mineralization was 87.4 and 92.8% in diets containing 5 or 6 g of added HSC/kg, respectively. © 2013 Poultry Science Association Inc. Source

Pirgozliev V.,Avian Science Research Center | Pirgozliev V.,Harper Adams University College | Bedford M.R.,AB Vista Feed Ingredients
British Journal of Nutrition | Year: 2013

A total of 364 female Ross 308 chicks (1 d old) were used in the present study conducted in floor pens to investigate the effects of graded levels of supplementary bacterial phytase on dietary energy utilisation and growth performance. For this purpose, four maize-soyabean-based diets were offered to the birds from 0 to 21Â d of age. These included a suboptimal P negative control (NC, 3·0Â g/kg non-phytate P), NC+250 phytase units (FTU)/kg feed, NC+500Â FTU and NC+2500Â FTU. The effect of phytase activity on bird growth performance was best described as a linear relationship between increasing dose and increased feed intake (P<Â 0·001), but was quadratic for body-weight gain (P=Â 0·002) and feed efficiency (P=Â 0·023). There was no significant response (P>0·05) of dietary apparent metabolisable energy (AME) to supplementary phytase. The birds fed phytase increased their retention of total carcass energy in a linear fashion (P=Â 0·009) with increased phytase dose. The efficiency of dietary AME used for overall carcass energy retention also improved (P=Â 0·007) in a linear manner with increased dietary phytase activity. Dietary net energy for production (NEp) increased (P=Â 0·047) with an increase in phytase dose following a linear pattern, as an increase of 100Â FTU increased dietary net energy by 15·4Â J (estimated within the range of doses used in the present experiment). Dietary NEp was more highly correlated with performance criteria than dietary AME, and it seems to be a more sensitive way to evaluate broiler response to phytase supplementation. Copyright © The Authors 2012. Source

Cowieson A.J.,AB Vista Feed Ingredients
Journal of Poultry Science | Year: 2010

The usefulness of carbohydrases in corn/soy-based diets for poultry is still unclear and all the more so when phytase is present in the feed. Though there are many interacting factors involved in dictating the measured response to an exogenous enzyme the most influential is the nutritional value of the diet to which it is added. The inherent ileal digestibility of starch, protein and lipid in a corn/soy-based diet varies from around 70% to over 95% and this variance explains up to 90% of the variance in enzyme response. An appreciation for the concentration of undigested starch, protein and lipid in any given diet is an important starting point for the prediction of the effect of the enzyme on digestible energy and amino acids. Instructively, around 15-25% of this undigested fraction can be rendered digestible with the addition of xylanase and so the magnitude of the response is largely explained by the quantity of this undigested portion. As phytase improves the digestibility of the diet, effectively reducing the concentration of undigested amino acids and energy it can be predicted that xylanase will deliver less value in a diet which has already been improved with phytase. It is the purpose of the current paper to describe these effects and the implications for the strategic selection of enzymes for corn/soy-based poultry diets. © 2010 Japan Poultry Science Association. Source

Cowieson A.J.,University of Sydney | Masey O'neill H.V.,AB Vista Feed Ingredients
British Poultry Science | Year: 2013

1. Five dietary treatments were used in a 49 d broiler trial to assess the effect of xylanase on performance, nutrient digestibility and thermal profiles of the caeca and head. Treatments included an industry-standard control diet and four further diets where xylanase was introduced with or without a metabolisable energy density dilution either from day one or the introduction was delayed until d 28. 2. The addition of xylanase with no associated energy dilution from day one resulted in the most consistent beneficial effects on performance, with significant improvements in weight gain compared with the industry-standard to d 28 and at d 49. Addition of xylanase from d 28 (with no energy dilution) was the second most successful strategy and resulted in a significant improvement in feed conversion ratio (FCR) from d 29 to 49 and overall. 3. Addition of xylanase improved ileal digestible energy values at d 28 by around 0.35 MJ/kg and ileal nitrogen digestibility coefficients by around 3%. On d 49 xylanase improved ileal digestible energy values by around 0.9 MJ/kg and ileal nitrogen digestibility coefficients by around 4.6%. 4. Thermal imaging of the head and caeca of three birds per replicate on d 49 revealed a significant increase in caecal surface temperature following xylanase addition with no effect on head temperature profile. These increases were particularly large (around 1.4°C, or 3.9%) when xylanase was added from day one with no corresponding energy dilution in feed formulation. 5. It can be concluded that supplemental xylanase is effective in improving performance and nutrient digestibility in broilers given wheat-based diets. The correlation between the magnitude of this effect and the increased temperature in the caeca presents additional evidence that the hind-gut microflora may play an important, if yet unquantified, role in the outworking of these mechanisms. © 2013 Copyright © 2013 British Poultry Science Ltd. Source

Agency: GTR | Branch: BBSRC | Program: | Phase: Research Grant | Award Amount: 546.67K | Year: 2012

Ruminant animals, including cattle, sheep and goats, rely on microbial activity in their digestive tract to digest grass and other forages that they consume. A balanced, stable digestion (fermentation) is essential for good growth or milk production. Most livestock producers require productivity higher than that which can be sustained by forage feeding alone, and include some grain in the diet to increase production rates. Gut microbes produce acids more rapidly from the starch in grain than the cellulose in forages, leading to lower pH values prevailing in grain-fed animals. This has adverse effects on the microbes, which require near-neutral pH to perform optimally. This sub-acute ruminal acidosis (SARA) is a major economic and health issue in ruminant livestock production. Animals suffering SARA are less productive, and they suffer from necrosis of the rumen wall, liver abscesses and laminitis. SARA is often difficult for the farmer to detect - it is sub-acute and can only be detected easily at slaughter. SARA is an under-researched condition, such that only a small number of papers have addressed the dietary and microbiological causes of SARA and its underlying pathology, particularly concerning the role of the large intestine. This project aims to understand why SARA is prevalent on some farms but not others, an observation that is common knowledge but not well documented. Farm management conditions and nutrition will be monitored in these farms, and the animals will be followed to slaughter, when the extent of pathological damage will be assessed. Samples of ruminal digesta and wall tissue will be taken for analysis and tissue necrosis, abscesses and laminitis will be scored. SARA also affects some animals but not others within a herd. Remote motion-sensing technology will be used to externally monitor movements, such as rumination activity, that may alert livestock producers to problematic animals. Post mortem analysis will also be carried out on these animals. The root cause of SARA lies in altered gut microbiology. Digesta samples will be taken forward to describe the microbes that are present in the rumen and intestine in susceptible and non-susceptible animals, with the idea that some microbial species may be particularly important in causing the disease while others may be protective. Candidate probiotic bacteria isolated from non-susceptible animals will be investigated with a view to developing them as feed additives. The role of soluble lipopolysaccharide (LPS) in the inflammation will be investigated. LPS is released when bacteria lyse - it is known as endotoxin in human medicine. Materials that may bind soluble LPS to prevent inflammation will also be investigated as potential feed additives. The overall aims are to explain the underlying mechanism of pathogenesis of SARA, to investigate if microbiome analysis can predict the severity of SARA, and to develop simple, non-invasive methods for monitoring animal behaviour relating to SARA and preventing the condition. Three academic partners, three complementary companies, Quality Meat Scotland and DairyCo are involved in the project. The industrial partners will ensure that relevance to the livestock industry is maintained throughout the project and that the pathway to impact will be short and rapid.

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