Peter Chrystal

I. INTRODUCTIONExogenous phytases increased apparent ileal digestibility coefficients of 17 amino acids by an average of 4.13% (0.833 versus 0.800) in one meta-analysis (Cowieson et al., 2017); however, the scale of responses varies. Phytases increased apparent ileal digestibility coefficients of 16 amino acids by averages of 12.7%, 7.24% and 9.15%, respectively, across three selected assays (Amer ...

1. IntroductionPoultry is the most consumed animal protein source in the world, and the trend is expected to continue increasing [1]. The world population reached 8 billion in 2022, and is likely to reach 9 billion in 2037 [2], which will continue to increase pressure on the global chicken-meat industry. One way to meet this increasing demand is to improve the efficiency of chicken-meat production ...

I. INTRODUCTIONThe digestive dynamics of starch and protein are considered pivotal to broiler performance (Liu and Selle, 2015). Moreover, it was proposed that the rates of starch digestion and glucose absorption exceed the rates of protein digestion and amino acid absorption and this asynchrony in digestive dynamics compromises the performance of broiler chickens. If so, it follows that the provi ...

In previous assays (Macelline et al., 2022), data on egg production rate (EP) and egg mass (EM) of Isa Brown layers from 27 to 33 weeks of age (peak production -PP) and from 42 to 48 weeks of age (Post PP) were used to predict amino acid (AA) requirements by fitting linear broken-line (LBL), and quadratic broken-line (QBL) models. Subsequently, the ideal ratios of Ile, Met + Cys, Thr, Trp, and Val ...

All grains, vegetable-based protein meals and their by-products used in poultry diets contain some levels of phytate phosphorous (PP). Depending on the ingredient type and source, a typical broiler chicken diet would contain between 2.2 to over 3.5 g/kg dietary PP. Research has shown that phytate anti-nutritional effects can reduce the digestibility of amino acids (AA) and minerals. Previously the ...

I. INTRODUCTIONIn Australia, the cost of tallow and vegetable oil has more than doubled over the past two years (www.finvis.com), prompting broiler nutritionists to re-evaluate dietary energy content for meat-type chickens. Globally, a wide range of lipids with diverse chemical composition, are routinely included in poultry feed including soapstocks or acid oil, crude vegetable oil, hydrogenated m ...

I. INTRODUCTIONMannan is a plant based-NSP derived from polymerisation of mannose sugars, it is categorised as galactomannan or glucomannan based on the presence of galactose and glucose side chains (Aspinall, 1973). Generally, galactomannan is the dominant form in legumes (Sundu et al., 2012). The ratio between mannose to galactose dictates the water solubility of galactomannan where galactose ha ...

I. INTRODUCTIONThe term ‘amino acid imbalances’ was probably originated by Elvehjem and Krehl (1955) and the topic was addressed by Harper and Rogers (1965). Their conclusion was that imbalances retard growth by altering the normal pathways of amino acid metabolism. Thus, while the relevance of amino acid imbalances to efficient chicken-meat production is recognised, a precise definiti ...