Peter Chrystal

I. IntroductionWheat and sorghum are the two major feed grains used in Australia for broiler diets; however, wheat is more common and is usually considered better quality than sorghum. The local chicken meat industry may have to increase by 60% to meet demand in 2050 so strategies are needed to promote sustainable chicken-meat production to meet this anticipated demand. Crude protein reductions in ...

1. IntroductionAs feed grade amino acids are commercialized at prices that are economically feasible for including in industry poultry diets, nutritionists are able to better supply diets containing amino acid profiles more closely representing ideal amino acid profiles (Baker, 1997). Refinement of dietary amino acid profiles allows for reductions in crude protein (CP), inclusion levels of protein ...

1. IntroductionThe global demand for chicken-meat is increasing. Globally, poultry meat is expected to represent 41% of all the protein from meat sources in 2030 and exceed the 34% share for pig meat, 20% for beef and 5% for sheep meat [1]. In Australia, the 46.9 kg per capita chicken-meat consumption in 2021/22 is clearly superior to pork (27.7 kg), beef (19.1 kg) and lamb (5.5 kg) with a 47.3% m ...

I. IntroductionThe development of reduced-CP diets in broiler chickens is gaining more interest as it would drastically lessen the dependence on imported soybean meal which is strategically important for non-soybean producing regions such as Australia and Europe. Modest reductions in CP are already being realised by inclusions of unbound (synthetic or crystalline) methionine, lysine and threonine, ...

I IntroductionIn recent years, based on ideal amino acids profile, a moderate reduction in dietary CP, 20 to 30 g/kg, has been reported to maintain broiler chicken performance and processing yields. However, further reduction of CP more than 30 g/kg has been shown to compromise bird performance and increase adipose fat accumulation (Kidd et al, 2021). These reduced CP levels are usually achieved b ...

I IntroductionThe development of reduced-crude protein (CP) diets for broiler chickens holds several potential advantages including reduced dependency on imported soybean meal by the Australian chicken-meat industry. Typically, reduced-CP diets contain less soybean meal but more feed grain (and starch) and more synthetic/crystalline amino acids. However, reducing dietary CP from 200 to 150 g/kg in ...

Evaluation of true ileal digestible energy, as a potential energy system for application in broiler feed formulations, requires accurate estimation of the ileal endogenous energy losses (IEEL). The IEEL estimates can be influenced by several factors including bird age and dietary cellulose levels (Khalil et al., 2020). Two experiments were conducted to investigate the influence of age and dietary ...

Despite extensive research on reduced protein (RP) diets in broiler chickens, the consequences of such practices for gut health and barrier function are not well defined. This study was conducted to investigate the effect of reduced protein and the source of protein. The control normal protein level diets had either meat and bone meal (MBM) or an all-vegetable diet (VEG). Accordingly, four diets w ...

Broiler chickens grow rapidly with nutrient requirements changing daily. However, broilers are fed 3-5 diet stages throughout their growth, meaning nutrients are under- and over-supplied throughout production (Kleyn, 2013). Thus, blending rations on a daily basis to meet the daily energy and lysine requirements may improve the efficiency and reduce the coefficient of variation (CV) in broiler floc ...

I. INTRODUCTION The inclusion of 175 g/kg fishmeal, essentially at the expense of soybean meal, in sorghum-based broiler diets was shown to improve weight gain by 12.1% (1260 versus 1124; P < 0.001) and feed conversion ratio by 8.13% (1.299 versus 1.414; P < 0.001) from 15 to 28 days post-hatch (Sydenham et al., 2017). The dietary treatments had an average crude protein (CP) content of 222 g ...