Article published the January 9, 2023
I. INTRODUCTION Broiler diets are formulated on the basis of ideal protein ratios (IPR) where selected amino acid requirements are expressed relative to lysine (100). However, IPR have been developed over decades for standard diets rather than diets with reduced-CP. This has led to the possibility that reduced-CP diets require modified IPR. For this reason, two sets of ratios were evaluated in die ...
Article published the January 6, 2023
IntroductionThere is a mandatory requirement for crude protein (CP) in broiler chicken diets ranging from 180 to 230 g/kg. When dietary energy density is not limiting, the quality and quantity of dietary CP dictates birds’ growth performance. The digestibilities of protein and amino acids are pivotal to the quality of the inclusion of any feedstuff in diets for chicken-meat production. ...
Article published the October 24, 2022
INTRODUCTIONMethionine (Met) is often considered to be the first limiting amino acid in modern broiler diets. Synthetic Met has been commercially available for animal feed since the 1950s and is routinely included in modern poultry diets. Whilst studies on Met requirements, based on growth performance parameters are not novel, understanding the impact of dietary Met supplementations on apparent di ...
Article published the October 20, 2022
I. INTRODUCTIONThere is widespread interest in the successful development of reduced-crude protein (CP) diets, focusing on alternative dietary strategies to reduce CP levels whilst maintaining acceptable growth performance (Greenhalgh et al., 2020). Reduced CP diets have the potential to provide advantages environmentally by decreasing outputs of nitrogen and ammonia, improving bird welfare by enh ...
Article published the May 3, 2022
INTRODUCTIONThere has been a substantial global expansion in egg production by the layer industry as the volume of egg production has increased by 119% (35.5 vs. 76.8 million tonnes) from 1990 to 2018 (http://www.fao.org) (Food and Agricultural Organization of the United Nations, 2018). This growth represents an average annual increase of 2.84%. China produced 458 billion eggs in 2018, and the USA ...
Article published the April 6, 2022
1. IntroductionThe conversion of dietary protein and amino acids into the protein of chicken-meat is indeed a dynamic process. Quite typically, broiler chickens attain a live weight of 2.918 kg at 42 days post-hatch and a carcass weight of 2.151 kg following processing. This translates to 376 g of carcass protein as a Ross 308 broiler carcass contains 175 g/kg protein [1]. Broiler chickens consume ...
Article published the March 7, 2022
I. INTRODUCTIONGlobal chicken-meat production has been predicted to increase considerably between 2005 and 2050 (Alexandratos and Bruisma, 2012) and this demands sustainable practices. Reducing dietary crude protein (CP) substantially without compromising broiler performance has the potential to provide tangible reductions in nitrogen excretion and environmental pollution, with improved bird welfa ...
Article published the February 25, 2022
I. INTRODUCTIONThe concept of “fast” and “slow” proteins in human nutrition was enunciated by Beaufrère et al. (2000) and consideration has been given to protein and starch digestive dynamics in poultry by Liu and Selle (2015). However, the digestion rate of protein has a greater bearing on broiler growth performance than that of starch (Liu et al. 2014). Thus, the o ...
Article published the January 31, 2022
I. INTRODUCTIONBoth glucose and amino acids are essential for muscle protein deposition and feed conversion efficiency and total tract nitrogen retention was reported to be influenced by protein and starch digestion in broiler chickens (Liu et al., 2013). Liu and Selle (2015) found that 76% of the variation in the feed-conversion ratio (FCR) could be attributed to starch and protein digestion rate ...
Article published the January 4, 2022
I. INTRODUCTIONGlobally, maize and wheat are the major cereal grains used in broiler feed. Maize is predominant in Asia and the Americas, whereas wheat is in Australia, New Zealand and Europe. Extensive research has been undertaken in refining dietary strategies to optimise broiler performance when offered reduced crude protein (CP) diets. In feed, these grains have been optimized by the inclusion ...