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www.poultrynews.com.au National Poultry Newspaper, March 2025 %u2013 Page 15BCS WALKING TRACTORSA wide range of implements also availableAvailable in petrol or diesel 3 Endeavour Street, Warragul, VIC, 3820(03) 5622 9100 %u2022 www.vinrowe.com.auBetter outcomes through advanced systemswww.stockyardindustries.comNorthern regionJoe Oliveira0437 322 446joe@stockyardindustries.comSouthern regionNiel Snyman0419 608 721niel@stockyardindustries.comJuan DiazNational Key Account Manager - Poultryjuan@ccdanimalhealth.com.au 0419 620 310Eddie PecotichNational Key Account Manager - Biosecurity eddie@ccdanimalhealth.com.au 0437 408 961Unit 2, 84-92 Barnes StTamworth NSW 2340ccdanimalhealth.com.au(02) 9898 1800sales@HydroInnovations.com.auwww.HydroInnovations.com.au %u2022 Wastewater Pumps%u2022 Lagoon Aerators%u2022 Sludge Pumps%u2022 DAF PumpsGarry GrantDANIEL FISHER0434 468 644KEVIN MARKHAM0421 078 855E: equipment@ifsaustralia.com.auwww.ifsaustralia.com.auU4/9 Cardiff CourtCavanSA 5094PO Box 2467 Dry Creek SA 5094INTENSIVE FARMING SUPPLIES AUSTRALIAPRECISION INTESTINAL NUTRITION SYNCHRONIZED FOR POULTRYSome companies talk about it - at Jefo, we do it For more information, contact:Wayne Bradsha 0429 301 500 wbradshaw@jefo.comor the office:ausinfo@jefo.comjefo.com Here%u2019s my Card Here%u2019s my Card Here%u2019s my CardTom Moore0417 085 139newenglandfreerange@hotmail.com%u2022 Custom small batch pullet rearing (BD Aviary) %u2022 Full vaccination options available%u2022 Truly separated, if required %u2022 Southern Queensland and northern NSWDietary CP reductions were shown to decrease nitrogen excretion and ammonia emissions, enhance litter quality and reduce the incidence of footpad and other lesions.Nowadays, supplementation of lysine, methionine and threonine is typical in broiler diets and supplemental amino acids %u2013 for instance, reduced the dietary CP content from 356 to 200g/kg in a typical maize-soybean meal diet.Hence, reduced CP diets is not a new practice, and dietary crude protein can be further reduced when more synthetic amino acids are available at affordable prices.With the focus on digestive dynamics, this paper summarises the research outcomes from the %u2018blue room team%u2019 in its efforts to restore growth performance in broiler chickens fed reduced crude protein diets. Additionally, recent efforts to replace imported soybean meal with locally available protein-rich ingredients are also discussed.Digestive dynamics and optimal NBAA inclusionsPreviously, Liu and Selle concluded that in conventional diets, feed conversion efficiency may be improved by using rapidly digestible protein and slowly digestible starch in broiler diets %u2013 more importantly, protein digestion rates have a more pronounced impact on feed conversion efficiency. Non-bound amino acids require no digestion and are immediately available for absorption. Therefore, it is straightforward to treat NBAA as a rapid protein or nitrogen source, and it was hypothesised that increasing NBAA concentrations in diets would enhance growth performance. This hypothesis initially motivated the authors to investigate the reduced crude protein diets started with Moss et al, and the journey has been both fruitful and enjoyable.The synchrony between protein-bound and non-bound amino acids was a notable research topic in 1970s when synthetic lysine become available. Efforts were put in to investigating whether lysine HCl utilisation was compromised by restricted feeding regimes as opposed to ad libitum feeding in pigs, where an interaction between feeding frequency and lysine supplementation for weight gain was reported and higher feeding frequency enhanced utilisation of Lysine HCl. Recently, we investigated the relevance of this consideration in poultry, particularly broiler chickens on ad libitum feeding. Yin et al offered broiler chickens%u2019 diets with or without 3.5g/kg lysine HCl, containing either 10.0 or 12.8g/kg digestible lysine, from seven to 28 days post-hatch. Meanwhile, birds were given access to diets for 12, 16 or 20 hours per day. Treatment interactions (P > 0.35) between lysine HCl and feed access intervals for growth performance parameters were not observed. The authors concluded that effective lysine HCl utilisation in poultry, irrespective of feeding frequency (unlike in pigs), may stem from anticipatory feeding behaviour, crop and gizzard functionality, shorted retention time and increased episodes of reverse peristalsis.While it is reassuring that poultry are not as responsive as pigs to changes in digestive dynamics in conventional diets, it remains important to understand whether there is a limit to how much NBAA can be included in broiler diets at higher levels without compromising growth performance. Baker pointed out that it has been known for well over 20 years that there are limits to how much intact protein can be replaced by free amino acids in terms of achieving maximal weight gain and feed efficiency of broiler chicks.Macelline et al used a triangular response surface design to compare three diets rich in soybean meal, whey protein concentrates or NBAA to determine the optimal level of NBAA inclusion in wheat-based diets. Superior weight gain and FCR was found in broiler chickens offered an equal blend of soybean meal and whey protein diets. This diet was constituted of 84.3g/kg whey protein concentrate and 13.4g/kg NBAA. Quadrative relationships were found between NBAA inclusions and different growth parameters, the mean optimal NBAA inclusion level was 19.23g/kg across weight gain, feed intake and FCR, above which performance commenced to decline.Grains with higher inherent protein content may present more challenges when formulating reduced crude protein diets. This is because, when least-cost formulating iso-energetic and iso-nitrogenous diets, those based on highprotein grains would lead to higher inclusion of cereal grains and NBAA. This was identified as one of the causes of sub-optimal growth performance in wheatbased reduced CP diets compared to maize and sorghum. A recently completed study by the authors further verified this hypothesis by utilising both high-protein and low-protein wheat grains where reduced CP diets based on high protein wheat depressed growth performance in comparison to the diet based on low protein wheat (unpublished data).Amino acid requirementsTwo studies were conducted to evaluate the fourth limiting amino acid in reduced crude protein diets based on wheat or maize.The studies utilised deletion methods, where three control diets were formulated, and then each tested amino acid was removed one at a time.Both studies confirmed the importance of BCAA in reduced CP diets, especially in wheat-based diets where removing Val caused more damage than removing the set of supplemented amino acids. The importance of balanced amino acid profile was further evaluated in Macelline et al, where different ideal protein ratios may be preferred by conventional and reduced CP diets.Proposed solutionThe increased cereal grain and NBAA in reduced CP diets is more likely to lead to imbalance between glucose, protein-bound and non-bound amino acids for absorption and utilisation. This may limit the inclusion of NBAA in the diets.Hence, the proposed solution to completely replace SBM is to combine alternative protein sources with a moderate level of inclusion of NBAA. Canola seed and canola meal is produced in large quantities in Australia but their inclusions in broiler diets are capped due to the impact of anti-nutritive factors on growth performance and bird welfare. Our recent study showed that including 5, 12, 16 and 22 percent canola products in the starter, grower, finisher and withdrawal diets respectively, compromised weight gain, reducing it from 3.73 to 3.60kg per bird (P < 0.05). This reduction was due to decreased feed intake, as no impact on FCR was observed.Macelline et al evaluated the possibility of including 15 percent canola meal in a reduced CP diets (190g/kg) to completely remove soybean meal and found that canola meal inclusion did not influence weight gain and FCR (P > 0.05) in broiler chickens from 16-35 days post-hatch. Moreover, we tested this approach for the whole production cycle and found that including field peas to diets with moderate CP reduction improved growth performance regardless of the dietary CP levels. These preliminary outcomes are truly encouraging, and the approach should be tested with other available local feed ingredients. Sonia LiuUniversity of Sydneysonia.liu@sydney.edu.auPromoting resilience %u2013 sustainable protein alternatives and low-protein diets for chicken-meat production* from P13