Acknowledgement
This work was supported by Korean Institute of Planning and Evaluation for Technology in Food, Agriculture and Forestry (IPET) through Livestock Industrialization Technology Development Program, funded by Ministry of Agriculture, Food and Rural Affairs (MAFRA) (321080-03-3-HD020).
References
- Summers JD. Reducing nitrogen excretion of the laying hen by feeding lower crude protein diets. Poult Sci 1993;72:1473-8. https://doi.org/10.3382/ps.0721473
- Wang J, Yue H, Wu S, Zhang H, Qi G. Nutritional modulation of health, egg quality and environmental pollution of the layers. Anim Nutr 2017;3:91-6. https://doi.org/10.1016/j.aninu.2017.03.001
- Iio W, Shimada R, Ogino A, Nonaka I. Egg production performance, nitrogen excretion, and environmental gas emissions from manure composting of laying hens fed low-protein diets supplemented with essential amino acids. Jpn Agric Res Q 2025;59:235-44. https://doi.org/10.6090/jarq.24s04
- Xin Q, Ma N, Jiao H, et al. Dietary energy and protein levels during the prelay period on production performance, egg quality, expression of genes in hypothalamus-pituitary-ovary axis, and bone parameters in aged laying hens. Front Physiol 2022;13:887381. https://doi.org/10.3389/fphys.2022.887381
- Azzam MMM, Dong XY, Zou XT. Effect of dietary threonine on laying performance and intestinal immunity of laying hens fed low-crude-protein diets during the peak production period. J Anim Physiol Anim Nutr 2017;101:e55-66. https://doi.org/10.1111/jpn.12559
- Mousavi SN, Khalaji S, Ghasemi-Jirdehi A, Foroudi F. Investigation on the effects of various protein levels with constant ratio of digestible sulfur amino acids and threonine to lysine on performance, egg quality and protein retention in two strains of laying hens. Ital J Anim Sci 2013;12:e2. https://doi.org/10.4081/ijas.2013.e2
- Sun M, Ma N, Liu H, et al. The optimal dietary arginine level of laying hens fed with low-protein diets. J Anim Sci Biotechnol 2022;13:63. https://doi.org/10.1186/s40104-022-00719-x
- Dong XY, Azzam MMM, Zou XT. Effects of dietary threonine supplementation on intestinal barrier function and gut microbiota of laying hens. Poult Sci 2017;96:3654-63. https://doi.org/10.3382/ps/pex185
- Zhou J, Qiu K, Wang J, Zhang H, Qi G, Wu S. Effect of dietary serine supplementation on performance, egg quality, serum indices, and ileal mucosal immunity in laying hens fed a low crude protein diet. Poult Sci 2021;100:101465. https://doi.org/10.1016/j.psj.2021.101465
- Torki M, Mohebbifar A, Ghasemi HA, Zardast A. Response of laying hens to feeding low-protein amino acid-supplemented diets under high ambient temperature: performance, egg quality, leukocyte profile, blood lipids, and excreta pH. Int J Biometeorol 2015;59:575-84. https://doi.org/10.1007/s00484-014-0870-0
- Bunchasak C, Poosuwan K, Nukraew R, Markvichitr K, Choothesa A. Effect of dietary protein on egg production and immunity responses of laying hens during peak production period. Int J Poult Sci 2005;4:701-8. https://doi.org/10.3923/ijps.2005.701.708
- Zhang H, Xuan Y, Guo D, et al. Effects of dietary low protein levels and amino acid patterns on production performance, egg quality and intestinal function in laying hens. Poult Sci 2025;104:105578. https://doi.org/10.1016/j.psj.2025.105578
- Iio W, Shimada R, Nonaka I, Ogino A. Effects of a low-protein diet supplemented with essential amino acids on egg production performance and environmental gas emissions from layer-manure composting in laying hens in the later laying period. Anim Sci J 2023;94:e13853. https://doi.org/10.1111/asj.13853
- Song JY, Heo YJ, Park J, et al. Effects of dietary additives on nitrogen balance, odor emissions, and yolk corticosterone in laying hens fed low-protein diets. Animals 2025;15:2021. https://doi.org/10.3390/ani15142021
- Ali U, Lee KJ, Cai D, Kim IH. Low protein diet with amino acid supplementation maintains laying performance and egg quality while reducing ammonia emissions in Hy-Line brown hens. Trop Anim Health Prod 2025;57:354. https://doi.org/10.1007/s11250-025-04611-4
- Liu H, Xu K, Wang H, et al. Effects of different forms of amino acid supplementation on the performance and intestinal barrier function of laying hens fed a low-protein diet. Poult Sci 2024;103:104375. https://doi.org/10.1016/j.psj.2024.104375
- Liu Y, Wang D, Zhao L, Zhang J, Huang S, Ma Q. Effect of methionine deficiency on the growth performance, serum amino acids concentrations, gut microbiota and subsequent laying performance of layer chicks. Front Vet Sci 2022;9:878107. https://doi.org/10.3389/fvets.2022.878107
- Zuberbuehler CA, Messikommer RE, Arnold MM, Forrer RS, Wenk C. Effects of selenium depletion and selenium repletion by choice feeding on selenium status of young and old laying hens. Physiol Behav 2006;87:430-40. https://doi.org/10.1016/j.physbeh.2005.11.007
- Guo S, Niu J, Xv J, et al. Interactive effects of vitamins A and K3 on laying performance, egg quality, tibia attributes and antioxidative status of aged Roman Pink laying hens. Animal 2021;15:100242. https://doi.org/10.1016/j.animal.2021.100242
- Li X, Uyanga VA, Jiao H, et al. Effects of low dietary calcium and lipopolysaccharide challenges on production performance, eggshell quality, and bone metabolism of laying hens. Front Physiol 2024;15:1396301. https://doi.org/10.3389/fphys.2024.1396301
- Attia YA, Al-Harthi MA, Abo El-Maaty HM. Calcium and cholecalciferol levels in late-phase laying hens: effects on productive traits, egg quality, blood biochemistry, and immune responses. Front Vet Sci 2020;7:389. https://doi.org/10.3389/fvets.2020.00389
- Park J, Heo YJ, Kim DH, et al. Nutritional and physiological responses to dietary phosphorus levels and phytase in pullets and laying hens. Poult Sci 2024;103:103886. https://doi.org/10.1016/j.psj.2024.103886
- Heo YJ, Park J, Kim YB, et al. Effects of dietary protein levels on performance, nitrogen excretion, and odor emission of growing pullets and laying hens. Poult Sci 2023;102:102798. https://doi.org/10.1016/j.psj.2023.102798
- Association of Official Analytical Chemists (AOAC) International. Official methods of analysis of AOAC International. 18th ed. AOAC International; 2007.
- Eklund B. Practical guidance for flux chamber measurements of fugitive volatile organic emission rates. J Air Waste Manag Assoc 1992;42:1583-91. https://doi.org/10.1080/10473289.1992.10467102
- Lee HG, Kim YB, Lee SH, et al. In vivo recovery of bacteriophages and their effects on Clostridium perfringens-infected broiler chickens. Vet Sci 2022;9:119. https://doi.org/10.3390/vetsci9030119
- Kim YB, Lee SH, Kim DH, et al. Incorporation of dietary methyl sulfonyl methane into the egg albumens of laying hens. Antioxidants 2022;11:517. https://doi.org/10.3390/antiox11030517
- Junqueira OM, de Laurentiz AC, da Silva Filardi R, Rodrigues EA, Casartelli CEM. Effects of energy and protein levels on egg quality and performance of laying hens at early second production cycle. J Appl Poult Res 2006;15:110-5. https://doi.org/10.1093/japr/15.1.110
- Torki M, Nasiroleslami M, Ghasemi HA. The effects of different protein levels in laying hens under hot summer conditions. Anim Prod Sci 2016;57:927-34. https://doi.org/10.1071/AN15463
- Gunawardana P, Roland DA Sr, Bryant MM. Effect of energy and protein on performance, egg components, egg solids, egg quality, and profits in molted Hy-Line W-36 hens. J Appl Poult Res 2008;17:432-9. https://doi.org/10.3382/japr.2007-00085
- Whitehead CC, Bowman AS, Griffin HD. The effects of dietary fat and bird age on the weights of eggs and egg components in the laying hen. Br Poult Sci 1991;32:565-74. https://doi.org/10.1080/00071669108417381
- Gunawardana P, Roland Sr. DA, Bryant MM. Effect of dietary energy, protein, and a versatile enzyme on hen performance, egg solids, egg composition, and egg quality of Hy-Line W-36 hens during second cycle, phase two. J Appl Poult Res 2009;18:43-53. https://doi.org/10.3382/japr.2008-00047
- Poosuwan K, Bunchasak C, Kaewtapee C. Long-term feeding effects of dietary protein levels on egg production, immunocompetence and plasma amino acids of laying hens in subtropical condition. J Anim Physiol Anim Nutr 2010;94:186-95. https://doi.org/10.1111/j.1439-0396.2008.00898.x
- Penz AM Jr, Jensen LS. Influence of protein concentration, amino acid supplementation, and daily time of access to high- or low-protein diets on egg weight and components in laying hens. Poult Sci 1991;70:2460-6. https://doi.org/10.3382/ps.0702460
- Roberts JR. Factors affecting egg internal quality and egg shell quality in laying hens. J Poult Sci 2004;41:161-77. https://doi.org/10.2141/jpsa.41.161
- Samiullah S, Roberts JR, Chousalkar K. Eggshell color in brown-egg laying hens: a review. Poult Sci 2015;94:2566-75. https://doi.org/10.3382/ps/pev202
- Technical Services and Supplies (TSS). QCM+ range [Internet]. TSS; c1985 [cited 2025 Oct 24]. Available from: https://www.tss-york.com/products/qcmrange#h.p_ID_150
- Committee on Animal Nutrition, National Research Council. Nutrient requirements of poultry. 9th ed. National Academies Press; 1994.
- Onbaşılar EE, Yalçın S, Bakıcı C, et al. Comprehensive evaluation of probiotic effects on laying hen physiology: from performance to bone and gut morphology. Animals 2025;15:2408. https://doi.org/10.3390/ani15162408
- Apajalahti J, Vienola K. Interaction between chicken intestinal microbiota and protein digestion. Anim Feed Sci Technol 2016;221:323-30. https://doi.org/10.1016/j.anifeedsci.2016.05.004
- Palomar M, Garcés-Narro C, Piquer O, et al. Influence of free fatty acid content and degree of fat saturation on production performance, nutrient digestibility, and intestinal morphology of laying hens. Anim Nutr 2023;13:313-23. https://doi.org/10.1016/j.aninu.2023.03.002
- Ndazigaruye G, Kim DH, Kang CW, et al. Effects of low-protein diets and exogenous protease on growth performance, carcass traits, intestinal morphology, cecal volatile fatty acids and serum parameters in broilers. Animals 2019;9:226. https://doi.org/10.3390/ani9050226
- Jomard A, Osto E. High density lipoproteins: metabolism, function, and therapeutic potential. Front Cardiovasc Med 2020;7:39. https://doi.org/10.3389/fcvm.2020.00039
- Ding Y, Bu X, Zhang N, Li L, Zou X. Effects of metabolizable energy and crude protein levels on laying performance, egg quality and serum biochemical indices of Fengda-1 layers. Anim Nutr 2016;2:93-8. https://doi.org/10.1016/j.aninu.2016.03.006
- Bezerra RM, Costa FGP, Givisiez PEN, Goulart CC, dos Santos RA, Lima MR. Glutamic acid supplementation on low protein diets for laying hens. Acta Sci Anim Sci 2015;37:129-34. https://doi.org/10.4025/actascianimsci.v37i2.25911
- Song X, Anas MA, Kurniawati A, et al. Effects of reduced-protein diets with protease supplementation on growth, carcass yield, intestinal morphology, organ development, nutrient digestibility, and blood biochemical of broiler chickens. Transl Anim Sci 2023;7:txad098. https://doi.org/10.1093/tas/txad098
- de Faria Viana E, de Carvalho Mello HH, Carvalho FB, et al. Blood biochemical parameters and organ development of brown layers fed reduced dietary protein levels in two rearing systems. Anim Biosci 2021;35:444-52. https://doi.org/10.5713/ab.21.0145
- Li Y, Li M, Zeng Q, et al. Maternal low-protein diets influence sex-specific growth performance, meat quality, and intestinal morphology of broiler offspring. Poult Sci 2025;104:105618. https://doi.org/10.1016/j.psj.2025.105618
- Jha R, Berrocoso JFD. Dietary fiber and protein fermentation in the intestine of swine and their interactive effects on gut health and on the environment: a review. Anim Feed Sci Technol 2016;212:18-26. https://doi.org/10.1016/j.anifeedsci.2015.12.002
- Wang YC, Han MF, Jia TP, et al. Emissions, measurement, and control of odor in livestock farms: a review. Sci Total Environ 2021;776:145735. https://doi.org/10.1016/j.scitotenv.2021.145735
- Vasconcelos MDC, Sousa LS, Lopes TSB, et al. Impact of increased pre-start diet density on broiler chick behavior, corticosterone levels, and performance responses under cold stress during early life. J Therm Biol 2024;124:103974. https://doi.org/10.1016/j.jtherbio.2024.103974
- Yan C, Xiao J, Chen D, et al. Feed restriction induced changes in behavior, corticosterone, and microbial programming in slow- and fast-growing chicken breeds. Animals 2021;11:141. https://doi.org/10.3390/ani11010141