{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,26]],"date-time":"2026-07-26T17:00:45Z","timestamp":1785085245634,"version":"3.55.0"},"reference-count":63,"publisher":"Wiley","issue":"1","license":[{"start":{"date-parts":[[2026,1,14]],"date-time":"2026-01-14T00:00:00Z","timestamp":1768348800000},"content-version":"vor","delay-in-days":13,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0\/"},{"start":{"date-parts":[[2026,1,1]],"date-time":"2026-01-01T00:00:00Z","timestamp":1767225600000},"content-version":"tdm","delay-in-days":0,"URL":"http:\/\/doi.wiley.com\/10.1002\/tdm_license_1.1"}],"content-domain":{"domain":["onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Veterinary Medicine & Sci"],"published-print":{"date-parts":[[2026,1]]},"abstract":"ABSTRACT<\/jats:title>\n \n Background<\/jats:title>\n Prior research has established that high ambient temperature and diets with reduced protein content exert detrimental effects on egg production and quality and the overall health of poultry. Supplementation with guanidinoacetic acid (GAA) has demonstrated the capacity to mitigate the negative effects of heat stress on broiler chickens. Notably, the impact of GAA supplementation on late\u2010laying hens subjected to cyclic high ambient temperatures remains largely unexplored.<\/jats:p>\n <\/jats:sec>\n \n Objectives<\/jats:title>\n This study was designed to evaluate the influence of dietary GAA supplementation on performance parameters, egg quality attributes, gastrointestinal morphology, antioxidant status, and some blood biochemical parameters in late\u2010laying hens exposed to high ambient temperatures under varying dietary crude protein (CP) concentrations.<\/jats:p>\n <\/jats:sec>\n \n Methods<\/jats:title>\n A total of 216 ninety\u2010week\u2010old laying hens were randomly allocated to four experimental groups, with each group further subdivided into six replicates of nine hens. The dietary treatments comprised: (1) a standard protein diet (15.5% CP, control), (2) the standard protein diet supplemented with 0.15% GAA (B\u2010GAA), (3) a diet with a 1% reduction in CP supplemented with 0.15% GAA (RP1\u2010GAA), and (4) a diet with a 2% reduction in CP supplemented with 0.15% GAA (RP2\u2010GAA). The reduction in dietary protein levels was accompanied by a concomitant decrease in the concentration of essential amino acids.<\/jats:p>\n <\/jats:sec>\n \n Results<\/jats:title>\n \n The findings revealed a significantly greater body weight gain (\n p<\/jats:italic>\n \u2264 0.05) in hens fed the B\u2010GAA diet compared to those receiving the basal or reduced protein diets. In contrast, dietary manipulation did not exert a significant effect on egg production and feed conversion ratio (\n p<\/jats:italic>\n > 0.05). Hens in the B\u2010GAA group exhibited enhanced feed intake, egg weight, and egg mass compared to those in the basal or RP2\u2010GAA groups (\n p<\/jats:italic>\n \u2264 0.05), while egg quality parameters remained statistically similar across all dietary treatments (\n p<\/jats:italic>\n > 0.05). No significant differences were detected among the experimental groups with respect to jejunal villus height, width, surface area, crypt depth, and the villus height\u2010to\u2010crypt depth ratio (\n p<\/jats:italic>\n > 0.05). Furthermore, feeding B\u2010GAA and RP1\u2010GAA diets resulted in significantly elevated serum glutathione peroxidase activity compared to the control and RP2\u2010GAA groups (\n p<\/jats:italic>\n \u2264 0.05). Moreover, the B\u2010GAA group displayed significantly higher serum superoxide dismutase activity when compared to all other treatment groups (\n p<\/jats:italic>\n \u2264 0.05). GAA supplementation led to an increase in serum total antioxidant capacity levels (\n p<\/jats:italic>\n \u2264 0.05) and indicated a trend towards reduced serum malondialdehyde levels (\n p<\/jats:italic>\n = 0.07). Serum levels of glucose, uric acid, albumin, calcium, and phosphorus were not significantly affected by the dietary treatments (\n p<\/jats:italic>\n > 0.05), whereas dietary GAA supplementation significantly increased serum nitric oxide (NO) concentrations (\n p<\/jats:italic>\n \u2264 0.05). Serum creatine level was significantly lower in hens fed the RP2\u2010GAA diet compared to all other treatment groups, while the B\u2010GAA group exhibited significantly higher serum total cholesterol and total protein levels (\n p<\/jats:italic>\n \u2264 0.05).\n <\/jats:p>\n <\/jats:sec>\n \n Conclusion<\/jats:title>\n The comparable responses observed in the B\u2010GAA and RP1\u2010GAA groups suggest the potential to reduce dietary protein concentration by 1% in aging laying hens exposed to elevated ambient temperatures through supplementation with 0.15% GAA, without compromising key production performance indicators. This strategy may offer significant economic and environmental advantages for sustainable poultry production.<\/jats:p>\n <\/jats:sec>","DOI":"10.1002\/vms3.70810","type":"journal-article","created":{"date-parts":[[2026,1,14]],"date-time":"2026-01-14T09:24:54Z","timestamp":1768382694000},"update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Efficacy of Supplementary Guanidinoacetic Acid at Different Dietary Crude Protein Levels on the Productive Performance, Egg Quality, Intestinal Morphology, Antioxidative Status, and Serum Metabolites of Aged Laying Hens Exposed to High Ambient Temperatures"],"prefix":"10.1002","volume":"12","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-9942-4273","authenticated-orcid":false,"given":"Reza","family":"Mahdavi","sequence":"first","affiliation":[{"name":"Department of Animal Science College of Agriculture and Natural Resources Razi University Kermanshah Iran"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ali Hossein","family":"Piray","sequence":"additional","affiliation":[{"name":"Department of Animal Science College of Agriculture and Natural Resources Razi University Kermanshah Iran"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shahab","family":"Ghazi","sequence":"additional","affiliation":[{"name":"Department of Animal Science College of Agriculture and Natural Resources Razi University Kermanshah Iran"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mohammad Ebrahim","family":"Nooriyan Soroor","sequence":"additional","affiliation":[{"name":"Department of Animal Science College of Agriculture Bu\u2010Ali Sina University Hamedan Iran"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Viktor Viktorovich","family":"Malorodov","sequence":"additional","affiliation":[{"name":"Department of Special Animal Husbandry Russian State Agrarian University\u2010 Moscow Timiryazev Agricultural Academy Moscow Russia"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2026,1,14]]},"reference":[{"issue":"4","key":"e_1_2_12_2_1","article-title":"Effect of Fluctuating Ambient Temperature on the Performance of Laying Hens in the Closed Poultry House","volume":"1","author":"Abbas T. E.","year":"2011","journal-title":"Research Opinions in Animal and Veterinary Sciences"},{"issue":"1","key":"e_1_2_12_3_1","article-title":"Impacts of Dietary Electrolyte Balance on Egg Production, Shell Quality, Hatchability and Some Physiological Parameters of Local Laying Hens Reared in Moderate Weather","volume":"13","author":"Abdallah A. G.","year":"2010","journal-title":"Egyptian Journal of Nutrition and Feeds"},{"key":"e_1_2_12_4_1","doi-asserted-by":"publisher","DOI":"10.3390\/ani11113091"},{"key":"e_1_2_12_5_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.anifeedsci.2019.114208"},{"key":"e_1_2_12_6_1","first-page":"1","article-title":"Creatine Supplementation and Oxidative Stress in Rat Liver","volume":"54","author":"Ara\u00fajo M. B.","year":"2013","journal-title":"Journal of the International Society of Sports Nutrition"},{"key":"e_1_2_12_7_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.psj.2023.103297"},{"key":"e_1_2_12_8_1","doi-asserted-by":"publisher","DOI":"10.1007\/s00726-008-0198-3"},{"key":"e_1_2_12_9_1","doi-asserted-by":"publisher","DOI":"10.3923\/jbs.2009.617.620"},{"key":"e_1_2_12_10_1","first-page":"1082","article-title":"Comparison of the Novel Compounds Creatine and Pyruvate on Lipid and Protein Metabolism in Broiler Chickens","volume":"5","author":"Chen J.","year":"2011","journal-title":"Animals"},{"key":"e_1_2_12_11_1","doi-asserted-by":"publisher","DOI":"10.1152\/ajpendo.90547.2008"},{"key":"e_1_2_12_12_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.aninu.2020.09.004"},{"key":"e_1_2_12_13_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.aninu.2023.03.012"},{"key":"e_1_2_12_14_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.livsci.2016.08.014"},{"key":"e_1_2_12_15_1","doi-asserted-by":"publisher","DOI":"10.3382\/ps\/pex378"},{"key":"e_1_2_12_16_1","doi-asserted-by":"publisher","DOI":"10.1249\/01.MSS.0000162690.39830.27"},{"key":"e_1_2_12_17_1","doi-asserted-by":"publisher","DOI":"10.1007\/s00726-016-2183-6"},{"key":"e_1_2_12_18_1","doi-asserted-by":"publisher","DOI":"10.3382\/ps.2012-02425"},{"key":"e_1_2_12_19_1","doi-asserted-by":"publisher","DOI":"10.3382\/ps\/pex185"},{"key":"e_1_2_12_20_1","doi-asserted-by":"publisher","DOI":"10.1007\/s00726-006-0467-y"},{"key":"e_1_2_12_21_1","doi-asserted-by":"publisher","DOI":"10.1016\/S0196-9781(03)00160-8"},{"key":"e_1_2_12_22_1","doi-asserted-by":"publisher","DOI":"10.1002\/vms3.737"},{"key":"e_1_2_12_23_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.psj.2025.105159"},{"key":"e_1_2_12_24_1","doi-asserted-by":"publisher","DOI":"10.1084\/jem.182.4.1143"},{"key":"e_1_2_12_25_1","doi-asserted-by":"publisher","DOI":"10.3382\/ps.2008-00386"},{"key":"e_1_2_12_26_1","doi-asserted-by":"publisher","DOI":"10.1071\/AN22012"},{"key":"e_1_2_12_27_1","doi-asserted-by":"publisher","DOI":"10.1080\/00071660310001643723"},{"issue":"1","key":"e_1_2_12_28_1","first-page":"99","article-title":"Effect of Guanidine Acetic Acid Addition to Corn\u2010Soybean Meal Based Diets on Productive Performance, Blood Biochemical Parameters and Reproductive Hormones of Laying Hens","volume":"24","author":"Khakran G.","year":"2018","journal-title":"Kafkas \u00dcniversitesi Veteriner Fak\u00fcltesi Dergisi"},{"key":"e_1_2_12_29_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.jevs.2015.02.009"},{"key":"e_1_2_12_30_1","doi-asserted-by":"publisher","DOI":"10.3390\/ani14071076"},{"key":"e_1_2_12_31_1","doi-asserted-by":"publisher","DOI":"10.1017\/S0043933917001003"},{"key":"e_1_2_12_32_1","doi-asserted-by":"publisher","DOI":"10.1093\/ps\/80.5.599"},{"key":"e_1_2_12_33_1","doi-asserted-by":"publisher","DOI":"10.3382\/ps.2011-01675"},{"key":"e_1_2_12_34_1","unstructured":"Lemme A. J.Ringel A.Sterk andJ. F.Young.2007. \u201cSupplemental Guanidine Acetic Acid Affect Energy Metabolism of Broiler.\u201d In16th European Symposium on Poultry Nutrition 339\u2013342. Vdf Hochschulverlag."},{"key":"e_1_2_12_35_1","doi-asserted-by":"publisher","DOI":"10.1111\/jpn.13028"},{"key":"e_1_2_12_36_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.psj.2023.102653"},{"key":"e_1_2_12_37_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.psj.2020.05.023"},{"key":"e_1_2_12_38_1","doi-asserted-by":"publisher","DOI":"10.1590\/S0100-879X1999001100007"},{"key":"e_1_2_12_39_1","first-page":"435","article-title":"Effects of Supplementing Broiler Diets With CreAMINO\u00aeon Broiler Performance, Carcass Traits and the Expression of Muscle Growth Related Genes","volume":"5","author":"Metwally A. E.","year":"2015","journal-title":"Research Opinions in Animal and Veterinary Sciences"},{"key":"e_1_2_12_40_1","doi-asserted-by":"publisher","DOI":"10.3382\/ps.2011-01585"},{"key":"e_1_2_12_41_1","doi-asserted-by":"publisher","DOI":"10.3382\/japr.2012-00575"},{"key":"e_1_2_12_42_1","doi-asserted-by":"publisher","DOI":"10.3382\/ps.2014-03894"},{"key":"e_1_2_12_43_1","doi-asserted-by":"publisher","DOI":"10.1080\/09712119.2018.1450751"},{"key":"e_1_2_12_44_1","volume-title":"Suplementa\u00e7\u00e3o de \u00c1cido Guanidinoac\u00e9tico e Minerais Org\u00e2nicos Sobre os Par\u00e2metros Reprodutivos de Matrizes de Corte e Desempenho de Suas Prog\u00eanies","author":"Paix\u00e3o S. J.","year":"2017"},{"key":"e_1_2_12_45_1","doi-asserted-by":"publisher","DOI":"10.1093\/jas\/skac355"},{"key":"e_1_2_12_46_1","doi-asserted-by":"publisher","DOI":"10.1242\/jeb.012674"},{"key":"e_1_2_12_47_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.neuint.2015.08.010"},{"key":"e_1_2_12_48_1","doi-asserted-by":"publisher","DOI":"10.1080\/1828051X.2019.1698325"},{"key":"e_1_2_12_49_1","doi-asserted-by":"publisher","DOI":"10.1111\/j.1439-0396.2007.00754.x"},{"key":"e_1_2_12_50_1","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pone.0189329"},{"key":"e_1_2_12_51_1","doi-asserted-by":"publisher","DOI":"10.1017\/S0021859620000477"},{"key":"e_1_2_12_52_1","doi-asserted-by":"publisher","DOI":"10.1590\/S1516-635X2012000400006"},{"key":"e_1_2_12_53_1","doi-asserted-by":"publisher","DOI":"10.12688\/f1000research.5218.1"},{"key":"e_1_2_12_54_1","doi-asserted-by":"publisher","DOI":"10.1093\/ajcn\/83.1.5"},{"key":"e_1_2_12_55_1","doi-asserted-by":"publisher","DOI":"10.1002\/jlb.50.1.49"},{"key":"e_1_2_12_56_1","doi-asserted-by":"publisher","DOI":"10.1080\/1828051X.2017.1305260"},{"key":"e_1_2_12_57_1","doi-asserted-by":"publisher","DOI":"10.1111\/j.1476-5381.2011.01484.x"},{"key":"e_1_2_12_58_1","doi-asserted-by":"publisher","DOI":"10.1002\/vms3.1035"},{"key":"e_1_2_12_59_1","doi-asserted-by":"publisher","DOI":"10.3390\/ijms19092837"},{"key":"e_1_2_12_60_1","doi-asserted-by":"publisher","DOI":"10.1098\/rspb.2004.2935"},{"key":"e_1_2_12_61_1","doi-asserted-by":"publisher","DOI":"10.1042\/bj3360001"},{"key":"e_1_2_12_62_1","doi-asserted-by":"publisher","DOI":"10.1152\/physrev.2000.80.3.1107"},{"key":"e_1_2_12_63_1","first-page":"1049","article-title":"Effect and Mechanism of Glutamine on Productive Performance and Egg Quality of Laying Hens","volume":"8","author":"Xiao\u2010Ying D.","year":"2010","journal-title":"Asian\u2010Australasian Journal of Animal Sciences"},{"key":"e_1_2_12_64_1","doi-asserted-by":"publisher","DOI":"10.1002\/jsfa.6749"}],"container-title":["Veterinary Medicine and Science"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/vms3.70810","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/full-xml\/10.1002\/vms3.70810","content-type":"application\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/vms3.70810","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,7,26]],"date-time":"2026-07-26T16:43:08Z","timestamp":1785084188000},"score":1,"resource":{"primary":{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/10.1002\/vms3.70810"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,1]]},"references-count":63,"journal-issue":{"issue":"1","published-print":{"date-parts":[[2026,1]]}},"alternative-id":["10.1002\/vms3.70810"],"URL":"https:\/\/doi.org\/10.1002\/vms3.70810","archive":["Portico"],"relation":{"has-review":[{"id-type":"doi","id":"10.1002\/VMS3.70810\/v1\/decision1","asserted-by":"object"},{"id-type":"doi","id":"10.1002\/VMS3.70810\/v2\/decision1","asserted-by":"object"},{"id-type":"doi","id":"10.1002\/VMS3.70810\/v2\/response1","asserted-by":"object"},{"id-type":"doi","id":"10.1002\/VMS3.70810\/v1\/review1","asserted-by":"object"},{"id-type":"doi","id":"10.1002\/VMS3.70810\/v1\/review2","asserted-by":"object"},{"id-type":"doi","id":"10.1002\/VMS3.70810\/v2\/review1","asserted-by":"object"}]},"ISSN":["2053-1095","2053-1095"],"issn-type":[{"value":"2053-1095","type":"print"},{"value":"2053-1095","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,1]]},"assertion":[{"value":"2025-05-08","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2025-12-24","order":2,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2026-01-14","order":3,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}],"article-number":"e70810"}}