Search

This study investigated the optimal dietary intake of zinc amino acid complex (Zn-AAC) for white-layer pullets, focusing on their productive performance, biochemical profile, organ biometry, and body zinc retention. The study involved 360 Dekalb White pullets (average weight: 433 ± 4.42 g) aged from 6 to 16 weeks and distributed into 6 treatments with 6 replications each. The Zn-AAC inclusion levels ranged from 5 to 75 mg kg-1. Zinc intake was modeled using a nonlinear equation, Y = ∝ *1- e-βX, where α is the maximum response, β is the rate at which the response approaches the maximum (P < 0.05). The Zn-AAC supplementation had significant effects on average daily gain (ADG), average daily feed intake (ADFI), and feed convention ratio (FCR) (P < 0.01). Optimal intake levels of Zn-AAC were estimated at 0.234, 0.340, and 0.315 mg bird-1 day-1 (5.42, 7.87, and 7.30 mg kg-1) for ADG, ADFI, and FCR, respectively. The Zn-AAC supplementation affected the Zn body retention in pullets (P < 0.01), with an optimal ingestion at 1.86 mg bird -1 day-1, corresponding to a dietary supplementation of 43.10 mg kg-1. Additionally, supplementation affected alkaline phosphatase (ALP) activity (P < 0.01) without significant changes in aspartate aminotransferase, albumin, and globulin levels. The optimal Zn-AAC intake level for ALP activity was 1.45 mg bird -1 day-1, corresponding to dietary supplementation of 33.60 mg kg-1. Based on Zn body retention, we recommend up to 1.86 mg bird -1 day-1 of Zn-AAC, which is equivalent to 43.10 mg kg-1., Competing Interests: We declare that we have no financial and personal relationships with other people or organizations that can inappropriately influence our work, and there is no professional or other personal interest of any nature or kind in any product, service and/or company that could be construed as influencing the content of this paper. The authors have declared that no competing interests exist., (Copyright: © 2024 Silva et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)