Animal Feed Science and Technology 106 (2003) 149–163 The effect of dietary supplementation with trivalent chromium on production performance of laying hens and the chromium content in the yolk  Andrea Piva a,∗ , Elena Meola a , Pier Paolo Gatta a , Giacomo Biagi a , Gastone Castellani a , Attilio Luigi Mordenti a , John Bernard Luchansky b , Sandro Silva c , Archimede Mordenti a a Dipartimento di Morfofisiologia e Produzioni Animali (DIMORFIPA), Università di Bologna, Via Tolara di Sopra 50, Ozzano Emilia 40064, Italy b Eastern Regional Research Center, Agricultural Research Service, USDA, Wyndmoor, PA 19038, USA c Istituto di Chimica del Suolo, Università Cattolica del Sacro Cuore, Via Emilia Parmense 84, Piacenza 29100, Italy Received 11 October 2001; received in revised form 12 November 2002; accepted 7 December 2002 Abstract The present study evaluated whether feeding laying hens high levels of trivalent chromium in different chemical forms modified egg production and egg quality or resulted in chromium accumulation in the yolk. The diets of 32 laying hens per each of four treatments were supplemented without chromium (control) or with chromium chloride (CrCl 3 ), chromium yeast, or chromium aminoniacinate. After 5 weeks, health status, feed intake, egg deposition, egg and yolk weight, and Haugh unit score did not differ between experimental and control treatments. Chromium in the yolk did not increase regardless of the chromium source, and averaged 0.48 ± 0.10 mg kg -1 DM. At the end of the study, the chromium content of the excreta of birds fed the control diet or the diets supplemented with CrCl 3 , chromium yeast, or chromium aminoniacinate increased linearly as a function of the chromium intake, regardless of the chemical form used. These data indicate that short-term feeding of laying hens with a diet high in chromium does not influence egg production or egg quality and does not result in abnormal levels of chromium in the yolk. © 2003 Elsevier Science B.V. All rights reserved. Keywords: Laying hens; Chromium; Nutrition; Overdose  Mention of brand or firm names does not constitute an endorsement by the US Department of Agriculture over others of a similar nature not mentioned. ∗ Corresponding author. Tel.: +39-051-79-2883; fax:+39-051-79-2869. E-mail address: apiva@alma.unibo.it (A. Piva). 0377-8401/03/$ – see front matter © 2003 Elsevier Science B.V. All rights reserved. doi:10.1016/S0377-8401(03)00006-3