Please cite this article in press as: Norambuena, M.C., et al., Effects of nutritional restriction on metabolic, endocrine, and ovarian function in llamas (Lama glama). Anim. Reprod. Sci. (2013), http://dx.doi.org/10.1016/j.anireprosci.2013.01.019 ARTICLE IN PRESS G Model ANIREP-4723; No. of Pages 9 Animal Reproduction Science xxx (2013) xxx–xxx Contents lists available at SciVerse ScienceDirect Animal Reproduction Science jou rn al h om epa ge: www .elsevier.com/locate/anireprosci Effects of nutritional restriction on metabolic, endocrine, and ovarian function in llamas (Lama glama) M.C. Norambuena a,∗ , M. Silva b,c , F. Urra a , C. Ulloa-Leal a , A. Fernández a , G.P. Adams d , W. Huanca e , M.H. Ratto a a Department of Animal Science, Faculty of Veterinary Science, Universidad Austral de Chile, Valdivia, Chile b School of Veterinary Medicine, Universidad Católica de Temuco, Temuco, Chile c Núcleo de investigación Agroalimentaria, Universidad Católica de Temuco, Temuco, Chile d Veterinary Biomedical Sciences, University of Saskatchewan, Saskatoon, SK, Canada e Faculty of Veterinary Medicine, Universidad Nacional Mayor de San Marcos, Lima, Peru a r t i c l e i n f o Article history: Received 20 August 2012 Received in revised form 12 December 2012 Accepted 28 January 2013 Available online xxx Keywords: Nutritional restriction LH Corpus luteum Leptin Camelids a b s t r a c t The objectives of the study were to determine the effects of nutritional restriction on ovar- ian function in llamas. Mature female llamas were assigned randomly to a Control group, fed 100% of maintenance energy requirements (MER) (n = 8), or a Restricted group (n = 8) fed from 70% to 40% of MER until a body condition score of 2.5 was attained. Blood samples were taken every-other-day to determine plasma concentrations of LH, estradiol, leptin and metabolic markers, and follicular dynamics were monitored daily by ultrasonography for 30 days (Experiment 1). Llamas were then treated with GnRH to compare the ovula- tory response and corpus luteus (CL) development between groups (Experiment 2). Blood samples were taken to measure LH, leptin, progesterone and metabolic markers and ovar- ian structures were assessed as in Experiment 1. Llamas in the Restricted group had lower body mass and body condition scores than those in the Control group (P < 0.001). Plasma concentrations of cholesterol, non-esterified fatty acids, triglycerides, and urea were higher in the Restricted group (P < 0.05) than in the Control group. The day-to-day diameter pro- files of the dominant follicles were smaller (P < 0.05) in the Restricted group than in the Control group but plasma estradiol concentration did not differ. The ovulation rate and LH secretion in response to GnRH did not differ. Day-to-day profiles of CL diameter, plasma progesterone and leptin concentrations were smaller (P < 0.01) in the Restricted group. In conclusion, nutritional restriction in llamas was associated with suppressed follicle and CL development, and lower plasma concentrations of progesterone and leptin. © 2013 Elsevier B.V. All rights reserved. ∗ Corresponding author at: Ernesto Riquelme 241, Valdivia, Chile. Tel.: +56 9 82286455. E-mail addresses: cecilia.norambuena@gmail.com, cnorambuena@hotmail.com (M.C. Norambuena), masilva@uct.cl (M. Silva), felipeurras22@hotmail.com (F. Urra), ceul1981@hotmail.com (C. Ulloa-Leal), anitafernandezast@gmail.com (A. Fernández), gregg.adams@usask.ca (G.P. Adams), whuanca2002@yahoo.com (W. Huanca), marceloratto@uach.cl (M.H. Ratto). 1. Introduction Food intake and body energy reserves are key deter- minants of reproductive success in mammals. The effect of negative energy balance and body condition on repro- ductive efficiency has been well documented in cattle (Bean and Butler, 1997; Buckley et al., 2003; Diskin et al., 2003; Roche et al., 2007). Subfertility associated with negative energy balance has been attributed to a lower conception rate, prolonged post-partum anestrus, ovar- ian dysfunction, abnormal estrous behavior, increased 0378-4320/$ – see front matter © 2013 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.anireprosci.2013.01.019