SHORT COMMUNICATIONS The potential of replacing soyabean oil cake with macadamia oil cake in broiler diets Owoahene Acheampong-Boateng 1 & Archibold G. Bakare 1 & Khanyisile R. Mbatha 1 Received: 8 August 2015 /Accepted: 18 April 2016 # Springer Science+Business Media Dordrecht 2016 Abstract A study was conducted to evaluate the potential of macadamia oil cake (MOC) as a replacement of soyabean oil cake (SOC) in Ross broiler diets. The 600 1-day-old male broiler chicks were randomly blocked into 30 equal-weight groups of 20 chicks. For each growth phase, basal and summit diets were blended in various proportions (100 % SOC and 0 % MOC, 75 % SOC and 25 % MOC, 50 % SOC and 50 % MOC, 25 % SOC and 75 % MOC, and 0 % SOC and 100 % MOC) to form five treatments. The diet with 100 % MOC had the least feed intake, final body weight and weight gain compared to other diets (P < 0.05). The increased abdominal fat of broilers fed more than 50 % levels of MOC could be due to high levels of lipids in MOC compared to soyabean oil cake. The feed conversion ratio did not differ significantly for most of the treatments (P >0.05). It was concluded that the threshold of 25 % MOC can replace soybean oil cake meal in the diets of broiler provided that this alternative feed ingredient is readily available at an affordable cost. Keywords Weight gain . Feed conversion ratio . European performance efficiency factor . Carcass characteristics Introduction Most traditional dietary feedstuffs fed to broiler chickens consist of maize as the main energy source. Soyabean oil cake (SOC) is generally a consistent plant protein ingredient, which contribute to the fast protein accretion of the birds. Both energy and protein feeds contribute more than 90 % of total cost for poultry feeds (Mengesha 2012). However, in the southern African context, plant protein sources are expensive and relatively scarce (Cotzee et al. 2008). Therefore, the identification of alternative plant protein sources that are readily available and inexpensive will be of great value to feed compounders and/or chicken producers. Agro-industrial by- product feedstuffs such as macadamia oil cake (MOC) have been identified as potential alternative protein feedstuff for animal production (Acheampong-Boateng et al. 2008). Macadamia oil cake is obtained from the extraction of oil from cracked and poorly formed macadamia nuts using a base of soyabean hulls to prevent the nuts from sticking to the sides of the oil-extracting machine (Acheampong-Boateng et al. 2008). Macadamia oil cake was suitable as a dietary protein supplement for tilapia when incorporated up to 50 % replace- ment for soyabean protein (Balogun and Fagbenro 1995). Also, studies of rural chickens (Phosa 2009) and New Hampshire (van Ryssen et al. 2014) observed that macadamia mixed with wood ash improved the quality of chickens. However, few studies have been undertaken to evaluate the feeding potential of MOC to broilers in southern Africa. Therefore, there is need to evaluate the feeding of MOC to broiler chickens and determine the extent to which they could be fed. Thus, the study was conducted to determine the extent to which SOC can be replaced with MOC in broiler diets. Materials and methods The experiment was conducted at the Agricultural Research Council (ARC), Irene (South Africa). The broilers were treat- ed in accordance with the ARC guidelines for the care and use of laboratory animals. A randomized complete block design * Khanyisile R. Mbatha mbathkr@unisa.ac.za 1 Department of Agriculture and Animal Health, University of South Africa, Private Bag X6, Florida 1710, South Africa Trop Anim Health Prod DOI 10.1007/s11250-016-1057-y