JOBIMB, 2016, Vol 4, No 1, 15-19 - 15 - Effects of Shackling and Cone Restraining on Meat Quality of Broiler Chickens Slaughtered at Two Categories of Live Weight Siti Nadirah Ismail 1 , Awis Qurni Sazili 1,2* , Zulkifli Idrus 2,3 , Goh Yong Meng 3,4 , Zeiad Amjad Aghwan 1 , Azad Behnan Sabow 2 and Ahmed Abubakar Abubakar 2 1 Halal Products Research Institute, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia. 2 Department of Animal Science, Faculty of Agriculture, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia. 3 Institute of Tropical Agriculture, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia. 4 Department of Veterinary Preclinical Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia. *Corresponding author: Assoc. Prof. Dr. Awis Qurni Sazili Department of Animal Science, Faculty of Agriculture, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia. Email: awis@upm.edu.my Tel: +60-3-89474870 Fax: +60-3-89381024 INTRODUCTION Environmental conditions existed shortly before an animal is slaughtered have been known to be stressful for broiler chickens and could even affect the meat quality [1]. Restraining methods and slaughter weight for example had been reported to have impacts on the pre and post slaughter physiological responses in broiler chickens [2,3,4]. While the most common broiler restraining method used under commercial practice is shackling, this method has been recognised to have a negative impact on the welfare of broilers [5,6,3] and their meat quality [7,8,9]. Struggling or wing flapping during shackling has been reported to fasten the initial rate of pH drop and increased the redness of breast meat [9]. Therefore, it is suggested that limiting this behaviour in shackled broilers could help to improve their meat quality [10]. Apart from the aforementioned factors, behavioural response to shackling may also vary among chicken types where the slow-growing line (lighter) being more reactive than the fast growing line (heavier) [6]. According to a report by authors in [11], broilers slaughtered at a target carcass weight of 1.2 kg exhibited a lower pH and higher redness compared with broilers slaughtered for 1.8 and 2.4 kg carcass weight. Darker meat was observed in broiler slaughtered above 3.3 kg when compared to broilers lighter than 3 kg. After a short transport distance, broilers slaughtered at below 2 kg were seen to have a lower ultimate pH than those slaughtered at more than 2.4 kg weight. Meanwhile, it has been discovered that cone restraining can reduce the movement in birds either pre slaughter, during slaughter or early post slaughter [12.13]. Authors in [12] considered that placing broilers in a cone during stunning and exsanguination reduce convulsion as compared to shackle restraining. It was also discovered that placing birds in cone followed by stunning successfully reduces struggling in chicken [12,13] as well as improves the carcass quality [2]. However, there is a dearth of information on how cone restraining, in comparison to shackling, affects the meat quality of broiler chickens HISTORY Received: 15 th June 2016 Received in revised form: 10 th of July 2016 Accepted: 21 st of July 2016 ABSTRACT A study was conducted to determine the effects of shackling and cone restraining methods on meat quality of broiler chickens slaughtered at two categories of live weight. Fourty Cobb 400 male broilers were randomly assigned to a 2 × 2 factorial arrangement in a completely randomized design with 10 birds of each treatment group. The birds were slaughtered at 2 kg and 2.5 kg live weights using shackling or cone restraining methods. Neither cone nor shackle restraining methods affected the pH change of both slaughter weights. Birds weighing 2 kg subjected to cone method had higher (P<0.05) a*, b* and lower (p<0.05) L*, drip loss, cooking loss and shear force than those subjected to shackle method. Birds weighing 2.5 kg subjected to cone method had higher (p<0.05) b* and lower (p<0.05) L* and cooking loss than those restrained with a shackle method. Results of shear force values, L*, a*, b*, and pH change were significantly higher (p<0.05) in 2.5 kg chickens compared with those 2 kg chickens using shackling restraining method. KEYWORDS broiler chickens cone restraining meat quality shackling slaughter weight JOURNAL OF BIOCHEMISTRY, MICROBIOLOGY AND BIOTECHNOLOGY Website: http://journal.hibiscuspublisher.com/index.php/JOBIMB/index