Contents lists available at ScienceDirect Livestock Science journal homepage: www.elsevier.com/locate/livsci Growth performance, carcass characteristics and fatty acid composition of fnishing pigs fed on graded levels of Vachellia tortilis leaf meal M. Khanyile a , C. Mapiye b , F. Thabethe c , C.N. Ncobela d , M. Chimonyo c, ⁎ a Department of Agriculture and Rural Development, Private Bag X 9059, Cedara 3200, Pietermaritzburg, South Africa b Department of Animal Sciences, Stellenbosch University, P. Bag X1, Matieland 7602, South Africa c Animal and Poultry Science, University of KwaZulu-Natal, P. Bag X01 Scottsville 3209, Pietermaritzburg, South Africa d Agricultural Research Council-Animal Production Institute (Poultry breeding unit), Private Bag X 2, Irene 0062, South Africa ARTICLE INFO Keywords: Longissimus dorsi Monounsaturated fatty acids Polyunsaturated fatty acids Proanthocyanidins Saturated fatty acids ABSTRACT The objective of the study was to determine growth performance, carcass characteristics and fatty acid com- position of pigs fed on graded levels of Vachellia tortilis leaf meal (VTLM) diets. Forty-eight male Large White × Landrace fnishing pigs with a mean ( ± standard deviation) body weight of 63.6 ± 0.73 kg (mean ± SD) aged 14 weeks were used. Pigs were allocated to individual pens in a completely randomized design and were assigned to six experimental diets containing 0, 30, 60, 90, 120, and 150 g/kg dry matter of VTLM. Each diet was ofered ad libitum with fresh water to eight pigs in individual pens. There was a linear increase (P< 0.05) in ADFI and a linear decrease (P<0.05) in ADG and G: F with increase inclusion levels of VTLM. There was a quadratic response (P < 0.05) in intramuscular fat with increasing levels of VTLM. The inclusion of VTLM linearly (P < 0.05) decreased slaughter weight, warm carcass weight, cold carcass weight, cooler shrink and back-fat thickness. Total saturated fatty acids (TSFA) and total n-6 polyunsaturated fatty acids (PUFA) decreased linearly (P <0.001) with increasing levels of VTLM. There was a quadratic increase (P <0.001) in monounsaturated fatty acids (MUFA), total PUFA and total n-3 PUFA with increase inclusion of VTLM diet. The inclusion of VTLM reduced the total SFA and total n-6 PUFA while increasing the proportion of total MUFA and n-3 PUFA of pork. The optimum MUFA and total n-3 fatty were obtained at approximately 70 g/ kg DM of V. tortilis leaf meal inclusion level. 1. Introduction Feed shortages in the tropics has necessitated the exploration of non-conventional feed sources for pigs. This is due to the soaring prices of conventional feed sources such as soybean meal (Li et al., 2018). The concerns about pig feed cost and consumer health issues in pig pro- duction have made it vital to consider alternative feed sources to ease the demand for conventional feeds while positively regulating pork quality (Hanczakowska et al., 2015). To reduce feed cost and compe- tition of feed ingredients between livestock and humans while fa- vouring consumer choice and preferences, utilization of leguminous trees such as Vachellia leaves is essential. Generally, the use of Vachellia leaves in the diets of pigs in Southern Africa has been explored. Most of the studies are focusing on growth performance (Khanyile et al., 2014; Ndou et al., 2015), ignoring pork quality attributes. Vachellia leaves have high levels of fbre, proteins, minerals, vitamins and proanthocyanidins (Dube et al., 2001; Mokoboki et al., 2005). Presence of proanthocyanidins and high fbre content in the Vachellia tortilis leaf meal (VTLM) has shown to reduce feed intake of by decreasing palatability and compromising digestibility of nutrients (Barry and McNabb, 1999). High fbre diets reduce density of nutrients available for digestion and absorption (Kyriazakis and Emmans, 1995), which subsequently compromise meat quality char- acteristics. Polyphenols such as condensed tannins interfere with pro- tein digestion and absorption by engulfng protein molecules (Mapiye et al., 2011). Thus, polyphenols from Vachellia tortilis could have a direct bearing to pork fatty acids. Literature about the efects of leguminous feedstuf such as Vachellia tortilis on pork fatty acid com- position is, if available, sparse. Most of the studies have been conducted in ruminants. In beef cattle, Polyphenolic compounds from Vachellia tortilis have advantages of increasing conjugated linoleic acid con- centrations (Mapiye et al., 2011; Patra and Saxena, 2011). In goats, polyphenols decreased short chains and saturated fatty acids (Cimmino et al., 2018). Conducting similar studies in pigs would boost https://doi.org/10.1016/j.livsci.2020.104259 Received 16 September 2019; Received in revised form 19 August 2020; Accepted 13 September 2020 ⁎ Corresponding author. E-mail address: chimonyo@ukzn.ac.za (M. Chimonyo). Livestock Science 241 (2020) 104259 Available online 14 September 2020 1871-1413/ © 2020 Published by Elsevier B.V. T