Effects of supplementing Pistachio skins in the diet on growth performance and the fatty acid profile of Biceps femoris and Longissimus lumborum muscles in rabbits

Abstract

Pistachios, a delicacy food product produced mostly in Sicily generates significant amounts of skins during its processing. This by-product was incorporated in growing/finishing rabbit diet formulation. Hence, the aim of this study was to investigate the effects of a 6% pistachio skin inclusion in rabbit grower/finisher diets on the rabbits' zootechnical performance and carcass quality. One hundred and fifty healthy Martini rabbits (male and female) were weaned at 30 days of age having body weight (IBW) of 0.82 ± 0.05 kg. The animals were assigned to one of the two treatment groups to be homogeneous for weight and sex. Diets were as follows: (1) a treatment diet (TRMT) having a 6% incorporation of pistachio skin meal and a (2) a control diet (CTRL) without the integration of pistachio skin meal. During the experimental period (from 30 to 63 days of age). Rabbits were weighed individually on day 30, day 42, and day 63 of the trial. Weight gain, daily feed intake, and feed conversion ratio were calculated. The loin and hind leg were carefully deboned and the Biceps femoris (BF) and Longissimus lumborum (LL) muscles were minced and homogenized. The treatment group fed a diet with 6% Pistachio skins showed no adverse effects on the growth performance nor on the carcass characteristics and did not trigger any physiological or clinical changes or show deleterious effects on the rabbits. Overall, while the total fat quantity did not register as significant in any of the muscles from either diet, significance was recorded with regards to the quality of the fatty acids profile between the two diets and between the two muscles. The analysis of the BF and LL muscles of the TRMT group showed a significant increase in MUFA (3.2 %, and 3.0%, P = 0.008 and 0.041, respectively) and in the PUFA groups (4.8% and 3.8%, P = 0.032 and 0.023, respectively), and a decrease in the SFA group (7.2% and 6.1%, P = 0.014 and 0.020, respectively) compared with CTRL group. In particular, both linoleic and α linolenic fatty acids registered a significant increase in the BF muscle, while only the α linoleic acid registered a significant increase in the LL muscle of TRMT compared with CTRL group (P < 0.05). Although rabbit meat offers excellent nutritional and dietetic properties in itself, this study confirms that it can be further fortified with bioactive compounds to obtain meat that will be considered functional.