Evaluation of pigeon pea leaves (Cajanus cajan) replacing alfalfa meal on growth performance, carcass trait, nutrient digestibility, antioxidant capacity and biochemical parameters of rabbits.

A 30-day experiment was performed to determine the effect of pigeon pea leaves (PPL) on growth performance, carcass trait, meat quality, nutrient digestibility, antioxidant capacity and biochemical parameters of growing rabbits. In a completely randomized design, PPL replaced alfalfa meal at the level of 0%, 10%, 20% and 30%, which were named PPL0 (control), PPL10, PPL20 and PML30 respectively. Two hundred New Zealand white rabbits at 6 weeks with similar weight (870.23 ± 15.98 g) were allocated to four dietary groups with five replicates containing 10 rabbits/per replicate (male). The results showed that: (a) PPL powder contained 24.26% crude protein, 4.34% crude fat, 17.86% crude fibre, 7.05% ash, 1.35% calcium, 0.28% phosphorus, 1.09% lysine and 0.20% methionine, and the chemical compositions are on DM basis; (b) the ratio of feed to gain of rabbits fed diet PPL10 was significantly better (p < 0.05) than those fed other three diets; (c) the content of longissimus dorsi (LD) moisture in the rabbits fed diets without PPL (control group) was 12% lower than that in the PPL30 diets (60.1 vs. 72.1; p < 0.05). In PPL10, PPL20 and PPL30 diets, the leg muscle (LM) b*(yellowness) value was 33%, 30% and 22.6% higher than the control group respectively. The rabbits fed diets PPL0 had lower (p < 0.05) LM crude protein and ash and higher (p < 0.05) crude fat of LD and LM as compared with those fed other diets; (d) crude protein and energy digestibility of PPL0 and PPL10 diets were significantly higher (p < 0.05) than PPL30 diets; and (e) serum glutathione peroxidase (GSH-Px) activity of the rabbits fed PPL10 and PPL30 diets was significantly higher (p < 0.05) than that fed PPL20 diets. Liver total antioxidant capacity (T-AOC) activity of the PPL30 groups was 1.3% higher (p < 0.05) than the PPL10 group. Additionally, the control group (PPL0) had the highest (p < 0.05) blood urea nitrogen (BUN), total cholesterol (TCHO) and low-density lipoprotein cholesterol (LDLC) content compared with the groups supplemented with PPL. The PPL30 group had the highest (p < 0.05) triiodothyronine (T3 ) and tetraiodothyroxine (T4 ) value among the dietary groups.