Ameliorative Effect of Neem Leaf and Pomegranate Peel Extracts in Coccidial Infections in New Zealand and V-Line Rabbits: Performance, Intestinal Health, Oocyst Shedding, Carcass Traits, and Effect on Economic Measures

Abstract

Healthy, weaned, coccidial-free male rabbits from two breeds (New Zealand white (NZ) and V-line (VL)) were divided into 10 equal groups (5 groups each for NZ and VL) (3 replicates/group, 6 rabbits/replicate, 18 rabbits/group). All rabbits were inoculated with 5 × 10⁴ Eimeria spp. oocysts (E. intestinalis (67%), E. magna (22%), and E. media (11%)) except for the rabbits in the first group (G1), which were inoculated with a sterile solution and served as a negative control. The remaining four groups were treated as follows: G2, no treatment/positive control, G3, treated with neem leaf extract, G4, treated with pomegranate peel extract (PPE), and G5, treated with a combination of neem leaf extract and PPE. For both breeds, our results showed that the use of neem leaf and/or pomegranate peel extract resulted in improved growth performance, with a significant improvement in relative feed conversion ratio (FCR) compared to the positive control groups, which recorded the worst values, as well as a significant (p ≤ 0.05) reduction in mean oocyst count compared to the positive control groups. We also observed downregulation of mRNA levels of IL-1βα, IL6, and TNF-α in the herbal treatment groups compared with the mRNA levels of these genes in the positive control groups. Herbal treatment with neem leaf and/or pomegranate peel extracts had positive effects on the NZ and VL rabbits experimentally infected with mixed Eimeria species, as evidenced by their healthy appearance, good appetite, no mortalities, an anticoccidial index > 120, and a significantly higher total return and net profit when compared to the positive control groups of both breeds. In NZ rabbits, the treatment with neem leaf extract alone (G3) or in combination with PPE (G5) recorded the most efficient economic anticoccidial activity.

Keywords: New Zealand rabbit; V-line rabbit; coccidial infection; neem; pomegranate.

Figure 1

The macroscopic findings in the intestines in the experimental groups showing hyperemic wall, fluid contents, and multiple white patches on the mucosal surface with the highest score of 3 in the positive control group (B), a score of 2 in the pomegranate peel extract-treated group showing scattered white patches (D), a score of 1 in the neem leaf extract-treated group showing mild distention with grey green semisolid content (C), a score of 0 in the combined treated group (E), and in the negative control (A) apparently normal architecture. Data obtained from 3 rabbits/group.

Figure 2

Microscopic findings in the intestines in the different experimental groups indicating: (A) apparently normal structure (HE × 100) in the negative control group, (B) positive control group showing sloughing and desquamation of the intestinal lining and different developmental stages of Eimeria spp. (red arrow) with lymphocytic infiltration (blue arrow) in the lamina propria and edema in the submucosa (HE × 100). (C–E), intestines from rabbits in the herbal treated groups showing a mild degree of sloughing of the epithelium lining and less infiltration with coccidial oocyte-infected epithelium (HE × 200). Data obtained from 3 rabbits/group. Blue arrow is pointing to lymphocytic infiltration in the epithelial lining while red arrow is pointing to developmental stages of Eimeria spp.

Figure 3

IL-1β, IL6, and TNF-α changes in NZ and VL rabbits in response to coccidial infection and herbal extract treatment. Data are presented as mean ± standard error of the mean. G1-N, negative control group of New Zealand rabbits; G2-N, positive control group of New Zealand rabbits; G3-N, neem leaf extract treatment of New Zealand rabbits; G4-N, pomegranate peel extract treatment of New Zealand rabbits; G5-N, combined treatment of New Zealand rabbits; G1-V, negative control group of V-line rabbits; G2-V, positive control group of V-line rabbits; G3-V, neem leaf extract treatment of V-line rabbits; G4-V, pomegranate peel extract treatment of V-line rabbits; G5-V, combined treatment of V-line rabbit. Data obtained from 3 rabbits/group. (A) New Zealand White groups. (B) V-Line groups. Means that have no superscript in common are significantly different from each other.