Sensitivity of field isolates of Eimeria acervulina and E. maxima from three regions in Brazil to eight anticoccidial drugs

Eucalyptus oil: A promising anticoccidial agent with multifaceted protective effects

In-feed preventive coccidiostat additives are regarded as the primary choice of coccidiosis control, whereas the lasting appearance of drug resistance seriously hampered its application. Eucalyptus oil (EUC) has been evidenced to possess anti-malaria and anti-helminth efficacy. Confronting the urgent requirements for novel anticoccidial remedies, EUC was picked to scrutinize its anticoccidial efficacy with the in vivo coccidiosis model. Birds were orally administrated with 8 × 104 sporulated oocysts and treated with 20 mg/kg EUC in feed during the whole experimental period, diclazuril (DIC) was selected as a positive control. The results manifested that EUC supplementation lessened cecal damage, oocyst shedding and mortality, and recovering body weight gain, so the anticoccidial index (ACI) was up to 160, indicating moderate anticoccidial activity. Additionally, the safeguarding effects of EUC on E. tenella-evoked cecal damage were respectively evidenced on macroscopic, histopathological, and ultrastructural levels. Meanwhile, EUC also exerted an inhibitory effect on redox imbalance and inflammatory response caused by E. tenella. Moreover, EUC treatment remarkably suppressed the invasion-related gene transcriptional level and enhanced the apoptosis mRNA expression level of coccidia. Besides, EUC noticeably decreased the Clostridium perfringens (C. perfringens) proliferation in vivo and in vitro. In conclusion, the EUC additive presented a moderate anticoccidial effect which is associated with the remission activity on E. tenella-induced cecal injury, redox imbalance, and inflammatory response which may be associated with inhibitory effect on Eimeria invasion and C. perfringens proliferation, and activating influence on coccidial apoptosis.

Effect of Substituting Polyether Ionophore Anticoccidial Drugs With 1, 8-Cineole for the Control of Eimeria Infections in Broilers

BACKGROUND

Coccidiosis is an important parasitic disease of broiler chickens. Drug resistance to the polyether polyether Ionophore anticoccidial drugs  (PACDs) caused by long-term use has emerged as a significant problem in commercial broiler chicken production.

OBJECTIVES

This study explored the feasibility of 1,8-cineole (CIN) in replacing PACD with broiler feeding experiments and intestinal microecological experiments.

METHODS

This experiment selected 21-day-old Lingnan yellow (LNY) broilers and randomly divided them into 8 groups, with 30 chickens in each group. They were uniformly fed with full feed during the breeding period. The experimental groups were as follows: (i) three broiler groups that were fed a PACD supplementation (G1: Salinomycin Premix [SAP] 60 mg/kg; G2: Monensin Premix [MOP] 100 mg/kg and G3: Maduramicin Premix [MAP] 5 mg/kg), (ii) three broiler groups that were administered different CIN dosages (G4: CIN-L 100 mg/kg, G5: CIN-M 150 mg/kg and G6: CIN-H 250 mg/kg) and (iii) two control broiler groups (G7: infected control group and G8: healthy control group). On the 23rd day, all groups were infected with coccidian cysts, except the G8 group which was used as a blank control. After 2 weeks of continuous feeding, the growth performance changes of broilers were analysed, and the intestinal lesions of eight groups of broilers were analysed after slaughter.

RESULTS

Compared with PACD treatment, the average daily feed intake (ADFI) of the three CIN-treated groups increased by 13%, whereas the feed conversion ratio (FCR) reduced by 28%. FCR value for the high-dose CIN treatment was 2.04, 34% decline which compared with control group infected with spore oocysts. The anticoccidial index (ACI) of all PACD treatments was less than 120, whereas the ACI of the middle- and high-dose CIN treatments was higher than 180. In comparison to the Eimeria-infected control group, the diversity and total number of the microbiota in the CIN treatments increased significantly. Moreover, CIN treatment favoured the proliferation of intestinal probiotics, especially Lactobacillus sp.

CONCLUSIONS

CIN could have an inhibitory effect on parasite development as suggested in the gene function annotation of the intestinal microbiota. These results demonstrate that CIN may be a feasible natural alternative to anticoccidiosis drugs. So it was important to take precautions against and control coccidiosis in poultry production which has a lesser risk of creating resistance to substitutive PACDs.

Focused review: The role of drug combinations for the control of coccidiosis in commercially reared chickens

A survey of drug combinations employed by the poultry industry indicates that they have played an important role in the control of coccidiosis in chickens. The mode of action of their component drugs is described. Advantages that accrue from their use may include a reduction in potential toxicity, a broadening of their spectrum of activity against different species of Eimeria, activity against different stages of the life cycle, and improved efficacy due to synergism between component drugs. Integration of management procedures involving rotation of drug combinations with vaccination is desirable because this has been shown to result in a restoration of drug sensitivity where drug resistance is present and could contribute to the sustainable control of coccidiosis. Threats to the future use of the most widely used combinations, those that include ionophores, stem from the recent desire to eliminate antibiotics from poultry feeds.