A meta-analysis was performed to compare the efficacy of Monimax® (nicarbazin/monensin) and a combination of nicarbazin/narasin against different Eimeria strains. The meta-analysis was performed using data from 27 different anticoccidial sensitivity tests (ASTs) conducted over a 7-year period from 2013 to 2019. The Eimeria isolates were collected from commercial farms with different anticoccidial control programs in 13 different countries.
AST’s included in this overview
The sensitivity trials were conducted by two different research institutes using comparable, standardized AST protocols (Figure 1). Groups of cage-reared birds were fed diets supplemented with either Monimax® or nicarbazin/narasin. Supplementation started two days before oral inoculation with the different Eimeria field strains (Table 1). Approximately six days after inoculation, lesion scores and performance parameters were recorded and compared to those from an uninfected, untreated control group (UUC) and an infected, untreated control group (IUC).
Figure 1: Standardized anticoccidial sensitivity test (AST) protocol
Table 1: Origin and composition of different inocula included in this meta-analysis
Year | Origin inoculum | Research Insitute | Eimeria species present in the inoculum |
2013 | Israel | INRA, France | E. acervulina, E. tenella |
2013 | UK | INRA, France | E. acervulina, E. maxima, E. tenella |
2013 | Italy | INRA, France | E. acervulina, E. maxima, E. tenella |
2013 | France | INRA, France | E. acervulina, E. maxima, E. tenella |
2014 | Belgium | Poulpharm, Belgium | E. acervulina, E. maxima, E. tenella |
2014 | EU | Poulpharm, Belgium | E. acervulina, E. maxima, E. tenella |
2014 | Poland | INRA, France | E. acervulina, E. tenella |
2014 | Poland | INRA, France | E. acervulina, E. tenella |
2014 | Germany | INRA, France | E. acervulina, E. maxima, E. tenella |
2015 | Russia | INRA, France | E. acervulina, E. maxima |
2016 | Lithuania | Poulpharm, Belgium | E. acervulina, E. tenella |
2016 | Poland | INRA, France | E. acervulina |
2016 | France | INRA, France | E. acervulina, E. maxima, E. tenella |
2016 | New Zealand | INRA, France | E. acervulina |
2017 | Russia | Poulpharm, Belgium | E. acervulina, E. tenella |
2017 | Russia | Poulpharm, Belgium | E. acervulina, E. maxima, E. tenella |
2017 | UK | Poulpharm, Belgium | E. acervulina, E. maxima, E. tenella |
2017 | Italy | Poulpharm, Belgium | E. acervulina, E. maxima, E. tenella |
2017 | New Zealand | INRA, France | E. acervulina |
2018 | Germany | Poulpharm, Belgium | E. acervulina, E. tenella |
2018 | Belgium | Poulpharm, Belgium | E. acervulina |
2018 | Russia | Poulpharm, Belgium | E. acervulina |
2018 | Denmark | INRA, France | E. acervulina, E. maxima, E. tenella |
2018 | New Zealand | INRA, France | E. acervulina, E. maxima |
2018 | New Zealand | INRA, France | E. acervulina, E. maxima, E. tenella |
2018 | Poland | INRA, France | E. acervulina, E. maxima, E. tenella |
2019 | Philippines | Poulpharm, Belgium | E. acervulina, E. maxima |
Results
Parasitology
Lesion scores were determined using the Johnson and Reid scoring system. The least square mean (LSM) by species is shown in Table 2.
The nicarbazin/narasin combination did not significantly reduce E. acervulina whereas Monimax® supplementation resulted in a significant reduction of all Eimeria species (E. acervulina, E. maxima and E. tenella) compared to the IUC. The Monimax® treatment group also showed significantly lower scores for both E. acervulina and E. maxima compared to the nicarbazin/narasin treatment group.
Table 2: Lesion scoring results (least square mean) per species using the Johnson and Reid scoring system
Treatment group | E. acervulina | E. maxima | E. tenella |
IUC | 2.02a | 1.20a | 1.81a |
Monimax | 1.69c | 0.93c | 1.39b |
Nicarbazin/narasin | 1.98a | 1.04b | 1.44b |
UUC | 0.34d | 0.48d | 0.49c |
Different letters in columns indicate significant differences at p<0.01
Performance
Daily weight gain (DWG), daily feed intake (DFI) and feed conversion ratio (FCR) were compared for the different groups during the administration period of the anticoccidial treatments. The results, shown in Table 3, indicate that Monimax® significantly improved all measured performance parameters (DWG, DFI and FCR) compared to the IUC. Although the differences were not statistically different, Monimax® supplementation resulted in better performance parameters compared to the nicarbazin/narasin treatment group.
Table 3: Performance parameters
DWG | DFI | FCR | |
IUC | 46.0c | 87.1c | 2.07c |
Monimax | 55.0b | 90.2b | 1.72b |
Nicarbazin/narasin | 53.8b | 89.2bc | 1.75b |
UUC | 67.0a | 97.4a | 1.47a |
Different letters in columns indicate significant differences at p<0.01.
Conclusions
A meta-analysis of data from 27 sensitivity tests with recently collected field strains indicates that: