Signis reduced mortality in broilers and was dependent on the level of challenge (as depicted by control mortality).
Background
Signis is a stimbiotic product, which is designed to improve animal’s own mechanisms to extract the value from dietary fibre and to improve animal performance. There are several benefits of supplementing with a stimbiotic like the solubilisation of arabinoxylans, viscosity reduction, nutrient digestibility enhancement, release of oligosaccharides developing a better fibrolytic environment in the gut, then resulting in higher animal performance. Increasing fibre utilisation is linked with higher fermentation activity, in particular butyric acid, thus improving gut functionality and the overall health status of the animal and growth. In 2021, on the first iteration of Signis holoanalysis, it was already evidenced a reduction on mortality of broiler chickens as a result of supplementing Signis. For the new iteration of the holoanalysis, the database has increased considerably and Signis effect into reducing mortality once again was significant.
Procedures
Signis holoanalysis consists of a compilation of all available data on the use of the product, looking into potential factors that can affect the response of the product on broilers’ growth and mortality. In Table 1, there is some descriptive statistics of the database used to generate the models in 2021 and 2023.
Table 1 – Descriptive statistics of trials included in the holoanalysis database in 2021 and 2023 to determine the effect of Signis in broilers
In 2023, Signis database included 53 broiler trials (+27 trials compared to 2021) increasing the number of observations from 35 to 74. Most trials had corn as the sole cereal source (46%), or corn combined with wheat (27%), or wheat was the sole cereal source (27%). Pellet was the main feed form used in the studies as well as the use of phytase. Almost all trials (99%) have been conducted without the supplementation of antibiotic growth promoters, while 19% of the trials have included coccidiostat in at least one of the feeding phases. Trials duration was on average 39 days (ranging from 10 to 42 days).
The efficacy of Signis across all studies has been measured by subtracting the result of Signis treatment to its corresponding control treatment also referred as delta observation (Δ). Delta observations have been calculated from the overall trial duration instead of by phases. In total, a maximum of 74 delta observations have been recorded in 2023. Bird mortality was the focus of the holistic exercise.
Results
In terms of absolute values across the 53 studies, data has shown an average mortality of the control and stimbiotic treatments of 4.6% ± 3.56 and 4.0% ± 2.66, respectively; meaning that Signis supplementation reduced, on average, 0.59 percentage units the mortality of the flock compared to non-supplemented birds (Table 2).
Table 2 – Overall mortality (%) of the Control and Signis treatments and ΔMortality
†The more negative is ΔMortality the better Signis efficiency
In 2021, it was observed that Signis reduced mortality, however with a limited number of observations (n=35). Based on the holistic approach, the mortality rate of the control group influenced the response of Signis (P < 0.01) explaining 19% of the variability of the model. For the 2023 iteration, the previous findings were corroborated by increasing the sample size and thus the robustness of the model. Sixty-four percent (64%) of the model variation is explained in a negative quadratic relationship being the control bird mortality as the only significant variable influencing ΔMortality (P < 0.05). The model has been validated twice by randomly splitting out 60% of the observations for training and using the remaining 40% of the observations for validation. Such a process increases the reliability and robustness of the prediction model given the limited sample size. In addition, the quadratic equation given in the model allows the prediction effect of Signis on mortality (Figure 2). For example, if the mortality of a control group is 5%, Signis could reduce the mortality by -0.5 percentage units (ranging from -1.14 to +0.2 considering the confidence intervals), however, if the mortality of a control group is 10%, Signis is predicted to reduce mortality by -3.5 percentage units (ranging from -4.6 to -2.4). The intercept for a zero effect of Signis (Δ = 0) on mortality is fixed at 4% of mortality in the control group showing the effectiveness of Signis, specially in challenge situations.
Figure 1 – Predicted effect as a result of supplementing with Signis in function of the mortality of the control group in broiler chickens
The holoanalysis demonstrates the efficacy of supplementing Signis by reducing mortality and likely ameliorating subclinical disturbances. Signis may act through different pathways in the animal physiology and its interaction with the intestinal microbiota with positive results, especially when the sanitary conditions are not guaranteed.
Conclusions
This holistic approach confirms the efficacy of Signis supplementation on mortality reduction highlighting its association with gut function and health.