# Research Progress in the Early Warning of Chicken Diseases by Monitoring Clinical Symptoms
## 4 Conclusions  
Disease control is a critical problem for poultry farmers. Traditional manual disease inspection methods cannot meet the needs of the growing number and scale of poultry farms. Clinical symptoms directly manifest from poultry disease. Automatic disease detection and early warning technology based on clinical symptoms have the potential to monitor poultry health status in a real-time, fast and non-destructive way. At present, the detection of poultry diseases is usually based on the sound characteristics, body temperature characteristics, fecal characteristics, production characteristics (water intake, feed intake, etc. ), activity characteristics and posture characteristics of the animals. Table 2 lists the comparison of five clinical symptoms used for the early warning of disease. The above characteristics are mainly collected by machine vision systems, sound pick-up equipment, wearable sensors and other methods, which have advantages and disadvantages. The machine vision method has been relatively mature from the construction of the system to the deployment of the algorithm, but it has the problems of easily limited vision and difficult individual tracking. Sound processing technology has broad application prospects. The price of related equipment is low, but the sound recognition results are susceptible to environmental noise, which means that sound analysis technology may be more suitable for use at night. The wearable sensor is easy to install, and the obtained data are highly reliable, but it may cause stress on poultry, and the signal transmission distance and endurance of the sensor need to be optimized. Although the importance of clinical symptoms in the early warning of poultry diseases has been recognized, it has not been fully utilized. Cockscomb abnormalities (abnormal color, swollen, scabby, shrunken), ocular anomalies (congestion, lacimation) and changes in the feathers (fluffy, matte, fall off) of chickens are also important clinical symptoms. Furthermore, Table 3 summarizes the clinical symptoms of common chicken diseases. We hope that these symptoms in column 4 of Table 3 can be used as indicators for the early warning of poultry diseases in future studies. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Clinical Symptoms** & **Collection Devices** & **Monitoring Level** & \multicolumn{2}{c}{**Advantages**} & \multicolumn{2}{c}{**Disadvantages**} \\ \hline \multirow{2}{*}{Vocalization} & Microphone and camera & \multirow{2}{*}{Group} & • Low cost & • High interference from \\  & & & • Easy installation & & environmental noise \\ \hline \multirow{4}{*}{Temperature} & Temperature sensor & Individual & • Relatively mature & • Insufficient endurance \\  & & & • Widely used & • Short transmission distance \\  & & & • Remote temperature & & \\  & & & • measurement & & \\  & & & • High visualization degree & & \\  & & & & of temperature distribution & \\ \hline \multirow{4}{*}{Feces} & Camera & \multirow{2}{*}{Group} & • Low cost & • A bad environment may result in \\  & & & • Can monitor the chickens & & poor equipment life \\  & & & • in the whole loop & • Strict light conditions \\  & & & • Can identify specific & • No relevant studies have been \\  & & & & biomarkers & found \\ \hline \multirow{4}{*}{Activity} & Acceleration sensor & Individual & • Low cost & & \\  & & • High sensitivity & • Easy to fall off \\  & & Camera & Group & • Can monitor multiple & • Severely affected by light \\  & & & & objects simultaneously & conditions \\ \hline \multirow{2}{*}{Posture} & \multirow{2}{*}{Camera} & \multirow{2}{*}{Individual} & • Little effect on chicken & • Algorithms for solving the \\  & & & • High intelligence & & chicken overlap problem are not \\ \cline{1-1}  & & & • High intelligence & & well developed \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Comparison of five clinical symptoms used for the early warning of disease. The transformation of the poultry industry to information and intelligence is the trend of future development.