A study of farm biosecurity and egg sanitation of the friendly layer production system in Taiwan

• Main Author: 蕭丞宏
• Other Authors: Ching-Hsien Chao, Ph. D.
• Format: Others
• Language: zh-TW
• Online Access: http://ndltd.ncl.edu.tw/handle/81985133036980859238

碩士 === 國立嘉義大學 === 動物科學系研究所 === 103 === Due to the global trend in the animal welfare for laying hens, some egg farms had changed the conventional cage system to the friendly non-cage system in Taiwan. However, the levels of pathogens contamination under friendly layer production system is an important factor influencing animal health and food safety. The aim of this research was to survey the microbial contamination of the rearing environment and egg products of friendly layer production system in Taiwan, and to investigate disinfection methods to improve farms biosecurity and eggs hygiene. Seven commercial friendly layer farms and an experiment ranch were surveyed in this research. Samples of the feeder, drinker, nest box or cage, cloacal swab, inside floor, outside floor, farm-fresh eggs, floor eggs and packed eggs were collected from farms in warm and cool season, respectively. All samples were determinated the total count of bacteria and coliforms and contamination rate of Salmonella. The bacteria count of the bottom of conventional cage was lower than that of nest box of friendly layer production system, but feeders in the conventional cage had higher contamination levels than that in friendly layer production system. Free-range system had higher bacteria and coliforms contamination levels at feeder and drinker than other friendly production system, but floor eggs had lower contamination levels. In warm season, feeder, bottom of nest box or cage, and floor eggs had higher bacteria and coliforms contamination levels, regardless of production system. Enclosed barn had the highest contamination rate of Salmonella in warm season. The combination of 0.015% citric acid and 5 ppm chlorine could significantly reduce the total count of bacteria in poultry drinking water. Ozone treatment performed at room temperature for 60 min could decrease total count of bacteria on the eggshell. In conclusion, commercial friendly layer production system had higher bacteria contamination, and a suitable biosecurity programs should be designed and implemented in warm season, especially for enclosed barn system. Combined citric acid with chlorine could improve poultry drinking water quality; and ozone treatment may have the potential to control and prevent microbial contamination of eggs.