Abstract: 【Objective】 The purpose of this study was to study the effects of semen collectors, temperature and humidity, ammonia concentration and light intensity of pigpen on semen quality of boars, in order to improve semen quality.【Method】 2 966 semen determination records were collected from 347 Duroc boars aged (580±48) d from November 2021 to February 2022. The sperm collector made a daily record of the boar's sperm collection.Temperature and humidity, ammonia concentration and light intensity parameters in the pigpen were measured daily at 09:00 am. The semen traits were correlated with the records of semen collectors and environmental parameters by R software.【Result】 ① The sperm collector had a significant effect on semen quality (P<0.05). The semen collected by the sperm collector No.8 had the highest sperm motility and the lowest sperm abnormality rate. ② When the ambient temperature of pigpen was 22 to 25 ℃, the sperm motility was significantly higher than 18.5 to 22 ℃ (P<0.05), and the sperm abnormality rate was significantly lower than 18.5 to 22 ℃ (P<0.05). ③ When the relative humidity was 70% to 77%, the sperm motility was the highest and the sperm deformity rate was the lowest, but the total sperm count was the lowest, and the difference was significant compared with the relative humidity 46% to 60% (P<0.05), while there was no significant difference when compared with the relative humidity of 60% to 70%(P>0.05). When the relative humidity was 60% to 70%, the sperm motility, sperm deformity rate and total sperm count were all at high level. ④ With the decrease of ammonia concentration, sperm motility and total sperm count showed an upward trend, and sperm abnormality rate showed a downward trend, when ammonia concentration was 2 to 4 ppm, sperm motility, total sperm count and sperm abnormality rate were significantly different from that when ammonia concentration was 5 to 7.3 ppm (P<0.05). ⑤ When the light intensity was 90 to 110 lx, the sperm motility and sperm progressive motility were the highest, which was significantly different from that when the light intensity was 130 to 164.5 lx (P<0.05). Light intensity had no significant effect on sperm malformation rate (P>0.05).【Conclusion】 The semen quality of boar was higher when the temperature range was 22 to 25 ℃, humidity range was 60% to 70%, ammonia concentration was 2 to 4 ppm and light intensity was 90 to 110 lx. In production, the management and training of semen collectors should be strengthened to reduce the mechanical damage and bacterial contamination in the process of semen collection, so as to provide reference and theoretical basis for the future research and revision of the comfortable environment parameters of breeding boars and scientific regulation of the piggery environment.

Key words: Duroc boars; sperm collectors; environmental parameters; semen quality