Effect of nonylphenol on semen quality and testosterone level in male breeders of Brown Tsaiya

Nonylphenol (NP), an estrogen like compound classified as an endocrine disrupter capably interfering hormonal system of numerous organisms, originates principally from the degradation of nonylphenol ethoxylates (NE) widely used in industrial, agricultural, commercial and household applications as detergents, emulsifiers, wetting and dispersing agents. Due to the extensive use of NE, NP may reach either sewage treatment fields or rivers and contaminate environments from many aspects. Water fowls mostly raised with water pools in which the water coming from either underground or rivers may be contaminated with NP and were consequently affected of their reproductive performances. Thus, the study was to investigate the effect of NP on reproductive performances in male breeders of Brown Tsaiya (MBBT) in Taiwan. Sixty MBBT at age of 50 wks were randomly assigned into five treatments, i.e., control, corn oil, and oral administration of either 1 (NP1), 10 (NP10) and 250 (NP250) mg NP dissolved in corn oil/kg body weight daily for 28 days. Semen was collected weekly for analyses of counts, viability, acrosome integrity, mitopotential integrity, total cytosolic calcium content and DNA condensation (sperm chromatin structure assay, SCSA) of sperms, and testosterone level. Fertility was determined with intermingled semen collected from each bird in the same treatment for artificial insemination. Results revealed that there were no significant differences among the treatments in counts, viability, acrosome integrity, mitopotential integrity and total cytosolic calcium content of the sperms as well as fertility. SCSA in NP10 or NP250 was, however, significantly higher than that in the other treatments (P<0.05). Testosterone level in NP1 was significantly lower than that in the other treatments (P<0.05). In conclusion, nonylphenol may affect semen quality and testosterone level in male breeders of Brown Tsaiya and consequently reduced their reproductive performance if the duration and/or the dosage of exposure are over the threshold which has not been fully and clearly elucidated so far.