The effects of age on the composition of uterine fluid of broiler breeder hens and on maintenance of quality of fowl spermatozoa when stored in uterine fluid or in a synthetic medium

Abstract

We studied effects of aging of hens on some physio-chemical parameters of uterine fluid taken at 2 stages of the ovulatory cycle (12 and 18 h after the oviposition) and of uterine fluid properties as a semen diluent in vitro at 41 °C. The volume, pH, osmotic pressure, Na+, K+, Ca2+, glucose and total protein concentrations of uterine fluid were measured. The percentage of motile spermatozoa and the fertilizing ability of fowl semen diluted 1:9 in uterine fluid were tested throughout the laying cycle in meat-type hens and compared to those of semen diluted in synthetic medium M199. The results showed that the volume and the K+ and Ca2+ concentrations in uterine fluid decrease with the hens' aging, while osmotic pressure is significantly higher in older hens. But in spite of the composition differences, uterine fluids from hens of different ages have little influence as semen diluents either on sperm motility or on fertilizing ability. These observations suggest that the variations of the composition of uterine fluid with hens' aging does not contribute to the late seasonal decline in fertility observed during the later stages of the reproductive season in this species. In any case, uterine fluid is harmful to sperm quality in vitro, while M199 is an appropriate semen diluent at 41 °C. The high glucose concentration in M199, however, slightly decreases motility and the duration of the fertile period of spermatozoa.