Relationship between Fertility of Eggs from Hens Continuously Inseminated for a Long Period and Their Agglutinin Titers against Cock Spermatozoa

An important event that fertility extremely declines after three to five months of successive artificial insemination in the chicken occurs sporadically in Japan. To elucidate this phenomenon, the relationship between fertility and agglutinin titers was studied using the laying hens which had been continuously inseminated with various doses of semen for a year.1. In the virgin White Leghorn and New Hampshire laying hens which had been mated naturally or artificially for three weeks, ones showing a positive agglutinative reaction against spermatozoa increased in number compared with those before mating.2. Agglutinin titers of sera in the group which showed the fertility above 90% throughout the year against spermatozoa from the same cocks which we used for the preceding experiment were lower than that of sera in the group which showed the fertility below 49%. No statistically significant difference was found between them. However, there found a significant difference between two groups when spermatozoa from different new males were used.3. There found a correlation coefficient of -0.20 between fertility in the laying hens continuously inseminated for the preceding year and agglutinin titers of the sera of the hens.4. Even when 0.04ml undiluted semen per hen was inseminated at 6-day intervals throughout the year, average agglutinin titer did not ascend so high. Fertility seems to be a little affected by sperm agglutinins in hen's sera, but it is not so striking compared with cases of subcutaneous or intravenous injection of spermatozoa as reported by previous workers. It is recommenbable to inseminate 0.005ml undiluted semen at 4-day intervals in order to get a higher fertility in the successive artificial insemination.