Determination of minimum insemination dose of spermatozoa for optimum fertility and profitability in White Leghorn chicken using artificial insemination

The breeder cocks of selected and control strains of White Leghorn were grouped into good and medium based on their predicted fertilizing ability of spermatozoa as per INT (Iodonitrotetrazolium) dye reduction test. In a group fertility trial, the pooled, fresh and diluted semen from cocks of good and medium groups of the strains were inseminated in hens with 5,10,15,20,25,35 and 50 millions of spermatozoa. The fertile dose 90 (FD90) i.e. the minimum number of spermatozoa to yield 90% fertility following single insemination) was calculated by regression of fertility on number of spermatozoa inseminated for both good and medium groups in selected and control strains. The FD90 for good and medium groups of selected and control strains were 24.30,30.65,30.89 and 33.66 millions of spermatozoa respectively. The overall FD90 for selected and control strains were 26.34 and 31.99 millions of spermatozoa. The small insemination dose of spermatozoa from superior cocks would cover large number of hens and help to eliminate inferior cocks resulting higher economic gain.