The effects of 0.1, 0.5, 1 and 3 g ovalbumin/100 ml diluent on spermatozoa stored for 24 h at 4 degrees C in TES diluent or BPSE diluent with or without seminal plasma were studied. 2. There was no effect of ovalbumin on the motility of spermatozoa stored in whole semen, except at an incorporation rate of 3 g/100 ml, when motility was reduced for spermatozoa stored in TES diluent. When sperm were stored in the absence of seminal plasma, ovalbumin stimulated motility but this effect was transitory. 3. The effects of ovalbumin on fertilisation rates were diluent- and concentration-dependent. Ovalbumin concentrations of 0.1 and 0.5 g/100 ml increased the fertilising ability of whole semen stored in TES diluent but 1 g/100 ml ovalbumin decreased it. However, 0.5 g ovalbumin/100 ml had no effect on the fertilising ability of spermatozoa stored in BPSE diluent, irrespective of the presence or absence of seminal plasma.
