Gonadal and epididymal sperm reserves in the stallion equus caballus

The current study was conducted on gonadal and epididy-mal sperm reserve of 42 Arab and Native Stallions with unknownbreeding history. These animals were surgically castO~atedat the Department of Surgery and Obestetric, Faculty of Ve-terinary Medicine, Giza, EI-Abbasia Veterinar,y~ $ospital(Brook Hospital), Veterinary Hospital of the Armed forces and.the Zoo-Garden, Giza. The study was under taken during aperiod of one year.The stallions were divided into six groups accordingto their age. The age ranged in these groups was 3.5-4 yearsfor the first (3 stallions); 4.5-5 years for the second (3stallions), 6-7 years for the third (8 stallions); 8-9 yearsfor the fourth (5 stallions); 10-13 years for the fifth (14stallions) and 15-18 years for the sixth group (9 tallions).The gonadal and epidiaymal sperm reserves were studiedhaemocytometrically from tissue homogenates using modifiedNeubauer haemooytometers.An increase in the three testis dimensions occurred installions of age group I through III (3.5-7 years). A slight