1. Equine Male Reproductive System

2. Consists of: 2 testes 3 accessory sex glands Series of tubules through which spermatozoa are transported to the female

3. Sperm can’t live at body temperature Heat regulation of the testes is critical Scrotal muscles expand and contract to regulate temperature

4. Ridgling or Cryptorchid Ridgling = no testicles descended Cryptorchid = only one testicle descends Testicle in the body cavity is sterile Suspended testicle is fertile Is hereditary – usually is the left testicle

5. Accessory Sex Glands: Seminal vesicle Prostate Bulbourethral gland These furnish alkaline fluid secretions to transport and neutralize the urethra in which sperm is transported from the epididymis through the urethra, to the end of the penis

6. Scrotum: Outpouching of the skin, divided into two sacs by a septum Each contain one testicle, located on either side of the penis Descend in a male between the last three weeks of gestation and the first two weeks after birth

7. Ejaculation consists of: Erection: stimulated by teasing the stallion -the penis lengthens and stiffens through engorgement with blood Emission: semen arrives in the pelvic urethra Ejaculation

8. Semen consists of: Spermatozoa Fluid from the cauda epidymis Fluid from the accessory glands

9. Hormones used by the male during reproduction: LH FSH Testosterone

10. Sperm Production: Occurs at age 1 Don’t reach reproductive capacity until age 4 Remains capable until age 20

11. Sperm output is influenced by: Season – need 16 hours of sunlight and 8 hours of dark Testicle size Age Frequency of ejaculation