In small flocks in particular, a single infertile or sub-fertile ram may have catastrophic results for next years lambing percentage and hence profits.
Ram fertility testing falls into two parts:-
Physical examination of the Ram. A physical examination may often reveal abnormalities which may lead to poor fertility. Obviously the majority of the lesions identified will involve the scrotum, testes and penis but lesions of the hips, legs and feet may also make a ram unwilling to mate.
Examination of semen samples. These are normally obtained by electro-ejaculation. The sample will then be examined under the microscope for motility, density and signs of abnormality in the individual spermatozoa. However, not all rams will respond to this technique and therefore a negative result is not always indicative of infertility.
Teaser rams may be required in order to advance the breeding season. A vasectomy can be carried out at the practice to create these teaser rams which as well as allowing ewes to be bred earlier can also help with heat detection to show how many ewes are in lamb. Because sterile rams can still transmit diseases it is advisable to use home-bred animals for this.