PRACTICAL: Male reproductive soundness Flashcards
How many teeth do adult sheep have?
32 in total
0/4 incisors, 3/3 pre-molars, 3/3 molars.
What are the ages of eruption of the different teeth in a sheep’s mouth?
Permanent Tooth Eruption in Sheep and Goats Permanent tooth Age at Eruption Incisor (I1) 1-1.5 years Incisor (I2) 1.5-2 years Incisor (I3) 2.5-3 years Incisor (I4) 3.5-4 years Premolars 1.5-2 years Molar (M1) 3 months Molar (M2) 9-12 months Molar (M3) 1.5-2 years
Define ‘broken mouth’
after the 8 permanent incisors have formed, this is the progressive deterioration of teeth, the rate depends on the conditions the sheep is kept in.
Outline pizzle rot pathophysiology
The bacterium Corynebacterium renale, breaks down urea with the enzyme urease. In the month before breeding, rams are fed higher levels of protein. Once protein is >16% of the diet, urea in the urine can be >4% which makes the urine alkaline. The bacterial urease breaks this down to form excess ammonia –> severe irritation on skin around the preputial opening –> ulceration –> bacteria and C.renale invade it and infect it –> debris from the ulcer may form a crust and block the preputial opening.
Any scar tissue formed around an untreated ulcer can permanently constrict the preputial opening to prevent extrusion of the penis at breeding.
Once the opening is blocked, urea dribbles out to stain the surrounding wool. Fly strike often follows ulceration and urine soiling of the preputial area. Internal ulceration is painful; the prepuce becomes enlarged and swollen, containing old urine and debris. If there is severe interference with urination, the ram may become uremic and die.
