Ram Fertility Testing
Ram fertility is paramount; they are responsible for 50% of flock
fertility. The consequences of running sub fertile or infertile rams are
fewer lambs born and a greater number of barren ewes. In the U.K
average infertility rates of rams in flocks is 8-10%, this number could
rise to 20-25% in some flocks. This may be related to systemic disease
within the flock such as a high incidence of lameness.
In order to identify problem rams it is essential to have a Breeding
Soundness Examination (BSE) performed on all rams 6-8weeks prior
to:

Breeding

Sale

Purchase
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Breeding Soundness Examination (BSE)
1. A complete physical examination.
2. A thorough examination of the reproductive tract.
3. A semen evaluation for colour, density and motility.
Physical Examination
A physical exam includes a complete examination of all conditions
that may interfere with the rams breeding ability.
Examination of reproductive tract
The penis prepuce is checked thoroughly for any sores or scar tissue.
The testicles and epididymis are checked for tone and size. The
scrotal circumference is measured on each ram.
Scrotal Circumference in cms;
Ram 8-14 months
Mature ram >14months
Questionable
<30
<32
2
Satisfactory
30-36
32-40
Exceptional
>36
>40
‘Examination of the testicles’
Semen Evaluation
Semen is collected with the use of an electro-ejaculator. The semen is
examined under the microscope for colour density and motility as well
as the proportions of live and abnormal sperm.
A ram with excellent fertility will have a scrotal circumference of 36+
(33+ for a ram lamb), forward motility of greater then 50%, normal
sperm of > 90% and no white blood cells.
The poor or questionable ram will have poor motility and more than
30% abnormal sperm. Any ram that has white blood cells present
would be considered of questionable fertility.
The acceptable or satisfactory ram would fall between these two
categories.
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‘Electro- ejaculator’
Motility
Morphology % Normal
‘Microscope’
Questionable
10-30
30-50
Satisfactory
30-70
50-80
`
4
Exceptional
70-100
>80
Ram Management
‘Texel Ram’
A ram may lose up to 15% of his body weight during the breeding
season consequently rams need to be in good body condition at the
time of breeding (BCS 3.5-4).
Rams should be sheared, treated for internal parasites (if necessary),
have their feet trimmed and be started on the diet that they will be
consuming during breeding 2-4 weeks prior to breeding. They should
also be included in the vaccination programme. All bought in rams
should be treated with levamisole and milbemycin and kept off sheep
pasture for 48hours to avoid the introduction of resistant worms.
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Selection of Ram
A breeding ram should have the following characteristics;

Ease of lambing

Rapid growth rate

Good conformation

Desirable body fat distribution

Wool production

Resilience or resistance to disease

Hardiness of their progeny
Ram to ewe Ratio:
The number of ewes that a ram can breed in a 34 or 51 day breeding
season varies according to the age and breeding experience of the
ram, the terrain in which the ram is working, the size of the pasture
and the number of ewes that will be cycling at the one time. A ram can
usually mate 3-4 ewes per day.
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Ram Lambs:
Most ram lambs reach puberty at 5-7months but he will be a better
breeder at 7-8months. As a general rule ram lambs should be 50-60%
of their mature weight before being used for breeding.
Ram lambs should be fed separately from mature rams. Ram lambs
and mature rams should never be run together in the same breeding
group. The older ram will dominate and may injure the younger ram.
Ram lambs should be observed closely and breeding behaviour
monitored and libido to ensure they are servicing ewes.
Recommended Ram: Ewe Ratio:
Mature rams:
1:35 to 1:50
Ram Lambs:
1:15 to 1:30
Synchronized Matings:
1:5 to 1:10
This can vary in large flocks lowland 1:80 or typically 3: 100/120.
In hill flocks 1:80/100.
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