Sheep breeding
General ram management

Nancy Ollerenshaw, formerly of the Agency for Food and Fibre Sciences
Revised by Tony Hamilton and Nicole McLennan, Agency for Food and Fibre Sciences 

Key points

• Examine and cull rams with testicular lesions and abnormalities.
• Rams should be in a forward store condition at joining; some supplementation may be necessary in dry years.
• Check for blowflies, lice and worms. Treat if necessary with the correct product.
• Vaccinate rams to protect against clostridial diseases and cheesy gland.
• The ram paddock should be securely fenced with ample feed, shade and water.
• Joining time should be determined by seasonal rainfall probabilities.
• Two to three per cent of rams may be needed for joining depending on age, health and condition of rams, whether the ewes are maidens, time of joining and the joining paddock features (timber, multiple waters etc).
• When replacing rams consider age, stud health status, genetics and cost of rams.

Introduction

Rams are a capital investment for any commercial or stud breeding enterprise. Therefore, they deserve special consideration. It is important to ensure they are in top working order, as ram management is a critical factor in determining the success of your breeding program.

Fertility

In order to utilise the full genetic potential of your rams, their fertility status must be optimal at joining. Surveys have shown that 10-15 per cent of flock rams in Australia are ‘duds’; fortunately most of these can be identified by carefully examining the rams for breeding soundness. All rams should be manually examined and culled for testicular lesions and abnormalities. This can be done prior to joining or at shearing, as well as before the purchase of replacement rams.

Swellings or lesions in the testicles reduce sperm production and can be caused by a variety of factors such as:

• Epididymitis: the head or tail of the epididymis becomes hard and swollen. Sperm may be completely restricted from flowing to the penis. Palpate to detect any swelling and hardness in the epididymis. Infection can be quite common and rams should be culled to eliminate spreading in the flock.
• Brucellosis: palpate rams to determine the shape and size of the testicles. Testicles should be firm and even in size, with no signs of softness or hardness. For more information refer to the DPI Note Sheep breeding: managing ovine brucellosis to maximise ram fertility.
• Cheesy gland: may be caused by shearing cuts and unhygienic dipping practices.
• Mechanical damage caused from sticks and logs.

For more information on sperm production refer to the DPI Note Sheep breeding: sperm production in rams.

Rams should not be shorn close to joining, as overheating (caused by exposure to high temperatures without the insulation properties of the fleece) may adversely affect sperm production. Rams are normally shorn twice a year, coinciding with the general shearing and crutching operations.

Mustering, lack of shade and infections can cause heat stress in rams prior to joining. This can delay sperm production causing infertility for most of the joining period.

Nutrition

To get the maximum reproductive performance out of rams, they should be in a forward store condition (score 3-4) at joining. Overweight rams are reluctant to work due to over-heating, while underweight rams may not have sufficient stores of viable sperm.

In good seasons, pasture growth may be adequate, but in some years, supplementation with protein and/or energy may be necessary. To receive the full benefit, feeding should start at least two months prior to joining, as viable sperm production takes 49 days (seven weeks). It also helps to build rams up slowly, as last minute excessive feeding tends to lay down fat rather than muscle.

General health

By shearing twice a year, it is easier to control parasites, avoid heat stress and wool blindness. Rams with shorter wool are also more active and able to better utilise the available pasture. Particular attention should be paid to:

• Blowflies and lice: to reduce fly numbers, use blowfly traps, but if a fly wave is anticipated then strategic jetting may be needed. Jetting may also be required to reduce poll strike caused by rams fighting. To prevent lice, check for lice and treat if appropriate with an effective chemical. For more information refer to the DPI Note Sheep parasites: managing blowflies and lice on rams.
• Worms: to minimise worms, worm check and treat if appropriate with an effective chemical. For more information refer to the DPI Note Sheep parasites: worm management in rams.
• Vaccination: a 6-in-1 vaccine protects against clostridial diseases (pulpy kidney, tetanus, malignant oedema, black leg and black disease) as well as cheesy gland. Two vaccinations are required four to six weeks apart, followed by an annual booster. Refer to DPI Note Livestock health: infectious diseases of rams.
• Horns: trim for ease of handling (about midway around the first curl, level with ear).
• Hooves: trim to ensure soundness, especially if rams are on black soil country. Care should be taken not to trim across the point of the hooves and to trim at least one month before joining to avoid lameness.
• Pizzle or penis: examine for damage from grass seeds, infections and shearing cuts.
• Scrotal skin: testicles are very sensitive to small changes in temperature. Inflammation and thickening of the scrotal skin interferes with temperature control in the testicles, ‘cooking’ the developing sperm. Chorioptic mange is a common cause of scrotal dermatitis, which can severely impair fertility.

For more information on the general health of rams refer to the DPI Note Sheep breeding: ram health and well being.

The ram paddock

The ram paddock should be securely fenced, with enough country and available feed to maintain rams in good condition (remember, rams need to be regarded as at least two dry sheep equivalents). Ample shade and cool, clean water are also important requirements of a ram paddock. For more information refer to DPI Note Sheep breeding: the ram paddock.

Joining

Rams should be joined with ewes at a time determined by seasonal rainfall probabilities. Join so that lambing occurs when there is a high probability of good quality feed being available. If joining occurs in spring and summer use the ram effect to improve pregnancy rates, as it is not the ewes’ natural breeding season. To take full advantage of the ram effect, in-between joinings, the rams should be separated from the ewes by at least one to two kilometres. For more information refer to the DPI Note Sheep breeding: the ram effect.

The joining paddocks should have single easily accessible waters with adequate shade to allow congregation of ewes and rams.

For adult ewes, two per cent of mixed age rams, in good health and condition, and free of testicular faults is more than adequate. Maiden ewes show a shorter, less distinct heat; so three per cent of rams can be used. In very large, heavily timbered paddocks, with multiple waters, or with spring joining, higher percentages of rams may be needed.

For more information on joining refer to the following DPI Notes:

• Sheep breeding: joining management to increase pregnancy rates
• Sheep breeding: time of joining
• Sheep breeding: joining percentages
• Sheep breeding: joining length.

Replacing rams

Leaving rams in the paddock until they physically wear-out is wasting genetic potential and costing you potential lambs. Once rams reach six years of age, their fertility, libido and serving capacity, can decline significantly. For more information refer to DPI Note Sheep breeding: desire, ability and stamina of rams. Older rams may also keep the younger rams away and not allow them to serve many ewes.

Replacing rams after four or five years use is a good idea. This means that a balance of mixed age rams is maintained, and you are buying improved replacement rams every year from your stud, thus maintaining the same rate of genetic gain as your stud.

When purchasing replacement rams, there are several things you need to consider:

• Health status and disease accreditation: allows avoidance of inherited problems like Ovine Johne’s Disease (OJD), Ovine Brucellosis and worm resistance.
• Genetic superiority of studs and rams: investigating the genetic superiority of different studs will help you to select the stud that best suits your production objective. Younger rams are also genetically superior to older rams, assuming the stud is making genetic progress.
• Cost: work out what your rams are costing you per lamb. This depends on weaning percentage, ram joining percentage, ram purchase price, and replacement costs.

For more information on replacing rams refer to the following DPI Notes:

• Sheep breeding: ram culling and replacement policy
• Sheep breeding: the role of genetics and the environment when replacing rams
• Sheep genetics: which stud to choose?
• Sheep genetics: which grade of ram to choose?
• Sheep breeding: what to do when you get your replacement rams home.

Further information

For further information contact the DPI Call Centre on 13 25 23 (Queensland residents) or (07) 3404 6999 (non-Queensland residents) between 8 am and 6 pm weekdays, or e-mail callweb@dpi.qld.gov.au.

This DPI Note is published on DPI’s web site and DPI’s PrimeNotes CD-ROM.

Information contained in this publication is provided as general advice only. For application to specific circumstances, professional advice should be sought. The Department of Primary Industries Queensland has taken all reasonable steps to ensure the information in this publication is accurate at the time of publication. Readers should ensure that they make appropriate inquiries to determine whether new information is available on the particular subject matter.