9 Nov 2015
Nick Hart
Job Title
A yearling ram carries a double copy of the MyoMAX gene, MyoMAX Gold, and is ARR/ARR for scrapie.
The mantra “fit for purpose and suitability for purpose” still rings true in sheep farming. The ram must be considered as a gene carrier that provides a farmer with the traits required to carry out his or her business.
The ram has the largest influence on the flock because of the number of progeny produced. With AI, this number can be much larger and in more than one flock in a season or multiple seasons. The multiplicity and combinations of breeds will deliver different traits.
Sheep breeders, with our knowledge and advice, need to maximise the potential for sperm to get from the testicles to the oviduct to fertilise the ova, whether by natural means or AI. To achieve this, good flock management and health is essential, as is careful selection of the ram.
Understanding the farm business is vital when looking at the suitability of rams. Returns from the slaughterhouse allow farmers to know the quality of the finished lamb they are producing. As a result, they have a better idea of the genetics they are using, which has a direct influence on the choice of ram they buy.
The individual farmer’s choice will depend on the nature of his or her sheep business and take into consideration:
It is important to know why the farmer is purchasing a new ram. There could be many reasons, but it may be a reflection on management or disease within the ewe flock, as well as replenishment of the ram team.
Purchasing a new ram is not a panacea or sticking plaster for poor lamb performance. It may prove more beneficial to spend money on blood samples for trace element status rather than a ram with a higher index.
Find out the following from the farmer:
Introducing rams that carry specific genes may be used to improve flock performance. They can be used to increase the desirability of the progeny produced to meet market trends, as well as disease control.
It must be remembered the ram only supplies half the genes, so it is important to consider the make-up of the dam line.
Remember, ewe lambs retained from a dam line sire can remain in the flock for five years, making selection of the sires an important task.
When selecting a breeding ram, farmers’ preferences are not always for specific reasons, but for fashion. The stratified sheep system is changing with the increased use of terminal breeds as dam lines. For example, more Texel-cross ewes are being used to produce finished lamb.
This has the potential to improve carcase quality, but this breed may not have environmental tolerance when moved higher up a mountain, nor the prolificacy required for economic levels of productivity.
When considering the replacement ram, age is important, as is maturity in anticipation of the workload and tupping date. Consideration needs to be given as to whether to purchase a ram lamb, yearling or mature ram. Ram lambs will vary in age by four months.
The mating load is the key question that needs to be addressed, as is seasonality of individual ram breeds and the size of ewe. Heavy, overweight and over-conditioned rams, with a large number of ewes to mate and area to roam, will not get round the ewes.
The farmer can source his or her new rams:
An insight into the breed selected is useful so a judgement can be made whether the ram is a good representative of the breed. Individual assessment of the ram, once he is chosen, must include feet, legs, teeth, head, neck, brisket, skin and fleece. The angularity of the hock and the pastern are important. There has been a general straightening of the hock in terminal sire breeds associated to the level of gigot muscularity.
Some basic knowledge of the structures of the testicles with regard to size and firmness is imperative. If the farmer is less than confident in this regard, the ram can be checked by his or her own vet once purchase is complete.
It is my opinion the best place to source rams is direct from the farm and, where possible, in good time before the ram is needed for work. All breeders are keen to show off their stock. One of the most important considerations is locomotion. The ram must have the ability to work and walk the fields, plus the athleticism to serve ewes. Looking at the vendor’s ram flock and the ewe flock will answer the question as to the level of lameness and condition of the flock.
Remember, many pedigree flocks produce progeny from sire rams that do not do much exercise. With the amount of AI and embryo transfer used in the pedigree flocks, the ram does not need to walk much. Is it possible to see whether his progeny has the ability to get round if you don’t visit the farm?
There is a trend towards the purchase of crossbred and stabilised crossbred rams/composites. The purchase of crossbred rams is not necessarily in the best interest of the flock. These rams only supply 25% of the genes from their constituency breed, as opposed to the 50% for a purebred ram. The progeny of crossbred rams tend to follow either one or other of the make-up breeds, leading to a lack of uniformity in the lambs. It is also reasonable to assume the heterosis gained by using the purebred ram is superior to the crossbred ram.
A further application of science that will influence the flock in a positive direction is to purchase purebred Signet performance-recorded rams. These, with the right genetics, have been shown to increase financial returns for farmers who buy and use them in pedigree and commercial sheep enterprises. This works well for dam line-producing farms, as well as finished lamb producers.
A proven way to gauge a ram’s genetic merit is to look at his estimated breeding values (EBVs). They are a useful guide to how a ram’s lambs will perform, whether a ram is suited to a particular production system and how he compares to others of his breed. This can be visualised by looking at the breed benchmark. It must be remembered comparisons can be made between flocks, but not between breeds.
Lamb traits of interest are:
Maternal traits of interest are:
In principal, the main contributing measurements collected for each recorded ram are:
Besides the information for dam, sire, birth date and siblings, additional data can be collected.
Some ram lambs can go through a CT scanner to accurately collect the data relating to muscle/fat/bone ratios and gigot muscularity. For further, more detailed reading and appreciation of EBVs, the author would recommend reading AHDB Beef and Lamb Better Returns information. The English Performance Recorded Flocks Directory 2014 lists 24 breeds.
Key information generally shown and discussed openly at sales for terminal breeds are:
Once the ram is purchased, the implications for biosecurity become paramount. When buying rams from any source, questions about the vaccination policy and disease status of the vendor’s farm is vital. Unfortunately, the answers are not always forthcoming. In the author’s experience, farmers are not averse to selling you their diseases, so the phrase “buyer beware” stands.
Purchasing rams carries the risk for disease entry, so isolation on arrival to the holding is a must.
This time should be as long as possible, preferably more than three weeks. This affords the ram time to get over the trauma of sale, movement and separation from his mates.
During the period of isolation, treatments and blood tests can be carried out. Observations about lameness, respiration and coughing can also be made. During this period the farmer can discuss with his or her vet the option for a ram fertility test. This can be especially important if there is evidence the purchased ram is overconditioned (this can be included with the routine examination of all the stock rams prior to them being put to work).
Overconditioned ram lambs will have rumen microflora adapted to a concentrate diet, not grass. They will require a three-week changing over period for the rumen microflora to adapt to the grass-based diet. Failure to consider this will result in the ram lamb rapidly losing weight, scouring and often becoming sub-fertile or temporarily infertile.
Treatments and vaccination considerations include:
Blood tests that need considering include:
The diseases perhaps more difficult to manage are those harder to detect, including:
The question about warranty can be raised with the vendor and a deal discussed in advance of any potential mishap or infertility. Society sales usually have a warranty listed in the sale catalogue; market sales involve the auctioneer.
Following the period of isolation, integration of the new ram into the ram team can be a dangerous time with regards to injury and needs to be managed with care.
Advice on use of a raddle for the new ram is important. Make sure harnesses used are in good shape and not likely to chafe or be too tight – especially if used on ram lambs. Finally, encourage the farmer to watch the new ram to make sure he covers the ewes correctly.
The author would like to thank AHDB Beef and Lamb – better returns and Sam Boon and Signet Recording.
