Are Your Rams Ready for Breeding? By Delma Kennedy, OMAFRA
H
ave you looked at your rams lately? Of course you have. But I mean really looked close. The farm is busy and sometimes breeding time arrives at times of the year when a lot of things are happening at the same time. Do you know what your conception rates are? I don’t mean that most of the ewes got pregnant. I mean, do you know what exact percentage of ewes became pregnant on the first heat and second heat in each breeding period and overall for the year? The table below shows average conception rates and excellent conception rates for in and out of season. Season
Average Conception
Excellent Conception
In
90%
96%+
Out
50-60%
70%+
If these conception rates are not being met in your operation, you might want to take a closer look at your rams. If they are being met, you might already be taking a good look at your rams. In 2012, 897 rams from 35 accelerated lambing flocks in Spain were evaluated as part of an objective to improve farm productivity. It turned out that 16.7% or 1 in 6 rams were classified as unsuitable breeders. This mean’t that there were fewer effective rams for breeding than the farmers thought there were. Could this be happening on your farm? A closer look at your rams could either give you some peace of mind or point out some changes that should be made.
Ram Evaluation Prior to Breeding Breeding soundness should be evaluated at minimum on an annual basis and ideally two months prior to breeding season. You need to put your hands on each ram and determine if they are likely good breeders. A basic evaluation can be done which considers three main components: general health, body condition score and the condition of the genitalia.
Body Condition Score A low body condition score is an obvious sign that there is either a health problem or a nutrition problem with your ram. To be ready for breeding, rams should be in a body condition score of 3 or 3.5. This means that when you feel the short ribs in the loin area, you should be able to feel them and they should be smooth and well rounded. You should not be able to put your fingers under the short ribs. The spine over the loin should also feel smooth with the bones well rounded. It has been proven that rams with low body condition scores will have poor reproductive performance. Nutrition has a direct effect on the size of the testicles and the efficiency of sperm production. Rams fed a high diet versus a low diet for 9 weeks had testis with 86% more mass and produced 250% more sperm (Martin, 2010). It is important to note that sperm production in rams takes 49 days. This means that changes in nutrition need to happen at least two months before the ram is turned in with the ewes. Genital Examination The primary objective of the examination is to look at the scrotal circumference, check testicular tone and check for lesions. Scrotal circumference is a direct indication of how much sperm can be produced. In a ram, larger is better. The best way to decide if the testicles are big enough is to measure them with a scrotal tape. Some basic rules of thumb are that a ram greater than 70kg should have a scrotal circumference greater than 30 cm and a ram greater than 110kg should have a scrotal circumference greater than 36cm. The following table shows some suggested guidelines by ram age. Ram Age
Exceptional
Satisfactory Questionable
8-14 months
>36cm
28-36cm
<28cm
>14months
>40cm
32-40cm
<32cm
Ridler, 2012
General Health In order to ensure the ram is keen and ready to breed, he needs to feel good and be in good general health. Soundness of the feet and legs is important to ensure that the ram is ready and willing to mount as many ewes as possible. Limping is a sign that the ram is not pain free. Inspect the hooves and trim them if needed. The teeth should be checked to ensure that the teeth are in good shape and that they still meet the top pad well enough to eat efficiently. Also have a look for any other defects like impaired vision, parasites, pneumonia, abcesses or pink eye. Photo courtesy of Paula Menzies
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OSN S e p t e m b e r 2 0 2 0
