Stock Bulls – Pre-Breeding Checks
Many suckler herds are in the midst of calving and lambing, and the attention is not yet on the next breeding season. However, this is fast approaching, as for many spring calving herds it is approx. eight to ten weeks before bulls will be turned out with cows, so it is important to ensure that bulls undergo pre-breeding checks. It is important that bulls are assessed in advance of the breeding season to allow time for management decisions to be made before the breeding season starts.
Body Condition
Bulls should be ‘fit not fat’. Aim for Body Condition Score (BCS) 3 at the start of the breeding season. Often where bulls are housed for winter, influences how they are fed, with many farms not having individual bull pens, bulls are often housed with in-calf cows or male youngstock. Neither of which is ideal as a pre-calving ration will not be adequate to maintain the bulls body condition and young animals could potentially be on a diet of high concentrates. Therefore, it is essential to access body condition now and make adjustments if required. Avoid feeding excess barley which can lead to feet problems.
Feed management of new stock bulls purchased at the recent bull sales is extremely important. You will need to allow time for him to adjust to the change in his diet. Sudden changes in quantity and feed type can cause stress, which can then cause fertility issues. Gradually transition newly purchased bulls from concentrates to forage diets.
Ensure there is appropriate mineral and vitamin supplementation in the diet. Vitamin E and Selenium are just some of the key supplements required for reproductive health.
Foot Trimming
Lameness reduces libido and the bull’s ability to serve cows. Check for signs of lameness and access whether foot trimming is required due to overgrown hooves. Ideally any trimming should be carried out at least eight weeks before mating. Do not leave foot trimming to the week before bulls go out, as the bull’s feet will be tender after trimming. Also handling and trimming too close to breeding can temporarily affect semen quality, thereby affecting fertility.
Bulls should, if possible, have access to an area of concrete as being on straw bedded pens all winter can lead to feet problems.
Exercise
To serve cows, bulls need to be mobile. It is important that bulls are given exercise. The more exercise a bull gets before breeding, the better (especially if he has been housed in a pen all winter). This will improve muscle tone and allow the bull to exercise the muscles he will use when serving cows. Also, exercise is likely to reduce the risk of injury when you start to use the bull.
Is it possible to move bulls to a bigger pen to allow for more exercise? As store cattle are sold off farm shed space may come available. Consider allowing the bull to exercise in a small paddock near the farm if possible.
Bull Breeding Soundness Examination (BBSE)
All bulls should undergo a Bull Breeding Soundness Examination (BBSE) at least six to eight weeks before the start of the breeding season to identify bulls that are potentially unfit for use as breeding bulls that might otherwise go undetected until cows are PD’d. There is no guarantee that bulls will retain fertility from one breeding season to the next. A three-year trial run by SRUC, found that on average, one in five bulls fail a fertility test irrespective of age or breed, with young bulls failing as much as older stock bulls.
Semen testing will identify sub-fertile bulls. Subfertility may be a result of testicular size or sperm quality. Whatever the cause of the bull’s subfertility the end results are the same – a reduced conception rate, therefore more empty cows and a prolonged calving period. For those herds who are rotating bulls, the severity of bull infertility could well be masked, with farmers not aware there is an issue and performance still being lost.
Fertility testing only gives an indication of the bull’s fertility on the day of the test. It does not guarantee that the bull will be fertile when he is out with cows in June. However, fertility testing allows the opportunity to source a replacement bull before breeding starts or look at other options. With a calving interval now linked to the Scottish Suckler Beef Support Scheme (SSBSS), it is even more important that you know that bulls are capable of doing their job - fertile bulls should achieve a 94% pregnancy rate in nine weeks.
The Scottish Government has recently announced that the ‘Preparing for Sustainable Farming’ payments associated with soil analysis, carbon audits and animal health and welfare interventions will continue for another year. There is funding available for assessment of bull fertility and bull pre-breeding examinations. This is the final year Preparing for Sustainable Farming Funding (PSF), will be available and I would encourage you all to make use of this. For more information on PSF, visit www.ruralpayments.org/topics/all-schemes/preparing-for-sustainable-farming--psf.
As well as collecting semen to test for fertility and assess semen quality a Pre-Breeding Soundness Examination also includes examination of the reproductive organs – penis and prepuce, scrotum and testicles and accessory sex glands. As well as this the bull is physically assessed including body condition scoring and locomotion. Measurement of scrotal circumference (SC) is a key component of the examination as the scrotal circumference measurement is highly associated with daily sperm production and semen quality.
Vaccinations
Bulls can be transiently infectious (including semen) after recent exposure to a disease. It is very important to ensure that all routine vaccinations (e.g. BVD, IBR, Leptospirosis) and routine treatments for liver fluke, worms and external parasites (e.g. flies, lice) are up to date.
Useful Links
Sarah Balfour, Beef Consultant, Sarah.Balfour@sac.co.uk
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Posted by Unearthed News on 13/03/2025
