One of the most important components of a profitable and productive cattle farm is the bull. The definition of a fertile bull is "a bull that is capable of naturally serving and impregnating at least 90% of 50 normally cycling cows within 9 weeks." But how do you know your bull is ready to serve? That is where we come in!
At Delatite Veterinary Services we are able to perform a breeding examination of your bull(s) tailored to your specific needs. A full physical examination, scrotal and accessory sex gland palpation, lameness check and semen collection and analysis (including morphogical examination) are carried out allowing us to give producers an in depth look at their bull's fitness and suitabilty to breed. Let's break these components down further.
Physical Examination: A bull's overall health is of vital importance to his fertility. Any illness or injury prior to joining can have disastorus results on pregnancy rates as it takes over 2 months for bulls to produce sperm. This also includes a measuring the scrotal circumference to ensure that it is greater than the minimum accepted standards and examination of the penis to rule out any abnormalities that may affect mating.
Palpation: Palpation of the testicles, epididymus and accessory sex glands (per rectum including seminal vesicles and prostate) is imperative to pick up areas of inflammation, scarring and causes for concern. Testicles that are too firm or too spongy, irregular, nodular or are differing sizes can all be indications of reduced fertility.
Gait/Conformation: While not affecting a bull's fertility as such lameness and poor conformation can a) prevent a bull from actively seeking, mounting and serving a cow in oestrus due to pain and b) pass on undesirable genetic traits eg. scissor claw. You may not think that a steer's conformation is significant in terms of hindleg conformation and hoof health but in a feedlot situation, abnormalities in these areas can result in lameness, breakdowns and reduced weight gain.
Semen Collection & Analysis: Collected by electroejaculation it allows semen colour, density and swirl motion to be evaluated. This is evaluation of live sperm in a large group.
Morphology: Evaluation of numerous individual sperm provides a direct insight into potential fertility of a bull and/or potential issues. Formalin fixed sperm are examined under a high powered microscope and checked for any abnormalities including proximal droplets, abnormal tails and detached heads. By obtaining percentages of normal and abnormal sperm in a sample we can provide an idea of a bull's fertility as only normal sperm is capable of fertilising an egg and producing a calf.
From this we can advise you on the suitability of the bull in question for intended use. We recommend bull testing be performed 2-3 months prior to joining as this allows time for some conditions to be treated and the bull to be ready are raring to go for joining.