Managing Your New Bull
Advice from John Bertram
John Bertram
Principal Extension Officer (Beef)
Agri-Science
Primary Industries, Queensland
The Roma (Droughtmaster) Tropical Breeds Sale bulls have been prepared with all good intent, incorporating performance measures, vaccinations for regular diseases and with varying Bull Breeding Soundness Evaluation measures. The relocation of bulls from the property of origin, holding at saleyards, mixing of vendors bulls into purchased lots, varying feed and water and the ultimate relocation to a new property, feed, water and bull social group can each and collectively have an impact on the bulls fertility. This impact will generally be short term, up to 6 to 8 weeks from the end of the stress, challenge by a new disease / organism with a corresponding rise in body temperature and ultimately settling in his new environment. It can be anticipated that the bull's semen morphology (structural soundness of the spermatozoa) will revert to a similar level as that formerly produced on the property of origin.
We therefore recommend that bulls should be managed to minimise stress at all stages of relocation. Should any subsequent breeding soundness evaluation be conducted post relocation, this should be carried out at least 2 months following the bull’s acclimatisation to his new home. Annual vaccinations should be maintained appropriately.
We suggest buyers should minimise potential longer term stressors on the newly purchased bull by ensuring that relevant vaccinations for the new location [additional to those done prior to sale by the vendor] are made soon after purchase while the bull is still subject to all other relocation effects. The bull should be managed to be free of ticks if entering a 'ticky area' when from a tick free area. The bulls should be maintained on a nutritional level to either preferably retain pre-sale body condition or if this is excessive, reflecting over feeding, (as unfortunately occurs in feedlot conditions on some studs), then there is justification to reduce body condition sharply soon after purchase to a more acceptable weight and then provide adequate nutrition to keep the bull healthy in body condition score 3-3.5 and better thereafter. Young bulls should be kept with other similar age and weight bulls avoiding mixing new young bulls with old herd sires which often predisposes to fighting and injury. Such injuries, if recovered from, often causes severe depression of semen morphology % normal spermatozoa as measured pre-sale. It can be beneficial to purchase new bulls well in advance of the time when they are required for mating allowing them time to acclimatise to their new environment. Annual vaccinations should be maintained appropriate to the environment.
