With recent challenging seasons, many bulls have been exposed to all kinds of environmental stresses that may have rendered them temporarily or permanently sub-fertile or in-fertile. So it’s even more important than ever to give each bull in your current bull battery a thorough test before using them this year So what should this involve?
For many important fitness and adaption traits general herd exposure is not enough to maximise the rate of genetic improvement. Ideally these traits are actually measured for and the results analysed and used as part of balanced selection criteria that picks the best animals to breed the next generation.
The Beef Co-operative Research Centre has stated a 14% weaning rate advantage from tropical composite cattle against Brahmans, based on nearly a decade of comparative monitoring at their Central Queensland breeding locations. They found tropical Composites had both higher calving rates and higher calf survival.
Sperm Morphology not only helps rate a bull’s fertility it is also an indicator of his daughters’ fertility. We all like to make sure a bull is of the right shape and structure before we use him, but what about his sperm?
Recent industry reports have suggested that over time, the average breeding cow in Northern Australia has increased substantially in size and that this may be contributing to lower branding rates due to a potential negative correlation between mature cow weight and fertility. There is however, a lot more to fertility than just mature cow size and there is a lot more to the economics of mature cow size than fertility alone.
The topic of fertility has received much more air time in the rural media and around the cattle yards, kitchen and board room tables of beef producers. There are several elements to a successful fertility improvement strategy including bull selection, bull fertility testing, pregnancy testing, and nutrition, however, have we forgotten about hybrid vigour?