Grange Breeding research on cattle sexual development and twinning
Researchers at Teagasc Grange have, and continue to investigate two areas of breeding; "Insights into the sexual development of cattle" and "Does twinning have a role for suckler beef systems?" You are invited to meet the researchers yourself by visiting Beef 2022 on 5 July next. Learn more here
Insights into the sexual development of cattle
David Kenny, Stephen Coen, Colin Byrne, Mark McGee and Kate Keogh, Teagasc, are the researchers working on this study
The costs involved in producing a young bull or heifer replacement necessitate that both genders are eligible for breeding as soon as possible and are subsequently sustained within the herd.
Bio-economic studies conducted by Teagasc show that heifers that are bred at the start of their first breeding season and subsequently calve at 24 months of age are much more profitable and produce lower greenhouse gas emissions than their later-calving contemporaries.
Despite its importance, age at puberty is a trait that has received relatively little research attention and is not routinely measured at farm level. In a series of studies led by Teagasc and funded by both Science Foundation Ireland and the Department of Agriculture, Food and the Marine, we investigated the underlying biology of sexual development in both bull and heifer calves, including the influence of diet and genetics. We offered both male and female calves either a high or moderate feed allocation at various stages of development from shortly after birth onwards. Age at puberty onset was measured in both genders together with other fertility-related traits.
Results
The results indicate that nutrition and rate of bodyweight gain during the first six months of a calf’s life has a much greater effect on the age at which either bull or heifer calves reach puberty, and thus are eligible for breeding, than diet or performance thereafter.
The work has also provided novel insights into the underlying biological mechanisms and some of the key genes affecting sexual development in cattle, which, following further validation, could be utilised as part of future national cattle breeding programmes.
Does twinning have a role for suckler beef systems?
Aoife Bergin and Paul Crosson, Teagasc, are the researchers working on this study
Twinning can increase the number of calves and weaned weight per cow thereby, increasing output for suckler systems. However, costs per cow tend to be greater and liveweight performance per individual calf is reduced.
Using data from international studies on ‘twinning’ herds, research at Teagasc Grange is analysing the effect of twinning on the economic performance of pasture-based suckler beef systems.
Preliminary results
Preliminary results indicate that higher twinning rates increased carcass output by up to 27% and increased farm net margin by up to 126% for spring-calving suckler-to-beef system. These results suggest that, when part of a defined management structure, twinning has the potential to substantially improve net margins on suckler calf-to-beef farms.
This research will also explore the impact of twinning on greenhouse gas emissions from suckler calf-tobeef systems.
Interested in finding out more? Then Beef 2022 is the place to be on July 5th!
BEEF2022 Open Day
Come along to Beef2022 where you will meet Teagasc research, advisory and education staff in person.
BEEF2022 on Tuesday 5th July in Teagasc Grange is a free event and is a day not to be missed!
Further information www.teagasc.ie/beef2022
These two articles were first published in Today's Farm - May/June 2022 where you can read more articles like this one.