The sheep system on Tullamore Farm is currently in its fifth production year. The ewe flock has increased significantly during this period, growing from 170 head joined to the ram in 2018 to over 270 head joined to the ram in the 2021 breeding season.

There has been considerable changes to the sheep enterprise since the last open day. Mule ewes remain the dominant ewe breed in the flock but in recent years Texel x Mule cross replacements have been retained and at this stage have two lamb crops under their belt.

This decision was influenced by feedback at the last open day with farmers keen to see how first-cross progeny from Mule ewes would perform. Early indications are positive and there is a few learnings starting to emerge.

Breeding policy changes

We were expecting a drop in prolificacy levels of 0.1 to 0.15 lambs when compared to output from Mule ewes.

Prolificacy in Mule ewes has been an issue in recent years due to high barren rates and lower in-lamb rates. The litter size was recorded at 1.68 lambs and 1.75 lambs per ewe joined in 2021 and 2022, respectively. Texel x Mule cross hoggets have scanned in the region of 1.85 to 1.9 lambs per ewe joined which is on par with what was hoped for.

There is no major difference with regards to growth rates of progeny but early indications would point to more consistent slaughter performance and the potential for a better grading lamb. It is still early days to assess but it appears that ewes will also realise a higher average liveweight.

That being said, many strains of Mule ewes also have the potential to mature into heavier weights. The liveweight of ewes pre-breeding ranges from the low 60kg to in excess of 100kg with the average liveweight in recent years falling around the 85kg mark at time of joining with rams.

Farm manager Shaun Diver has also transitioned the flock replacement policy for Mule sheep from purchasing ewe hoggets to purchasing ewe lambs.

This fits in nicely with the move to retaining homebred replacements and Shaun has found that provided ewe lambs are at least 60% of mature weight when joining with rams and they receive preferential treatment in their first year there is no negative effect on performance in the subsequent breeding season.

The breeding policy has also undergone further changes in the last year with a Suffolk ram mated with ewes for the first time. This again is due to satisfy a question which repeatedly arises during farm visits regarding the performance of Suffolk x Mule cross ewes, with this cross a common breed of ewe in the sector.

Prolificacy issues

Breeding performance in the last two seasons has dipped below the targets set. Prolificacy of Mule ewes in the early years of Tullamore Farm excelled with the litter size recorded well in excess of two lambs per ewe joined.

In the last two seasons the flock has faced challenges with regards to a higher barren rate and lower litter size in ewes in lamb.

Extensive testing has taken place and unfortunately has not shed any light on what is responsible for the dip in breeding performance.

Ewe lambs pictured pre scanning in January 2022. The breeding profile of the flock has changed significantly since the last open day and continues to do so.

In 2021 empty ewes were blood tested for infectious diseases and post-slaughter kidney and liver samples were collected and analysed by the Department’s Regional Veterinary Laboratories to assess if there were any underlying mineral imbalances. Body condition was also monitored /assessed and fertility testing of rams also took place.

The one upshot of a lower numbers of triplet and quadruplet litters has been lower mortality in the flock. Mortality in 2019 and 2020 from scanning through to the last lamb being sold was recorded in the region of 17% with an underlying enzootic abortion issue contributing to losses in 2019 and listeriosis in 2020.

Mortality for the 2021 year was recorded at 13% and to-date in 2022 is running at about 11%. Weaning rate information across ewes and ewe lambs will be presented at the open day.