Are lame sheep a problem on your farm? Maybe it’s because of genetics

Health is one of the biggest costs on sheep farms, but genetics can be used to breed healthier sheep, according to Teagasc’s Noirin McHugh.

“It is difficult for management to compensate for bad genetics, if there are bad genes in a flock there will be consistent problems. One of the biggest issues the sheep industry faces is health,” she said.

McHugh spoke at the Teagasc National Sheep conference, where she said that lameness is definitely a problem in a lot of Irish sheep flocks.

“There has been a lot of health data gathered by Sheep Ireland over the last number of years. There are about 33,000 lameness records.

23% of ewes show some signs of lameness, while 19% of lambs that were looked at by Sheep Ireland had some incidences of lameness.

She said that lameness on sheep farms is relatively heritable, as it passed from parents to offspring.

McHugh said that in the future, lameness could be controlled by genetics and it may even be incorporated in breeding programmes.

“Genetics can help identify rams that have superior genetics for health. Sheep Ireland is hoping to have indexes and star ratings on health traits such as lameness in the near future,” she said.

McHugh also spoke about the current Euro-star rating system for sheep.

“There are two indexes published by Sheep Ireland. There is a terminal and a replacement index. They are an indicator of the profitability that will be generated by the rams progeny.

“Rams are classified as one of five-star ratings, with one-star rams sitting in the bottom 20% of the breed and five-star rams being in the top 20%.”

The Teagasc expert presented the results of a study which compared the performance of one-star and five-star ewes in a 100 ewe commercial flock.

She said that the five-star ewes required less labour at lambing, as fewer ewes needed assistance, compared to the one-star flock.

“The five-star flock also had a higher litter size and a lower mortality, which meant that there were more lambs to sell.

The lambs from the five-star flock were also heavier at weaning, there were just over 1kg heavier.

She said that the research also showed that the five-star ewes were lighter, which is beneficial when increasing stocking rate as more of these ewes can be kept.

“Good traits will pass on to the rams progeny, if you retain some of the subsequent ewe lambs, it will pass on to the next generation again,” she said.

The terminal index
  • Meat traits
  • Carcass fat and confirmation
  • Growth traits – days to slaughter
  • Lambing traits  – lambing difficulty and survival

The replacement index

  • Ewe traits
  • Milk yield
  • Number of lambs born
  • Ewe weight
  • Lambing traits – lambing difficulty and survival
  • Meat traits – carcass confirmation and carcass confirmation