Two genetic indices are available on a large proportion of pedigree rams. These indices allow farmers to rank animals based on their genetic potential across a range of terminal and replacement traits.
Terminal index: this ranks animals based on their ability to produce live, fast-growing terminal progeny with little lambing difficulty. This takes into account the progeny’s growth rate, carcase characteristics, days to slaughter and also lamb survival and lambing difficulty.Replacement index: ranks animals on the expected maternal performance such as milk yield, lamb survival and the ease of lambing. However, it also includes some terminal traits to account for the efficiency at which animal’s progeny are finished. Before selecting a breeding ram, each farmer should focus on a couple of key aspects of the €uro-Star indices of each ram:
Index of choice: farmers should pay particular attention to the index of choice. For example, if farmers are interested in finishing all of their lambs then they should focus on the terminal index. On the other hand, if a farmer is looking to retain replacements from a ram then they should focus on the replacement index. €uro-Star value: from 2019 onwards the €uro-Star value of each ram will be presented across all breeds, which allows any two breeds to be compared to each other. For example a ram with a €uro-Star value of €1.15 is expected on average to produce progeny that will generate €1.15 more profit compared with their average contemporaries. Assuming that a ram produces 100 progeny per year and survives within a flock for four mating seasons, this ram is expected to generate €460 more profit across his lifetime compared with the average ram.Star rating: within each index animals are ranked on a scale of one to five stars. One star indicates that the animal lies within the bottom 20% of ranked animals for the given trait and five stars corresponds to the top 20% of animalsAccuracy: irrespective of the type of animal that is needed, careful attention should be placed on the accuracy associated with the index or trait of interest. The higher the accuracy, the more information that is known about the animal and the greater the confidence we have that their index value will reflect their true performance potential. For ram lambs, farmers should aim to select animals with an accuracy value of at least 30% or more. Data quality index (DQI): this index rates flocks based on the quality and quantity of the data recorded on the flock over the previous year. This index can be used to help pedigree farmers identify the areas where their data recording needs the most attention in the year ahead. When selecting rams from pedigree flocks, farmers should aim to purchase rams from flocks with a high DQI (ie 65% or greater).€uro-Star indices – do they work?
Sheep Ireland €uro-Star indices have been available on a large selection of pedigree rams over the last number of years. However, the question remains, are high star-rated rams outperforming lower star-rated rams?
To assess the relevance and accuracy of the €uro-Star sheep indices for improving lamb performance, the star ratings of rams were compared with the subsequent performance of their progeny on commercial sheep farms over a four-year period.
The commercial data was collected from seven commercial flocks with records available on over 10,000 progeny from the rams. Information was available on key parameters including liveweights of ewes and lambs, lambing and reproduction data.
The performance of the progeny from the one- and five-star rams is highlighted in Table 1 and the results clearly show that lambs from rams with five-star ratings had greater performance compared with lambs from one-star rams.
The key differences between progeny born to five- and one-star rams are highlighted below.
Replacement index
More lambs: ewes from five-star replacement index rams had a higher number of lambs born and also had less dead lambs at lambing More efficient ewes: ewes from five-star replacement index rams, on average, had a lighter mature weight relative to one-star ewes. At the same levels of output, this would allow farmers to increase the number of ewes in the flock.Terminal index
Less labour at lambing: on average, lambs born to five-star terminal index rams experienced less lambing difficulty relative to rams of lower star ratings.Greater growth rates: lambs from five-star index rams were on average 2.13kg heavier than one-star lambs at seven weeks of age. This resulted in heavier lambs at weaning relative to one-star lambs. These results show the benefit of selecting a high star-rated ram based on either the replacement or terminal index, depending on the most suitable ram for their production system.
The greater on-farm performance of progeny sired by high star-rated rams also increases the profitability at farm level.
In economic terms, the benefit of selecting high star-rated rams can increase the profit on a per-ewe basis by as much as €5/year.
You can find €uro-Star rams at most pedigree society sales. You can also search for rams on Ramsearch.ie where you can apply filters for breed, location and star rating.
There is a list of performance recording breeders on www.sheep.ie where you can find breeders in your area.
You can also source rams at the annual Sheep Ireland Elite €uro-Star multi-breed ram sale, a sale of over 300 rams from several breeds.
They are all five-star, from high DQI flocks with high accuracy. The sale will begin at 12pm in Tullamore Mart on Saturday 24 August.
Two genetic indices are available on a large proportion of pedigree rams. These indices allow farmers to rank animals based on their genetic potential across a range of terminal and replacement traits.
Terminal index: this ranks animals based on their ability to produce live, fast-growing terminal progeny with little lambing difficulty. This takes into account the progeny’s growth rate, carcase characteristics, days to slaughter and also lamb survival and lambing difficulty.Replacement index: ranks animals on the expected maternal performance such as milk yield, lamb survival and the ease of lambing. However, it also includes some terminal traits to account for the efficiency at which animal’s progeny are finished. Before selecting a breeding ram, each farmer should focus on a couple of key aspects of the €uro-Star indices of each ram:
Index of choice: farmers should pay particular attention to the index of choice. For example, if farmers are interested in finishing all of their lambs then they should focus on the terminal index. On the other hand, if a farmer is looking to retain replacements from a ram then they should focus on the replacement index. €uro-Star value: from 2019 onwards the €uro-Star value of each ram will be presented across all breeds, which allows any two breeds to be compared to each other. For example a ram with a €uro-Star value of €1.15 is expected on average to produce progeny that will generate €1.15 more profit compared with their average contemporaries. Assuming that a ram produces 100 progeny per year and survives within a flock for four mating seasons, this ram is expected to generate €460 more profit across his lifetime compared with the average ram.Star rating: within each index animals are ranked on a scale of one to five stars. One star indicates that the animal lies within the bottom 20% of ranked animals for the given trait and five stars corresponds to the top 20% of animalsAccuracy: irrespective of the type of animal that is needed, careful attention should be placed on the accuracy associated with the index or trait of interest. The higher the accuracy, the more information that is known about the animal and the greater the confidence we have that their index value will reflect their true performance potential. For ram lambs, farmers should aim to select animals with an accuracy value of at least 30% or more. Data quality index (DQI): this index rates flocks based on the quality and quantity of the data recorded on the flock over the previous year. This index can be used to help pedigree farmers identify the areas where their data recording needs the most attention in the year ahead. When selecting rams from pedigree flocks, farmers should aim to purchase rams from flocks with a high DQI (ie 65% or greater).€uro-Star indices – do they work?
Sheep Ireland €uro-Star indices have been available on a large selection of pedigree rams over the last number of years. However, the question remains, are high star-rated rams outperforming lower star-rated rams?
To assess the relevance and accuracy of the €uro-Star sheep indices for improving lamb performance, the star ratings of rams were compared with the subsequent performance of their progeny on commercial sheep farms over a four-year period.
The commercial data was collected from seven commercial flocks with records available on over 10,000 progeny from the rams. Information was available on key parameters including liveweights of ewes and lambs, lambing and reproduction data.
The performance of the progeny from the one- and five-star rams is highlighted in Table 1 and the results clearly show that lambs from rams with five-star ratings had greater performance compared with lambs from one-star rams.
The key differences between progeny born to five- and one-star rams are highlighted below.
Replacement index
More lambs: ewes from five-star replacement index rams had a higher number of lambs born and also had less dead lambs at lambing More efficient ewes: ewes from five-star replacement index rams, on average, had a lighter mature weight relative to one-star ewes. At the same levels of output, this would allow farmers to increase the number of ewes in the flock.Terminal index
Less labour at lambing: on average, lambs born to five-star terminal index rams experienced less lambing difficulty relative to rams of lower star ratings.Greater growth rates: lambs from five-star index rams were on average 2.13kg heavier than one-star lambs at seven weeks of age. This resulted in heavier lambs at weaning relative to one-star lambs. These results show the benefit of selecting a high star-rated ram based on either the replacement or terminal index, depending on the most suitable ram for their production system.
The greater on-farm performance of progeny sired by high star-rated rams also increases the profitability at farm level.
In economic terms, the benefit of selecting high star-rated rams can increase the profit on a per-ewe basis by as much as €5/year.
You can find €uro-Star rams at most pedigree society sales. You can also search for rams on Ramsearch.ie where you can apply filters for breed, location and star rating.
There is a list of performance recording breeders on www.sheep.ie where you can find breeders in your area.
You can also source rams at the annual Sheep Ireland Elite €uro-Star multi-breed ram sale, a sale of over 300 rams from several breeds.
They are all five-star, from high DQI flocks with high accuracy. The sale will begin at 12pm in Tullamore Mart on Saturday 24 August.
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