As the focus shifts towards the breeding season, for most flocks it is important to remember that management and decisions made in your flock in the next couple of weeks will have a major impact on the flock next year and for subsequent years.
The selection and production of replacements is one key area that will influence flock productivity. However, it is one where greater emphasis is needed in many flocks. With a large proportion of lowland flocks producing their own replacements, this article will focus on some of the practical steps that should be considered for these flocks.
Having a breeding policy for your flock should be the starting point for any producer. This needs to deliver the type of replacement needed to meet the breeding objectives and performance targets set out for your flock. Breeding objectives for many flocks tend to focus on terminal lamb production; although highly important, it often comes at the detriment of the maternal characteristics needed for a highly productive flock.
As flock improvement is a continual process, traits like prolificacy, maternal ability, etc, need to be strongly considered. When deciding on a breeding policy to suit your flock, there are some inherent characteristics and performance differences between breeds that should be considered. However, we also know that there is huge variation within each breed. The challenge for most farmers is striking the right balance for their system.
At a practical level, operating a two-breed back cross (terminal x maternal) will achieve this on most farms. This breeding system needs to be in place on an annual basis to consistently deliver. It also offers the potential to use a third breed for terminal lamb production on ewes not producing replacements, thereby maximising the production benefits gained from heterosis (hybrid vigour).
Typically depending on a number of factors a flock requires between 20% to 25 % replacement rate each year to maintain flock size. In order to achieve this, there needs to be sufficient replacements produced to meet demand and allow the bottom 5% to 10 % to be discarded. To deliver this on the ground, appropriate numbers of ewes should be assigned to producing replacements. The percentage required will depend on the flock’s output.
In Table 1, a guide to the percentage of ewes in the flock required to meet replacement needs is outlined.
When identifying ewes to produce replacements, records are key. Ideally, the best-performing ewes would be selected, but in the absence of detailed flock recording this can be difficult to determine. However, problematic ewes should be avoided – lambing difficulty, mothering ability, incidences of lameness. All these traits have heritable characteristics and will also result in performance losses in replacements produced.
Sire selection
Sire selection will have a big influence on flock performance. Since the introduction of the Eurostar system and its continual development by Sheep Ireland, farmers now have the potential to use the best available information available on an animal’s genetic potential when selecting a ram. Information on traits like lamb survival, ease of lambing and milk ability are now available that will have an impact on productivity of the flock.
The long-term impact of a ram on a flock is often overlooked. To get a better idea of the effect of a ram, we will use an example of a farmer who purchases a ram lamb to produce replacements this August as a case study. We assume the following: 200 ewe flock, weaning 1.5 lambs per ewe joined, and selecting replacements from the ram he purchased. We will assume that he is active in the flock for four seasons and that there is typical culling levels present in the flock.
If all goes to plan, lambs from this ram will hit the ground next spring and continue to do so up to 2020. In Table 1. we can see the production level of the ram. The farmer will have potentially weaned 240 of his progeny over the lifespan of the ram on that farm. For the farmer, the effect of the terminal traits (growth rate, etc) are directly related to the number of ewes the ram successfully mates and how many lambs they wean. Therefore, the benefits are more easily returned to the farmer.
However, the potential maternal effect for the flock is dependent on being able to identify the progeny and incorporate them as replacements into the flock. Identifying these maternal replacements needs to start when joining the ram with the ewe intended to produce replacements. These ewes need to be clearly identified in a more permanent manner that will last up to lambing – marking fluid, branding options, use of temporary tags all provide easy visual markers to identify these ewes. Then, at lambing, the female lambs produced can be clearly identified.
Again, using the previous example in Table 2, we assume the farmer retains ewe lambs from this ram that enter the flock as 18-month-old hoggets. These will enter the flock in 2018 and lamb for the first time in 2019. The farmer continues to select replacements from this ram for a further three seasons. The effect of this ram on the female population of the flock is outlined in Table 3. There are still daughters of this ram in the flock 10 years after his purchase, with potentially over 300 lambings from his daughters in the flock – thus highlighting the long-lasting impact of a ram on a ewe flock.
The implications of this are important as many of the key traits that influence productivity are not easily identified. For example, it may take a number of seasons to identify ewes with poor milk yield or those that require more assistance at lambing.
By the time these traits become obvious, a large percentage of the daughters have already entered the flock and may not be easily identifiable. On the flip side, if the farmer selected a high-indexed ram from a flock with good levels of recording (high DQI score), he will potentially reap the benefits for many seasons to come for these harder-to-identify traits.
Furthermore, the genetic advantage gained will also affect subsequent generations in the form of granddaughters that may enter the breeding flock. Therefore it is essential that sufficient emphasis is placed on the ram chosen to produce replacements.
Breeding policy is essential.Join sufficient number of ewes to produce replacements.Ram selection has long-lasting effects on the flock.Make use of Eurostar information. Read the full focus section on sheep breeding here
As the focus shifts towards the breeding season, for most flocks it is important to remember that management and decisions made in your flock in the next couple of weeks will have a major impact on the flock next year and for subsequent years.
The selection and production of replacements is one key area that will influence flock productivity. However, it is one where greater emphasis is needed in many flocks. With a large proportion of lowland flocks producing their own replacements, this article will focus on some of the practical steps that should be considered for these flocks.
Having a breeding policy for your flock should be the starting point for any producer. This needs to deliver the type of replacement needed to meet the breeding objectives and performance targets set out for your flock. Breeding objectives for many flocks tend to focus on terminal lamb production; although highly important, it often comes at the detriment of the maternal characteristics needed for a highly productive flock.
As flock improvement is a continual process, traits like prolificacy, maternal ability, etc, need to be strongly considered. When deciding on a breeding policy to suit your flock, there are some inherent characteristics and performance differences between breeds that should be considered. However, we also know that there is huge variation within each breed. The challenge for most farmers is striking the right balance for their system.
At a practical level, operating a two-breed back cross (terminal x maternal) will achieve this on most farms. This breeding system needs to be in place on an annual basis to consistently deliver. It also offers the potential to use a third breed for terminal lamb production on ewes not producing replacements, thereby maximising the production benefits gained from heterosis (hybrid vigour).
Typically depending on a number of factors a flock requires between 20% to 25 % replacement rate each year to maintain flock size. In order to achieve this, there needs to be sufficient replacements produced to meet demand and allow the bottom 5% to 10 % to be discarded. To deliver this on the ground, appropriate numbers of ewes should be assigned to producing replacements. The percentage required will depend on the flock’s output.
In Table 1, a guide to the percentage of ewes in the flock required to meet replacement needs is outlined.
When identifying ewes to produce replacements, records are key. Ideally, the best-performing ewes would be selected, but in the absence of detailed flock recording this can be difficult to determine. However, problematic ewes should be avoided – lambing difficulty, mothering ability, incidences of lameness. All these traits have heritable characteristics and will also result in performance losses in replacements produced.
Sire selection
Sire selection will have a big influence on flock performance. Since the introduction of the Eurostar system and its continual development by Sheep Ireland, farmers now have the potential to use the best available information available on an animal’s genetic potential when selecting a ram. Information on traits like lamb survival, ease of lambing and milk ability are now available that will have an impact on productivity of the flock.
The long-term impact of a ram on a flock is often overlooked. To get a better idea of the effect of a ram, we will use an example of a farmer who purchases a ram lamb to produce replacements this August as a case study. We assume the following: 200 ewe flock, weaning 1.5 lambs per ewe joined, and selecting replacements from the ram he purchased. We will assume that he is active in the flock for four seasons and that there is typical culling levels present in the flock.
If all goes to plan, lambs from this ram will hit the ground next spring and continue to do so up to 2020. In Table 1. we can see the production level of the ram. The farmer will have potentially weaned 240 of his progeny over the lifespan of the ram on that farm. For the farmer, the effect of the terminal traits (growth rate, etc) are directly related to the number of ewes the ram successfully mates and how many lambs they wean. Therefore, the benefits are more easily returned to the farmer.
However, the potential maternal effect for the flock is dependent on being able to identify the progeny and incorporate them as replacements into the flock. Identifying these maternal replacements needs to start when joining the ram with the ewe intended to produce replacements. These ewes need to be clearly identified in a more permanent manner that will last up to lambing – marking fluid, branding options, use of temporary tags all provide easy visual markers to identify these ewes. Then, at lambing, the female lambs produced can be clearly identified.
Again, using the previous example in Table 2, we assume the farmer retains ewe lambs from this ram that enter the flock as 18-month-old hoggets. These will enter the flock in 2018 and lamb for the first time in 2019. The farmer continues to select replacements from this ram for a further three seasons. The effect of this ram on the female population of the flock is outlined in Table 3. There are still daughters of this ram in the flock 10 years after his purchase, with potentially over 300 lambings from his daughters in the flock – thus highlighting the long-lasting impact of a ram on a ewe flock.
The implications of this are important as many of the key traits that influence productivity are not easily identified. For example, it may take a number of seasons to identify ewes with poor milk yield or those that require more assistance at lambing.
By the time these traits become obvious, a large percentage of the daughters have already entered the flock and may not be easily identifiable. On the flip side, if the farmer selected a high-indexed ram from a flock with good levels of recording (high DQI score), he will potentially reap the benefits for many seasons to come for these harder-to-identify traits.
Furthermore, the genetic advantage gained will also affect subsequent generations in the form of granddaughters that may enter the breeding flock. Therefore it is essential that sufficient emphasis is placed on the ram chosen to produce replacements.
Breeding policy is essential.Join sufficient number of ewes to produce replacements.Ram selection has long-lasting effects on the flock.Make use of Eurostar information. Read the full focus section on sheep breeding here
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