The potential of forage crops in store lamb finishing systems has attracted more attention in recent years.
The most recent spike in interest stems from the Fodder Production Incentive Measure for tillage farmers, bringing about a sharp increase in crop availability in 2018.
The Green Low-Carbon Agri-Environmental Scheme and a growing appreciation of the positive benefits of planting catch crops in tillage ground have also raised awareness and demand for information related to grazing techniques, crop management, lamb performance etc in recent years.
A new trial assessing the potential role of a selection of forages in finishing store lambs has commenced in Teagasc Mellows Campus, Athenry.
The five-year study, headed by Frank Campion, has two main objectives – to examine the performance of hill and crossbred hill lambs when grazed on a selection of forages post weaning and to quantify the differences in crop yield potential and carrying capacity of these forages, when utilised in store lamb finishing systems.
Six treatments
There are six treatments under scrutiny, including three forage crops: kale (Maris Kestral variety), forage rape (Stego variety) and the hybrid brassica redstart.
It is important to assess how these perform against the more common store lamb finishing options of grassland swards and indoor finishing.
Utilisation of forage crops started well, but has understandably dipped following heavy rainfall.
A permanent pasture sward comprising predominately perennial ryegrass is included, along with a perennial ryegrass reseed comprising a mixture of the varieties Abergain and Aberchoice.
The indoor finishing treatment is an ad-lib concentrate diet with a small volume of silage offered for rumen function.
Production records
In terms of lamb performance, the aim is to draft the majority of lambs fit for slaughter direct from the grazing treatments.
This will allow daily liveweight and slaughter performance (kill-out, carcase conformation and fat score) to be assessed across treatments.
There will also be analysis carried out within treatments on the performance of wether versus ram lambs.
Additionally, a small level of work will be completed on meat quality characteristics in future years.
Other important production aspects such as the incidence of lameness and dag / wool soiling scores will also be monitored.
Trial metrics
Pure Scottish Blackface lambs and hill crossbreds, including mainly Texel cross lambs, were purchased in August from farms in the west Mayo/Connemara region.
Lambs on the trial have a wide range of liveweight, currently averaging 31kg across the groups and ranging from 22kg to 40kg liveweight.
Frank says the variance in liveweight will also answer the question of whether the weight of lambs has an effect on performance.
There is a wide variation in the weight of lambs, with groups averaging 31kg and possessing a weight range from 22kg to 40kg liveweight.
Since purchase, lambs have undergone a robust bio-security protocol and have been grazed on permanent pasture.
They started to become acclimatised to their new diet on 24 October and were transferred full time onto their treatment on 31 October.
For lambs grazing forage crops, the transition was aided by allowing lambs access to the forage crop for a few hours on a daily basis with a runback to grass.
Lambs also received a cobalt, selenium and iodine bolus to address mineral deficiencies associated with grazing brassica crops.
Crop performance
The economics of sowing forage crops stack up financially when incorporated at a lower cost into stubble ground.
The economics of replacing a grassland sward with a forage crop are highly questionable, with the exception of incorporating it as part of a land reclamation project.
Therefore, the aim of the trial is to try and mimic as close as possible crops incorporated with tillage. The target, as such, is to achieve a crop yield in the region of 3t to 4t dry matter yield.
Crop yields are lower than anticipated, with a strong weed burden and heavy rainfall stiffling crop performance.
Crops were sown on 12 July and received 35 units N (protected urea) at sowing and 35 units three weeks post emergence.
The first year’s yield has fallen short of this target, due to a combination of a heavy weed burden and in excess of 500mm of rainfall received during August and September seriously limiting further management and spraying.
Initial estimates show the redstart crop performing the best, delivering a yield of 2.9t DM/ha at 12.75% DM.
The forage rape crop returned a yield of 2.75t/ha at a slightly higher DM of 15.5%, while kale performed the worst with a yield of 1.8t DM/ha at 14.75% DM.
Daily management
Yield and utilisation measurements are being collected at least twice a week. Frank said the first week of grazing was ideal, with utilisation in the region of 77% to 82%.
Lambs started with two-day grazing allocations and while utilisation dipped over the weekend during heavy rainfall two-day allocations have been maintained.
The crop is split with four strands of electrified polywire.
Frank explains that the wire held a good current, even when touching dry leaves.
Feed allocations are given using four strands of electrified polywire.
However, once leaves got wet, the voltage in the fence dropped significantly. Since then, a narrow strip is being clipped back with a strimmer and this is working well to contain lambs.
Lambs grazing forage crops are also being offered straw. Intakes to-date are low, with lambs only eating in the second day after entering a fresh area of crop.
Grazing allocations on grass swards are based on predicted utilisable yield, with the aim to move lambs twice weekly.
Utilisation on all crops has reduced over the weekend, with a fresh allocation of crop offered on a daily basis.
Lambs are entering swards with an average grass height of 9cm and a post-grazing target of 3.5cm.
Grazing period
Each treatment has been allocated four grazing areas measuring 0.75ha.
A feed budget has been carried out with a target of achieving eight weeks grazing.
Depending on utilisation this may be less for some crops. Lambs that are not fit for slaughter at this stage are likely to be housed for finishing.
No meal is being fed, as the objective is to see what performance lambs can achieve on the crop alone.
The potential of forage crops in store lamb finishing systems has attracted more attention in recent years.
The most recent spike in interest stems from the Fodder Production Incentive Measure for tillage farmers, bringing about a sharp increase in crop availability in 2018.
The Green Low-Carbon Agri-Environmental Scheme and a growing appreciation of the positive benefits of planting catch crops in tillage ground have also raised awareness and demand for information related to grazing techniques, crop management, lamb performance etc in recent years.
A new trial assessing the potential role of a selection of forages in finishing store lambs has commenced in Teagasc Mellows Campus, Athenry.
The five-year study, headed by Frank Campion, has two main objectives – to examine the performance of hill and crossbred hill lambs when grazed on a selection of forages post weaning and to quantify the differences in crop yield potential and carrying capacity of these forages, when utilised in store lamb finishing systems.
Six treatments
There are six treatments under scrutiny, including three forage crops: kale (Maris Kestral variety), forage rape (Stego variety) and the hybrid brassica redstart.
It is important to assess how these perform against the more common store lamb finishing options of grassland swards and indoor finishing.
Utilisation of forage crops started well, but has understandably dipped following heavy rainfall.
A permanent pasture sward comprising predominately perennial ryegrass is included, along with a perennial ryegrass reseed comprising a mixture of the varieties Abergain and Aberchoice.
The indoor finishing treatment is an ad-lib concentrate diet with a small volume of silage offered for rumen function.
Production records
In terms of lamb performance, the aim is to draft the majority of lambs fit for slaughter direct from the grazing treatments.
This will allow daily liveweight and slaughter performance (kill-out, carcase conformation and fat score) to be assessed across treatments.
There will also be analysis carried out within treatments on the performance of wether versus ram lambs.
Additionally, a small level of work will be completed on meat quality characteristics in future years.
Other important production aspects such as the incidence of lameness and dag / wool soiling scores will also be monitored.
Trial metrics
Pure Scottish Blackface lambs and hill crossbreds, including mainly Texel cross lambs, were purchased in August from farms in the west Mayo/Connemara region.
Lambs on the trial have a wide range of liveweight, currently averaging 31kg across the groups and ranging from 22kg to 40kg liveweight.
Frank says the variance in liveweight will also answer the question of whether the weight of lambs has an effect on performance.
There is a wide variation in the weight of lambs, with groups averaging 31kg and possessing a weight range from 22kg to 40kg liveweight.
Since purchase, lambs have undergone a robust bio-security protocol and have been grazed on permanent pasture.
They started to become acclimatised to their new diet on 24 October and were transferred full time onto their treatment on 31 October.
For lambs grazing forage crops, the transition was aided by allowing lambs access to the forage crop for a few hours on a daily basis with a runback to grass.
Lambs also received a cobalt, selenium and iodine bolus to address mineral deficiencies associated with grazing brassica crops.
Crop performance
The economics of sowing forage crops stack up financially when incorporated at a lower cost into stubble ground.
The economics of replacing a grassland sward with a forage crop are highly questionable, with the exception of incorporating it as part of a land reclamation project.
Therefore, the aim of the trial is to try and mimic as close as possible crops incorporated with tillage. The target, as such, is to achieve a crop yield in the region of 3t to 4t dry matter yield.
Crop yields are lower than anticipated, with a strong weed burden and heavy rainfall stiffling crop performance.
Crops were sown on 12 July and received 35 units N (protected urea) at sowing and 35 units three weeks post emergence.
The first year’s yield has fallen short of this target, due to a combination of a heavy weed burden and in excess of 500mm of rainfall received during August and September seriously limiting further management and spraying.
Initial estimates show the redstart crop performing the best, delivering a yield of 2.9t DM/ha at 12.75% DM.
The forage rape crop returned a yield of 2.75t/ha at a slightly higher DM of 15.5%, while kale performed the worst with a yield of 1.8t DM/ha at 14.75% DM.
Daily management
Yield and utilisation measurements are being collected at least twice a week. Frank said the first week of grazing was ideal, with utilisation in the region of 77% to 82%.
Lambs started with two-day grazing allocations and while utilisation dipped over the weekend during heavy rainfall two-day allocations have been maintained.
The crop is split with four strands of electrified polywire.
Frank explains that the wire held a good current, even when touching dry leaves.
Feed allocations are given using four strands of electrified polywire.
However, once leaves got wet, the voltage in the fence dropped significantly. Since then, a narrow strip is being clipped back with a strimmer and this is working well to contain lambs.
Lambs grazing forage crops are also being offered straw. Intakes to-date are low, with lambs only eating in the second day after entering a fresh area of crop.
Grazing allocations on grass swards are based on predicted utilisable yield, with the aim to move lambs twice weekly.
Utilisation on all crops has reduced over the weekend, with a fresh allocation of crop offered on a daily basis.
Lambs are entering swards with an average grass height of 9cm and a post-grazing target of 3.5cm.
Grazing period
Each treatment has been allocated four grazing areas measuring 0.75ha.
A feed budget has been carried out with a target of achieving eight weeks grazing.
Depending on utilisation this may be less for some crops. Lambs that are not fit for slaughter at this stage are likely to be housed for finishing.
No meal is being fed, as the objective is to see what performance lambs can achieve on the crop alone.
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