Incorporating white clover and other companion forages into sheep grazed swards

The impact of incorporating white clover and other companion forages into sheep grazed swards on the productivity of pasture-based lamb production systems is being researched in Athenry. Researcher Philip Creighton is currently evaluating this imapct and here he gives an update and more information.

Main messages

• Current grazing studies in Athenry are focused on animal, environmental and economic impacts.
• Incorporating white clover into sheep grazed swards can reduce days to slaughter in lambs
• Perennial ryegrass-white clover swards require less chemical N compared to perennial ryegrass only swards
• The role of other companion forages is also under investigation

Introduction

Current grazing systems research projects in Athenry are focusing on the impact of incorporating white clover and other companion forages into sheep grazed swards on the productivity of pasture-based lamb production systems with special focus on the animal, environmental and economic impacts.  These projects are split into two main studies:

1. An evaluation of incorporating white clover into sheep grazed swards at two fertiliser nitrogen and stocking rate levels on the productivity of pasture-based lamb production systems
2. An evaluation of alternative forages in combination with perennial ryegrass to increase animal intake, performance and output in sheep pasture based production systems.

Grazing studies

Study 1 is investigating two stocking rate levels (11 or 13 ewes/ha) with three pasture treatments at each stocking rate i) Perennial ryegrass receiving 145kg N/ha/yr, ii) Perennial ryegrass plus white clover receiving 145kg N/ha/yr and iii) Perennial ryegrass plus white clover receiving 90kg N/ha/yr.

Key findings to-date show that the inclusion of white clover in the sward relative to perennial ryegrass alone resulted in lambs reaching slaughter weight 7 days earlier.  In terms of sward DM production including yields to-date for 2020  the grass only swards have grown 12,063 kg DM/ha, grass clover swards at 145kg N/ha grew 12,037 kg DM/ha and the grass clover swards at 90kg N/ha grew 11,936 kg DM/ha.  While no difference is evident between treatments a positive aspect is that the low N treatment (90kg N/ha) is growing just as much grass or slightly more than the other higher N treatments (145kg N/ha) with or without white clover inclusion. This is the third year (including establishment year) that this has been achieved.  Sward clover content has averaged 7% of the sward pre weaning and 15% post weaning for the grass + clover treatments. This has major implications from both an economic and environmental point of view while also improving animal performance.

Study 2  consists of five forage or forage mixture treatments: i) perennial ryegrass only, ii) perennial ryegrass plus white clover, iii) perennial ryegrass plus grazing tolerant red clover, iv) perennial ryegrass plus plantain and v) perennial ryegrass plus chicory. This study is part of the PhD studies of Walsh Scholar Lisa McGrane.  A key focus of this study will be plot based trials which will be grazed by sheep investigating establishment method, post grazing height and establishment seeding rate effects of the grass and companion forage mixtures in an effort to identify if any of these key management steps influence the persistency and longevity of the companion forages as well as their contribution to animal and sward performance.