Assessment of Cattle Preference for Perennial Ryegrass Varieties in Association with White Clover. Does White Clover Content Interfere? |
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| Authors: | D Stilmant P Limbourg Ph Lecomte |
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| Institution: | Authors' addresses: Dr D. Stilmant (corresponding author;e-mail: ), Ir P. Limbourg and Dr Ph. Lecomte, Walloon Agricultural Research Center –Farming System Section, 100, rue du Serpont –B-6800 Libramont, Belgium |
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| Abstract: | There is a need to evaluate grass varieties under grazing management to allow selection of varieties to increase animal performance. However, the evaluation of animal performance under grazing with each variety is arduous and time-consuming. An alternative is to describe the preference by grazing animals when given a choice of different varieties. Indeed, there is some indications that preference is related to variety characteristics such as leaf content or digestibility, characteristics having also an impact on the level of intake of this variety. However, preference for grass varieties, when sown alone, may not reflect agricultural practice as grasses often occur in mixed swards, associated with white clover. So, the aim of the present work was to determine whether, under grazing management, cattle expressed selections when given a choice of mixed swards in which different perennial ryegrass varieties were grown in association with a common white clover variety at two levels of fertilizer application (60 or 160 kg N ha?1 annum?1). The preference for perennial ryegrass variety per se was then assessed after taking white clover content into consideration. The results show that there were significant differences in preference for perennial ryegrass varieties, per se, even for varieties with the same heading date and ploidy. The effect of white clover cover on sward selection was more marked in swards which received the higher level of nitrogen fertilizer application which may have been related to a more variable white clover content between swards. This suggests that, under low nitrogen fertilizer application, differences in perennial ryegrass varieties preference can be determined in the same experiments as are used to determine ryegrass varieties persistence in association to white clover. Nevertheless, before such ‘variety preference’ tests can be applied in practice, a validation of the possible correlation between ‘variety preference’ and ‘variety intake’ will be necessary. |
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| Keywords: | heading date mixed swards ploidy selection variety preference white clover |
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