Lucerne is well recognised for its value as a high quality, protein rich diet during the warmer months, but all too frequently lambs fail to perform to their potential. By comparison, chicory is gaining a reputation for providing a similar amount of feed during summer, but limited information is available to compare the potential feeding value when compared directly to lucerne grown under the same conditions
Nick and Janelle Edwards from Avenue Range, have been putting an effort into understanding the nutritional value of their pastures to finish carry-over lambs during summer, as part of a Meat and Livestock Australia funded Producer Initiated Research and Development trial (PIRD). Nick and Janelle are also members of South East Prime Livestock Achievers Group which has been leading the way for producers looking to optimise red meat production from perennial pasture systems.
Data collected from the trial site over the past few years shows that the two key nutrients in both plants, that is energy and protein, have varied widely between collection dates. For crude protein, lucerne has varied from 15% to 33% CP (average = 24%), and chicory from 18% to 32% (average = 24%); a very similar result for both species.
The interesting difference comes with energy. For the lucerne samples, metabolisable energy has varied from 8.4 MJ to 11.9 MJ, with an average across all samples of 10.4 MJ. By comparison, chicory has covered the range from 9.9 MJ to 12.1 MJ, with an average of 11.1 MJ; 0.7 MJ higher than lucerne on average.
So what does this mean in practice for summer finishing lambs? When this data is applied in a growth modelling tool, it suggests that chicory fed lambs are likely to gain weight at least 10% faster than lucerne fed lambs. However, the lamb growth model tends to overestimate the growth potential of lambs on lucerne. This is because of the often highly soluble nature of the protein in lucerne that tends to limit digestive efficiency and hence lamb growth rate.
In the paddock this frequently translates as lambs growing at less than 200 g/day when their potential gain is suggested to be 300 g/day+. Hence the common and well proven recommendation to provide a grain supplement, such as oats or barley to lambs grazing lucerne.
The key point to consider is whether either or both of these pasture species have a place in your enterprise. Both are summer active species that provide valuable high quality feed in response to summer rain or irrigation, and both can be used to finish lambs successfully. Chicory and lucerne have a wide range of adaptation across the state; with chicory extending its range to more acid soils than normally tolerated by lucerne and both pasture species require good management to get the best out of them.
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