Farm Table says:
What is the problem?
Improvements to pasture production and utilisation through appropriate grazing management and renewal of poorly performing pasture can provide economic benefits to ruminant based farm systems that rely on pasture.
This study provides a look at the potential economic value of changes in metabolisable energy (ME) concentration of a significant temperate pasture plant species.
Indecision over the most desirable characteristics of plants; the lack of demonstrable benefits to animal production in experiments; and the complexity of management, have all contributed to nutritive characteristics of plants receiving less attention than total dry matter yield
Greater interest is being directed toward traits that improve feeding value by modifying plant chemical composition. In particular the water soluble carbohydrate (WSC) component has been targeted. This can improve the estimated ME.
What did the research involve?
Data from two contrasting environments in temperate Australia were used to estimate the economic value of changes in ME concentration of perennial ryegrass consumed by dairy cows. These were the medium rainfall region of Terang, in south- west Victoria and the high rainfall region of Elliott, in northern Tasmania.
Perennial ryegrass intake was limited to home-grown sources as either forage or silage.
The replacement cost, method of benefit cost analysis was used to estimate the economic value of having more ME available on the farm through an increase in the concentration of ME in perennial ryegrass.
For each year of the two farm experiments economic values for changes in pasture ME were calculated
What were the key findings?
If genetic progress for increasing ME concentration of pasture is made at a time of year when dairy cow pasture intake is regularly low due to management, soil temperatures or soil moisture, this would limit the overall economic benefit to the farmer.
An implication for plant breeders is that they should consider seasons to target genetic progress in traits that improve the availability of ME in order to maximise economic value to dairy farmers
A range of breeding programs for increasing WSC concentrations in perennial ryegrass have been developed because perennial ryegrass is a significant pasture plant species in temperate regions around the world
The magnitude of the economic benefits that genetic improvement in the ME concentration of pasture plants could have on Australian dairy farms warrants consideration by plant breeders developing breeding programmes.