Pasture and Grazing Systems Synthesis

A comprehensive review of pasture sward management, grazing systems, and the ecological interactions between plants and animals as discussed in the Week 10 synthesis lecture.

What is the lecturer's definition of a 'pastoral sward'?

A combination of different plant species that make up a pasture, viewed as a population or community of plants within a specific area.

How do temperate and tropical pasture swards differ in terms of production constraints?

Temperate systems allow for more focus on establishment and nutrition, while tropical systems face production constraints around sward structure because they contain more stem relative to leaf.

According to the lecture, what two factors most heavily influence which plant species grow in a specific location?

Climate and soil type.

What is the '7 km' guideline in northern extensive grazing systems?

A guideline suggesting that watering points should be placed no further than $7\,km$ apart to manage animal behavior and utilization.

What is the 'rule of thumb' range for maintaining an adequate amount of biomass in many grazing systems?

Between $1000$ and $2500\,kg$.

Describe the three phases of the grass growth curve mentioned in the lecture.

Phase 1 is slow growth of very high quality; Phase 2 is rapid growth where biomass increases quickly but quality begins to decline; Phase 3 is where growth plateaus and quantity/quality both decrease.

According to data from Queensland, how much did land prices increase per year compared to beef production over the last 20 years?

Land prices increased by approximately $16.6\%$ per year, while beef production increased by only $0.54\%.$

What is the national average for pasture utilization in Australia, and why is it at this level?

The average is approximately $30\%$ because of the large amount of extensive grazing focused on native species.

Why is it recommended to move livestock before they begin re-grazing reshooting grass, and when does this typically occur?

Re-grazing new shoots, which typically happens after $7$ days, can have a detrimental impact on overall pasture production.

What are the three levels of management in a grazing system?

1. Feed profile (long-term planning); 2. Feed budget (medium-term, 3-6 months); 3. Grazing plan (short-term, day-to-day/week-to-week).

What is a 'feed wedge' and how is it used in high-production systems like dairy?

A visual tool that ranks paddocks by biomass to show the progression of the rotation, helping managers identify feed shortfalls or excesses (for hay/silage conservation).

How does the application of phosphorus fertilizer affect the grass-legume balance in an ecosystem?

It can shift the balance to favor legume growth, depending on the starting soil fertility.

What are the four levels of ecology mentioned that apply to a grazing system?

Individual organism, population, community, and ecosystem.

Why is it beneficial to fence off different soil types or terrains into separate paddocks?

It allows for more precise grazing pressure management because different soils (e.g., basalt vs. granite) and terrains (north vs. south facing) produce different amounts and types of feed.

What does 'DSC' stand for, and why is it used?

Dry Sheep Equivalent; it is a way to standardize different animal requirements based on their level of maintenance and production.