Principle #1- Rest
Giving pasture adequate rest is crucial. Learning how to guage the right amount of rest time can be tricky though, because it’s not as simple as just giving each paddock a set number of days before grazing it again. The rest time between grazing will vary depending on a lot of factors that change throughout the season, as well as from one season to the next. The best way to tell if the grass has had adequate rest is by walking out and checking the plants’ stage of growth. Is the grass just starting to regrow? Is it over mature and already seeding out? When the grass has had plenty of leafy growth and starting to form reproductive heads, then you know it’s ready to be grazed again.
Here are a few of the variables that determine how long the rest period will need to be before a paddock is ready to be grazed again.
- How severely was it grazed? (this affects how much of the grass’ roots were lost and how fast the plants will recover)
- Climate – How wet or dry is it? How hot is it?
- Plant Species – Some forages regrow much more rapidly than others.
Principle #2- Over Grazing
The principle of over-grazing sounds simple, but it’s easy to get “over-grazing” mixed up with “severe grazing”. Over grazing simply means that the grass has been grazed, and then re-grazed AGAIN before the plants have fully recovered from the first grazing. This can happen in two ways. 1) Animals are left in a paddock too long and they begin to re-graze some of the same plants a second time before being moved off that paddock. And 2) Animals are brought back to a paddock too soon and plants are grazed before they’ve fully recovered from the last time the paddock was grazed.
As long as grass is given a long enough rest period, it can be grazed severely without being considered “over-grazed”.
If your animals have been grazing in a paddock long enough for that grass to start to re-grow and you see new growth being eaten, you are over-grazing that paddock and need to get the animals moved to the next paddock.
Principle #3- Stocking Density
Stocking Density and Stocking Rate are closely related terms but they’re not the same thing. Stocking Rate is the number of livestock grazing the whole pasture. So if you have a quarter section of 160 acres, with 320 head of cattle, that means the stocking rate is 2 head per acre. Stocking Density is the number of animals grazing a single paddock at one time. So if your herd of 320 cattle are confined to a paddock that is 10 acres in size, that works out to 32 head per acre. If the next paddock is only 3.2 acres in size, that would be a stocking density of 100 head per acre.
Principle #4- Monitoring
Here are some specific things to monitor that will tell you a lot about the health of your pasture:
- Regrowth – How quickly are the plants recovering and going through their productive cycle? You don’t want to come back to a paddock too early and end up over-grazing it, but also don’t want to wait too long and end up with grass that has lost nutritional value by over-maturing.
- Manure – You know your pasture is in good health when manure shoots out about 6 ft and spreads out on the ground. If it’s too runny, likely your pasture is lacking fibre. And if it lands in a pile and doesn’t spread out, likely your pasture has too much fibre and dead material.
- Bare ground – If the amount of bare ground on your pasture is starting to increase, something is definitely not working. Most likely it’s a sign of over-grazing.
- Weeds – If weeds such as thistles, yarrow, prairie sage or wild strawberry start to appear or their size/numbers start increasing, it’s a sure sign that the health of the pasture is in decline and something needs to change, like increasing rest duration.
- Trends – By taking photos in the same locations each year you can start to see trends forming. Tracking the increase or decrease of particular grass species, legumes or invasive weeds over time can be very helpful with planning.
- Alberta Environment and Sustainable Resource Development has produced a helpful Range Health Assessment tool that walks you through several questions and scores the health of your pasture.
- Beef Cattle Research Council has some great information about rangeland health assessment, how to improve and maintain the health of riparian areas, and some resources around establishing or rejuvenating stands of forage crops.