| ||Pasture recovery is an important topic for Alberta producers on the heels of last year’s dry conditions, particularly given this year’s poor snow cover in the central and southern regions of Alberta. “If we have a dry spring, producers will need to balance potential feed shortages with the need to protect their recovering pastures” says Karin Lindquist, forage/beef specialist with Alberta Agriculture and Forestry.
Pasture quality is key to maximizing the grazing season, so don’t get in a rush to get your cows on the greening-up pasture. “Typically, animals should not begin grazing until pasture forages are at least eight to 12 inches tall, or at the four or five-leaf stage, which is usually in mid-May for northern Alberta, and mid to late-April for southern Alberta.”
Early grazing can set the pasture back several weeks or months, and nutrient quality is lacking, “when cattle are consuming plants at emergence, they are getting 90 to 95 per cent water rather than essential nutrients like energy and protein” says Lindquist.
So what’s the science behind deferring spring grazing? “Plants use energy stored in their roots to begin growth, and do not start generating their own energy with their leaves through photosynthesis until they are at the second to third-leaf stage” says Lindquist. However, nutrients from the roots continue to be used for growth by the plant until after the plant reaches the fourth or fifth leaf stage. “After that, energy is primarily produced from the leaves via photosynthesis, and extra energy is stored in the roots,” says Lindquist.
The recovery time will ultimately maximize or extend available grazing days: “The rule we use is this: if producers are looking to extend grazing into the fall, for every day early they put their cattle out to graze in the spring, they may have three less days to graze in the fall.”