With much of Kentucky feeling the effects of below-normal rainfall and historically drier months yet to come, it’s more important than ever to consider rotational grazing, says Garry Lacefield, University of Kentucky (UK) forage Extension specialist.

“During a drought, we can’t afford to waste pasture, and rotational grazing permits us to use more of what we grow and waste less,” he says.

Tall fescue, orchardgrass and Kentucky bluegrass make up many of the state’s pastures. Unfortunately, these cool-season grasses will produce less and less as hot, dry weather continues. Incorporating warm-season perennial grasses into rotational grazing systems can help supply quality forages during summer months.

It may be too late to seed those perennials, including eastern gamagrass, switchgrass, big bluestem, indiangrass and little bluestem, Lacefield warns. They’re normally planted in late May to early June and take a full growing season to become established.

Another option is to add alfalfa or alfalfa-grass mixes into grazing systems. Alfalfa’s deep root system makes it more drought-tolerant than other cool-season legumes and grasses, and it will continue to produce while cool-season grasses go dormant during extreme drought, he says.

If dry conditions continue, plant late-season summer annuals such as sudangrass, sorghum-sudangrass or pearl millet to provide emergency pasture, the forage specialist adds. The caveat: These grasses need to be planted after a rain to establish well.

They’re also a short-term fix, warns UK forage Extension specialist Ray Smith. Producers hesitate to grow sudangrass and sorghum-sudangrass because they can cause prussic acid and/or nitrate poisoning; pearl millet can produce nitrate poisoning. But the toxicity of these high-yielding and high-quality forages can be low when they’re not grazed at early growth stages, right after a frost or during a severe drought, the specialists point out.

To prevent poisonings, they say to only give animals access to enough pasture for one to three days, graze warm-season annuals at least 18” tall and avoid grazing them during or shortly after droughts, when growth is severely reduced.

For more information, visit the UK forage Web site.