Effect of native warm season grasses

Native warm season grasses offer increased growth during summer months and taller plants that allow grazing at greater heights. The objective of a two year study conducted on a farm in the piedmont region of North Carolina was to evaluate native warm season grasses as a forage for post-weaning development of lambs in spring lambing, forage-based systems.

Weaned Katahdin lambs (year 1, 30; year 2: 30) were randomly assigned to graze either Big Bluestem and Indiangrass or cool season grass (Kentucky 31 Tall Fescue base) pasture. Lambs were continuously grazed for 70 days in the first year and 55 days in the second year. Fecal egg count (FEC), FAMACHA© score, and body weight were measured every two weeks. Lambs were dewormed at FAMACHA© ≥ 3. Forage analysis was conducted at the start and end of the grazing period.

In both years, no differences were observed in FEC between grazing groups. However, FEC did increase in both groups throughout the grazing period. In the first year, no differences were observed in total weight gain. However, in the second year, lambs grazing the cool season grasses had greater total weight gain than the warm season grass group. In both years, there were no differences in the percentage of lambs requiring deworming, Nutrient quality of warm season pasture was less than the cool season pastures.

While while native warm season grasses may provide additional biomass for summer grazing, rapid maturity rates may limit nutrient availability for lambs resulting in decreased growth performance despite similar levels of parasitism. Source: Supplement to the Journal of Animal Science, March 2024 | SARE Grant Update (EAPK)