Forage intake and digestibility of Angus, Hereford, and Hereford-Angus first-calving beef females grazing fescue-legume and fescue pastures

Forage intake and digestibility were measured from March 10 to September 15 for 80 lactating Angus, Hereford, and Hereford-Angus first-calf females. Females were fed Cr₂0₃ twice per day during this period, and an AM and PM fecal sample was collected for each female each week, and samples were composited. Fecal samples were analyzed for calcium, chromium, dry matter (DM), and crude fiber, and these components were used in a fecal index to calculate DM intake, DM digestibility, and digestible DM intake for each female each sampling time. Females grazing fescue-legume and fescue pastures had similar DM digestibility as an average (P > .1). However, females on fescue-legume had significantly higher (P < .0001) DM intakes and digestible DM intakes over the grazing season than did females on fescue pastures. The advantage for females on fescue-legume was primarily due to higher DM and digestible DM intakes during late spring and summer. However, females on the two pasture types consumed similar amounts of forage during the fall and early spring. A breed X pasture type interaction was detected for average DM digestibility for Hereford-Angus females. As an average of the season, Hereford-Angus on fescue-legume had higher DM digestibility, DM and digestible DM intake over Angus and Hereford on same pasture type, while Angus and Hereford females on fescue-legume had similar DM digestibilities, and DM and digestible DM intakes. Angus and Hereford females on fescue had similar digestibilities, DM, and digestible DM intake, while Hereford-Angus had higher DM and digestible DM intakes, however Hereford-Angus on fescue had the lowest digestibility of any breed on fescue. Over time, Hereford-Angus on fescue-legume had higher peaks during the late spring and stayed higher during late spring and summer for DM digestibility than Angus and Herefords on fescue-legume. However, Angus, Hereford, and Hereford-Angus on fescue-legume had similar patterns for DM and digestible DM intakes. Hereford-Angus on fescue had lower levels of digestibility during spring and summer than Angus and Herefords on fescue, but Hereford-Angus on fescue showed an increase for DM and digestible DM intake during the late summer and fall over Angus and Hereford females on fescue.