ARS | Publication request: Evaluation of winter cereals for pasture in Montana

Submitted to: Montana Nutrition Conference
Publication Type: Abstract
Publication Acceptance Date: April 10, 2008
Publication Date: N/A

Technical Abstract: In the southern Great Plains, it is common to graze winter wheat pastures prior to grain harvest to take advantage of economic returns from the grain crop and value added to livestock. In Montana, a similar management practice, using winter cereals, could provide complementary pasture for livestock in the late spring to relieve pressure on cool season native rangelands. A two year study was conducted to evaluate the forage yield and quality of winter cereals, when grazed in the spring, at three growth stages; vegetative stage, boot stage, and at heading. Grazing occurred prior to hay and grain harvest. Ewes were used to graze plots at each growth stage and ungrazed and regrowth forage yield and quality was measured at each grazing date and at 14 day intervals following grazing. `Willow Creek¿ winter wheat and `Trical 102¿ triticale were planted in the fall of 2005, using the best management practices for grazing experiments in 2006. For the 2007 trial, only winter wheat was evaluated. In 2006, total forage yield of wheat and triticale were the same at the vegetative stage, however at the boot stage, heading and haying, triticale forage yields were higher than wheat. Following grazing by ewes, forage yield losses measured at haying in wheat were 30, 54, and 75%, and forage yield losses in triticale were 21, 66, and 86% when grazed at the vegetative stage, boot stage, and at heading. Forage utilization by ewes of wheat and triticale were similar at the vegetative stage and at heading, but wheat utilization was lower than triticale when grazed at the boot stage. Forage quality and nitrate concentrations were highest at the vegetative stage, and declined similarly in wheat and triticale through the boot stage. Ungrazed wheat at heading had higher forage quality with higher digestibility and crude protein compared to triticale and lower fiber concentrations. Grazing delayed forage maturity and resulted in higher forage quality of subsequent regrowth in both triticale and wheat. In 2007, forage yield of ungrazed wheat at haying was 5.23 tons/acre. Hay yield losses for wheat were 34, 85, and 65% for grazed forage at the vegetative stage, boot stage, and at heading. Forage utilization by ewes was 66, 62, and 55% respectively. Forage quality was highest at the vegetative stage, and declined through haying. These results indicate that spring grazing of winter cereals in an integrated crop livestock system should occur during the vegetative state. Forage quality was excellent at this stage and subsequent forage loss was minimal.