HIGH MOISTURE GROUND EAR CORN, HIGH MOISTURE BARLEY OR SODIUM HYDROXIDE TREATED BARLEY FOR LACTATING COWS: MILK PRODUCTION AND RATION UTILIZATION

Abstract

Whole barley was treated with sodium hydroxide (NaOH) in laboratory trials. Dry matter disappearance from nylon bags in the rumen of whole barley treated with 2.5, 3.5, or 4.9% NaOH for 30 h was 59.6, 72.4, and 93.0%, respectively, compared with 82.2% for untreated ground barley. In a subsequent lactation trial, 24 Holstein cows (eight per treatment) were fed high moisture ground ear corn, high moisture rolled barley or high moisture whole barley treated with 3.5% NaOH. Milk persistencies tended to be greater for cows fed high moisture rolled barley, next for ground ear corn and least for NaOH-treated barley. Milk composition was similar for all treatments. Dry matter intake was greatest for cows fed ground ear corn and lower for those fed the barley diets. Alpha-linked glucose and pH of feces were similar for cows fed ground ear corn and high moisture rolled barley diets, but fecal pH was lower and alpha-linked glucose concentrations three times greater for NaOH-treated barley. Digestibility percents of dry matter, acid detergent fiber and nitrogen were 61.4, 25.3, 64.7 for ground ear corn; 64.4, 38.0, 67.1 for high moisture rolled barley; and 56.8, 43.2, 54.8 for NaOH-treated barley, respectively. Rumen grain turnover estimated by excretion of ytterbium in feces was greatest for NaOH-treated barley (9.09%/h), intermediate for ground ear corn (6.10%/h) and lowest for high moisture rolled barley (4.93%/h). Key words: Dairy, sodium hydroxide, high moisture grains