The Effect of Inclusion of Naked Oats in the Concentrate Offered to Dairy Cows on Milk Production, Milk Fat Composition and Properties

Abstract

Dairy cows in early or mid-lactation were offered naked oats- or barley-based concentrates in addition to ad libitumaccess to grass silage in a continuous design experiment of 10 weeks duration. Concentrates were formulated on an isonitrogenous basis and contained either 500 g barley or 565 g naked oats kg−1 concentrates as the principal energy source in the concentrate. Concentrate type had no effect on silage intake, milk yield or milk protein concentration. However, nitrogen and modified acid detergent fibre digestibility were significantly reduced by inclusion of naked oats and this was reflected in a significant reduction in milk fat concentration. Milk fat from early lactation cows on the naked oats diet contained the highest proportion of unsaturated and the lowest proportion of saturated fatty acids. Sensory and instrumental analyses determined that this milk fat produced the softest, most spreadable butter. This was supported by solid fat content results. The degree of change in milk fat composition due to diet was similar irrespective of stage of lactation but milk fat compositions with the control treatment differed with stage of lactation. Dietary effects were established by the end of the first week of the trial and persisted for the 10-week trial period.