Effect of Time of Feeding Concentrates and Ground, Pelleted Alfalfa Hay on Milk Fat Percentage and Fatty Acid Composition

In a trial of three-period switchback design, six Holsteins and six Jerseys were fed ground, pelleted alfalfa hay at 6 A~ and PM, plus concentrates at either 2 AM and p~ (Treatment 1) or 6 A~ and P~ (Treatment 2). Both feeding schedules decreased milk fat percentage significantly below that of the preliminary period (long hay fed). The decrease, however, was significantly less when the concentrates were fed separately from the hay than when they were fed at the same time. Similarly, the proportions of the short-chain fatty acids of the milk fat were also decreased less. It is postulated that feeding hay pellets and grain at separate times provides a more even supply of rumen fermentation products for milk fat synthesis.