EFFECTS OF ACID DETERGENT FIBER INTAKE ON EARLY POSTPARTUM MILK-PRODUCTION AND CHEWING ACTIVITIES IN DAIRY GOATS FED ALFALFA HAY

Forty multiparous Alpine does were studied for effects of incremental levels of acid detergent fiber (ADF) on milk production, milk composition and chewing activities, during the first four weeks of lactation. Diets consisted of combinations of chopped alfalfa hay, com and soybean meal with 14, 18, 22 or 26% ADF (DM). Increasing ADF intake did not affect DM intake or milk yield but increased (P < 0.05) milk fat concentration linearly. Milk fat yield was not affected by treatments. This could be attributed to a tendency for milk yield to decrease when ADF intake was increased. Feeding higher amounts of ADF to dairy goats increased total chewing and rumination time (P < 0.001). Plasma non-esterified fatty acids (NEFA) and glucose were not affected by ADF intake, but beta-hydroxybutyrate was elevated at 18% ADF (P < 0.05). High fiber intake did not limit milk production in high producing goats during early lactation. Requirements for ADF to maintain normal rumen function and milk fat content during the first four weeks of lactation can be derived from a linear equation: Chewing time (min/d) = 33.11 + 30.13 ADF (%) (P < 0.001, r = +O.83) and Milk fat (%) = 3.606 + 0.0013 ADF (g/d) (P < 0.01, r = +0.38).