Nutrition

Business-focused dairies are wired to think in terms of controlling costs per hundredweight. This mindset is no different than those managing businesses that manufacture tractors, air conditioners, or sneakers. Producing more is irrelevant if we’re not economically efficient in doing so.

Today’s dairy farms typically feed a large amount of fermented forages and processed feeds which contain little sugar. Because of this, lactating dairy rations usually contain about 1.5% to 3% sugar, if no supplemental sugar is fed. Since sugars are generally rapidly digestible, they can help the rumen microbes capture and use nitrogen. Supplemental sugars can improve rumen pH. When more sugars are incorporated into the rumen bacteria, less organic matter is converted into fermentation acids. Furthermore, dietary sugar often increases the molar proportion of butyrate, which yields only one hydrogen ion while propionate and acetate generate two hydrogen ions. Butyrate also stimulates the rumen epithelial cells, increasing volatile fatty acid (VFA) absorption from the rumen.

We recently completed a trial evaluating how dietary protein and amino acid supplementation affected production during the first 3 or 4 weeks of lactation and to determine how production was affected after treatments stopped (i.e., carry-over effects). The forage in the diets was a blend of about 68% corn silage and 32% alfalfa. The control diet (CONT) contained 17% crude protein (CP) and the concentrate was mostly corn grain and soybean meal.