Energy: Does your Milk Replacer Fall Short?

With winter right around the corner, you might begin to wonder if the energy in your milk replacer is enough for your precious calves.  The goal should be to manage the calf nutrition program to provide for 1.75 to 2.25 lbs. average daily gain and to double the calf’s birth weight in 56 days. One of the confounding problems of meeting these goals is the increased energy demand of the calf as the ambient temperature declines below the calf’s thermoneutral zone of 60-75 degrees F.  This is especially important this time of year as temperatures are falling.  A 100 lb. calf needs at least 25% more milk dry matter to meet maintenance requirements and gain 1.5 lb. per day when the temperature is 15ₒF as it does at 68ₒF.  If this additional energy is not supplied via the milk/ milk replacer the calf may use body stores to maintain its body temperature.  This can result in weight loss, reduced immune function and possible illness or even death. The traditional 2 quarts, twice a day of a 20-20 milk replacer falls far short of providing the nutrition needed for optimal growth.  In fact it only provides about 55% of the energy and 48% of the protein needed to meet the goal of 1.8 lb. daily gain at 32ₒF.  To reach optimal growth potential, feeding 3 quarts 3 times a day of a high quality replacer is needed to deliver the needed nutrition. The energy supplied in replacers come from two main sources: fat and carbohydrate.   The predominant source of carbohydrates is lactose, which is a readily available source of energy. ...