Nutritional Management of Transition Dairy Cows

Abstract

Nutrition and management during late gestation impact peripartal health problems and influence subsequent milk production. Obesity at calving is a known risk factor for health problems and suboptimal production. Our evidence indicates that higher energy-density close-up diets do not increase subsequent milk production or energy balance. Our data indicate that even modest overfeeding results in changes analogous to obesity, with elevated insulin and NEFA and poor dry matter intake before calving, but substantial body fat mobilization, increased liver fat deposition, and prolonged increases in blood ketone bodies after calving. Modest energy excess during the dry period can lead to substantial internal fat deposition even without detectable changes in body condition. We conclude that requirements for energy (and other nutrients) should be met but not greatly exceeded during the dry period. This can be achieved by limit-feeding of moderate-energy diets or ad libitum feeding of high-roughage low-energy diets. Requirements for energy for dry cows and first-gestation heifers are modest (ca. 100 MJ ME or 14 Meal NE per cow daily) and can be met with relatively low-energy diets. Conversely, diets high in starch from corn silage or whole-crop cereals and supplemented with additional concentrates result in excess energy intake relative to requirements, as cows do not regulate intake to meet energy needs over the short-term. Dilution of those diets with low-quality roughages such as cereal straws can control energy intake to near cow’s requirements. Careful feeding management is critical to ensure that formulated nutrient intakes are actually achieved in practice.