A review of the energy and protein nutrition of dairy cows through their dry period and its impact on early lactation performance

Abstract

This review considers the current literature on the energy and protein nutrition of dry cows and its subsequent impact on early lactation performance. Energy intake close to calving appears to be critical to events that occur post-partum, such that a key objective of dry cow feeding should be to maximise or maintain feed intake immediately prior to calving, or at least to minimise the decline in intake. Although a decline in dry matter intake seems to be a normal adaptive event in peri-parturient ruminants, it is the magnitude and duration of the decline that are of concern. Most research has been undertaken using total mixed rations or conserved forage and concentrates, where a wide range of quantities and types of feeds have been used. However, no clear conclusions can be drawn regarding optimum levels of feeding, types of forage, or proportions of concentrates that should be fed to cows in the late dry period to minimise the intake decline. The importance of maintaining energy intake is associated with the reduction of the incidence and severity of metabolic diseases post-partum, by reducing triglyceride mobilisation from adipose tissue, and preventing excessive depletion of hepatic glycogen levels.