Factors affecting dry matter intake prepartum in relationship to etiology of peripartum lipid-related metabolic disorders: A review

Transition from gestation to lactation is a tremendous Challenge for dairy cattle and requires metabolic and hormonal adjustments. The periparturient period, particularly the last week of gestation, is characterized by a dramatic decline (20 to 40%) in dry matter intake (DMI) prior to parturition and a slow rate of increase in DMI after parturition. As a result of negative energy balance during the periparturient period, excessive fat mobilization in adipose tissue and inability of disposing fatty acids (FA) via beta-oxidation and exporting triglyceride (TG) as very low density lipoproteins (VLDL) in the liver cause hepatic lipidosis. Controlling hepatic lipidosis, therefore, depends on either limiting non-esterified fatty acids (NEFA) uptake by the liver or increasing oxidation of FA and export of TG by the liver, or both. Results of studies regarding lipid metabolism in the liver to minimize lipidosis are controversial. Thus, until factor(s) limiting hepatic VLDL-TG export are identified, limiting fat mobilization from adipose tissue will play a key role in prevention of hepatic lipidosis and ketosis. Depression in DMI prior to parturition shifts metabolism from anabolism to catabolism. Animal factors such as parity and body condition score and dietary factors such as density of organic nutrients influence DMI. Particularly, increasing energy density of the transition cow diet, without causing acidosis, by supplemental nonstructural carbohydrate (NFC) increases DMI and serum insulin concentration, which suppress lipolysis in adipose tissue and favors anabolic status. In summary, level of DMI and magnitude of DMI depression prior to parturition are linked to the etiology of postpartum lipid-related metabolic disorders. Thus, easing transition from gestation to lactation by offering high dietary NFC in consideration with other factors allows cows to produce more milk, become healthier, and be rebred sooner during postpartum.