Fat supplement for dairy cows during early lactation–potentials, challenges, and risks–a meta-analysis

Abstract

The most critical challenge in early lactation is to meet the increasing energy demand for milk production, which results in a negative energy balance (EB). The objective of this study was to evaluate the productive performance and plasma metabolite responses of early lactating dairy cows fed diets supplemented with increasing levels of different fat sources. Diets were categorized as diets supplemented with saturated fatty acid rich fat sources (SFAR), with Ca-soaps of fatty acids (CaFA), and with polyunsaturated fatty acid rich fat sources (PUFAR). There was an interaction between crude fat level and source for dry matter intake (DMI); each percentage-unit increase reduced DMI by 0.38 and 0.77 kg/d in CaFA and PUFAR, respectively, and increased DMI by 0.55 kg/d in SFAR. Corrected milk yield increased by 0.44 kg/d for each percentage-unit increase in crude fat level. Plasma non-esterified fatty acid (NEFA) concentration increased with 0.04 mmol/L per percentage-unit increase. In conclusion, the increased crude fat level increased corrected milk yield. Fat supplementation in early lactation does not seem to cause negative effects on productive performance or metabolism, and despite a small increase, both plasma NEFA and β-hydroxybutyrate (BHB) concentrations stayed below the threshold for incidence of subclinical ketosis.