Effect of supplementing essential fatty acids to prepartum Holstein cows and preweaned calves on calf performance, metabolism, immunity, health and hepatic gene expression

A series of experiments were conducted to examine the effect of supplementing essential fatty acids (FA) to prepartum Holstein cattle and newborn calves. The overall objective was to evaluate the effect of increasing intake of linoleic acid (LA) during the preweaning period on overall calf performance. In the first study prepartum cattle were fed one of three supplements, namely control (no fat), hydrogenated FA (SFA) or Ca containing essential FA (EFA). Colostrum FA profile of dams fed EFA reflected the concentration of LA in the fat supplement. Colostrum from nulliparous heifers was a better source of n-3 FA. Calves born from dams fed SFA had greater serum concentrations of total Immunoglobulin G (IgG), but efficiency of IgG absorption did not differ. In same study, 96 Holstein cattle were fed prepartum the same supplements as in experiment 1 and newborn calves were fed milk replacer (MR) of low LA (LLA) or high LA (HLA). Feeding SFA prepartum increased grain intake and average daily gain (ADG) without improving feed efficiency (FE) of calves born from fat-fed dams. Feeding HLA increased ADG, FE, plasma glucose and IGF-I, LA and its derivatives in liver, blood lymphocytes, phagocytosis by neutrophils and interferon-gamma from mononuclear cells. Expression of liver genes was strongly affected by the combination of prepartum diets and MR. Upregulated pathways included the PPAR signaling pathway, glycolysis/gluconeogenesis and oxidative phosphorylation whereas downregulated pathways included genes involved in inflammatory processes and ubiquitin-mediated proteolysis. Cardiomyopathy and tight junction pathways were upregulated in calves fed HLA-MR, but were downregulated if calves born from SFA- or EFA-fed dams. Calves born from fat-fed dams prepartum produced more milk at first lactation, possibly mediated by fetal programming. The last study aimed to determine the requirement of LA for preweaned calves. Heifers gained more BW in the first 30 d of life as intake of LA increased. Wither and hip growth was greater in calves consuming LA exceeding 0.206 g/kg of BW0.75 during the 60-d study. Several markers of immunity were increased when LA was fed between 0.206 and 0.333 g/kg of BW0.75.