Effects of prepartal body condition score and peripartal energy supply of dairy cows on postpartal lipolysis, energy balance and ketogenesis: an animal model to investigate subclinical ketosis

Abstract

Subclinical ketosis is a metabolic disorder which often goes undiagnosed and leads to constricted performance and an impairment of general condition. In the current study subclinical ketosis was characterised by a β-hydroxybutyrate (BHB) concentration of >1·2 mmol/l in blood serum. To generate this metabolic situation, an animal model was created. The model, based on group-specific interaction of dietary energy supply and body condition, is appropriate for testing the medical effectiveness of treating this kind of ketosis and its concomitants. During the trial, 18 dairy cows (primiparous and pluriparous) were assigned, according to their body condition score (BCS) 6 weeks before expected parturition, to a normal [6.78 MJ net energy for lactation (NEL)/kg dry matter; 20% concentrate] or to a high-energy feeding group (7·71 MJ NEL/kg dry matter; 60% concentrate). Therefore cows with the highest BCS were allocated to the high-energy group to enhance the contrast with the control group. Statistical analysis was done using the MIXED procedure of SAS. Effects were declared significant when P-values were ⩽0.05. Owing to the higher energy concentration and dry matter intake, the energy intake and balance was significantly higher in the high-energy feeding group, with strong effects on lipid metabolism and health in blood and liver post partum. Within the first 2 weeks after calving, 8 out of 9 cows (89%) of the high-energy group had BHB values indicative of subclinical ketosis. These cows also had significantly higher values of non-esterified fatty acids (NEFA), aspartate transaminase (AST) and glutamate dehydrogenase (GLDH) post partum, as well as a raised total lipid content of the liver. RQUICKI, a calculated parameter which is based on serum concentrations of glucose, insulin and NEFA to assess the insulin sensitivity, was not affected by treatment. Therefore, RQUICKI does not seem to be the right parameter for diagnosing decreased insulin sensitivity in cows affected by subclinical ketosis. The milk fat and the fat:protein ratio of the high-energy group was also higher, even though there was no decrease in milk yield for cows with subclinical BHB values.

Milk fatty acid composition as an indicator of energy status in Holstein dairy cows

“…NEFA levels can be increased through increased mobilization of stored lipids, which can thereby indicate metabolic disorders, such as ketosis and fatty liver syndrome (Duffield et al, 1998;Fiore et al, 2017). The first measurable indicator of ketogenesis is an increase in BHB concentration in the blood (Payne and Payne, 1987;Schulz et al, 2014) The utilization of energy reserves is also reflected in the milk fat content (Bauman et al, 2006), namely in the fatty acid (FA) composition and mutual ratios between individual FA groups (Ducháček et al, 2014). Milk FA and protein contents are correlated with metabolic status (Mulligan et al, 2006); therefore, measurement of these two parameters is usually recommended for the determination of negative energy balance (Gross et al, 2011).…”

Impacts of CLA and dietary concentrate proportion on blood metabolite concentration and proliferation of peripheral blood mononuclear cells of periparturient dairy cows

“…Perhaps, a longer overfeeding period a.p. or feed intake restriction or deprivation during early lactation, as realized in other trials (Loor et al, 2007;Kuhla et al, 2009;Schulz et al, 2014), might have been a more successful approach to induce a ketotic state p.p.…”

Pre- and postpartum effects of starch and fat in dairy cows: A review

“…Third, it may be esterified to triglycerides or phospholipids and stored in the liver as TAG, with the possibility of causing fatty liver syndrome (Drackley et al, 2001). This mobilization highlights that the metabolic effects of a NEB status in early lactation induce an imbalance in the ratio of plasma glucogenic and lipogenic compounds derived from feed nutrients and body reserves (Schulz et al, 2014). Hence, the physiological consequences of postpartum EB deficit causes low plasma glucose and insulin levels associated with high levels of plasma NEFA, BHB, acetone, acetoacetate, and liver TAG (Van Knegsel et al, 2005;Evans & Walsh, 2012).…”

“…First, NEFA can be oxidized to carbon dioxide to supply energy as alternative energy fuel for other tissues, while most of the glucose is diverted for lactose synthesis in the mammary gland (Vernon, 2002). Second, it can be partially oxidized to produce ketone bodies, acetone, aceto-acetate and BHB, which may result in ketosis (Schulz et al, 2014;Esposito et al, 2014). Third, it may be esterified to triglycerides or phospholipids and stored in the liver as TAG, with the possibility of causing fatty liver syndrome (Drackley et al, 2001).…”

“…Non-esterified fatty acids are consequently released from body fat reserves, with increasing NEFA levels in the bloodstream, suggesting an EB shortfall (Duffield, 2000;Wathes et al, 2007). The NEFA metabolites are directed into the mammary gland to supply milk triglycerides (Drackley, 2000) or utilized in the liver (Drackley et al, 2001;Vernon, 2002;Schulz et al, 2014). Following their uptake by the liver, NEFA can be utilized in three pathways.…”