Performance and metabolic and endocrine changes with emphasis on glucose metabolism in high-yielding dairy cows with high and low fat content in liver after calving

Abstract

Elevated liver fat content occurs in high-yielding dairy cows during the transition from pregnancy to lactation after fat mobilization and may affect hepatic glucose metabolism, but the degree of liver fat storage is highly variable. Therefore, we studied metabolic and endocrine changes and hepatic glucose metabolism in cows that markedly differ in liver fat content. Multiparous cows from the same herd with high (HFL; n = 10) and low (LFL; n = 10) liver fat contents (mean of d 1, 10, and 21 after calving for each cow, respectively) were studied from 60 d before expected calving to 56 d in milk. Cows were fed ad libitum and all cows received the same diets. Liver samples were taken on d 1, 10, and 21 after calving; mean fat content (+/-SEM) in liver of HFL cows was 174 +/- 9.6 mg/g, whereas mean liver fat content in LFL cows was 77 +/- 3.3 mg/g. Blood samples were taken 20 and 7 d before expected calving and 0, 7, 14, 28, and 56 d after calving to measure plasma concentrations of nonesterified fatty acids, beta-hydroxybutyrate, glucose, insulin, glucagon, insulin-like growth factor-I, and leptin. In liver, glycogen content as well as mRNA levels of phosphoenolpyruvate carboxykinase, pyruvate carboxylase, glucose-6-phosphatase, and glucose transporter were measured by quantitative real-time PCR. Back fat thickness decreased and dry matter intake increased with onset of lactation, and back fat thickness was higher but dry matter intake was lower in HFL than in LFL. Energy-corrected milk yield did not differ between groups, but milk fat content was higher and lactose content was lower in HFL than LFL at the beginning of lactation. Energy balance was more negative in HFL than in LFL. Plasma nonesterified fatty acids and beta-hydroxybutyrate concentrations increased and plasma glucose concentration tended to decrease more in HFL than LFL with onset of lactation. Glucagon to insulin ratios increased more in HFL than LFL with onset of lactation. Hepatic glycogen content was higher in LFL than HFL, whereas mRNA levels of glucose-6-phosphatase and pyruvate carboxylase were higher in HFL than in LFL, and cytosolic phosphoenolpyruvate carboxykinase mRNA level increased similarly after parturition in both groups. In conclusion, an elevated liver fat content was related to greater fat mobilization and reduced feed intake and was associated with effects on hepatic glucose metabolism. As environment and feeding management were the same, individual cow factors were responsible for differences in energy metabolism during the transition period.

Variation in fat mobilization during early lactation differently affects feed intake, body condition, and lipid and glucose metabolism in high-yielding dairy cows

“…Insulin concentrations were determined by RIA as described by van Dorland et al (2009). Glucagon concentration was detected by RIA using a kit from Linco (GL-32K; Linco Research, St. Charles, MO; Hammon et al, 2009).…”

“…High rates of fat mobilization lead to markedly increased plasma concentrations of NEFA and, in consequence, the accumulation of triglycerides (TAG) in the liver (Bobe et al, 2004;Overton and Waldron;2004). Recent research has suggested considerable variation among high selected dairy cows for releasing energy fuels from stored adipose tissues (Chilliard et al, 2000;Hammon et al, 2009). Tamminga et al (1997) observed great differences among cows in fat mobilization during the first 8 wk of lactation, ranging from 8 to 57 kg of body fat.…”

“…It is well established that metabolic adaptation is a complex process, which is also highly variable among cows (Jorritsma et al, 2003;Hammon et al, 2009;van Dorland et al, 2009). Many studies have investigated metabolic changes during the transition period, and how prenatal nutrition and feeding management in early lactation and infectious stressors can affect the metabolism (Grummer, 1993;Drackley et al, 2001;Geelen and Wensing, 2006).…”

Physiological adaptations and ovarian cyclicity of Holstein and Montbéliarde cows under two low-input production systems

“…However, statistical differences of 'backfat thickness' are due to the greater skin thickness (D0) observed in MONT, which became evident after the depletion of subcutaneous adipose and connective tissues (D1 − D0) postpartum. 'Backfat thickness' is correlated with total body fat (Schroder and Staufenbiel, 2006), and allowed to differentiate body reserve mobilization among cows that calve with different degree of body fatness (Hammon et al, 2009;Weber et al, 2013). However, it does not take into account internal adipose depots, which may have different dynamics of mobilization during early lactation (Weber et al, 2013).…”

Organic Feed: A Bottleneck for the Development of the Livestock Sector and Its Transition to Sustainability?

“…It is noteworthy that transition dairy cows (cows in the period from three weeks before to three weeks after parturition) experience a negative energy balance (NEB) [37,38]. This arises from the increased energy demands at parturition, especially due to their genetic potential to produce high levels of milk.…”