Characterization of Insulin Sensitivity and the Plasma Lipidome in Periparturient Dairy Cows

During the transition from gestation to lactation, dairy cows experience negative energy balance due to an increased demand for energy to support milk production coupled with inadequate energy intake. Energy deficit during the peripartum is associated with the development of insulin resistance which contributes to adipose tissue lipolysis. In turn, elevated free fatty acids (FFA) in circulation increase triacylglycerol (TAG) deposition in liver. This metabolic impairment is known to cause postpartum metabolic diseases including fatty liver and ketosis. Consequently, postpartum metabolic disease can lead to reduced milk production in early lactation, impaired reproductive performance, and increased culling rates. Moreover, cows with enhanced prepartum adiposity are at greater risk for postpartum metabolic disease, relative to lean animals. Therefore, our first objective was to evaluate the effect of adiposity on insulin and glucose tolerance in lean and overweight dairy cows during the transition from gestation to lactation. We also wanted to compare these direct measurements with several indirect measurements, including the commonly utilized revised quantitative insulin sensitivity check index (RQUICKI). For our second objective we wanted to identify novel biomarkers for the progression of postpartum metabolic disease in periparturient dairy cows. To achieve this objective, we utilized a contemporary mass spectrometry-based lipidomics approach and a bioinformatics workflow. We demonstrate (1) that excess prepartum adiposity does not influence postpartum systemic insulin sensitivity, (2) surrogate indices for insulin sensitivity do not correlate with direction measurements, and (3) biomarkers for metabolic disease include several phosphatidylcholines

Effects of limonene on ruminal fusobacterium necrophorum concentrations, fermentation, and lysine degradation in cattle

Citation: Samii, S. S., Wallace, N., Nagaraja, T. G., Engstrom, M. A., Miesner, M. D., Armendariz, C. K., & Titgemeyer, E. C. (2016). Effects of limonene on ruminal fusobacterium necrophorum concentrations, fermentation, and lysine degradation in cattle. Journal of Animal Science, 94(8), 3420-3430. doi:10.2527/jas2016-0455Previous in vitro data showed that Fusobacterium necrophorum was inhibited by limonene. We further evaluated effects of limonene on growth of F. necrophorum in vitro as well as on ruminal concentrations of F. necrophorum in vivo. With in vitro cultivation in anaerobic brain-heart infusion broth, limonene decreased growth of F. necrophorum. Thymol also reduced growth of F. necrophorum, but it was less effective than limonene. Tylosin effectively reduced growth of F. necrophorum in vitro. Although the response over fermentation times and concentrations of antimicrobials differed somewhat between tylosin and limonene, the 2 antimicrobial agents yielded similar inhibitory effects on growth of F. necrophorum at concentrations ranging from 6 to 24 mg/L. The effects of limonene on ruminal F. necrophorum concentration in vivo were tested in 7 ruminally cannulated heifers (225 kg initial BW) used in a 7 × 4 Youden square design. Treatments included: 1) control, 2) limonene at 10 mg/kg diet DM, 3) limonene at 20 mg/kg diet DM, 4) limonene at 40 mg/kg diet DM, 5) limonene at 80 mg/kg diet DM, 6) CRINA-L (a blend of essential oil components) at 180 mg/kg diet DM, and 7) tylosin at 12 mg/kg diet DM. Each period included 11 d with 10 d washouts between periods. Samples of ruminal contents were collected before treatment initiation and after 4, 7, and 10 d of treatment for measuring F. necrophorum by the most probable number method using selective culture medium. Limonene linearly decreased (P = 0.03) ruminal F. necrophorum concentration, with the lowest concentration achieved with 40 mg of limonene/kg dietary DM. Limonene tended (P ? 0.07) to linearly reduce ruminal molar proportions of propionate and valerate while tending to linearly increase (P ? 0.10) those of butyrate and 2-methyl butyrate. Limonene did not affect ruminal NH3 concentrations or degradation rates of lysine. Neither CRINA-L (P = 0.52) nor tylosin (P = 0.19) affected ruminal F. necrophorum concentrations. CRINA-L significantly decreased ruminal concentrations of NH3 and molar proportions of 3-methyl butyrate, whereas tylosin significantly decreased molar proportions of propionate while increasing those of butyrate and tending to increase those of acetate. Limonene supplementation reduced ruminal concentrations of F. necrophorum suggesting that it may have the potential to reduce the prevalence of liver abscesses, although further research is needed to assess the effect of limonene in feedlot cattle. © 2016 American Society of Animal Science. All rights reserved

Characterization of Insulin Sensitivity and the Plasma Lipidome in Periparturient Dairy Cows

During the transition from gestation to lactation, dairy cows experience negative energy balance due to an increased demand for energy to support milk production coupled with inadequate energy intake. Energy deficit during the peripartum is associated with the development of insulin resistance which contributes to adipose tissue lipolysis. In turn, elevated free fatty acids (FFA) in circulation increase triacylglycerol (TAG) deposition in liver. This metabolic impairment is known to cause postpartum metabolic diseases including fatty liver and ketosis. Consequently, postpartum metabolic disease can lead to reduced milk production in early lactation, impaired reproductive performance, and increased culling rates. Moreover, cows with enhanced prepartum adiposity are at greater risk for postpartum metabolic disease, relative to lean animals. Therefore, our first objective was to evaluate the effect of adiposity on insulin and glucose tolerance in lean and overweight dairy cows during the transition from gestation to lactation. We also wanted to compare these direct measurements with several indirect measurements, including the commonly utilized revised quantitative insulin sensitivity check index (RQUICKI). For our second objective we wanted to identify novel biomarkers for the progression of postpartum metabolic disease in periparturient dairy cows. To achieve this objective, we utilized a contemporary mass spectrometry-based lipidomics approach and a bioinformatics workflow. We demonstrate (1) that excess prepartum adiposity does not influence postpartum systemic insulin sensitivity, (2) surrogate indices for insulin sensitivity do not correlate with direction measurements, and (3) biomarkers for metabolic disease include several phosphatidylcholines

Effect of limonene on ruminal Fusobacterium necrophorum

Master of ScienceDepartment of Animal Sciences and IndustryEvan C. TitgemeyerSeven ruminally cannulated heifers approximately 225 kg initial BW were used in a 7 × 4 Youden square design to determine the effects of different levels of limonene on ruminal Fusobacterium necrophorum populations. Treatments included: 1) control, 2) limonene at10 mg/kg diet DM, 3) limonene at 20 mg/kg diet DM, 4) limonene at 40 mg/kg diet DM, 5) limonene at 80 mg/kg diet DM, 6) CRINA-L (a blend of essential oil components) at 180 mg/kg diet DM, 7) tylosin at 12 mg/kg diet DM. Each period included 11 d with 10 d washouts between periods. Samples were collected on d 0 (before treatment initiation), 4, 7, and 10 for measuring F. necrophorum by most probable number (MPN) method using selective culture medium. Results indicate that CRINA-L (P = 0.52) and tylosin (P = 0.19) did not affect ruminal F. necrophorum populations. Limonene linearly decreased (P = 0.03) F. necrophorum populations, and the optimal dietary concentration for limonene was 40 mg/kg DM. Limonene did not affect ruminal degradation rate of lysine, NH3 concentration, or VFA profiles in ruminal fluid. Limonene was useful for reducing ruminal concentrations of F. necrophorum. It may have potential to control liver abscesses, although further research will be needed to assess the effect of limonene under feedlot conditions

Characterization of the Plasma Lipidome in Dairy Cattle Transitioning from Gestation to Lactation: Identifying Novel Biomarkers of Metabolic Impairment

The discovery of novel biomarkers for peripartal diseases in dairy cows can improve our understanding of normal and dysfunctional metabolism, and lead to nutritional interventions that improve health and milk production. Our objectives were to characterize the plasma lipidome and identify metabolites associated with common markers of metabolic disease in peripartal dairy cattle. Multiparous Holstein cows (n = 27) were enrolled 30 d prior to expected parturition. Blood and liver samples were routinely collected through to d 14 postpartum. Untargeted lipidomics was performed using quadrupole time-of-flight mass spectrometry. Based on postpartum measures, cows were categorized into low or high total fatty acid area under the curve (total FAAUC; d 1–14 postpartum; 4915 ± 1369 vs. 12,501 ± 2761 (μmol/L × 14 d); n = 18), β-hydroxybutyrate AUC (BHBAAUC; d 1–14 postpartum; 4583 ± 459 vs. 7901 ± 1206 (μmol/L × 14 d); n = 18), or liver lipid content (d 5 and 14 postpartum; 5 ± 1 vs. 12 ± 2% of wet weight; n = 18). Cows displayed decreases in plasma triacylglycerols and monoalkyl-diacylglycerols, and the majority of phospholipids reached a nadir at parturition. Phosphatidylcholines (PC) 32:3, 35:5, and 37:5 were specific for high total FAAUC, PC 31:3, 32:3, 35:5, and 37:5 were specific for high BHBAAUC, and PC 31:2, 31:3, and 32:3 were specific for high liver lipid content. PC 32:3 was specific for elevated total FA, BHBA, and liver lipid content. Lipidomics revealed a dynamic peripartal lipidome remodeling, and lipid markers associated with elevated total FA, BHBA, and liver lipid content. The effectiveness of nutrition to impact these lipid biomarkers for preventing excess lipolysis and fatty liver warrants evaluation

Temporal changes in sphingolipids and systemic insulin sensitivity during the transition from gestation to lactation

<div><p>Reduced insulin action develops naturally during the peripartum to ensure maternal nutrient delivery to the fetus and neonate. However, increased insulin resistance can facilitate excessive lipolysis which in turn promotes metabolic disease in overweight dairy cattle. Increased fatty acid availability favors the accumulation of the sphingolipid ceramide and is implicated in the pathogenesis of insulin resistance, however, the relationship between sphingolipid metabolism and insulin resistance during the peripartum remains largely unknown. Our objectives were to characterize temporal responses in plasma and tissue sphingolipids in lean and overweight peripartal cows and to establish the relationships between sphingolipid supply and lipolysis, hepatic lipid deposition, and systemic insulin action. Twenty-one multiparous lean and overweight Holstein cows were enrolled in a longitudinal study spanning the transition from gestation to lactation (d -21 to 21, relative to parturition). Plasma, liver, and skeletal muscle samples were obtained, and sphingolipids were profiled using LC/MS/MS. Insulin sensitivity was assessed utilizing intravenous insulin and glucose challenges. Our results demonstrated the following: first, insulin resistance develops postpartum concurrently with increased lipolysis and hepatic lipid accumulation; second, ceramides and glycosylated ceramides accumulate during the transition from gestation to lactation and are further elevated in overweight cows; third, ceramide accrual is associated with lipolysis and liver lipid accumulation, and C16:0- and C24:0-ceramide are inversely associated with systemic insulin sensitivity postpartum; fourth, plasma sphingomyelin, a potential source of ceramides reaches a nadir at parturition and is closely associated with feed intake; fifth, select sphingomyelins are lower in the plasma of overweight cows during the peripartal period. Our results demonstrate that dynamic changes occur in peripartal sphingolipids that are influenced by adiposity, and are associated with the onset of peripartal insulin resistance. These observations are in agreement with a putative potential role for sphingolipids in facilitating the physiological adaptations of peripartum.</p></div

Skeletal muscle content of C16:0-ceramide increases progressively during peripartum.

<p>(<b>A</b>) Ceramide profile of skeletal muscle (μg/mg of wet skeletal muscle), concentrations of (<b>B</b>) C16:0-ceramide, (<b>C</b>) C24:0-ceramide, and (<b>D</b>) total ceramide. Data are represented as least squares means and their standard errors. †, <i>P</i> < 0.10. Total ceramide was calculated by summation of C16:0-, C18:0-, C20:0-, C22:0-, C24:0-, and C26:0-ceramide.</p

Glycosylated ceramides increase during peripartum and are elevated in overweight cows.

<p>Peripartal plasma concentrations (ng/mL) of monohexosylceramides (GlcCer), and lactosylceramides (LacCer) in lean and overweight cows. Plasma (<b>A</b>) C16:0-GlcCer, (<b>B</b>) C24:0-GlcCer, (<b>C</b>) total GlcCer, (<b>D</b>) C16:0-LacCer, (<b>E</b>) C24:0-LacCer, and (<b>F</b>) total LacCer. Data are represented as least squares means and their standard errors. *, <i>P</i> < 0.05; †, <i>P</i> < 0.10. Total GlcCer was calculated by summation of C16:0-, C16:1-, C18:0-, C18:1-, C20:0-, C22:0-, C22:1-, C24:0-, C24:1-, and C26:0-GlcCer. Total LacCer was calculated by summation of C16:0-, C18:0-, C22:0-, C24:0-, and C24:1-LacCer.</p

Plasma ceramides are elevated in overweight cows during the transition from gestation to lactation.

<p>Peripartal plasma concentrations of (<b>A</b>) C16:0-, (<b>B</b>) C18:0-, (<b>C</b>) C20:0-, (<b>D</b>) C22:0-, (<b>E</b>) C24:0-ceramide, and (<b>F</b>) total ceramide in lean and overweight dairy cows. Data are represented as least squares means and their standard errors. *, <i>P</i> < 0.05; †, <i>P</i> < 0.10. Total ceramide was calculated by summation of C16:0-, C18:0-, C20:0-, C22:0-, C22:1-, C24:0-, and C26:0-ceramide.</p

Animal performance and metabolic responses during peripartum.

<p>Animal performance and metabolic responses during peripartum.</p