Body Fat Mobilization Research Articles

Genetic and nongenetic profiling of milk β-hydroxybutyrate and acetone and their associations with ketosis in Holstein cows

Ketosis is a metabolic disorder of increasing importance in high-yielding dairy cows, but accurate population-wide binary health trait recording is difficult to implement. Against this background, proper Gaussian indicator traits, which can be routinely measured in milk, are needed. Consequently, we focused on the ketone bodies acetone and β-hydroxybutyrate (BHB), measured via Fourier-transform infrared spectroscopy (FTIR) in milk. In the present study, 62,568 Holstein cows from large-scale German co-operator herds were phenotyped for clinical ketosis (KET) according to a veterinarian diagnosis key. A sub-sample of 16,861 cows additionally had first test-day observations for FTIR acetone and BHB. Associations between FTIR acetone and BHB with KET and with test-day traits were studied phenotypically and quantitative genetically. Furthermore, we estimated SNP marker effects for acetone and BHB (application of genome-wide association studies) based on 40,828 SNP markers from 4,384 genotyped cows, and studied potential candidate genes influencing body fat mobilization. Generalized linear mixed models were applied to infer the influence of binary KET on Gaussian-distributed acetone and BHB (definition of an identity link function), and vice versa, such as the influence of acetone and BHB on KET (definition of a logit link function). Additionally, linear models were applied to study associations between BHB, acetone and test-day traits (milk yield, fat percentage, protein percentage, fat-to-protein ratio and somatic cell score) from the first test-day after calving. An increasing KET incidence was statistically significant associated with increasing FTIR acetone and BHB milk concentrations. Acetone and BHB concentrations were positively associated with fat percentage, fat-to-protein ratio and somatic cell score. Bivariate linear animal models were applied to estimate genetic (co)variance components for KET, acetone, BHB and test-day traits within parities 1 to 3, and considering all parities simultaneously in repeatability models. Pedigree-based heritabilities were quite small (i.e., in the range from 0.01 in parity 3 to 0.07 in parity 1 for acetone, and from 0.03-0.04 for BHB). Heritabilites from repeatability models were 0.05 for acetone, and 0.03 for BHB. Genetic correlations between acetone and BHB were moderate to large within parities and considering all parities simultaneously (0.69-0.98). Genetic correlations between acetone and BHB with KET from different parities ranged from 0.71 to 0.99. Genetic correlations between acetone across parities, and between BHB across parities, ranged from 0.55 to 0.66. Genetic correlations between KET, acetone, and BHB with fat-to-protein ratio and with fat percentage were large and positive, but negative with milk yield. In genome-wide association studies, we identified SNP on BTA 4, 10, 11, and 29 significantly influencing acetone, and on BTA 1 and 16 significantly influencing BHB. The identified potential candidate genes NRXN3, ACOXL, BCL2L11, HIBADH, KCNJ1, and PRG4 are involved in lipid and glucose metabolism pathways.

Effects of Propylene Glycol on Negative Energy Balance of Postpartum Dairy Cows.

Simple SummaryAfter calving, the milk production of dairy cows increases rapidly, but the nutrient intake cannot meet the demand for milk production, forming a negative energy balance. Dairy cows in a negative energy balance have an increased risk of developing clinical or subclinical ketosis. The ketosis in dairy cows has a negative impact on milk production, dry matter intake, health, immunity, and reproductive performance. Propylene glycol can be used as an important gluconeogenesis in ruminants and can effectively inhibit the formation of ketones. Supplementary propylene glycol to dairy cows during perinatal is an effective method to alleviate the negative energy balance. This review summarizes the reasons and consequences of negative energy balance as well as the mechanism and effects of propylene glycol in inhibiting a negative energy balance in dairy cows. In addition, the feeding levels and methods of using propylene glycol to alleviate negative energy balance are also discussed.With the improvement in the intense genetic selection of dairy cows, advanced management strategies, and improved feed quality and disease control, milk production level has been greatly improved. However, the negative energy balance (NEB) is increasingly serious at the postpartum stage because the intake of nutrients cannot meet the demand of quickly improved milk production. The NEB leads to a large amount of body fat mobilization and consequently the elevated production of ketones, which causes metabolic diseases such as ketosis and fatty liver. The high milk production of dairy cows in early lactation aggravates NEB. The metabolic diseases lead to metabolic disorders, a decrease in reproductive performance, and lactation performance decline, seriously affecting the health and production of cows. Propylene glycol (PG) can alleviate NEB through gluconeogenesis and inhibit the synthesis of ketone bodies. In addition, PG improves milk yield, reproduction, and immune performance by improving plasma glucose and liver function in ketosis cows, and reduces milk fat percentage. However, a large dose of PG (above 500 g/d) has toxic and side effects in cows. The feeding method used was an oral drench. The combination of PG with some other additives can improve the effects in preventing ketosis. Overall, the present review summarizes the recent research progress in the impacts of NEB in dairy cows and the properties of PG in alleviating NEB and reducing the risk of ketosis.

Impacts of feeding a fish-oil based feed supplement through 160 days in milk on reproductive and productive performance, as well as the health, of multiparous early-lactation Holstein cows

A major cause of reproductive failure in contemporary lactating dairy cows is early post-partum negative energy balance (NEB). A strategy to alleviate NEB is to reduce milk energy density by feeding supplements to suppress milk fat synthesis, which could reduce body fat mobilization to favor earlier ovulation and improved pregnancy rates. As fish oils (FO) can cause milk fat depression, and are rich in n-3 PUFA which are beneficial to reproduction, our objective was to evaluate impacts of feeding the FO based feed supplement ‘Optomega Plus’ (OP+) on production, EB, reproduction and health of multiparous Holstein cows through ∼160 days in milk (DIM). Two pens, each of ∼310 multiparous early lactation cows, were fed rations formulated to deliver 0 (C) or 77 g/cow per day of FO (2.53 g/kg DM) as OP+, which contains 3.9 g/cow per day of eicosapentaenoic acid (EPA; C20:5 n-3) and 7.2 g/cow per day of docosahexaenoic acid (DHA; C22:6 n-3). Milk yields and components were recorded monthly for five months after cows were assigned to treatments from a common fresh cow pen at 13.3 ± 0.19 DIM, and body condition (BCS) was scored monthly on a subset of the cows. Dry matter intake (pen basis) was unaffected by treatment, while milk yield, milk components and BCS all had treatment*DIM interactions (P < 0.05), which suggested different responses to the diets before and after ∼130 days post treatment assignment. Feeding OP+ did not impact milk production, but moderately reduced (P < 0.05) milk fat output in the earlier period, which mitigated the NEB as judged by BCS change, but 1st service pregnancy rate was unaffected. There were no treatment impacts on indices of cow health, but feeding OP + improved the healthfulness of the milk FA profile to its human consumers. Results suggest that OP + as a source of FO modestly reduced milk fat output and the extent of early postpartum NEB, without negatively affecting DM intake, health or reproductive performance, while improving the nutritional value of milk fat to its human consumers.

A two-component feeding strategy with high supply of energy and lysine ensured a high milk yield, minimal mobilization and improved feed efficiency of lactating sows

This study investigated the impact of energy supply and dietary lysine concentration on body reserve mobilization pattern, milk yield, nutrient balances and feed efficiency of sows fed 1 of 4 different dietary treatments. Two dietary components were formulated to meet the requirement for maintenance (basal; low in lysine) and milk production (lactation; high in lysine). A total of 24 second-parity lactating sows were assigned to the dietary treatments using a 2-component feeding strategy. Sows were supplied either high (HE) or low (LE) energy (i.e. two feeding levels), and within each feeding level, sows were supplied with high (HL) or low (LL) dietary lysine concentration from their total ration. The four dietary strategies, HEHL, HELL, LEHL, and LELL, were obtained by supplying different amounts and ratios of the basal and the lactation components. The dietary strategies were defined to generate distinct mobilization patterns in the four groups, i.e. mainly muscle mobilization (HELL), mainly fat mobilization (LEHL), muscle + fat mobilization (LELL), or no mobilization (HEHL). Sows and piglets were weighed on d 2, 7, 14, 21, and 28 of lactation and milk samples were collected weekly. Sows were enriched with deuterium oxide on d 3 and 28 of lactation to estimate body mobilization. Sows fed LEHL and LELL strategies lost greater BW (P = 0.005), mobilized greater body protein (P = 0.001) and body fat (P = 0.01) than HEHL or HELL fed sows. Sows fed HEHL and LELL had greater milk yield (12.9 kg/d) than sows fed LEHL (11.6 kg/d) with HELL fed sows being intermediate (12.7 kg/d; P = 0.04). Negative energy balances and mobilization of body fat and protein were observed for all 4 dietary strategies to various extent, indicating that sow mobilization pattern is rather complex. The study revealed that high BW loss and high body reserve mobilization are not necessary to achieve a high milk yield when dietary supply of nutrients were optimized according to the requirements. Feed efficiency, evaluated as net energy corrected for mobilization of body reserves, was greater in HEHL and HELL strategies (P < 0.001) than in LEHL or LELL strategy. In conclusion, nutrient balances and mobilization patterns were affected by the dietary strategies but all sows had greater fat mobilization than muscle mobilization. The HEHL dietary strategy seemed to be superior to the other dietary strategies as these sows had both a high milk yield and a high feed efficiency.

Genetic parameters for milk fatty acid composition of Holstein in Korea.

ObjectiveMilk fatty acid (FA) is a main nutritional component that markedly effects human health. Intentional modification of the FA profile has the potential to improve milk quality. This study aimed at the factors affecting elevated FA levels and the estimation of the genetic parameters for milk FAs in the Korean Holstein population.MethodsTotal 885,249 repeated test-day milk records including, milk yield, saturated fatty acids (SFA), polyunsaturated fatty acids (PUFA), monounsaturated fatty acids (MUFA), total unsaturated fatty acids (TUFA), fat and protein percentages were analyzed using CombiFoss FT+ system (Foss Analytical A/S, Denmark). Genetic parameters were estimated by the restricted maximum likelihood procedure based on the repeatability model using the Wombat program.ResultsThe FA profile varies along with the lactation and the energy balance (EB). With the negative EB in early lactation, mobilization of body fat reserves elevates the desirable FA levels. As a result of that, milk quality is increased by means of nutritionally and usability aspects during the early lactation. Moreover, heritability estimates for SFA, MUFA, PUFA, TUFA were 0.33, 0.42, 0.37, 0.41 respectively. According to the parity wise heritability analysis, first parity cows had relatively lower heritability for SFAs (0.19) than later parities (0.28).ConclusionGenetic parameters indicated that FAs were under stronger genetic control. Therefore, we suggest implementing animal breeding programs towards improving the milk FA profile.

Hepatic metabolomics and transcriptomics to study susceptibility to ketosis in response to prepartal nutritional management

BackgroundKetosis in dairy cows is associated with body fat mobilization during the peripartal period. Sub-clinical and clinical ketosis arise more frequently in cows that are overfed energy during the entire dry (last 50 to 45 days prior to parturition) or close-up period (last ~ 28 days prepartum).MethodsA retrospective analysis was performed on 12 cows from a larger cohort that were fed a higher-energy diet [1.54 Mcal/kg of dry matter (DM); 35.9% of DM corn silage and 13% of DM ground corn] during the close-up dry period, of which 6 did not develop clinical ketosis (OVE, 0.83 mmol/L plasma hydroxybutyrate; BHB) and 6 were diagnosed with clinical ketosis (KET, 1.4 mmol/L BHB) during the first week postpartum. A whole-transcriptome bovine microarray (Agilent Technologies) and metabolomics (GC-MS, LC-MS; Metabolon® Inc.) were used to perform transcript and metabolite profiling of liver tissue harvested at − 10 days relative to parturition which allowed to establish potential associations between prepartal transcriptome/metabolome profiles and susceptibility to clinical ketosis postpartum.ResultsCows in KET had greater (P = 0.01) overall body weight between − 2 and 1 week around parturition, but similar body condition score than OVE. Although dry matter intake (DMI) did not differ prepartum, KET cows had lower (P < 0.01) DMI and similar milk yield as OVE cows during the first week postpartum. Transcriptome analysis revealed a total of 3065 differentially expressed genes (DEG; P ≤ 0.05) in KET. Metabolomics identified 15 out of 313 total biochemical compounds significantly affected (P ≤ 0.10) in KET. Among those, greater concentrations (P ≤ 0.06, + 2.3-fold) of glycochenodeoxycholate in KET cows also have been detected in humans developing non-alcoholic fatty liver disease. Bioinformatics analysis using the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway database and the DEG revealed that, among the top 20 most-impacted metabolic pathway categories in KET, 65% were overall downregulated. Those included ‘Metabolism of cofactors and vitamins’, ‘Biosynthesis of other secondary metabolites’, ‘Lipid’, ‘Carbohydrate’, and ‘Glycan biosynthesis and metabolism’. The lower relative concentration of glucose-6-phosphate and marked downregulation of fructose-1,6-bisphosphatase 2 and pyruvate dehydrogenase kinase 4 support a strong impairment in gluconeogenesis in prepartal liver of cows developing KET postpartum. Among the top 20 most-impacted non-metabolic pathways, 85% were downregulated. Pathways such as ‘mTOR signalling’ and ‘Insulin signalling’ were among those. ‘Ribosome’, ‘Nucleotide excision repair’, and ‘Adherens junctions’ were the only upregulated pathways in cows with KET.ConclusionsThe combined data analyses revealed more extensive alterations of the prepartal liver transcriptome than metabolome in cows overfed energy and developing ketosis postpartum. The causative link between these tissue-level adaptations and onset of clinical ketosis needs to be studied further.

PPARA/RXRA signalling regulates the fate of hepatic non-esterified fatty acids in a sheep model of maternal undernutrition

Maternal undernutrition during late gestation accelerates body fat mobilization to provide more energy for foetal growth and development, which unbalances metabolic homeostasis and results in serious lipid metabolism disorder. However, detailed regulatory mechanisms are poorly understood. Here, a sheep model was used to explore the regulatory role of PPARA/RXRA signalling in hepatic lipid metabolism in undernutrition based on RNA sequencing and cell experiments. KOG function classification showed that lipid transport and metabolism was markedly altered in an undernourished model. In detail, when compared with the controls, fatty acid transport and oxidation and triglyceride metabolism were up-regulated in an undernourished model, while fatty acid synthesis, steroid synthesis, and phospholipid metabolism were down-regulated. Kyoto Encyclopaedia of Genes and Genomes (KEGG) pathway analysis demonstrated that PPARA/RXRA signalling pathway was altered. Moreover, PPARA signalling associated genes were positively correlated with hepatic non-esterified fatty acid (NEFA) levels, while retinol metabolism associated genes were negatively correlated with blood beta-hydroxybutyric acid (BHBA) levels. Results of primary hepatocytes showed that NEFAs could activate PPARA signalling and facilitate fatty acid oxidation (FAO) and ketogenesis, while BHBA could inhibit RXRA signalling and repress FAO and ketogenesis. Excessively accumulated NEFAs in hepatocytes promoted triglyceride synthesis. Furthermore, activation of PPARA/RXRA signalling by WY14643 and 9-cis-retinoic acid could enhance FAO and ketogenesis and reduce NEFAs accumulation and esterification. Our findings elucidate the regulatory mechanisms of NEFAs and BHBA on lipid metabolism as well as the potential role of the PPARA/RXRA signalling pathway in hepatic lipid metabolism, which may contribute to exploring new strategies to maintain lipid metabolic homeostasis in human beings.

The effect of serum β-hydroxybutyric acid and calcium levels on left displaced abomasum in Holstein cows on transition period

In this study, the effect of serum β-hydroxybutyric acid and calcium concentrations, which are the parameters used in the diagnosis of ketosis and hypocalcemia in lactation period, on left displaced abomasum (LDA) has been investigated. The lactation period covering the 3 weeks before and after parturition, known as the transition period, is highly important for high yield dairy cows (Holstein Friesian cattle). Hormonal and metabolic changes occur in this period. The energy requirement, which increases in direct proportion with the milk yield at the beginning of lactation, cannot be met with insufficient dry matter consumption, however, it is compensated with the mobilization of body fat. Ketosis and fatty liver are nutritional diseases that are observed in animals with high milk yield resulting from the disturbances in energy metabolism. Hypocalcemia and ketosis are the most important risk factors in the development of left displaced abomasum (LDA) in high-yield milk cows. Hypocalcemia and ketosis are also the most important nutritional diseases in the transition period. In this study, 17 Holstein Friesian cattle were used in group 1 that were diagnosed with left displaced abomasum after hearing the ‘‘ping’’ sound, and 17 healthy, randomly selected Holstein Friesian cattle were used in group 2. Blood analyses (BHBA and Ca) were performed in group 1 and 2 after parturition.

The α/β-hydrolase domain-containing 4- and 5-related phospholipase Pummelig controls energy storage in Drosophila

Triglycerides (TGs) are the main energy storage form that accommodates changing organismal energy demands. In Drosophila melanogaster, the TG lipase Brummer is centrally important for body fat mobilization. Its gene brummer (bmm) encodes the ortholog of mammalian adipose TG lipase, which becomes activated by α/β-hydrolase domain-containing 5 (ABHD5/CGI-58), one member of the paralogous gene pair, α/β-hydrolase domain-containing 4 (ABHD4) and ABHD5 In Drosophila, the pummelig (puml) gene encodes the single sequence-related protein to mammalian ABHD4/ABHD5 with unknown function. We generated puml deletion mutant flies, that were short-lived as a result of lipid metabolism changes, stored excess body fat at the expense of glycogen, and exhibited ectopic fat storage with altered TG FA profile in the fly kidneys, called Malpighian tubules. TG accumulation in puml mutants was not associated with increased food intake but with elevated lipogenesis; starvation-induced lipid mobilization remained functional. Despite its structural similarity to mammalian ABHD5, Puml did not stimulate TG lipase activity of Bmm in vitro. Rather, Puml acted as a phospholipase that localized on lipid droplets, mitochondria, and peroxisomes. Together, these results show that the ABHD4/5 family member Puml is a versatile phospholipase that regulates Drosophila body fat storage and energy metabolism.

Maternal undernutrition induces fetal hepatic lipid metabolism disorder and affects the development of fetal liver in a sheep model.

Undernutrition accelerates body fat mobilization to alleviate negative energy balance, which disrupts homeostasis of lipid metabolism in maternal liver. However, little is known about its effect on fetal metabolism and development. Here, a sheep model was used to explore whether maternal undernutrition induces fetal lipid metabolism disorder and further inhibits fetal hepatic development. Twenty pregnant ewes were either fed normally or restricted to 30% level for 15 d, after which fetal hepatic samples were collected to conduct transcriptome, metabolome, histomorphology, and biochemical analysis. Results showed that maternal undernutrition altered the general transcriptome profile and metabolic mode in fetal liver. Fatty acid oxidation and ketogenesis were enhanced in fetal livers of undernourished ewes, which might be promoted by the activated peroxisome proliferator-activated receptor α signaling pathway, whereas cholesterol, steroid, and fatty acid synthesis were repressed. Maternal undernutrition increased triglyceride synthesis, decreased triglyceride degradation, and inhibited phospholipid degradation and synthesis in fetal liver. In addition, our data revealed that maternal undernutrition extremely inhibited DNA replication, cell cycle progression, and antiapoptosis and broke the balance between cell proliferation and apoptosis in fetal liver, indicating that maternal undernutrition affects the growth and development of fetal liver. Generally, these findings provide evidence that maternal undernutrition during pregnancy disturbs fetal lipid metabolism and inhibits fetal hepatic development in sheep, which greatly contribute to the further study of fetal metabolism and development in human beings.-Xue, Y., Guo, C., Hu, F., Zhu, W., Mao, S. Maternal undernutrition induces fetal hepatic lipid metabolism disorder and affects the development of fetal liver in a sheep model.

Estimation Metabolic Status in High Yielding Dairy Cows During Transition Period and Full Lactation

Background: Major changes in the metabolic functions in high-yielding dairy cows occur during the transitional period and during lactation. Parturition and lactogenesis are accompanied by many physiological changes that facilitate the maintenance of homeostasis Consequently, physiological situations leading to a negative energy balance are coupled to an increased uncontrolled rate of body fat mobilisation and the increased fatty acids accumulation in hepatocytes and blood ketone bodies, resulting in disturbances of the morphological and physiological liver integrity. The objective of the present study was to estimate metabolic status in late pregnant, early lactation and full lactation Holstein dairy cows on the basis changes of blood concentrations of selected biochemical markers.Materials, Methods &amp; Results: The experiment included 36 Holstein cows. Three groups of clinically healthy cows were chosen from the herd. Group 1 consisted of late pregnant cows (n = 12) from 30 to 1 day (20 ± 15) to partus; Group 2 comprised early lactation cows (n = 12) in the first month of lactation (15 ± 12 days), and Group 3 included full lactation cows (n = 12) between 60 to 90 days of lactation (81 ± 30 days). Blood samples were collected from all cows, by punction of the jugular vein. Biochemical testing for markers in the blood serum showed significantly lower values (P &lt; 0.05) of glucose, TG, Tchol. and urea in early cows than in full lactation and late-pregnant cows. The blood concentration of NEFA and BHB was significantly increased (P &lt; 0.05) in the group of cows in early lactation compared to the other groups of cows. The mean tBIL. concentration and the serum AST, GGT and ALT activities were markedly increased (P &lt; 0.01) in the lactation cows compared to the late pregnant cows. Furthermore, the intensity of lipomobilisation (NEFA or BHB concentrations) correlated positively (P &lt; 0.05) with the markers of cell damage or liver function impairment (tBIL., serum AST, ALT and GGT activities), but negatively (P &lt; 0.05) with the circulating concentrations of compounds synthesised in liver (glucose, TG and urea).Discussion: In dairy cows, it was observed that up to 50 % of females exhibited some lipid accumulation in liver in the first 3 weeks after calving and that fatty liver occurs primarily in this period. Liver can be categorized into mild, moderate and severe fatty liver as dependent on the degree of pathology and a mild fatty infiltration of liver in dairy cows during lactation is considered to be almost physiological. The blood BHB and NEFA concentrations are markers of lipomobilisation and positively associated with the ketosis and liver steatosis intensity. The simultaneous and parallel variations observed between the extent of the fat infiltration in liver and the serum BHB and NEFA concentrations in puerperal cows clearly indicated that the intense lipomobilisation in the post-partum period has induced lipid overloading and ketogenesis in the liver. On the other hand, it was observed significant decreases in the serum biochemical markers, at least partially synthesised in the liver, such as glucose, TG, Tchol., urea, albumin and TP during the postpartum period. However, the liver steatosis has induced some cellular lesions as evidenced by significant increases in the serum tBIL. concentrations and in the AST, ALT, GGT and LDH enzyme activities in puerperal cows. All these biochemical metabolites may be used as important biochemical markers in the determination of the metabolic status in high-yielding dairy cows during the transition period and during lactation.

Possible involvement of the RARRES2/CMKLR1-system in metabolic and reproductive parameters in Holstein dairy cows

BackgroundIn dairy cows, the energy cost of milk yield results in a negative energy balance (EB) and body fat mobilization that impairs reproductive efficiency. Emerging evidence suggests that the novel adipokines, Retinoic acid receptor responder protein 2 (RARRES2), and its main receptor, Chemokine-like receptor 1 (CMKLR1) are involved in the regulation of metabolic and ovarian functions. So, we investigated in a first experiment the plasma RARRES2, and RARRES2 and CMKLR1 mRNA expression levels in subcutaneous adipose tissue (SAT) and granulosa cells (GC) at different times of body fat mobilization in dairy cows (4, 8, 20 and 44 weeks postpartum, wk. pp. for SAT and 8, 20 and 44 wk. pp. for GC). Then, in a second experiment we examined the effect of high (HE) and low energy (LE) diets on the RARRES2 system and its links with metabolic and reproductive parameters.MethodsThe first experiment included 9 animals fed with HE diet from 4 to 44 wk. pp. and the second one included animals fed either a HE diet (n = 8) or a LE diet (n = 8) from − 4 to 16 wk. peripartum. In both experiments, various metabolic and reproductive parameters were determined and associated with plasma RARRES2 as measured by bovine ELISA. RARRES2 and CMKLR1 mRNA expression levels were analyzed by RT-qPCR in SAT after biopsy and GC after aspiration of follicles.ResultsPlasma RARRES2 levels were higher at 4 wk. pp. as compared to 20 and 44 wk. pp. and they were positively correlated with body fat mobilization and milk yield. RARRES2 and CMKLR1 mRNA expression levels increased from 4 to 8 wk. pp. (fat mobilization, EB < 0) and remained unchanged at 20 and 44 wk. pp. (fat reconstitution, EB > 0) as compared to 4 wk. pp. in SAT. RARRES2 and CMKLR1 mRNA levels decreased from 8 to 44 wk. pp. in GC from small follicles. In the second experiment, plasma RARRES2 increased from − 4 to 8 wk. peripartum similarly in both LE and HE cows. In addition, the area under of plasma RARRES2 curve was highly negatively associated with the number of small follicles obtained in HE animals during the cycle before the first artificial insemination. In SAT of HE cows, RARRES2 mRNA expression decreased at 1 wk. pp. compared to − 4 and 16 wk. peripartum whereas opposite expression patterns were obtained for CMKLR1. Similar results were observed for CMKLR1 mRNA expression in LE cows while there was no variation in RARRES2 mRNA expression. Moreover, RARRES2 mRNA was higher expressed in LE than in HE cows at 1 wk. pp.ConclusionsThe lactation-induced fat and energy mobilization influenced plasma RARRES2 profile and mRNA expression pattern of RARRES2 and CMKLR1 similarly in both SAT and GC. In addition, the energy content of the diet did not affect plasma RARRES2 but it altered RARRES2 mRNA expression in SAT and the area under the curve of plasma RARRES2 that was negatively associated to the number of small follicles in HE animals. Thus, RARRES2 could be a metabolic or ovarian signal involved in the interactions between metabolic and reproductive functions in dairy cows.

Comparison of performance and metabolism from late pregnancy to early lactation in dairy cows with elevated v. normal body condition at dry-off

Excessive mobilization of body reserves during the transition from pregnancy to lactation imposes a risk for metabolic diseases on dairy cows. We aimed to establish an experimental model for high v. normal mobilization and herein characterized performance, metabolic and endocrine changes from 7 weeks antepartum (a.p.) to 12 weeks postpartum (p.p.). Fifteen weeks a.p., 38 pregnant multiparous Holstein cows were allocated to two groups that were fed differently to reach either high or normal body condition scores (HBCS: 7.2 NEL MJ/kg dry matter (DM); NBCS: 6.8 NEL MJ/kg DM) at dry-off. Allocation was also based on differences in body condition score (BCS) in the previous and the ongoing lactation that was further promoted by feeding to reach the targeted BCS and back fat thickness (BFT) at dry-off (HBCS: >3.75 and >1.4 cm; NBCS: <3.5 and <1.2 cm). Thereafter, both groups were fed identical diets. Blood samples were drawn weekly from 7 weeks a.p. to 12 weeks p.p. to assess the serum concentrations of metabolites and hormones. The HBCS cows had greater BCS, BFT and BW than the NBCS cows throughout the study and lost more than twice as much BFT during the first 7 weeks p.p. compared with NCBS. Milk yield and composition were not different between groups, except that lactose concentrations were greater in NBSC than in HBCS. Feed intake was also greater in NBCS, and NBCS also reached a positive energy balance earlier than HBCS. The greater reduction in body mass in HBCS was accompanied by greater concentrations of non-esterified fatty acids, and β-hydroxybutyrate in serum after calving than in NBCS, indicating increased lipomobilization and ketogenesis. The mean concentrations of insulin across all time-points were greater in HBCS than in NBCS. In both groups, insulin and IGF-1 concentrations were lower p.p than in a.p. Greater free thyroxine (fT4) concentrations and a lower free 3-3′-5-triiodothyronine (fT3)/fT4 ratio were observed in HBCS than in NBCS a.p., whereas p.p. fT3/fT4 ratio followed a reverse pattern. The variables indicative for oxidative status had characteristic time courses; group differences were limited to greater plasma ferric reducing ability values in NBSC. The results demonstrate that the combination of pre-selection according to BCS and differential feeding before dry-off to promote the difference was successful in obtaining cows that differ in the intensity of mobilizing body reserves. The HBCS cows were metabolically challenged due to intense mobilization of body fat, associated with reduced early lactation dry matter intake and compromised antioxidative capacity.

The Effect of Asparaginase on Serum Triglycerides during Therapy for Acute Lymphoblastic Leukemia

Introduction: Treatment for acute lymphoblastic leukemia (ALL) with asparaginase (ASP) and glucocorticoids, such as dexamethasone (DEX), can cause changes in serum triglycerides (TGs). Glucocorticoids increase the activity of lipoprotein lipase (LPL), the enzyme responsible for removing TGs from the plasma, and increase production of TG-rich particles, resulting in the mobilization and redistribution of body fat. In contrast, ASP decreases the activity of LPL. Therefore, when glucocorticoids and ASP are given together, it is likely that TG-rich particles are rapidly formed, but insufficiently cleared, resulting in elevated serum TGs. The ASP formulation, e.g., native E. coli ASP (Elspar, L-ASP) vs. PEGylated ASP (Oncaspar; PEG-ASP), may influence the magnitude of TG changes. Our aim was to compare changes in TGs, the incidence of hypertriglyceridemia (hyperTG), and associated toxicities in two front-line pediatric St. Jude ALL trials that used different formulations of ASP: Total XV (L-ASP) and Total XVI (PEG-ASP).Methods: Patients on TXV (n=392) and TXVI (n=583) were assigned to the low-risk (LR) or standard/high risk (SHR) therapeutic arms. Serum TGs were measured as research biomarkers at four time-points: consolidation day 15 (“baseline” was > 35 days after the last dose of ASP during remission induction and > 21 days after the last dose of glucocorticoid); day 1 of week 7, 8, and either week 12 (TXV) or week 17 (TXVI) of continuation. Patients received DEX for 5 days/week during weeks 1, 4, and 14, for 8 days at week 7, and for 7 days at week 9 of continuation. In TXV, SHR patients received L-ASP weekly during the observed course of continuation (25,000 U/m2/dose); LR patients received L-ASP thrice weekly during continuation weeks 7-9 (10,000 U/m2/dose). In TXVI, patients were randomized to receive PEG-ASP 2,500 or 3,500 U/m2/dose during continuation: SHR weeks 1, 3, 5, 7, 9, 11, 13, and 15; LR weeks 7 and 9. HyperTG was defined as TG > 1000 mg/dL (dotted horizontal line in Figure 1). Clinically relevant toxicities in TXV, including thrombosis (≥ grade 3), osteonecrosis (≥ grade 2) and pancreatitis (≥ grade 3) were graded according to CTCAE v2.0; in TXVI CTCAE v3.0 was used, with identical grades except for pancreatitis (≥ grade 2).Results: Similar trends in TGs were observed in both protocols for LR patients: there was a decrease in TGs from baseline to week 7, when DEX but not ASP had been given (TXV: p= 2 x 10-8, TXVI: p< 2 x 10-16); TGs increased from week 7 to 8 after both DEX and ASP (TXV: p=3 x 10-14, TXVI: p< 2 x 10-16); and the week 12/17 TG did not differ from baseline (> 16 days after last dose of DEX and ASP, TXV: p= 0.7, TXVI: p= 0.1). Among LR patients, the only difference between protocols was that the week 12/17 TG was higher on TXVI (with PEG-ASP) than TXV (with L-ASP) (p= 0.04). In contrast, among SHR patients, TGs were elevated at all time points relative to baseline (e.g. week 7 compared to baseline, TXV: p= 1 x 10-5, TXVI: p < 2 x 10-16); TGs increased from week 7 to 8 after both DEX and ASP (TXV: p= 6 x 10-16, TXVI: p < 2 x 10-16); and the week 12/17 TG remained higher than baseline (TXV: p= 9 x 10-9, TXVI: p < 2 x 10-16) at 7-16 days after last dose of DEX or ASP. Among SHR patients, TGs were higher in TXVI vs. TXV after baseline: at week 7 (p= 8 x 10-7), week 8 (p= 6 x 10-4), and at the week 12/17 TG (p= 8 x 10-4), suggesting a greater effect of PEG-ASP vs. L-ASP in increasing TGs. More patients developed hyperTG on TXVI vs TXV: 10% (59/583) vs. 5% (20/392), respectively (p= 0.007). In both protocols, only patients on SHR therapy developed hyperTG, suggesting an association with ASP. Patients with hyperTG were more likely to be diagnosed with thrombosis and osteonecrosis. However, this association was only significant after adjustment for age and risk group in TXVI: 17% of patients with vs. 4% without hyperTG developed post-induction thrombosis (p= 0.009); 39% of patients with vs. 11% without hyperTG developed osteonecrosis (p= 0.006). In TXV, associations of hyperTG with thrombosis (p= 0.2) and osteonecrosis (p= 0.08) were not significant after adjustment for age and risk group. There was no association between hyperTG and pancreatitis in either protocol.Conclusions: These data support a greater association of PEG-ASP than L-ASP with elevation of serum TGs, and a greater effect of ASP than DEX. Whether serum hyperTG contributes to toxicities such as thrombosis or osteonecrosis, or is a biomarker of greater drug exposure or sensitivity, is unclear. [Display omitted] DisclosuresInaba:Shire: Research Funding. Relling:Shire Pharmaceuticals: Research Funding.

Short communication: Effects of body fat mobilization on macrophage infiltration in adipose tissue of early lactation dairy cows

Intense lipolysis triggers an inflammatory response within adipose tissue characterized by adipose tissue macrophage (ATM) infiltration; however, the mechanisms triggering this process are poorly characterized in transition dairy cows. The aim of this study was to determine the association between ATM infiltration and body fat mobilization in the transition period, markers of excessive lipolysis, and adipose tissue expression of genes related to chemotactic and inflammatory responses. Subcutaneous adipose tissue samples were taken from the tailhead of 9 multiparous Holstein cows, 27 ± 2.2 d (far-off) and 10 ± 1.5 d (close-up) before and 9 ± 0.3 d after calving (fresh). Blood samples were collected by coccygeal venipuncture 2 h before adipose sample collections. Body condition score (BCS) was assessed independently by 3 experienced technicians at every time point. Based on BCS loss intensity between the close-up and fresh period, cows were divided into 2 groups: low BCS loss (LBCSL, change in BCS <0.25 units, n = 5) and high BCS loss (HBCSL, change in BCS >0.25 units, n = 4). Although none of the LBCSL cows had a health event, all cows in the HBCSL group suffered from one or more clinical disorder (retained placenta, milk fever, or ketosis) in the transition period. The number of ATM was determined by immunohistochemistry, and expression of selected chemotactic and inflammatory genes was determined by reverse-transcription quantitative real-time PCR in subcutaneous adipose tissue samples. The proportion of ATM in subcutaneous adipose tissue increased in HBCSL during the postpartum period. The proportion of ATM was not associated with serum β-hydroxybutyrate or free fatty acid concentrations on the day of adipose tissue collection. The ATM infiltration in the fresh period was associated with local expression of the chemotactic genes, C-C motif chemokine ligand 22 (CCL22), osteopontin (SPP1), and the receptor for SPP1, cluster of differentiation 44 (CD44). This supports a potential chemotactic role of CCL22 and SPP1 for ATM in bovine adipose tissue. None of the genes encoding pro- or anti-inflammatory mediators, tumor necrosis factor (TNF), IL6, and IL10 were associated with the proportion of ATM. Our results indicate that ATM infiltration of subcutaneous adipose tissue is associated with body fat mobilization in early-lactation dairy cows and supports a role for ATM in the adaptation of adipose tissues to the metabolic challenges of the transition period.

Accuracy and application of milk fatty acid estimation with diffuse reflectance near-infrared spectroscopy.

Near infrared spectroscopy (NIRS) has the potential to estimate contents of fatty acids (FA) in milk frequently at-farm or during daily milking routine. In this study, a total of 738 raw milk spectra collected from 33 Holstein cows over a period of 30 weeks were recorded. Reference data on FA composition in milk and in milk fat were analysed in laboratory. Calibration models were calculated for single FA and groups of FA in milk and in milk fat. Validation resulted in sufficient Ratio of Prediction to Deviation (RPD) values for some single FA and in higher RPD values for groups of FA when concentrations of FA in milk were predicted. Since the concentrations of most FA in milk are highly correlated with milk fat content, the prediction of FA contents in milk fat is more meaningful when independent predictions are intended. The accuracy of predicting single FA concentrations in milk fat is rather poor for most FA but still comparable to alternative analysing methods such as MIR analysis. The estimation of different groups of FA in milk fat resulted in an improved accuracy based on higher RPD values, which was sufficient to mirror the development in the different lactation phases. The course of cow individual long chain fatty acid (LCFA) concentration in the early lactation stage can be an indicator for body fat mobilisation. The accurate estimation of the extent and duration of body fat mobilisation in cow individuals was rather difficult with NIR predicted LCFA concentrations and would require a higher measuring frequency than applied in this study.

Responses of body fat mobilization to isoproterenol or epinephrine challenge in adult cows: influence of energy level, breed, and body fatness.

The sustainability of livestock production systems facing climatic or economic changes is linked in part to the potential of the female ruminants to adapt to feeding constraints through metabolic and hormonal regulation, notably responses of body fat mobilization, depending on adipose tissue (AT) lipolysis. Our hypothesis was that these responses could change according to genotype (breed) and body fatness. Six fat, nonpregnant, nonlactating Charolais cows, six fat Holstein cows, and six lean Holstein cows were used in a 2 × 2 crossover design with two treatments (underfeeding or overfeeding, at 62% [low] or 128% [high] of maintenance energy requirements [MER], respectively) and two periods. Isoproterenol (ISO, a nonselective β-adrenergic agonist) or epinephrine (EPI, a β- and α2-adrenergic agonist) was injected (6 nmol/kg of lean mass). Blood samples were collected regularly from -20 to 75 min after the injection and then were analyzed for NEFA, glycerol, glucose, and L-lactate. Underfeeding greatly increased (P < 0.001) basal plasma NEFA concentrations (+467%, +264%, and +600% for fat Charolais, fat Holstein, and lean Holstein cows, respectively). For each drug, underfed cows had higher NEFA or glycerol responses to adrenergic challenges than overfed cows. Fat Charolais cows had higher basal plasma NEFA (P < 0.05) concentrations (+64.9%) than fat Holstein cows. The plasma NEFA or glycerol response at 5 min (P < 0.05) was higher for fat Charolais than for fat Holstein cows, whatever the injected drug. Basal plasma lactate concentration and lactate response to ISO or EPI were higher (P < 0.05) for fat Charolais cows than for fat Holstein cows. Fat Holstein cows had higher (P < 0.01) basal glycerol (+18.4%) than lean Holstein cows. This increase could be linked to the increased AT mass. ISO increased more lipolytic responses in fat than in lean Holstein cows, whereas EPI increased more these responses in lean than in fat Holstein cows (drug × fatness interaction), suggesting an increased antilipolytic effect due to α2-AR stimulation in fat cows. Breed had a significant effect on basal and stimulated fat mobilization as well as lactate concentrations, suggesting that the Charolais breed could be more sensitive to stress.

Effects of magnesium source and monensin on nutrient digestibility and mineral balance in lactating dairy cows

The interaction of monensin and 2 supplemental Mg sources (MgO and MgSO4) on total-tract digestion of minerals and organic nutrients and milk production was evaluated in lactating dairy cattle. Eighteen multiparous Holstein cows (139 ± 35 DIM) were used in a split-plot experiment with 0 or 14 mg/kg diet DM of monensin as the whole-plot treatments and Mg source as split-plot treatments. During the entire experiment (42 d), cows remained on the same monensin treatment but received a different Mg source in each period (21 d) of the Latin square. Diets were formulated to contain 0.35% Mg with about 40% of that provided by MgO or MgSO4. Diets were formulated to have similar concentrations of major nutrients and K concentrations were elevated (2.1% of DM) with K2CO3 to create antagonism to Mg absorption. Apparent digestibility was measured by total collection of urine and feces. Supplemental MgSO4 decreased DMI (26.9 vs. 25.7 kg/d) and tended to decrease milk yield (40.2 vs. 39.3 kg/d), but increased the digestibility of OM (68.3 vs. 69.2%) and starch (91.9 vs. 94.4%) compared with MgO. Feeding MgSO4 with monensin decreased NDF digestibility compared with other treatments (46.7 vs. 50.2%). That diet also had decreased apparent absorption of Mg compared with diets without monensin (15.6 vs. 19.2%), whereas MgO with monensin had greater apparent absorption of Mg (23.0%) than other treatments. Cows consuming MgSO4 had increased apparent Ca absorption (32.2 vs. 28.1%) and balance. A diet with MgSO4 without monensin increased the concentration of long-chain fatty acids in milk, suggesting increased mobilization of body fat or decreased de novo fatty acid synthesis in the mammary gland. Overall, when dietary Mg was similar, MgO was the superior Mg source for lactating dairy cattle, but inclusion of monensin in diets should be considered when evaluating Mg sources.

A prospective cohort study of digital cushion and corium thickness. Part 2: Does thinning of the digital cushion and corium lead to lameness and claw horn disruption lesions?

The aim of this study was to determine whether a decrease in thickness of the sole soft tissues (SST) beneath the flexor tuberosity of the distal phalanx (i.e., the digital cushion and corium) predisposed a claw to develop claw horn disruption lesions (CHDL) or a leg to lameness. Data were analyzed from a longitudinal study of 179 cows, which had been examined at 5 assessment points -8, +1, +9, +17, and +29 wk relative to their first, second, third, or fourth calving. At each assessment point, SST were measured using ultrasonography. Additional assessment point data included sole lesions and back fat thickness (BFT), and cows had been locomotion scored every 2 wk from calving. One hundred fifty-eight cows completed the study. Separate logistic regression survival analyses were constructed to assess the outcomes, either lameness on a leg or CHDL on a claw; combinations of lameness and lesions were tested as outcomes. Cow level variables tested included farm and lactation number. Variables were tested describing previous SST thickness, minimum previous SST thickness, BFT, and change in either variable between prior assessment points. Prior lesions/lameness strongly predicted repeat cases and the final models had the outcome first lesion or lameness on a claw or leg. In the reported lameness models, lameness was defined as a leg being recorded as lame twice within 3 consecutive scores, and in the reported lesion models, lesion was defined as the first presence of either a sole ulcer or a severe sole hemorrhage on a claw. Thin SST increased the likelihood of lesion occurrence; thin SST on the lateral claw predicted subsequent lameness on a leg. Thin BFT and thinning of BFT between previous assessment points increased the likelihood of future lesion occurrence. Thin SST and thinning of BFT had additional effects on the likelihood of lesion occurrence, suggesting that BFT and sole SST had independent effects on lesion occurrence. However, change in SST thickness between assessment points did not influence the likelihood of future lesions or lameness. This suggests that thin SST were not simply a result of depletion of body fat and challenges the theory that thinning of the digital cushion with body fat mobilization leads to CHDL. Other possible mechanisms by which SST become thin are discussed and could include changes in integrity of the suspensory apparatus with physiological events.

Far-off and close-up dry matter intake modulate indicators of immunometabolic adaptations to lactation in subcutaneous adipose tissue of pasture-based transition dairy cows

The common practice of increasing dietary energy density during the close-up dry period (last ∼3 wk prepartum) has been recently associated with a higher incidence of metabolic disorders after calving. Despite these reports, over-feeding of metabolizable energy (ME) during the far-off, nonlactating period is a common management policy aimed at achieving optimum calving body condition score (BCS) in pasture-based systems, as cows are generally thinner than total mixed ration cows at the end of lactation. Our hypothesis was that both far-off and close-up overfeeding influence the peripartum adipose tissue changes associated with energy balance and inflammatory state. Sixty mid-lactation, grazing dairy cows of mixed age and breed were randomly allocated to 1 of 2 groups that were managed through late lactation to achieve a low and high BCS (approximately 4.25 and 5.0 on a 10-point scale) at dry-off. The low BCS cows were then overfed ME to ensure that they achieved the same BCS as the higher BCS group by calving. Within each rate of BCS gain treatment, cows were offered 65, 90, or 120% of their pre-calving ME requirements for 3 wk pre-calving in a 2 × 3 factorial arrangement of treatments (i.e., 10 cows/treatment). Subcutaneous adipose tissue was collected via biopsy at -1, 1, and 4 wk relative to parturition. Quantitative PCR was used to measure mRNA and microRNA expression of targets related to adipogenesis and inflammation. Cows overfed in the far-off period had increased expression of miR-143 and miR-378 prepartum (-1 wk) indicating greater adipogenesis, consistent with their rapid gain in BCS following dry-off. Furthermore, the lower postpartum expression of IL6, TNF, TLR4, TLR9, and miR-145, and a higher abundance of miR-99a indicated lower body fat mobilization in early lactation in the same group. In the close-up period, feeding either 65 or 120% of ME requirements caused changes in FASN, IL1B, IL6R, TLR9, and the microRNA miR-143, miR-155, and miR-378. Their respective expression patterns indicate a tentative negative-feedback mechanism in metabolically compromised, feed-restricted cows, and a possible immune-related stimulation of lipolysis in apparently static adipocytes in overfed cows. Data from cows fed 90% of ME requirements indicate the existence of a balance between lipolytic (inflammatory-related) and anti-lipolytic signals, to prime the mobilization machinery in light of imminent lactation. Overall, results indicate that far-off dry cow nutrition influences peripartum adipose tissue metabolism, with neither strategy negatively affecting the physiological adaptation to lactation. Furthermore, to ensure a favorable transition, cows should be subjected to a small feed restriction in the close-up period, irrespective of far-off nutritional management.