Interactions of metabolic challenges with fertility in dairy cows

Transcription

1 Interactions of metabolic challenges with fertility in dairy cows Geert Opsomer Department of Reproduction, Obstetrics and Herd Health Faculty of Veterinary Medicine Ghent University Belgium 1 Aims of the presentation To set the scene and indicate main metabolic challenges modern high yielding dairy cows are confronted with. Innovative research topics currently going on to unravel the pathophysiology of major metabolic stress in modern dairy cows especially focussing on the interaction with fertility problems

2 High producing dairy cow 60Kg/day

3 (Fricke, 2012) 7 Major challenge for high milk production Availability of glucose: 1 kg of milk: 72 g of glucose 60 kg of milk: mammary glucose requirement: 4 kg/d Glucose mainly derived from gluconeogenesis up 75% of glucose is made from propionate in the liver 8 Introduction Dry period Lactation Energy for milk production Dry matter intake Metabolic diseases Energy for foetal growth Negative energy balance 3 weeks 3 weeks Days in lactation Calving Transition period 9 3

4 RATION : Propionicacid Lipogenesis Lipolysis GLUCOSE Insuline FAT LACTOSE GLUCONEOGENESIS LIVER KREBS CYCLE KETONES NEFA Alternative source of energy 10 Intake drop at calving means increased fat mobilization (Blood NEFA) Dry Matter Intake Kg/day Non- Esterified 1000 Fatty Acids um/l % intake depression (Grummer, 1993) % Increased 400 fat mobilization Weeks relative to calving 11 Glucose uptake by the mammary gland Major challenge for the cow since at that time dry matter intake is not maximal yet Maximal production only possible via absolute prioritization of glucose uptake by the mammary gland: restriction of glucose consumption in peripheral tissues maximization of (hepatic) glucose production mobilization of energy reserves to provide alternative (=non-glucose) fuels for peripheral tissues 12 4

5 Adaptation towards high milk yield: Glucosesparing state Similar for most pregnant/lactating mammals Lowerinsulinconcentration Peripheralinsulinresistance Result: Lower expression GLUT-4 in muscle, fat More glucose available for insulin-independent organs Mammary gland Gravid uterus 13 - Insulin concentration -Insulinresponsivenessandsensitivity Feed intake Brain Gluconeogenesis Liver GLUT 4 Fat NEFA GLUT 4 GLUCOSE 90% GLUT 1-3 Mammary gland (Bossaert, 2010) 15 5

6 In vitro effect of elevated NEFA levels on proliferation of granulosa cells 48 hr with palmitic, stearic and/or oleic acid fatty acids like palmitic and stearic acid have a significant negative effect on granulosa cell growth and proliferation (Vanholder, 2005) 16 In vitro effect of elevated NEFA levels on oocyte and embryo quality 24 hr with -palmitic acid -stearic acid -oleic acid parameters: oocyte maturation, fertilisation rate, cleavage rate and blastocyst formation palmitic and stearic acid: negative effect on all parameters, oleic acid: no effect (Leroy, 2005) 17 Fat specificity of the dye Nile Red (Leroy, 2005) Lipid droplet 18 6

7 BHB and glucose Normal: 3.3 mm glucose and 0.3 mm BHB Subclinical ketonemia: 2.8 mm glucose and 1.8 mm BHB Clinical ketonemia: 1.4 mm glucose and 4.0 mm BHB In vitro maturation model Conclusions Simultaneous exposure to low glucose and high BHB concentrations during oocyte maturation had a negative effect on cleavage and blastocyst formation. Especially low glucose rather than high BHB was responsible for the 19 observed effect. 20 Energy Balance Energy Balance and Reproduction o o Calving o o o o Insemination o o o o o o o o o o o o Days in Relation to Parturition 20 (Britt, 1995) Overconditioned cows have a lower dry matter intake larger fat depots to be broken down Hence are at a higher risk to suffer from: -metabolic diseases: ketosis, fatty liver, hypocalcemia -inflammatory/infectious diseases -fertility problems Fat cow syndrome (Morrow, 1975) 21 7

8 Fat cow syndrome Metabolic syndrome 22 The health consequences of obesity in men Cancer Respiratory disease Gallbladder disease Atherosclerosis Hypertension Obesity Kidney failure Type 2 diabetes Stroke Heart failure 23 What is this Syndrome? Etiology not fully elucidated Environment Polygenic causes Insulin resistance Hyperinsulinemia Hyperglycemia IFG, IGT, T2DM Abd. Obesity ( WC, WC / ht ratio), BMI Hypertension, Endothelial Dysfunction (ED) Dyslipidemia(TG, sldl, HDL) Pro-inflammatory state ( CRP, TNF-α, IL-6) Pro-coagulant state ( PAI-1, Fibrinogen) Premature atherosclerosis 24 8

9 Evolution of Man Hormones secreted by the Adipocytes Leptin Food intake Energy expenditure Lipolysis lipogenesis Insulin sensitivity TNF-α Food intake Energy expenditure Lipolysis lipogenesis Insulin sensitivity GLUT-4 LPL Resistin Contradicting reports, possibly improvement of insulin sensitivity Adiponectin Plasma glucose -> Mechanism? -> gluconeogenesis FFA oxidation ASP triglyceridesynthesis via DAG GLUT-4 lipolysis via HSL IL-6 Food intake Energy expenditure Lipolysis lipogenesis Many others 27 9

10 (Wellen et al., 2005) M.J. Zhu et al. / Placenta 31 (2010) 2011 Shankar Maternal Obesity Promotes a Pro inflammatory Signature in Rat 10

11 31 LeBlanc, 2014 Cytobrush: Taking samples during insemination Bogado-Pascottini et al., submitted 33 11

12 Cytotape versus Cytobrush - Similar PMNs % - Same cellularity - Cytobrush is more bloody - Cytotape has better quality (Bogado Pascottini et al., 2015) Preliminary results - Total of samples 1,496 inseminations - SCE prevalence 14,5% (3% PMNs) - Total conception rate 43,58% SCE (+) 21,18% SCE (-) 46,36% P = < 0,05 Measuring insulin sensitivity Gold standard: hyperinsulinemic euglucemic clamp the amount of glucose needed to infuse/time to keep glucose concentration constant following an insulin infusion Several surrogate indices: HOMA, Quicki, RQuicki, RQuicki BHB (D. Haarstrich) 36 12

13 Insulin resistance = decreased biological response of insulin sensitive tissues Biological response Dose-response curve R max,1 Normal insulin response R max,2 Decreased insulin sensitivity Decreased insulin responsiveness ED 50,1 ED 50,2 Insulin concentration (Kahn, 1978) Study design 9 healthy dairy cows selected based on BCS 3-3,5 (n = 4) 4-5 (n = 5) Dry, pregnant cows Fed according to NRC requirements Mais silage Hay HEC test 19 days before expected parturition date (min 16 and max 21 days) 38 HEC test Hyperinsulinemic Constant insulin infusion to reach a steady state after 60 to 90minutes (hyperinsulinemic state) 4 consecutive insulin infusions: 0,1; 0,5; 2 and5 mu/kg/min (140 minutes each) Euglycemic Monitor blood glucose Speed of glucose infusion adapted to keep blood glucose constant and normal Clamp Steady state where insulin is in a steady state and no or minor changes are necessary to keep blood glucose constant At least 30 minutes 39 13

14 4/10/2015 HEC test: practice Glucose infusion HEC test: practice rate adapted according to blood glucose Insulin infusion constant rate at 1 ml/min High glucose infusion rate = low insulin resistance Low glucose infusion rate = high insulin resistance Cows were relaxed HEC test: practice 14

15 10 Steady state GIR and glucose Insulin concentration Time glucose (mmol/l) GIR (ml/min) insulin (µu/ml) GIR = glucose infusion rate SSGIR (µmol/kg/min) 10 BCS<4 (n=4) BCS>4 (n=5) SSIC (µu/ml) * : P< 0,05 between groups 44 ISI = insulinsensitivityindex = GIR divided by the averageinsulin concentration during the steady state = an indication of the amount of glucose taken up per unit insulin ISI 0,40 0,35 0,30 Not significant P<0,01 0,25 0,20 0,15 0,10 0,05 P<0,05 0,05<P<0,1 0,00 I1 I2 I3 I4 BCS<4 BCS>

16 Conclusion The glucose metabolism of precalving dairy cows with a BCS>4 is more insulin resistant compared to cows with a BCS<4 Decreased insulin sensitivity and decreased insulin responsiveness Possible explanations NEFA Adipokines (adiponectin, leptin, resistin, TNFα, IL6) 46 Hyperlipidemia causes insulin resistance in cows IVGTT 8 hours after infusion of tallow emulsion (Pires et al., ) Hyperlipidemia causes insulin resistance in cows IVITT 8 hours after infusion of tallow emulsion (Pires et al., ) 16

17 Notallfat depots are the same Fat depots: visceral depots are considered more dangerous than subcutaneous depots direct contact to the liver, higher possibility to produce adipokines, more sensitive for lipolysis, higher concentration of saturated fatty acids 49 Intra-abdominal fat is highly predictive of insulin sensitivity 30 S I (x10-5 min -1 /pm) Intra-abdominal fat area (cm 2 ) Dr.Sarma@works About apples and pears 51 17

18 The IDF Consensus 2006 Central Obesity TG HDL Hypertension FPG 52 Omentum score 1: omentum is a rather thin peritoneal mebrane with clearly visible blood vessels 53 (Van Eetvelde, 2009) Omentum score 5: The omentum is that fat that there is no longer a net structure is visible 54 (Van Eetvelde, 2009) 18

19 Correlation body condition score omental score 6,00 5,00 Omentum score 4,00 3,00 r= 0,202 P=0,085 2,00 1,00 0,00 0,00 1,00 2,00 3,00 4,00 5,00 6,00 Body condition score 55 (Van Eetvelde, 2009) Nikkah (Nikkahet al., 2010) 56 Notall fattyacidsare the same Nefas: saturated fatty acids are proven to be more toxic than unsaturated fatty acids 57 19

20 Multiple Factors May Drive Progressive Decline of β-cell Function Protein glycation Hyperglycemia (glucose toxicity) β-cell Obesity Insulin resistance Lipotoxicity (elevated FFA, TG) Adapted from Unger RH, Orci L. Biochim Biophys Acta. 2002;1585: The hyperbolic relationship Insulin secretion Lean non-diabetic subjects Insulin sensitivity Insulin secretion Obese non-diabetic subjects Insulin sensitivity Insulin secretion (Obese) Type 2 diabetic patients Insulin sensitivity Scheen AJ IVGTT in periparturient dairy cows Insulin (µu/ml) INS1 INS2 INS3 NEFA: negatively correlated with AUC ins and Peak ins Time relative to infusion (min) AUC ins Peak ins * * * * d + 14 d + 42 d - 14 d + 14 d + 42 d (Bossaert, 2010) 20

21 61 62 HUMAN Malnutrition during pregnancy DAIRY COW High milk yield/ NEB during gestation Nutrient restriction embryo/fetus Nutrient restriction embryo/fetus Birth weight Long term health Reproduction Birth weight Long term health Reproduction? 21

22 (Lucy, 2010) 64 (Lucy, 2010) 65 22

23 IVGTT in neonatal calves BB HF BB HF Insulin (µu/ml) Glucose (mmol/l) Time relative to glucose infusion (min) Time relative to glucose infusion (min) HF Higher AUC ins Lower ER gluc More insulin resistant 68 (Bossaert, 2010) IVITT in neonatal calves IV insulinbolus (0.05 IU/kg) Glucose (mmol/l) BB HF Time relative to insulin infusion (min) Glucose constantly at a higher level in HF calves 69 (Bossaert, 2010) 23

24 Take home message Modern cows and men seem to struggle with very similar diseases: striking similarities between metabolic syndrome in humans and fat cow syndrome in high yielding dairy cows Exploring the knowledge in human medicine may help to improve our knowledge in veterinary medicine: pathophysiology, treatment and prevention 70 Questions? 24