Báo cáo khoa học: "Endocrine Profiles, Haematology and Pregnancy Outcomes of Late Pregnant Holstein Dairy Heifers Sired by Bulls Giving a High or Low Incidence of Stillbirth" ppt

Acta vet scand 2004, 45, 47-68 Endocrine Profiles, Haematology and Pregnancy Outcomes of Late Pregnant Holstein Dairy Heifers Sired by Bulls Giving a High or Low Incidence of Stillbirth By B Kornmatitsuk1, E Dahl3, E Ropstad3, J F Beckers4, H Gustafsson2 and H Kindahl1 1Department of Obstetrics and Gynaecology, Centre for Reproductive Biology in Uppsala (CRU), Swedish University of Agricultural Sciences, Uppsala, 2Swedish Dairy Association, Eskilstuna, Sweden, 3Department of Reproduction and Forensic Medicine, Norwegian College of Veterinary Medicine, Oslo, Norway, and 4Department of Physiology of Reproduction, Faculty of Veterinary Medicine, University of Liège, Sart-Tilman, Belgium Kornmatitsuk B, Dahl E, Ropstad E, Beckers J.F, Gustafsson H, Kindahl H: Endocrine profiles, haematology and pregnancy outcomes of late pregnant Holstein dairy heifers sired by bulls giving a high or low incidence of stillbirth Acta vet scand 2004, 45, 47-68 – The high incidence of stillbirth in Swedish Holstein heifers has increased continuously during the last 15 years to an average of 11% today The pathological reasons behind the increased incidence of stillbirth are unknown The present experiment was undertaken to investigate possible causes of stillbirth and to study possible physiological markers for predicting stillbirth Twenty Swedish Holstein dairy heifers sired by bulls with breeding values for a high risk of stillbirth (n = 12) (experimental group) and a low risk of stillbirth (n = 8) (control group, group B) were selected based on information in the Swedish AI-data base The experimental group consisted of subgroups of heifers (groups A1 and A2) inseminated with different bulls with 3.5% and 9% higher stillbirth rates than the average, and the control group consisted of heifers pregnant with different bulls with 0%-6% lower stillbirth rates than the average The bull used for group A1 had also calving difficulties due to large calves as compared to the bull in group A2 showing no calving difficulties The heifers were supervised from 6-7 months of pregnancy up to birth, and the pregnancies and parturitions were compared between groups regarding hormonal levels, haematology, placental characteristics and calf viability In group A1, stillborn, weak and normal calves were recorded In group A2, stillborn and normal calves were registered All animals in the control group gave birth to a normal living calf without any assistance The weak calf showed deviating profiles of body temperature, saturated oxygen and heart rates, compared with the normal living calves No differences of the placentome thickness, measured in vivo by ultrasonography were seen between the groups The number of leukocytes and differential cell counts in groups A1 and A2 followed the profiles found in the control group In group A1, a slight decrease of oestrone sulphate (E1SO4) levels was found in the animal delivering a stillborn calf from the first 24-h blood sampling at weeks to the second at weeks prior to delivery, while the levels of E1SO4 at both periods in the animal delivering a weak calf followed the profile in animals delivering a normal living calf During late pregnancy and at the time of parturition, the levels of E1SO4 and PAGs in animals delivering a stillborn or weak calf (from group A1) followed the normal profiles found in animals delivering a normal living calf In group A2, low levels of E1SO4 and pregnancy associated glycoproteins (PAGs) over 24 h at both and weeks prior to parturition (0.05) In animals delivering a stillbor n or weak calf During late pregnancy, the levels of P4 in all animals showed the same pattern but higher levels of P4 were recorded in animal no 465 Low levels of P4 were also found at the end of pregnancy After parturition, the levels of P4 in animals no 145 and 465 were very close to zero, whereas the levels were slightly higher in animals no 58 and 716 (Figs 4-5, left upper panels) The levels of PG-metabolite in all animals were similar during late pregnancy and parturition The levels remained low during most of the period studied and a peak of PGmetabolite was recorded on the day of parturiActa vet scand vol 45 no 1-2, 2004 62 B Kornmatitsuk et al Table Endocrine concentrations in the calves at birth (0) and h (1) after birth summarised by groups Data of the weak calf from animal no 716 is presented separately P4 (nmol/L) PG (pmol/L) Cortisol (nmol/L) E1SO4 (nmol/L) PAGs (ng/ml) Group / calf no (n) 1 1 A1* (4) 0.8 ± 0.8 0.6 ± 0.3 9932 ± 2581 3146 ± 642 342 ± 76 351 ± 35 224 ± 81 59 ± 23 209 ± 44 177 ± 39 A2* (4) 0.9 ± 0.6 1.3 ± 1.1 13072 ± 4415 ± 7399 3016 404 ± 140 385 ± 87 128 ± 87 46 ± 33 114 ± 42 107 ± 41 B (8) 1.0 ± 0.4 1.1 ± 1.0 9589 ± 8098 2643 ± 1160 341 ± 124 355 ± 102 104 ± 37 ± 11 65 211 ± 107 202 ± 85 716 0.5 0.3 3762 1290 302 315 236 233 90 12 Group A1 = an index of stillbirth equal to 85; Group A2 = an index of stillbirth equal to 94; Group B = an index of stillbirth ranged between 100-111; n = the number of observations tion In animal no 716, a lower increase of the PG-metabolite on the day of parturition was found (< 4000 pmol/L) and the levels increased 1-2 d after parturition, whereas in other animals, the levels of PG-metabolite sharply decreased (Figs 4-5, right upper panels) The levels of cortisol in animals no 58 and 716 fluctuated within a magnitude of about 30 nmol/L, whereas the levels in animals no 145 and 465 fluctuated with a higher range through the period of late pregnancy and after parturition (Figs 4-5, left middle panels) The levels of E1SO4 in all animals increased considerably, reaching a peak at the time of parturition and then dropping markedly to the basal levels afterwards However, the levels of E1SO4 in animals no 58 and 716 were high or relatively normal during late pregnancy and at the time of parturition In animals no 145 and 465, the levels were lower during late pregnancy and increased with a lower magnitude at the time of parturition (Figs 4-5, right middle panels) In animals no 58 and 716, the levels of PAGs were low and constant during late pregnancy An increased level of PAGs was Acta vet scand vol 45 no 1-2, 2004 recorded during the last 10 d prior to parturition and reached high levels on the day of parturition similar to those found in animals delivering a normal living calf In animals no 145 and 465, the levels of PAGs were low during late pregnancy and increased with a low magnitude (