   Use of a homologous radioimmunoassay (RIA) to evaluate the effect of maternal and foetal parameters on pregnancy-associated glycoprotein (PAG) concentrations in sheep; ; et al in Theriogenology (2005), 63(7), 1914-1924 Early pregnancy detection and prediction of the number of lambs would be profitable for sheep breeders because it enables them to adjust nourishment of pregnant ewes according to the individual needs in ... [more ▼] Early pregnancy detection and prediction of the number of lambs would be profitable for sheep breeders because it enables them to adjust nourishment of pregnant ewes according to the individual needs in order to prevent health problems around parturition. The concentration of ovPAG has previously been reported to be related with maternal parameters (farm, breed and age) as well as foetal parameters (number of lambs, their sex and birth weight), but contradictory results were obtained in different small-scale studies. This large-scale study evaluates the effect of these parameters on the ovPAG concentration, determined by a homologous radioimmunoassay (RIA), and it further investigates the possibility to predict the number of lambs by means of homologous ovPAG determination. Eighty-three and ninety-five ewes of the Suffolk and Texel breed, respectively, housed on four different farms (experiment 1) and 68 ewes of the Suffolk breed, housed on two different farms During the last 6 weeks of pregnancy determination of 3-OH butyrate can be used to determine a necessary nutrition correction [4]. In conclusion, the present study has shown an effect of different parameters such as farm, breed of the ewes, and number and birth weight of the lambs on ovPAG concentrations at all time points. Prediction of litter size based on ovPAG concentrations at the individual ewe level was not useful due to small sensitivity and/or specificity, notwithstanding significantly increased odds of multiple lambs. Furthermore, age of the ewes and sex did not have an impact oil ovPAG levels. [less ▲] Detailed reference viewed: 21 (2 ULg)A new test for early pregnancy diagnosis in sheep: Determination of ovine pregnancy associated glycoprotein (ovPAG) concentration by means of a homologous radioimmunoassay; ; et al in Vlaams Diergeneeskundig Tijdschrift (2004), 73(2, MAR-APR), 119-127 Early pregnancy diagnosis is a useful tool in the management of sheep breeding. In this study different methods for pregnancy diagnosis in sheep, including the assessment of ovine Pregnancy-Associated ... [more ▼] Early pregnancy diagnosis is a useful tool in the management of sheep breeding. In this study different methods for pregnancy diagnosis in sheep, including the assessment of ovine Pregnancy-Associated Glycoproteins (ovPAGs), are briefly discussed. Subsequently, in a field trial the use of transrectal ultrasound is compared with the assessment of the concentration of ovPAGs for early pregnancy diagnosis. At the start of the breeding season in 2002, 192 Texel ewes at 4 different farms were synchronized and afterwards mated or artificially inseminated (AI). At the moment of synchronization (D-14) and at 25 (D25), 35 (D35) and 45 (1345) days after mating/AI, transrectal ultrasound was performed and blood was collected by jugular vein puncture. The ovPAG concentration in the plasma of the ewes was measured by means of a homologous radioimmunoassay (RIA). The specificity of transrectal ultrasound was 85%, and the sensitivity was 92% at D25, 94% at D35 and 95% at D45. The specificity of the homologous RIA was 100%, and the sensitivity was 99% at D25, and 100% at D35 and D45. Higher ovPAG concentrations were detected at D35 and D45 than at D25 (P<0.01). An interesting finding was that within the same breed (Texel), ovPAG concentrations were significantly affected by the farm (P<0.01). In conclusion, determination of ovPAG concentration by means of homologous RIA can be used for early pregnancy diagnosis in sheep and is more reliable than transrectal ultrasound at 25,35 or 45 days of gestation. [less ▲] Detailed reference viewed: 105 (0 ULg) |
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