İvesi Koyunlarında Gebeliğin Erken Teşhisi İçin Sığır Hızlı Görsel PAG ELISA Testi ve Transabdominal Ultrasonografinin Değerlendirilmesi

Mehmet Akköse

doi:10.18016/ksutarimdoga.vi.668707

Abstract

The aim of this study was to evaluate two different methods (a bovine rapid visual PAG ELISA test and transabdominal ultrasonography) for early diagnosis of pregnancy in Awassi sheep. The ewes used in this study (n=50) were hand-mated in June of 2019 and lambed in October of 2019. Pregnancy diagnosis was performed 34-38 days after mating by rapid visual PAG ELISA test and transabdominal ultrasonography in standing position. The diagnostic test characteristics of both methods were calculated using lambing results as a gold standard. Kappa analysis was conducted to analyze the agreement between each pregnancy diagnosis method and the lambing results. McNemar's analysis and the comparison of the receiver operating characteristic (ROC) curves demonstrated that there was no significant difference between the pregnancy diagnosis methods and lambing results (p ≤ 0.05). According to the lambing results, it was determined that, of the 50 ewes, 42 (84%) were pregnant and 8 (16%) were not. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of rapid visual PAG ELISA and transabdominal ultrasonography were 97.6%, 62.5%, 93.2%, 83.3%, 92% and 95.2%, 100%, 100%, 80%, 96%, respectively. The Kappa coefficient was 0.669 (good agreement) between rapid visual PAG ELISA and lambing, and 0.865 (very good agreement) between transabdominal ultrasonography and lambing. In McNemar’s analysis, no difference was found between the pregnancy diagnosis methods and lambing results. ROC analysis revealed that the areas under the curves were 0.801 and 0.976 for rapid visual PAG ELISA and transabdominal ultrasonography, respectively, and the difference between the two pregnancy diagnosis methods was statistically insignificant. In conclusion, both rapid visual PAG ELISA and transabdominal ultrasonography in standing position proved to be practical and reliable methods for pregnancy diagnosis as of day 34 post-mating in Awassi ewes.

Highlights

The sheep industry stands out as a promising economic sector
Transabdominal ultrasonography was performed after blood collection
To evaluate the pregnancy outcomes of each pregnancy diagnosis method in ewes, a 2X2 contingency table was constructed (Table 1) and test characteristics were calculated for transabdominal ultrasonography and rapid visual PAG ELISA (Table 2)

Summary

Introduction

Sheep breeding has an important place in Turkey's economy in terms of meat, milk, wool and leather production. The milk yield of Awassi sheep, which is one of the highest milk-producing sheep breeds native to Turkey, can reach up to 250–300 kg in breeder flocks (Taşan, 2016). The increased demand for lamb meat requires increased reproductive performance. Nonpregnant ewes can be either re-bred in the breeding season, fed only for wool and leather production or culled to reduce feeding costs. The separation of the flock into pregnant and non-pregnant groups might reduce productive and reproductive losses caused by abortions, stillbirths and birth of weak lambs (Karen et al, 2001; Ulusoy and Kaymaz, 2009; Chaves et al, 2017)

Objectives

Methods

Results