COMPARATIVE EVALUATION OF TWO METHODS OF EARLY PREGNANCY DIAGNOSIS IN BOVINES IN THE CENTRAL HIGHLANDS OF PERU

Villar F.A.; Sánchez N.M.; Huamán R.D.; Payano I.U.; Eulogio C.Q.; De La Cruz A.H. · Spermova (2022) · DOI: 10.18548/aspe/0010.24

Resumen

An early diagnosis of pregnancy in bovine is of great importance because this improves farmers' profitability, avoiding any delay in fertilization or significant economic losses. Thus, the objective of this study was to evaluate and compare two diagnostic methods of pregnancy: determination of pregnancy-associated glycoproteins (PAG) and transrectal ultrasound, for which 46 animals (14 heifers and 32 cows) of the Brown Swiss breed were evaluated between 3 and 8 years old and with a body condition between 2.8 - 3.5, considering two periods (28 and 35 days) post service, collecting blood samples from the coccygeal vein of the animals to perform the serological test and simultaneously performing the transrectal ultrasonography technique; 60 days after service, rectal palpation was performed, according to the establishment's protocols, to detect the animals' pregnancy or not. Of the 100% of animals with which the work began, 17.4% returned to heat and 30.4% were diagnosed as pregnant and 52.2% empty. Both diagnostic methods had a "very good" kappa concordance index (κ = 0.95 and 0.89 for 28 and 35 days respectively). The serological method in relation to rectal palpation had a concordance of 0.78 and 0.89 for days 28 and 35 respectively, while the ultrasonography obtained concordances of 0.833 and 1.00 for days 28 and 35. To the MacNemar test, serological and ultrasound diagnoses made at 28- and 35-days post-service have not changed significantly. The sensitivity values at 28 and 35 days for both methods were 92.9%and 100.0%, and specificity for the immunological method 87.5% and 91.7%, and with the ultrasonography 91.7% and 100.0%, at 28 and 35 days respectively. The positive predictive values (PPV) for the serological method were 81.3% and 81.25%, and with the ultrasonography 95.65% and 100%, at 28 and 35 days. 5.3% of cases were interpreted as cases of late embryonic abortion, which requires further investigation, so we have to consider the experimental error. Both methods of pregnancy diagnosis are very reliable and precise, from day 28 post service, being the immune diagnosis method with the detection of PAG proteins in the serum more versatile from the practical point of view.

Instituciones: Universidad Peruana Los Andes; Universidad Nacional del Centro del Perú; Universidad Nacional Intercultural de la Selva Central Juan Santos Atahualpa; Universidad Peruana Unión