Utilização das proteínas associadas à gestação como método de diagnóstico precoce em vacas leiteiras da raça girolando

Abstract

The milk production chain in Brazil is very widespread in all territorial extension, and when it comes to production systems that aim to increase productivity in the sector, intensive animal reproduction techniques must primarily be an important part of this integration. In this context, everything starts from the diagnosis of pregnancy of the dairy cow. In view of this approach, the aim of this study was to use the proteins associated with pregnancy (PAG’s) as a method for early diagnosis of pregnancy in Girolando dairy cows. For the experiment the VISUAL-PAG commercial kit from IDEXX Laboratories (Inc., Westbrook, Maine, USA) was used, a colorimetric reaction test, whose visual color change determines the result. Despite of the manufacturer's recommendation to be used in cows from the 28th post insemination day, this study aimed to determine the sensitivity and specificity of the test at 25, 26, 27 and 28 days post-Timed Artificial Insemination (TAI). For this, 57 multiparous females were used in equal management conditions, and each animal was submitted to four sequential collections of blood samples on the days described. The biological material collected was obtained by venipuncture of the coccidian vessels through needles and vacuum tubes without anticoagulant, and after clot retraction followed by the centrifugation process for 10 minutes at 900g for better use of serum and blood formation of aliquots properly identified and stored at -20ºC for further analysis. At 32 days of TAI all females were submitted to pregnancy diagnosis by ultrasonography (US) performed by a skilled professional. This is considered the Gold Standard Test of the experiment. The results were obtained through a concordance study, which revealed a sensitivity of 100% and specificity of 94.7% for days 25, 26, 27 and 28 post-TAI. In view of these results, it can be considered that the research of the PAGs through the VISUAL kit can be used as a diagnostic method of early and safe gestation in dairy cows of the Girolando breed 25 days after artificial insemination.