Comparação de métodos auxiliares na identificação de estros em vacas e novilhas mestiças leiteiras

Abstract

The objective of this study was to evaluate the efficiency of auxiliary tools for the detection of estrus in cows. In experiment 1, we evaluated the efficiency of Estrotect ® in comparison with visual observation in 58 crossbred cows. The animals were divided into two groups: the TAI (n = 21) was subjected to a protocol of a fixed timed insemination (TAI) and 10 days after insemination device was fixed to the animals. In the group PG (n = 37) was administered prostaglandin (Dinoprost Tromethamine, Lutalyse ®, Pfizer) and immediately 25mg/animal/IM pasted adhesive. In the experiment 2, aimed to compare the Estrotect ® with chalk marker in crossbred heifers. After synchronization of estrus with P4 (CIDR) + GnRH - 7 days - PGF2a, heifers were randomly divided into two groups: Group 1 (n = 56) received the Estrotect ® and Group 2 (n = 56) received in the insertion of the marking tail with the chalk marker. The visual detection of estrus was performed daily in the same way in first experiment, from 07:00 to 08:00 and from 17:00 until 18:00. In experiment 2, the devices were only reached two times a day. After detection were artificially inseminated and diagnosed by ultrasound after 30 days in both estudies. In experiment 1, there was no effect of group (P> 0.05) on the efficiency of visual detection of estrus or auxiliary tool. There was no detectable difference between the efficiency of estrus and the visual detection device (P> 0.05) 92.5%. In experiment 2, not detected a group effect (P> 0.05) in the detection of estrus or the range of CIDR removal to the manifestation of estrus. The heat detection and conception rate was 92.86% (52/56), and 46,15% (24/52) for Estrotect® and 85,71% (48/56), and 58.33% (28/48) to chalk marker. It is concluded that the methods of estrus detection aids are effective and help in improving the efficiency of artificial insemination programs.