Eficiência do Estrotect® na identificação de estros em vacas leiteiras mestiças

Abstract

IntroduçãoConsideráveis avanços tecnológicos ocorreram na inseminação artificial (IA) de bovinos nas últimas décadas, com significativo comércio internacional de sêmen e material genético, revelando que esta biotecnologia reprodutiva oferece grandes oportunidades e benefícios a produtores de todo o mundo 1 . Porém, a eficiência de detecção visual de estros é menor ou igual a 50% na maioria das fazendas leiteiras. Além Eficiência do Estrotect® na identificação de estros em vacas leiteiras mestiçasEstrotect® efficiency in identifying estrus in crossbred dairy cows AbstractAmong the problems that reduce the reproductive efficiency in dairy cows the failure in estrus detection is a major factor. The objective of this study was to evaluate the efficiency of Estrotect®, a device that aids heat detection in cattle, and to compare it with visual detection in 58 crossbred Holstein/Gyr dairy cows producing 18.5Kg/milk/cow. The animals were divided into two groups: the TAI (n = 21) underwent a fixed-time artificial insemination protocol (TAI), and 10 days after insemination, the device was fixed to the cows. In the PG group (n = 37) prostaglandin (dinoprost tromethamine) 25mg/animal/IM was administered, and then the device was put in place. These cows were then monitored by ultrasound over a period of 28 days to verify the development of the corpus luteum. Logistic regression was used to find out if there were alterations in the efficiency of Estrotect® within the groups, and the McNemar test was used to compare its efficiency to that of visual observation. No group effect was detected (P> 0.05) on the efficiency of visual detection nor on that of the auxiliary device. Neither was there observed any difference between the efficiency of visual detection of estrus and that of the device (P> 0.05). The auxiliary tool for the detection of estrus, (Estrotect ®), proved to be just as effective as visual detection. Thus, it can be used as an auxiliary device in conjunction with visual observation, and also as a unique tool for the detection of estrus in order to simplify the management of large herds.

Relação entre diâmetro folicular, indicador de estro comercial e taxa de prenhez em gado de corte

“…The total pregnancy rate was 72.9% (31/43) from the FTAI protocol used in the present study, presenting a higher value than that found in the literature. Bonato et al (2012) cited a pregnancy rate of 40%-60% using a conventional FTAI technique. According to Ribeiro Filho et al (2013), Estrotect ® can determine the ovulation response of females submitted to FTAI protocols.…”

“…This change in color was divided into a score based on the variation in the placement of the device, classified scores from 1 to 4, according manufacture's protocols. Score 1 referred to an animal that did not accept mounts, score 2 indicated animals that accepted from 1 to 3 mounts, score 3 animals that accepted from 3 to 5 mounts, and score 4 indicated an animal that accepted more than 5 mounts (Bonato et al, 2012). After 30 days of FTAI, the animals were submitted to ultrasonographic evaluation to diagnosis gestation.…”

“…AI is the mechanical deposition of semen in the female genital tract that is performed by special instruments and has become an important method to aid in the breeding and genetic multiplication of the Brazilian herd (Mies Filho, 1970;Prado et al, 2015). Fixed time artificial insemination (FTAI) is a biotechnology that has emerged to solve the difficulties with conventional AI because there is no requirement to observe estrus or to decrease the period of anestrus post calving; thus, increasing the pregnancy rate of the herd (Bonato et al, 2012). FTAI is performed through protocols of estrus synchronization and ovulation in a batch of females, making it possible to inseminate a larger number of animals in a shorter period (Martins et al, 2009;Morotti et al, 2013).…”

“…FTAI is performed through protocols of estrus synchronization and ovulation in a batch of females, making it possible to inseminate a larger number of animals in a shorter period (Martins et al, 2009;Morotti et al, 2013). FTAI has shown pregnancy rates of 40% -60%, making this biotechnology the most successful biotechnology in beef cattle in Brazil (Bonato et al, 2012).…”

“…Currently, there are commercial products that can assist in the detection of heat without the need for continuous observation of the animals. Estrotect ® is a device that assists in the detection of estrus, which consists of a color-changing adhesive based on the number of times that the animal accepts it, demonstrating the proximity of estrus (Bonato et al, 2012). Based on the observations of the device, it is possible to measure how close to estrus the animal is, with the closest being the area that shows a fluorescent orange coloration (Bonato et al, 2012).…”