Evolução e perspectivas da inseminação artificial em bovinos / Evolution and perspectives of timed artificial insemination in cattle

A inseminação artificial (IA) em bovinos tem sido aplicada em todo o mundo com o intuito de melhorar o ganho genético e a eficiência reprodutiva dos rebanhos. Com o objetivo de facilitar a utilização da IA foram desenvolvidos protocolos de inseminação artificial em tempo fixo (IATF) que promovem o controle do crescimento folicular e da ovulação e permitem a aplicação da IA em dias predeterminados, sem a necessidade de detecção de estro e com elevadas taxas de prenhez. Nos últimos 20 anos, vários protocolos de sincronização para IATF foram estudados para atender diferentes realidades de manejo, raças e categorias de animais. Atualmente, 86% das inseminações no Brasil estão sendo realizadas por IATF (13,6 milhões de IATF de um total de 15,4 milhões de doses de sêmen comercializadas em 2018). Com a colaboração dessa tecnologia, verificou-se que o percentual de fêmeas em idade reprodutiva inseminadas artificialmente passou de 5,8% em 2002 para 13,1% em 2018. O aumento de uso da IATF representa considerável incremento de produtividade quando comparado com a monta natural, maximizando o retorno econômico para as fazendas de corte e de leite.(AU)

Artificial insemination in cattle has been used worldwide to improve the genetic gain and reproductive efficiency of the herds. In order to facilitate the use of AI, several protocols for timed artificial insemination (TAI) have been developed, which promote the control of follicular growth and ovulation, allowing the use of AI in predetermined days, without the necessity of estrus detection and with satisfactory pregnancy rates. In the last 20 years, a wide variety of protocols have been studied to address different management realities, breeds and animal categories. Currently, 86% of artificial inseminations in Brazil are performed using TAI (13.6 million TAI of 15.4 million batches of semen commercialized in 2018). The percentage of females in reproductive age inseminated in Brazil went from 5.8% in 2002 to 13.1% in 2018. Reproductive programs that use TAI present increase in productivity when compared to natural breeding, maximizing the economic gain for beef and dairy properties.(AU)

Challenges to increase the AI and ET markets in Brazil

Artificial insemination (AI) and embryo transfer (ET) are the most widely used biotechnologies in the world with the goal of increasing genetic gain and improving reproductive efficiency of beef and dairy herds. The protocols for ovulation synchronization for timed AI (TAI) or ET (TET) are tools that allow artificial insemination or transfer of a high number of embryos in a pre-established moment and without the necessity of estrous detection. Currently, 86% of inseminations in Brazil are performed using TAI (13.6 million TAI out of a total of 15.4 million doses of semen marketed in 2018). With the use of TAI, it was possible to verify that the percentage of artificially inseminated females in Brazil went from 5.8% in 2002 to 13.1% in 2018. The ET market also presented considerable growth in the last 20 years. There was an increase of approximately 8 fold in the number of produced embryos, escalating from 50,000 in 1999 to 375,000 in 2017. In this period, there was a significant increase on the in vitro embryo production, which represented 92.1% of embryos produced in Brazil in 2017. Also, in this period, there was an increase on the embryo production of dairy breeds and reduction on the embryo production of zebu breeds in comparison to data from the early 2000’s. TET increases significantly the number of recipients suitable to receive an embryo. After synchronization, 75 to 85% of recipients present a suitable CL for ET without estrous detection. Currently, many synchronization and resynchronization protocols for TAI/TET have been studied to attend different managements, breeds and animal categories, with predictable and satisfactory results. With the intensification of the use of these biotechnologies, it is possible to obtain elevated reproductive efficiency with increase on the genetic gain, which determines greater productivity and economic return for dairy and beef farms. However, the challenge to keep the market growing in the next decade could depend on some factors, such as: increase of the extension services for producers and of the extension training for specialists, improvement of the technological advances to develop more efficient and cost-effective products and practical protocols, increase the integration between universities, research institutes, veterinarians and industries and also, asses market demand for production of animal protein with higher quality, efficiency and environmental and economic sustainability.

Challenges to increase the AI and ET markets in Brazil

Artificial insemination (AI) and embryo transfer (ET) are the most widely used biotechnologies in the world with the goal of increasing genetic gain and improving reproductive efficiency of beef and dairy herds. The protocols for ovulation synchronization for timed AI (TAI) or ET (TET) are tools that allow artificial insemination or transfer of a high number of embryos in a pre-established moment and without the necessity of estrous detection. Currently, 86% of inseminations in Brazil are performed using TAI (13.6 million TAI out of a total of 15.4 million doses of semen marketed in 2018). With the use of TAI, it was possible to verify that the percentage of artificially inseminated females in Brazil went from 5.8% in 2002 to 13.1% in 2018. The ET market also presented considerable growth in the last 20 years. There was an increase of approximately 8 fold in the number of produced embryos, escalating from 50,000 in 1999 to 375,000 in 2017. In this period, there was a significant increase on the in vitro embryo production, which represented 92.1% of embryos produced in Brazil in 2017. Also, in this period, there was an increase on the embryo production of dairy breeds and reduction on the embryo production of zebu breeds in comparison to data from the early 2000s. TET increases significantly the number of recipients suitable to receive an embryo. After synchronization, 75 to 85% of recipients present a suitable CL for ET without estrous detection. Currently, many synchronization and resynchronization protocols for TAI/TET have been studied to attend different managements, breeds and animal categories, with predictable and satisfactory results. With the intensification of the use of these biotechnologies, it is possible to obtain elevated reproductive efficiency with increase on the genetic gain, which determines greater productivity and economic return for dairy and beef farms. However, the challenge to keep the market growing in the next decade could depend on some factors, such as: increase of the extension services for producers and of the extension training for specialists, improvement of the technological advances to develop more efficient and cost-effective products and practical protocols, increase the integration between universities, research institutes, veterinarians and industries and also, asses market demand for production of animal protein with higher quality, efficiency and environmental and economic sustainability.(AU)

Evolução e perspectivas da inseminação artificial em bovinos / Evolution and perspectives of timed artificial insemination in cattle

A inseminação artificial (IA) em bovinos tem sido aplicada em todo o mundo com o intuito de melhorar o ganho genético e a eficiência reprodutiva dos rebanhos. Com o objetivo de facilitar a utilização da IA foram desenvolvidos protocolos de inseminação artificial em tempo fixo (IATF) que promovem o controle do crescimento folicular e da ovulação e permitem a aplicação da IA em dias predeterminados, sem a necessidade de detecção de estro e com elevadas taxas de prenhez. Nos últimos 20 anos, vários protocolos de sincronização para IATF foram estudados para atender diferentes realidades de manejo, raças e categorias de animais. Atualmente, 86% das inseminações no Brasil estão sendo realizadas por IATF (13,6 milhões de IATF de um total de 15,4 milhões de doses de sêmen comercializadas em 2018). Com a colaboração dessa tecnologia, verificou-se que o percentual de fêmeas em idade reprodutiva inseminadas artificialmente passou de 5,8% em 2002 para 13,1% em 2018. O aumento de uso da IATF representa considerável incremento de produtividade quando comparado com a monta natural, maximizando o retorno econômico para as fazendas de corte e de leite.

Artificial insemination in cattle has been used worldwide to improve the genetic gain and reproductive efficiency of the herds. In order to facilitate the use of AI, several protocols for timed artificial insemination (TAI) have been developed, which promote the control of follicular growth and ovulation, allowing the use of AI in predetermined days, without the necessity of estrus detection and with satisfactory pregnancy rates. In the last 20 years, a wide variety of protocols have been studied to address different management realities, breeds and animal categories. Currently, 86% of artificial inseminations in Brazil are performed using TAI (13.6 million TAI of 15.4 million batches of semen commercialized in 2018). The percentage of females in reproductive age inseminated in Brazil went from 5.8% in 2002 to 13.1% in 2018. Reproductive programs that use TAI present increase in productivity when compared to natural breeding, maximizing the economic gain for beef and dairy properties.

Timed artificial insemination: current challenges and recent advances in reproductive efficiency in beef and dairy herds in Brazil

Beef and dairy productivity depends directly on the reproductive efficiency and genetic gain of the herd, which can be related to the appropriate use of biotechnologies, such as timed artificial insemination (TAI). When considering variations in synchronizations protocols, longer or shorter periods of progesterone (P4) device treatment could provide benefits to fertility. However, our studies evidenced that protocols with six (J-synch), seven, eight and nine days of P4 device treatment had similar pregnancy per AI (P/AI). In cyclic cows, the early prostaglandin (PGF) administration, moving from the day of P4 device removal to two days earlier, which results in four handlings of cows, or the administration of one extra dose of PGF at the onset of the protocol and a single PGF on the day of P4 device removal (three handlings) are both efficient to induce early luteolysis, reducing serum P4 concentrations and, therefore, stimulating LH pulsatility, which improves growth of the dominant follicle and results greater P/AI when compared with protocols with the administration of PGF only on the day of P4 device removal. Resynchronization is another valuable tool to reduce the interval between AI. Traditional Resynch is initiated at pregnancy diagnosis (28 to 32 days after TAI) and the interval between AI is around 40 days; Resynch 22 and Resynch 14 respectively initiates 22 and 14 days after the previous AI in all cows (unknown status of pregnancy) and reduces the interval between AI to 32 and 24 days. The novelty about Resynch 14 is the need to use of Doppler ultrasonography for pregnancy diagnosis [evaluation of corpus luteum (CL) vascularization].

Timed artificial insemination: current challenges and recent advances in reproductive efficiency in beef and dairy herds in Brazil

Beef and dairy productivity depends directly on the reproductive efficiency and genetic gain of the herd, which can be related to the appropriate use of biotechnologies, such as timed artificial insemination (TAI). When considering variations in synchronizations protocols, longer or shorter periods of progesterone (P4) device treatment could provide benefits to fertility. However, our studies evidenced that protocols with six (J-synch), seven, eight and nine days of P4 device treatment had similar pregnancy per AI (P/AI). In cyclic cows, the early prostaglandin (PGF) administration, moving from the day of P4 device removal to two days earlier, which results in four handlings of cows, or the administration of one extra dose of PGF at the onset of the protocol and a single PGF on the day of P4 device removal (three handlings) are both efficient to induce early luteolysis, reducing serum P4 concentrations and, therefore, stimulating LH pulsatility, which improves growth of the dominant follicle and results greater P/AI when compared with protocols with the administration of PGF only on the day of P4 device removal. Resynchronization is another valuable tool to reduce the interval between AI. Traditional Resynch is initiated at pregnancy diagnosis (28 to 32 days after TAI) and the interval between AI is around 40 days; Resynch 22 and Resynch 14 respectively initiates 22 and 14 days after the previous AI in all cows (unknown status of pregnancy) and reduces the interval between AI to 32 and 24 days. The novelty about Resynch 14 is the need to use of Doppler ultrasonography for pregnancy diagnosis [evaluation of corpus luteum (CL) vascularization].(AU)