Comparison between the use of timed artificial insemination protocols and observed estrus in the fertility of dairy cows in Portugal and in the United Kingdom

Dissertação de Mestrado Integrado em Medicina Veterinária, área científica de Clínica ; ABSTRACT - COMPARISON BETWEEN THE USE OF TIMED ARTIFICIAL INSEMINATION PROTOCOLS AND OBSERVED ESTRUS IN THE FERTILITY OF DAIRY CATTLE IN PORTUGAL AND THE UNITED KINGDOM- Oestrus detection (ED) and hormonal protocols can be used as reproductive strategies in dairy cows. In recent years, oestrus detection efficiency through visual observation (VO) has decreased and timed artificial insemination (TAI) has successfully been implemented to aid or replace it. Automated oestrus detection technologies also have been used as an alternative to TAI protocols. Economic profitability of a dairy herd is heavily dependent on reproductive performance. As a way of comparing different reproductive strategies and evaluating their economic profitability, 12 reproductive indicators were collected from 29 farms across Portugal and the United Kingdom. Farms were accompanied by one practitioner in Portugal and two practices in the UK. The farms were divided into groups according to their reproductive strategy: ED; ED+TAI; TAI+ED; TAI; and a comparison between the indicators was made in order to understand which reproductive strategy obtained the best results. The same indicators were also used to compare differences between the countries and practices. Then, an economic analysis was made by calculating the costs of each groups’ reproductive strategy, determining the Net Return Gain per cow based on pregnancy rate (PR), as well as the amount spent on AIs, to determine the net profit for each group. The value of an additional day open was also calculated. Since the net profit was obtained based on the Portuguese market, a sensitivity analysis was also performed to compare different outcomes according to price changes. The group that had the best reproductive performance was group TAI (PR of 21,0%). Group TAI+ED had the second highest reproductive performance, as PR was 19,2%. Pregnancy rates for group ED and group ED+TAI were 16,8% and 18,7%, ...