The traditional long-term progestagen based oestrous synchronisation protocols normally range from 10-19 days. The long-term protocol, however, has been associated with low fertility rates.  This low fertility has been linked to some abnormalities in follicular development, ovulation, oocyte health, and luteal function. The short-term oestrous synchronisation protocol is a process of targeting female mammals to come to heat within a short time frame.

It has been documented that fertility can be influenced depending on whether fresh, cooled or frozen semen is used. On the other hand, the timing of insemination either by use of artificial insermination (AI) or natural mating following synchronised oestrus plays a crucial role in determining the fertility of an animal.

Such findings necessitated the need for research by D.L.M. Gore, J.N. Mburu, T.O. Okeno, T.K. Muasya on ‘Short-term oestrous synchronisation protocol following single fixed-time artificial insemination and natural mating as alternative to long-term protocol in dairy goats’ to assess how different types of synchronisation protocols and mating methods influence fertility.

Procedure

Twenty eight (28) females Toggenburg dairy goats were randomly allocated to two synchronisation protocols in a completely randomised design. Within each synchronisation protocol, the animals were subdivided into two mating methods. Oestrus was synchronised using short (7 days) and long-term (12 days) protocols and animals mated using natural mating and AI.

Results

The onset and duration of oestrus, response to oestrus, conception and kidding rates were analysed. Generally, the two protocols realised 100 % response to oestrus. The two protocols did not significantly differ in onset and duration of oestrus, conception, kidding and twinning rates.

The findings from the scientists confirmed the premise that targeting female mammals to come to heat within a short time frame following single fixed-time AI with extended cooled semen and natural mating would be as good as the traditional long-term protocol in the fertility of dairy goats raised in the tropics. This was confirmed by no observable significant difference between the two protocols on response to oestrus cycle, the onset of oestrus, duration of oestrus, conception rate, kidding rate, and twining rate when single fixed-time AI with extended cooled semen and natural mating was applied.

Which way to go? Short-term or long-term oestrous synchronization?

Although there were no significant differences between the two synchronisation protocols, the scientists reported that short-term protocol can be a better alternative to long-term protocol. This is because short-term protocol takes few days to synchronise animals and thus reduce time spent by farmers to breed their animals.

The study is Small Ruminant Research Journal and was  supported by the United States Agency for International Development (USAID) through Borlaug Higher Education for Agricultural Research and Development Programme (BHEARD Programme), Centre of Excellence for Livestock Innovation and Business (CoELIB) and Tatton Agriculture Park (TAP), Egerton University.