*Reproduction in Small Ruminants (Goats) DOI: http://dx.doi.org/10.5772/intechopen.93481*

*Animal Reproduction in Veterinary Medicine*

than those treated on day 12 [18, 19].

prostaglandins is started.

doses. Besides, it should be considered that only the goat that is cycling with the presence of an active luteal body, would work this protocol. Currently, the male effect is used, so that an estrus occurs, a CL is formed, and the protocol based on

**2.3 Advances and use of the male effect, a case study until today!**

In goats, PGF2α and its analogs are effective luteolytic agents, where very small doses (1.25 mg) of PGF2α are currently required, with the corpus luteum being more sensitive compared to cows. Likewise, responses to low doses of its analogues, such as cloprostenol, have been observed; 125 μg doses have been used in goats, but even a 26 μg dose has been shown to be effective [15, 16]. As in sheep, the age of the corpus luteum and, therefore, the day of the cycle in which PGF2α is administered determines the degree of synchronization obtained and the time required for the heat to appear, the LH peak and the ovulation [17]. Several studies indicate that goats treated on day 6 of the cycle go into heat and show an LH peak much earlier

The use of the male effect (**Figure 2**) has been a case study up to nowadays at a global level [20, 21], where different alternatives have been evaluated in order to understand its way of acting under different scenarios of a goat production system and achieve further efficiency in reproduction in the goat [22]. The sudden introduction of the goat increases the release of LH in goats [23], where the first estrus is not silent [24], so the goat effect produces a high degree of estrus synchronization [25]. Also, short cycles of 5–6 days or 10–12 days may appear after introducing the male, in these cases fertility is lower than in normal cycles [26]. Over the years, different scenarios of the male effect have been validated, modified or compared [27]; for example, [28] determined that the male-female ratio does not decrease the ability of sexually active males to induce sexual activity in anovulatory goats, but it does delay the response to the male effect. Likewise, [29] determined that the separation of the goats from the male goats is not necessary as it was thought in previous years to be able to stimulate the sexual activity of goats subjected to the male effect. Followed by another investigation where they verified that the bleating

**78**

**Figure 2.**

*Sequence of sexual behavior in bucks.*

(vocalizations) of the goat were not sufficient to stimulate the presence of estrus and ovulation, therefore, the frequency of pulses of the LH was not increased [30]. Likewise, there are studies where the introduction of estrogenized females when introducing the buck can stimulate the estrous activity of anovulatory goats [31]. Delgadillo et al. [32] reviewing the male effect on goats, mention that in previous years it was mentioned that the male should be in permanent contact with the goats, their studies elucidated that it is not necessary and with a minimum contact of 4–16 hours, percentages of estrus can be reached in goats subjected to the male effect, the same as in groups that are in permanent contact with the males.

However, despite the advantages of using the male effect in goats, even today in large goat populations its use has been limited to continue with the natural breeds according to the time of year. Perhaps the lack of basic infrastructure to install and separate the bucks who are going to have the light programs have made their practical application until today still limited.
