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

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

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**Figure 3.**

*Factors influencing the presentation of the male effect in goats.*

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

application until today still limited.

bucks [34–36].

(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.

**2.4 Male social hierarchy and its impact on reproduction**

efficiency and profitability of the reproductive unit (**Figure 3**).

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

One of the key aspects to improve the performance of the herd is the proper evaluation of the reproductive capacity of the male, performing both a general physical examination, a specific examination of the reproductive system, a seminal quality examination and another of their libido and ability to mount. [33], with the aim of ensuring an adequate selection of males that contribute to improving the

Previous studies have evaluated the social hierarchy in rams raised in pairs, identifying that the dominant males exhibit a greater sexual precocity and a greater reproductive capacity compared to the subordinate males. A negative influence on testosterone production has also been reported, due to the stress of the grouping of

In goats housed in herds with different densities, the social interactions registered between them were evaluated, as well as the levels of cortisol in blood to determine if the levels of said hormone vary depending on the size of the herd,

#### **Figure 2.**

*Sequence of sexual behavior in bucks.*
