Repeat breeder is one of the most important problem
s in addition to many etiological factors affecting reproductive performance in dairy cattle enterprises (
Gustafsson and Emanuelson, 2002;
Yusuf et al., 2010). The important etiologies include ovarian dysfunction, failure of fertilization and subclinical endometritis
(Pothmann et al., 2015; Yusuf et al., 2010). Hormones, antibiotics and immunomodulators are widely used in the treatment of uterine infections in cattle
(Purohit et al., 2015) and it is difficult to suggest a specific treatment. Accordingly, in this study, it was aimed to determine the efficiency of treatment with
Momordica charantia L. in RB cattle on the level of E2, P4, IGF-1 and pregnancy rate, supposing that it can provide activation of natural defense mechanism in the uterus and may be an alternative treatment with immunomodulatory properties.
Endometrial cytology
The incidence rate of SCE was determined as 82.5% (33/40) as a result of cytological examinations in RB cattle at the beginning of the study. According to the results of the cytological examination of animals considered as healthy, prismatic uterine epitheliums were observed intensively. In the animals diognised with SCE, lymphocytes and neutrophil cells were intensively determined along with prismatic epithelium.
It is stated that clinical and subclinical endometritis (SCE) is one of the most important reason
s for delaying the time of resumption of postpartum ovarian activity
(Sheldon et al., 2009). In previous studies, it was determined that the incidence of SCE in RB cattle ranged from 12.7 to 94%
(Agaoglu et al., 2020; Pothmann et al., 2015; Salasel et al., 2010; Yazlýk et al., 2021). In the presented study, similar to the results of previous studies
(Agaoglu et al., 2020; Salasel et al., 2010), one of the most important causes of RB was found to be SCE (82.5%). Pothmann
et al. (2015) determined this ratio as 12.7% and reported that SCE is not an important factor in the etiology of RB. The reason for such a high rate of SCE in our study may be explained by the fact that the pp day and neutrophil threshold values are different from other studies. However, as another reason, it was thought that the farm in which we were conducting the study was not a professional enterprise and therefore it might have been caused by management errors.
Pregnancy findings
In group I, group II and group III pregnancy rates were determined as 55%, 35% and 35%, respectively (P>0.05).
The highest pregnancy rate at the first insemination was determined as 55% in the phytotherapy group. Pregnancy rates had variety in studies where intrauterine plant extract was applied in RB cattle with SCE.
Bhardwaz et al., (2019) reported that the pregnancy rate at the first insemination was 50% in the group where neem extract was applied every 24 hours for 7 days and the same researcher determined this rate was 60% when garlic was applied in another study
(Bhardwaz et al., 2018). Brahmanand et al., (2019) determined the pregnancy rate at first insemination was 66.67% in the methanol fractioned neem oil (2 days at 24 hrs interval) group and 33.33% when it was applied as 2 days at 48 hrs intervals. They found 16.67% in the Neem bark extract group (3 days at 24 hrs intervals) and showed a similar pregnancy rate (16.67%) when applied for 3 days at 48 hrs intervals.
Brahmanand et al., (2019) found that the pregnancy rate increased (total pregnancy rate 83.33, 66.67, 50 and 33.33%, respectively) as the number of inseminations increased in comparison with the first insemination rate in RB cattle with SCE. It was thought that the basis of the the variety in the pragnency rate might be
ay depend on the severity or intensity of the infection, the concentration of the therapeutic agent, the frequency of administration and the duration of treatment. For higher pregnancy rates, the number of intrauterine applications may be increased in further studies. It should be considered that there may have been an increase in the pregnancy rate in all groups depending on the double-dose PG protocol (
Galvão et al., 2009;
Hendricks et al., 2006) used as a treatment option for uterine infections from the 14
th day of the study.
Hormonal measurement findings
The mean values of the hormonal parameters belonging to all three groups and the time-dependent change curves are presented in the relevant Table 1, 2, 3.
The intra-group time-dependent variation in E2 value was not significant (p>0.05) and there was no interaction between the groups and E2 variation (p>0.05) (Fig 1).
The intra-group time-dependent variation in the P4 value was not significant (p>0.05), but an interaction between the P4 value and the groups was determined (p<0.05). On the seventh day, the differences between group I and II (p<0.05) and between group II and III were significant (p<0.05), while there was no significant difference between group I and III (p>0.05) (Fig 2).
The time-dependent change in IGF-1 value within the group was significant (P<0.05) and there was an interaction between the groups and the IGF-1 variation (p<0.001). While there was a difference between group I and III on day 0 (p<0.05), there was no difference between group I and II (p>0.05) and group II and III (p>0.05). On day 7, there was a significant difference between group I and II (p<0.05) and group I and III (p<0.05), while no differences were found between group II and III (p>0.05). On the 14
th day, there was a significant difference between group I and II (p<0.05) and group I and III (p<0.05), while no differences were found between group II and III (p>0.05) (Fig 3).
The number of neutrophil leukocytes, immunoglobulins, cytokines and pregnancy rates was evaluated in intrauterine medicinal herbal treatment studies
(Bhardwaz et al., 2019; Brahmanand et al., 2019), however, evaluations on ovarian activity were not encountered. In this study, serum concentrations of P4, E2 and IGF-1 were measured to evaluate the ovarian activity of intrauterine MC extract administration. For estradiol, no interaction was recorded between the three time-dependent measurements and the groups. However, the absence of any changes in the E2 concentration after phytotherapy administration suggested that the effectiveness of a single application on the ovary was not sufficient and that better results could be obtained from the longer-term application. For P4; it was observed that there was no significant difference in the change between the three time-dependent measurements and the P4 value was always high in group I which underwent phytotherapy. It was thought that intrauterine MC extract with PG administration in group I, where the level of progesterone is still high on the 14th day, increased the pregnancy rate due to both luteolysis and immunomodulatory effects (
Lewis, 2004). However, a significant decrease in the average P4 level was observed on the 7
th day in the pure olive oil group. Here it can be considered that pure olive oil exerts a luteolytic effect. In the study, intrauterine application of MC extract did not affect estradiol and progesterone concentrations depending on time. Unfortunately, the effect of phytotherapy on three time-dependent measurements was not fully scrutinized in this study since the application was not started in the same period of the sexual cycle. It was shown that many studies should be conducted on the administration of MC. However, the values obtained as a result of the hormone measurement on the day 0 and the high SCE incidence in the study reveal that ovarium is active and RB did not occur by ovarium dysfunction
(Agaoglu et al., 2020; Pothmann et al., 2015). Contrary to our findings, it was also reported that besides an affected endometrium, it may also be associated with impaired ovarian function as a possible cause of failure to conceive in RB (
López-Gatius et al., 2004;
Kendall et al., 2009). However,
Pothmann et al., (2015) reported that SCE, uterine infections, or inactive ovaries were not strongly associated with RB.
Insulin-like growth factor-1 (IGF-1) is known to be highly associated with energy balance, follicular growth, ovarian cycle resumption and prediction of reproductive performance in cattle
(Velazquez et al., 2009; Zulu et al., 2002). For IGF-1, significant differences was observed depending on time between three measurements of the groups in which we were able to monitor the effect of the treatment. In the 7
th and 14
th days, IGF-1 levels were observed to maintain concentration and remain high compared to other groups in the phytotherapy group. The results here indicate that IGF-1 has an important role in the fertility of dairy cattle and MC administration may affect the treatment. However, there are many studies in which there is a low concentration of IGF-1 in uterine infections
(Kasimanickam et al., 2013; Pascottini and LeBlanc, 2020). It is noted that estradiol-17b stimulates the development of the uterus by increasing DNA synthesis and cell proliferation in the uterus and regulating the activity of growth hormone and IGF-1
(Leung et al., 2004; De Catanzaro, 2015). Although there was no significant difference in E2 concentration in this study, it should be considered that it supports IGF levels. Because IGF-1 levels remained high in the group undergoing phytotherapy and in parallel, the pregnancy rate was also observed to be the highest. Considering that the endometrium of heifers was not affected by any pathological changes, they were selected as a healthy/control group. However, another point that drew attention was that the IGF-1 values were low because these heifers in the control group did not reach sufficient body weight due to environmental and management conditions, despite being of an appropriate age. Because it was determined that the level of IGF-1 in the systemic circulation is closely related to the feeding of the animals and ovarian functions
(Zulu et al., 2002).