Results schowed that the farm scale had significant effects on CI and SP, which are among the fertility parameters, and as the farm scale increases, these values also increase asthe highest values were obtained from Group III. This situation indicates that there were herd management problems related to fertility in Group III (enterprises with more than 101 animals). This may be relate to that the large enterprises preferred young and inexperienced veterinarians to avoid overpaying veterinarians. CI and SP values were lower in Group I and Group II compared to those of Group III. According to these results, it was concluded that raising Simmentals up to 100 heads in terms of enterprise scale in Teke Region would be suitable for CI and SP, which are important fertility parameters. In a study conducted by Özkan and Güneş (2011) on Simmental breed cattle in Kayseri, it was found out that the enterprise scale had no effect on CI and SP. This difference may be due to differences in province, care and feeding management of the animals, or different classifications methods of enterprise scale. In this study, it was determined that the effects of enterprises scale on IPP and FCA were insignificant, and a similar situation was reported by Özkan and Güneş (2011).
It was reported that in enterprises with good herd management, the best CI value was 365 days, SP was 60–90 days, and IPP was 1.5-2 (Alpan and Aksoy, 2012). It was determined that Burdur Province was the best in terms of CI and SP. The CI, SP, and IPP values determined in this study were better than those reported by Öztürk and Sipahi (2021) in the Holsteins in the Teke Region. This shows that Simmental cattle in the Teke Region have better fertility traits than Holstein cattle. In the present study, it was determined that there was no difference between provinces in terms of IPP values and that these values were within normal limits. The highest value in terms of FCA is in Isparta, and the FCA value determined in this trial were similar to the findings by Özkan and Güneş (2011) and higher than the value reported by Öner (2022) as 842.35.
The effects of calving year on CI, SP, and IPP were statistically significant in this study. Öztürk and Sipahi (2021) found the significant effects of calving year on CI, SP, and IPP in Holsteins raised in Teke Region. Gündoğan (2019) found significant effects of calving year on CI, SP, and IPP in Simmentals raised in Balıkesir Province. Öner (2022) found a significant effect of calving year on CI in Simmentals raised in Aydın Province.. However, Duru and Tuncel (2002) and Özkan and Güneş (2011) reported that the calving year had no significant effects on CI and SP.
In this study, it was determined that the effects of the calving season on CI and SP was important. It was determined that the best values in terms of CI and SP were observed in the autumn season. Demirgüç (2015) found that the effect of the calving season on CI in Simmentals grown in Gökhöyük Agricultural Enterprise was important with the best CI value 342.29 days in winter season. The studies of Öztürk and Sipahi (2021) in Teke Region, Kaya and Bardakçıoğlu (2016) in Holsteins raised in Denizli Province, Gündoğan (2019) in Simmentals raised in Balıkesir Province, Çilek and Tekin (2005) in Simmentals raised in Kazova agricultural enterprise showed that there was no significanteffect of calving season on CI and SP. In this study, it was determined that the calving season had no effect on IPP and IBD.
In this study, it was determined that the order of lactation had no effect on CI and SP, but had an effect on IPP. Demirgüç (2015) found that the effect of lactation number on CI was significant and its effect on SP was insignificant in Simmentals grown in Gökhöyük Agricultural Enterprise.
In this study, the CI value was determined as 401.99 days, compared to 379.1 days by Çilek and Tekin (2005) and 379.1 days by Willam et al. (2002), which were 380.5 days, Demirgüç (2015) 367.37 days, Erdem et al. (2015) as 373.2 days, and lower than the values reported by Akbulut (1998) as 408.00 days, Gündoğan (2019) as 411.9 days, and Öner (2022) as 422.98 days.
The SP value determined as 118.99 days in this study was 93.9 days by Çilek and Tekin (2005) and 93.9 days by Erdem et al. (2015) as 92.8 days, lower than the value reported by Gündoğan (2019) as 139.8 days, close to the value reported by Akbulut (1998) as 116.00 days and Demirgüç (2015) as 116.45 days while the similar value as Akbaş and Türkmut (1990) reported as 118.86 days.
IPP is one of the important fertility traits and was found to be 1.48 in this study. This value was determined by Alpan et al. (1976) in Brown, Holstein, and Simmental cattle, respectively, as 2.1, 1.9, and 2.3, while Deliömeroğlu et al. (1996) between 1.6 and 2.0, Çilek and Tekin (2005) between 1.76, Erdem et al. (2015) reported 1.96 units and Gündoğan (2019) reported 2.00 units.
In the current study, the FCA determined as 896.26 days was lower than those of Akbulut (1998) 908 days, Demirgüç (2015) 34.23 months, and higher than those of Gündoğan (2019) 27.3 months and Öner (2022) 842.35 days.
In this study, it was determined that the effects of the province on LL, 305-day MY, LMY, and LDP, which are milk yield traits, were statistically important. The highest LL was determined in Denizli Province and the lowest one in Burdur Province. In this study, the LL value determined as 365.80 days in Denizli Province, which were similar to the values reported by Sipahi (2022) as 366.50, 366.60, and 363.80 days in Holsteins raised in Burdur, Denizli, and Isparta provinces in the Teke Region, respectively. However, Sipahi (2022) determined the effect of province on LL was insignificant. In this study, the general LL determined as 337.71 days which was higher than the values reported by Akbulut (1998) as 291 days, Özkan (2007) as 310.20 days, Petrovic et al. (2009) as 313.88 days, and Gündoğan (2019) as 339.20 days. It was found out that the closer value was reported by Küçük Baykan (2016) as 337.70 days, and higher value was reported by E-Islah (2018) as 359 days for Türkiye.
In this study,, 305-day MY and LMY were detected higher in Denizli Province and lower in Isparta Province compared to the other provinces. In this study, the average 305-d MY and LMY values werelower than those reported by Küçük Baykan (2016) as 7693.44 and 8351.05 kg in Simmentals in Manisa Province, by Gündoğan (2019) as 7602.60 and 7888.40 kg in Simmentals in Balıkesir Province, while our values higher than those of Demirgüç (2015) as4181.47 and 4363.01 kg in Amasya Gökhüyük Agricultural Enterprise, and by Erdem et al. (2015) as 5700.00 and 5764.50 kg in Amasya Gökhüyük Agricultural Enterprise. Our current values were close to the values reported by Bolacalı and Öztürk (2018) as 6060.30 and 6413.04 kg in Simmentals grown in Çorum Province. In this study, the general average of LDP was determined as 44.94 days, the highest value in Burdur Province (57.41 days) and the lowest value in Isparta Province (18.31 days). In this study, the general average LDP 44.94 days was lower than the findings 73.6 days in Simmentals in Gündoğan (2019), 64.89 days in Simmentals in Manisa Province by Küçük Baykan (2016), and 64.89 days in Simmentals in Manisa Province by Erdem et al. (2015) in Amasya Gökhüyük Agricultural Enterprise as 66.6 days, and as 57.67 days reported by Bolacalı and Öztürk (2018) in Simmentals grown in Çorum Province.
This study resulted that the effects of enterprise scale on 305-day MY and LMY were significant. 305-day MY and LMY were determined as the highest in Group III and the lowest in Group I. These findings determined that as the enterprises scale increases, the amount of milk obtained and the enterprise are more likely to benefit from the advantages of economies of scale. These findings are compatible with the results of some studies showing the relationship between farm scale and milk yield (Zepeda 1995, Zimmermann and Heckelei 2012, Sipahi 2022). It was also reported in the studies that there was a positive relationship between enterprise scale and farm size and that enterprise scale had a positive effect on farm profitability (Bravo-Ureta and Rieger 1990, Gloy et al. 2002). In light of these findings, as the scale of the enterprise grows, the success of management, organization, care, feding management, and breeding in dairy farms and their awareness and knowledge on these issues increase (Sipahi 2022). In this work, it was determined that the effects of enterprise scale on LL and LDP were insignificant. However, Sipahi (2022) reported that the effect of enterprise scale on LL was significant.
In this study, it was determined that the effects of calving year on LL, LMY, and LDP were significant, but it was insignificant on 305-day MY. In various studies, it was reported that the effects of calving year on LL, 305-day MY, LMY, and LDP were important (Demirgüç 2015, Bolacalı and Öztürk 2018, Gündoğan 2019, Ağrap 2022).
It was determined that the effects of the calving season on 305-day MY and LMY were significant, but its effects on LL and LDP were insignificant. 305-day MY and LMY were the highest in winter season. Özkan and Güneş (2007) and Sipahi (2022) reported that the effects of the calving season on 305-day MY and LMY were significant and the highest values were obtained in autumn and winter.
It was determined that the effects of lactation number on LL, 305-day MY, LMY, and LDP were insignificant. 305-day MY and LMY were detected the highest values in the fifth lactation.
In conclusion
With this work, it was concluded that the values of CI, SP, and insemination number per pregnancy in Simmental cattle raised in the Teke Region were generally better than those reported in Türkiye. According to our study, the effects of the production scale on CI and SP were statistically significant. The biggest factor in the prolongation of the lactation period may be due to the longer SP, which is the time from birth to pregnancy, and the period between the two calving periods.
This study revealed the significant relationship between farm scale and fertility and milk yield traits in Simmental breed cattle raised in the Teke Region, and that CI, SP, LMY, and 305-day MY increase as the farm size increases. Increasing enterprise scale, herd management, care and feding management, etc. Increases the opportunity to provide technological innovations in subjects. For this reason, it can be recommended that dairy cattle breeders develop and implement a comprehensive model that focuses on preventing breast, foot, and nutritional diseases and economic efficiency through studies aimed at increasing both fertility and milk yield.