Investigation of effects of vitamin D3 applications on BLOOD serum anti-müllerian hormone level in holstein heifers

There are various factors affecting the level of AMH and vitamin D is just one of them. Through many studies carried out both as vivo and in vitro, particularly in humans, Vitamin D has been reported to affect the level of AMH either directly or indirectly. However, there hasn't been a single study examining the effects of Vitamin D on serum AMH levels in heifers yet. In this study, the effects of both oral and intramuscular Vitamin D3 administrations on AMH and 25(OH)D levels in 11-13 months-old dairy heifers were investigated. The animal material used in the study was divided into 3 groups as oral (Group1, n=20), intramuscular (Group2, n=20) and control group (Group3, n=20). 5 million IU Vitamin D3 was administered to the oral and intramuscular group at once while Vitamin D3 was not administered to the control group. Blood samples were collected both before administration (day 0) and on days 7, 14 and 28 following administration. The AMH concentrations were determined in blood serum by electrochemiluminescence method while 25(OH)D concentrations were determined via chemiluminescent immunological test method. As a result of the study, it was determined that the oral and intramuscular vitamin D3 administration significantly increased the 25(OH)D concentration on the 7th, 14th and 28th days compared to the pre-application (p<0.05). After the oral Vitamin D3 administration, especially the 25(OH)D level was found to have reached the peak on the 7th day, whereas decreased on the 14th and 28th days (p<0.05). On the other hand, in intramuscular administration, the 25(OH)D level was found to have increased continuously compared to the pre-application phase and have also reached the peak on the 28th day (p<0.05). It was determined that the changes in AMH levels on the 7th, 14th and 28th days in both oral and control groups compared to the pre-administration were statistically insignificant (p>0.05). In the intramuscular group, the AMH level was found to be statistically higher on the 7th and 28th days than it was before the application (p<0.05), whereas a decrease in AMH levels was observed in the control group compared to day 0. Based on the findings, the route of administration of Vitamin D3 was determined to affect the 25(OH)D level, reaching the peak level on the 7th day in the oral group, while increasing continuously in the intramuscular group. Increases in AMH concentration were observed in the groups administered Vitamin D3 and it was determined that it followed a regular course unlike the fluctuations in AMH concentrations observed in the control group.