Evaluation of serum anti-Müllerian hormone concentrations following treatment with vitamin D in Holstein Friesian heifers

Anti-Müllerian Hormone Concentrations Can Be Reliably Determined by a Single Measurement, Irrespective of Cycle, in Synchronised Ewes During Non-Breeding Season

Improvement of yield characteristics in animal breeding is important in terms of increasing animal production and sustainability. Fertility is one of the most important yield traits affecting economic gain in sheep breeding. Anti-Müllerian Hormone (AMH) is widely recognised as a dependable biomarker for assessing ovarian reserves and fertility potential. The aim of this study was to evaluate the dynamics of AMH during different phases of the sexual cycle in Norduz ewes the non-breeding season. Additionally, the study sought to assess the effects of age and body condition score (BCS) on AMH concentrations during these phases. A total of 32 Norduz ewes with a body condition score (BCS) of 3-4.5 and aged between 2 and 4 years were used as animal material in the study. All experimental procedures were carried out outside the breeding season and when the ewes were lactating. In all ewes in anestrus, intravaginal sponges (Esponjavet, 60 mg MAP, Hipra, Turkey) were kept in the vagina for 7 days for estrus synchronisation. Intramuscular injections of PMSG (Oviser, 500 IU, Hipra, Turkey) and PGF2α analog (Gestavet, 50 μg, Hipra, Turkey) were administered 48 h prior to sponge removal. Twenty-four hours after sponge removal, ewes were exposed to the ram for estrus detection. Since 5 ewes did not show estrus, blood samples were collected regularly from animals (n = 27) in which estrus was detected at three different stages: one just before the insertion of vaginal sponges (anestrus), another when heat was detected exposing to the ram (estrus), and the final one 10 days after estrus (diestrus). The serum samples were assessed for the levels of AMH and progesterone through the electrochemiluminessence immunoassay technique (ECLIA). The results of the analyses showed that serum AMH concentration did not vary between anestrus, estrus and diestrus phases of the sexual cycle of Norduz ewes outside the breeding season (p > 0.05). Furthermore, age and BCS had no effect on progesterone and AMH levels in different phases of the sexual cycle (p > 0.05). In conclusion, this study shows that serum AMH levels are constant at any stage of the estrus cycle. This suggests that phenotypic evaluation of ewes can be performed with a single measurement and that AMH is a reproducible and dependable biomarker that can be measured at any stage of the estrus cycle at an arbitrary time point.

Anti-Müllerian hormone as a promising novel biomarker for litter size in Romanov sheep

Anti-Müllerian hormone (AMH) is a hormone produced by growing preantral and antral follicles of the ovary. AMH is accepted as an important biomarker for fertility and superovulation parameters in livestock species. This study aimed to evaluate changes in serum AMH level in the oestrous cycle, repeatability of AMH, the effect of age on serum AMH level and the effects of AMH on litter size in Romanov sheep. In the study, a total of 36 Romanov sheep were used as animal material. First blood samples (0th day) were collected from 36 ewes to evaluate AMH and progesterone levels. Second blood samples were collected randomly from 20 ewes 9 days after first sampling to compare AMH levels at two different periods of the oestrous cycle in Romanov ewes. The ewes were categorized into three groups as low, medium and high AMH based on their first AMH levels. Results indicated that serum AMH level did not change during the oestrous and dioestrous phases of the oestrous cycle and two random time points of the oestrous cycle (p > .05). Pearson correlation analysis revealed that there is a high (r = .95) and significant (p < .001) correlation between AMH levels at the 0th (AMH-1) and 9th (AMH-2) days. The effect of AMH level on litter size was found to be significant. Litter size was significantly higher in the high AMH group than in the low AMH group (p < .05). In addition, the age of ewes did not affect serum AMH levels (p > .05). ROC analysis indicates that AMH cut-off value >320 pg/mL with 70% sensitivity and 100% specificity can be used for litter size in Romanov ewes. In conclusion, AMH is highly repeatable and its serum AMH level did not change during the oestrous cycle in Romanov sheep. In addition, AMH affects litter size and can be reliably used as a marker for litter size in Romanov sheep.

Elecsys® AMH assay: Determination of Anti-Müllerian hormone levels and evaluation of the relationship between superovulation response in Holstein dairy cows

BACKGROUND

Anti-Müllerian Hormone (AMH) serves as a crucial parameter in assessing the reproductive herd life and ovarian reserve in cattle. Consequently, extensive research is conducted on AMH levels. Various measurement methods can be employed to determine AMH levels. However, to our knowledge, no study has been conducted on Holstein donors using the Elecsys® AMH kit.

OBJECTIVE

This study was designed to determine AMH levels in donors utilising the Elecsys® AMH kit and to evaluate the relationship between superovulation response parameters and AMH levels.

METHODS

In this study, we measured the serum AMH levels of 36 cows using the Elecsys® AMH automated assay before the superovulation protocol (1st sample) and FSH injections (2nd sample). The cows were categorised into three groups based on their AMH levels: low, medium, and high AMH.

RESULTS

Positive correlations were identified between AMH and parameters associated with superovulation response. The high AMH level group exhibited significantly greater numbers of corpus luteum, total embryos, transferable embryos, and grade 1 embryos compared to the medium and low AMH groups (p < 0.05) There was no significant difference between AMH levels before the superovulation protocol and FSH injections(p > 0.05). Body condition score and parity did not significantly affect AMH levels in cows (p > 0.05). Also, AMH cut-off values for the number of corpus luteum, total embryo, and transferable embryos were detected as 234, 227, and 210 pg/mL, respectively.

CONCLUSION

These findings demonstrate that a high serum AMH level has a positive influence on the superovulation response. AMH can be used as a reliable marker for the selection of donors in Holstein cows.

Effect of serum anti-Müllerian hormone levels on the superovulation response in Holstein heifers

BACKGROUND

Anti-Müllerian hormone (AMH) holds potential as a biomarker for assessing the superovulation (SO) response in cattle. Nonetheless, there exists scant information regarding this aspect in the literature concerning dairy heifers. Given this gap, our objective is to explore the viability of AMH as an indicator for gauging the SO response specifically in Holstein heifers. Furthermore, our aim encompasses examining the variations in AMH levels within the same individuals before and after undergoing SO.

METHODS

The study included 41 Holstein heifers. All heifers were superovulated and blood samples were taken both before and after the SO protocol.

RESULTS

The findings revealed that the mean values of serum AMH concentrations before and after SO were 0.122 ng/mL (0.093-0.248 ng/mL) and 0.119 ng/mL (0.084-0.170 ng/mL), respectively. AMH concentrations in heifers were stratified into low (<0.106 ng/mL), medium (0.107-0.126 ng/mL) and high (>0.127 ng/mL) categories both before and after SO.

CONCLUSIONS

There was no significant correlation between AMH levels in the heifers both before and after SO treatment with the number of follicles, corpora lutea, total embryos collected or embryos transferred (p > 0.05). Furthermore, this study showed that serum AMH concentrations in Holstein heifers did not change after SO treatment. In this study, as AMH levels in Holstein heifers were in a narrow range, a relationship between AMH and SO response could not be determined. In future studies, we believe that it would be more useful to plan more studies in Holstein donor heifers, taking into account the number of animals and AMH levels.

Comparison of blood ΒHBA measurement devices for diagnosis of subclinical pregnancy toxaemia in sheep: A field study

Pregnancy toxaemia is a serious disease that occurs during the last trimester of pregnancy in sheep. Yet, in most cases, the disease may have a subclinical course. This study was aimed at comparing blood βHBA measurement devices for diagnosis of subclinical pregnancy toxaemia in late pregnant sheep. In the study, a total of 50 blood samples were collected from Romanov (n = 30) and cross-bred Hamdani (n = 20) sheep. Blood βHBA levels were measured using TaiDoc TD-4235 and CentriVet βHBA hand-held meter. Randox βHBA (Ranbut) assay was used as a reference laboratory method to compare hand-held meters. βHBA value of 0.8 mmol/L was set as the cut-off value for diagnosis of subclinical pregnancy toxaemia. Statistical analyses were carried out using Minitab 21 and Jamovi software. In the study, the correlation of Randox-TaiDoc TD-4235 and Randox-CentriVet was .822 (p < .001) and .728 (p < .001), respectively. Based on the Ranbut assay, nine ewes out of 50 were diagnosed with subclinical pregnancy toxaemia. Specificity (detection of healthy ewes) and sensitivity (detection of ewes with subclinical pregnancy toxaemia) for TaiDoc TD-4235 and CentriVet hand-held meters were 100%, 77.8%, and 100%, 66.7%, respectively. In the receiver operating characteristic (ROC) analysis, areas under the ROC curve (AUC) were 0.976 and 0.920 for TaiDoc and CentriVet, respectively. Bland-Altman analysis revealed a bias of 0.092 mmol/L for TaiDoc and a bias of 0.132 mmol/L for CentriVet. TaiDoc hand-held meter shows a better correlation with the Randox Ranbut assay and greater sensitivity compared to the CentriVet hand-held meter. In conclusion, both TaiDoc and CentriVet hand-held meters can be securely used in the diagnosis of subclinical pregnancy toxaemia in sheep. For these reasons, subclinical pregnancy toxaemia and these devices will be evaluated within the scope of herd management programme in the sheep industry. It should also be taken into account that these conditions will affect the future fertility of the mother and offspring.

Anti-Müllerian hormone: A novel biomarker for detecting bovine freemartinism

The anti-Müllerian hormone (AMH) indicates ovarian reserve in cattle, maintaining a consistent trajectory post-puberty. In heterosexual pregnancies, the development of the Müllerian duct in female foetuses is inhibited, resulting in an anticipated minimal or absent ovarian reserve capacity. This investigation aimed to compare AMH levels in healthy Holstein heifers that had reached puberty with those of freemartin animals of the same breed and age. The study incorporated Holstein heifers reaching puberty between 11 and 15 months of age in Group 1 (G1, n = 20) and freemartin animals in Group 2 (G2, n = 19, 16). AMH measurements (AMH-1/AMH-2) were recorded at 12-day intervals for the study participants. Notably, AMH levels in three freemartin animals could not be detected, prompting statistical analysis based on measurements from the remaining 16 freemartin animals in G2. A statistically significant correlation was observed between two separate measurements in G1 and G2 (p < .001). Furthermore, AMH-1 and AMH-2 levels were statistically higher in G1 than in G2 (p < .001). In G1, AMH-1 levels ranged from 227 to 677 pg/mL, with an average of 367.3 ± 25.5 pg/mL, and AMH-2 levels ranged from 234 to 645 pg/mL, with an average of 380.8 ± 24.4 pg/mL. Conversely, in G2, AMH-1 levels ranged from 10 to 72 pg/mL, with an average of 26.8 ± 4.44 pg/mL, and AMH-2 levels ranged from 12 to 68 pg/mL, with an average of 28.75 ± 4.18 pg/mL. The mean AMH levels in G1 were approximately 14 times higher than in G2 (p < .001). Consequently, ROC analysis utilizing AMH-1 and AMH-2 data established cut-off values of ≤72 and ≤ 68 pg/mL respectively for distinguishing freemartin animals. In conclusion, AMH could be used as a reliable biomarker for identifying Holstein freemartin animals.