Urinary Peptides for Predicting Ovulation Period in Murrah Buffaloes: An Opinion

Abstract

was observed by a cost-effective, comprehensible estrus prediction model, 1 but this might better assist a valid biochemical parameter to increase the sensitivity of ovulation prediction. Though estrus-specific pheromones and proteins have been reported in buffaloes, 2,3 no sensitive biochemical kit has yet been developed for estrus detection and/or ovulation period prediction.Excretory fluids like urine reflect the internal status of the animal and have been proposed to be a better medium for assessing the reproductive status, non-invasively. Timed-artificial insemination by assessing urine for peptide hormones is in practice for many mammals. Luteinizing hormone (LH) is a heterodimeric glycoprotein, has an important role in ovulation, and its presence in urine is detected by its metabolite LHβ-core fragment (LHβcf). The pattern of LH surge in buffalo urine was analysed and found that the extended LH surge window increases the success rate of prediction of ovulation period in this species. 4 In addition, an increased rate of conception was observed when inseminated artificially after positive-prediction of ovulation period through a cut-off LH value.5 Though, efficacy of LH peptide based prediction method was evidenced, sensitivity of this method was limited by occurrence of multiple LH waves with different amplitudes, before and after the core pre-ovulatory LH surge. 4Increasing the sensitivity of the prediction method is indispensable, before the LH peptide is put forth for a portable kit development. In order to increase the sensitivity, certain valuable peptide markers in the same sample have to be identified and utilised. These markers should distinguish the period of ovulation from other phases of estrous cycle such as pre-estrus, estrus and post-estrus phases (Figure 1), where non-ovulatory LH surge and false prediction happens. Methods has to be put-forth for the effective extraction of proteins from buffalo urine and phase specific urinary proteins has to be documented through 2D Polyacrylamide gel followed by LC-MS/MS analysis. Ovulation prediction strip comprising antibodies for LH and phase specific proteins (separately) increases the sensitivity and reliability of the prediction of ovulation period, thereby achieves increased conception rate by determining precise time for artificial insemination.