Expression and Role of PIWI Proteins and piRNAs in Reproduction of Water Buffalo (Bubalus bubalis, Linn.)

Abstract

High-fertile and productive dairy animals are important to satisfy the growing population's demand. Sire fertility is one of the essential factors that regulate the overall pregnancy rate of dairy herds. However, sire fertility varies from 10 to 90%, suggesting that male fertility largely accounts for varying fertility levels across the herd. Sub-fertile bulls and females should be identified and discarded promptly to improve the dairy herd's productivity. The most dominant factors implicated in culling are poor semen quality, poor semen freezability (<35% post-thaw motility), and poor libido for the bulls and hard breeders for females that cause huge economic loss to the raisers. Understanding the basic mechanism of male and female fertility has undergone tremendous change in recent times owing to the advancement of molecular tools judging the essential molecules responsible for fertility. Presently, a new molecular niche has surfaced in testes, strongly influencing the fertilization potential of spermatozoa. Over the last decade, there has arrived a conclusion that out of several factors, piRNA and PIWI proteins are largely implicated in regulating the vital aspects of fertility and embryogenesis. While this development is advancing in other animals, very limited information is available on PIWI protein and piRNAs in large animals. Except for a few sporadic information on PIWI protein in cattle, very limited information is available on piRNAs and PIWI protein in regulation with buffalo bull fertility and growth of embryos of buffaloes, posting a huge demand for research.

Female Reproductive Organ Monitoring (FROM) as a method of enhancing livestock reproduction

“…Real-time ultrasonography has been utilized to identify [35,36,37]. According to Fricke (38), follicles are characterized as fluid-filled structures that possess the ability to absorb ultrasonic waves, resulting in their appearance as black on the screen. This black appearance is referred to as anechoic or non-echogenic.…”

“…It has been reported that the prediction of stage of cycle in postpartum cows is most accurate when based on palpation findings, good estrus detection like vaginal cytology [38] and progesterone profiles [26,28]. However, in the absence of additional information, a clinician must be aware of the limitations of a diagnosis based on palpation alone.…”

Vaginal Cytology as a tool for estrus detection improves the success of artificial insemination in water buffalo

“…Determination of the phases of the estrous is useful in synchronizing the reproductive function of the animals. Vaginal cytology is a simple clinical tool used to detect estrus and the stages of the estrous cycle [2]. This is used in canines to determine the perfect time of breeding [3] and estrus cyclicity in the female [4].…”

“…Application of vaginal cytology in other livestock is limited vis the need to collect the vaginal cell samples in the field and bring it to the lab for analysis making it time-consuming to the field practitioners. However, studies showed that vaginal cytology is an efficient way to check the estrous stage in water buffaloes that includes the Philippine Carabao, Bulgarian, Brazilian, and Indian buffaloes [2,5,6], cattle [7], and goat [8,9]. This paper discusses the vaginal cytology in water buffalo and its application potential in improving reproductive efficiency in artificial insemination programs.…”

“…Vaginal cytology in water buffaloes A review article on vaginal cytology in water buffalo was published in Buffalo Bulletin by Thai scientists [10] indicating that few reports are available with our study [2] was one of the featured research articles. This reality is brought by the nature of the procedure where samples are collected from the large animal that is located elsewhere in the field and bringing the samples to the lab for examination to get the results.…”