Interested in buffalo farming? Scientists from the National Dairy Research Institute (ICAR-NDRI), Karnal and the Indian Veterinary Research Institute (ICAR-IVRI), Izatnagar, may have good news for you! In a study published in the journal Theriogenology, they have described how some proteins present in the saliva of a female buffalo might help in detecting their estrus or mating stage.
Buffaloes are essential livestock for milk production in Southeast Asia and the Middle East. However, detection of the estrus in female buffaloes, which is crucial for insemination, is a complicated process. “Accurate and efficient detection of estrus is a key factor for right time artificial insemination and successful conception in buffaloes. This is a major constraint in buffalo as expressions of visible behavioural signs common during the mating time like bellowing, swelling and reddening of the vulva, and sniffing of genitalia are not very obvious in them,” say the authors of the study. The short span of the mating stage and changes in their sexual behaviour in different seasons make the detection all the more difficult.
The researchers studied 38 estrus cycles from 19 animals during the study. They collected saliva from these buffaloes during different stages of their estrus cycle, namely ‘proestrus’ or the stage before the onset of estrus, ‘estrus’ or when the female is sexually receptive, and the stages following the estrus called ‘metestrus’ and ‘diestrus’. The proteins isolated from the saliva samples were identified using a technique called nano-LCMS/MS—an efficient method for detecting proteins from a mixture.
The researchers identified hundreds of proteins from the saliva collected during different stages of the estrus cycle. Out of these, 31, 62, 32 and 104 proteins were found to be specific to proestrus, estrus, metestrus and diestrus stage of the estrus cycle respectively.
“The higher number of proteins in the estrus and diestrus stages suggest that the protein synthetic activity is induced during these stages in response to an increase in estrogen and progesterone hormone levels. These proteins might support the important processes of reproduction and embryonic development”, explain the researchers.
Some estrus-specific proteins like cullin associated NEDD8-dissociated protein 1, heat shock 70 kDa protein 1A, 17-beta-hydroxysteroid dehydrogenase type 1, inhibin beta A chain, and testin are essential for physiological processes related to reproduction. The researchers believe that these proteins might help in the accurate detection of estrus stage and understanding the buffalo reproductive biology in detail.
“The estrus specific proteins identified in this study could be explored further for their possible use as biomarkers for detection and confirmation of estrus in buffalo after thorough validation”, remark the researchers, about the implications of the findings.