Is animal saliva a prominent factor in pasture regrowth?

Over a period spanning more than 100 years, a substantial amount of research has been undertaken to determine the impact that grazing ungulates have on grassland production systems globally, as they are the primary source of feed for these animals. Productivity of these lands, however, is highly dependent on a variety of factors such as quality and quantity of the forage, regrowth rates, and grazing rates. Expected regrowth rate of pasture, may be more influenced by animals than originally thought, as the direct effect of saliva deposition on plants on both the above and belowground biomass of plants remains relatively unclear. Though research is evident on grazing impacts on pasture, those which have utilised saliva have often found contradictory results, or do not discuss the mechanisms behind the responses in pasture observed. As such, we believe though it is a miniscule aspect of the entire grazing picture, investigating the effect of saliva in further detail may highlight gaps apparent in current research, such as what compounds are evident in saliva, and what those individual components functions are in plants, or what result may occur when applied on to plants. This review discusses what is currently known about animal saliva, the impact on pasture, and the greater practical applications of this knowledge for graziers. Research has occurred over 100 years on the effects that grazing livestock have on pasture systems globally, however, the influences that it has on regrowth rates above and belowground remains relatively unclear due to contradictory results often evident. Prior studies have highlighted that the answers may lie in the effect of livestock saliva, and the authors of this review discuss the current knowledge such as the impact saliva has on plants, and the greater applications of this knowledge for producers.