**6. Conclusions and recommendations**

Feed additives are frequently studied and new products are introduced to the market in order to keep the function animal metabolism healthy. A wide variety of additives are used in order to protect animal health at the maximum level, to obtain higher efficiency and direct animal products according to consumer and market demands. Melatonin has positive effects, especially on the productivity of poultry. However, different melatonin sources should be tested on animals in different life periods. The effects of melatonin, which is used as a feed additive and as an implant, on ruminant animals are not certain. As a result of a small number of studies in ruminant animals, it has been found that only daylight and lighting duration are sometimes more effective than melatonin feeding. Apart from melatonin secreted by animals at night, the effects of melatonin added to feed should be examined in more detailed studies. The effects of melatonin as a silage additive, should be investigated on the most commonly ensiling forages used in ruminant feeding. Benefits of melatonin on silage quality by comparing it with other additives that affect silage fermentation should be proven. In conclusion, melatonin is a promising feed additive whose antioxidant and immune system support properties have been proven in many studies in animals.

*Use of Melatonin as a Feed Additive DOI: http://dx.doi.org/10.5772/intechopen.105999*
