Glycerol, is being an attractive feed ingredient for cattle, is a by-product of a wide range of industrial applications. Glycerol has potential value in livestock feeding since it improves feed efficiency, metabolism, and can avoid ketosis. Research indicates that glycerol can be a suitable partial grain replacement in the diet of cows during the transition period and at early lactation. The impact on milk yield is not significant, but glycerol mostly decreases milk fat content. The inclusion of glycerol in the dairy ration has an effect on ruminal fermentation patterns. Glycerol is rapidly fermented in the rumen into propionate, and it is metabolized to glucose in the liver through the process of glycogenolysis, additionally, glycerol administration to ruminants can reduce greenhouse gas emissions. The purpose of this review is to highlight the potential benefits and drawbacks related to the use of glycerol in cattle. Glycerol, from biodiesel Industries, must be purified in order to make it a useful product for livestock feeding. The use of glycerol in ruminant nutrition can be justified for several reasons: (i) as a source of energy, (ii) as a glycogenic precursor, and (iii) it may have an effect on milk composition. The high energy value of glycerol provides the opportunity to use it as a partial substitute for grain in dairy rations. Supplementation of glycerol in dairy animals' diets is associated with increased propionate, butyrate, valerate, and isovalerate concentrations in the rumen. Glycerol can be used as 10%–15% of the dietary dry matter (DM) and is a well-established tool for treatment for ketosis in cows. Glycerol increases plasma glucose and may reduce non-esterified fatty acids and hydroxybutyrate levels. The dietary supplementation of glycerol does not have a direct effect on DM intake, milk yield, or milk composition. However, some researchers reported an increase in milk yield after glycerol supplementation associated with decreased milk fat concentration. It is also possible that the concentration in the milk of odd-chain fatty acids and cis-9, trans-11 conjugated linoleic acid may increase after glycerol application.