Glycerol: dietary supplement and response in dairy cattle

Abstract

Introduction. Animal production technologies have allowed the efficient use of food resources to meet nutritional needs and generate food for the human population. Alternative feed sources in ruminants have been used to increase the productive and reproductive indicators. The expansion of the oil palm area (Elaeis guineensis) for biodiesel production as a renewable energy source has favoured the development of agro-industrial processes through the generation of by-products, such as glycerol, which due to its glycogenic effect, could be considered as an alternative energy source. Objective. To substantiate the nutritional effect of glycerol as a dietary supplement on the response in dairy cattle. Development. Studies have reported beneficial effects of the glycerol use as therapy in the prevention of metabolic disorders associated with the transition period, characterized by nutritional deficiencies and imbalances. Several results have shown that its response is associated with the level of inclusion (5 to 12 % DM) in the diet and the rate of disappearance at the ruminal level, which concerns the intake. Its composition varies according to the quality of the raw material (degree of impurities), which could be considered unsafe for its supply. The energy sources have shown a favourable effect on the reproductive response expressed by the increase in the ovulation rate, the improvement in the modulation of the uterine prostaglandin synthesis, better quality of oocytes, greater competition in embryonic development, and an increase in the conception rates, in which the use of glycerol could be associated. Conclusion. Glycerol could be considered an essential ingredient in diets due to its high energy value and beneficial effect on productive and reproductive indicators, however, it is necessary to expand its study.