Digestibility and palatability of adding crude glycerin to the diet of ponies

Abstract

Crude glycerin has a potential for use as a nutritional additive and/or substitute for some feed components. Although proven in some animal species, there are no reports of its use in horses. The aim of this study was to determine the effect of adding different levels of crude glycerin on the digestibility and palatability of nutrients in the equine diet. Eight pony geldings were used in this study, aged 9 years, weighing 149.80 ± 17.20 kg and body condition score 5.4 ± 0.7. A contemporary Latin square 4 × 4 double experimental design was used. Diets differed in the level of inclusion of glycerin (0, 4, 8 and 12%) over the concentrate. To verify the effect of adding crude glycerin to the diet, the total apparent digestibility of nutrients in the diet was assessed. Data were analyzed using the Statistical Analysis System (SAS Institute Inc., 2010). For statistical significance, Tukey test was used with P < 0.05. Digestibility analyses showed that glycerin addition, even at different levels in the diet, did not affect the feed intake nor the apparent variables of digestibility and fermentation of the total tract (P > 0.05). Additionally, no differences were found between treatments for glucose and insulin values (P > 0.05). In this study the addition of glycerin, even at the amount of 12%, did not affect the acceptability and digestibility of nutrients in the diet. These results are encouraging, yet more research is needed to clarify the appropriate levels of inclusion and/or substitution using this product.