Calorimetry, physicochemical characteristics and nitrogen release from extruded urea

Abstract

Our hypothesis was that extrusion of urea associated with corn may reduce N solubilization and increase the nutritional quality of this food for ruminants. We aimed to physically and chemically characterize a corn and urea mixture before and after the extrusion process. It was evaluated morphological differences by scanning electron microscopy, nitrogen solubilization, and compound mass loss by thermogravimetry. In scanning electron microscopy, extruded urea showed agglomerated and defined structures, with changes in the morphology of starch granules and urea crystals, differing from the arrangement of the corn and urea mixture. The extruded urea maintained a constant nitrogen release pattern for up to 360 min. In thermogravimetry, extruded urea presented a higher temperature to initiate mass loss, that is, the disappearance of the material with increasing temperature, but the mass loss was lower when compared to the first event of the corn and urea mixture. In conclusion the process of extrusion of urea with corn modifies the original structures of these ingredients and controls the release of nitrogen from the urea, maintaining in its formation an energy source optimizing the use of nitrogen by ruminal bacteria, because the more synchronized the release of starch (energy) and nitrogen, the better the use by ruminal microorganisms.

A new feed additive composed of urea and soluble carbohydrate coated with wax for controlled release in ruminal fluid

“…The UE is a product obtained by extruding a mixture of starch and urea, by means of high temperature and pressure, leading to the gelatinization of the starch. Extrusion causes the incorporation of urea into the starch structure, reducing its solubility 6 , 11 , 12 .…”

“…For example, a study 5 found that coating of urea chitosan did not bring significant effect on pH, dry matter and organic matter digestibility, microbial protein synthesis, and amonia concentration in the rumen. On the other hand, some authors 6 cite that the extrusion of urea with corn, in addition to controlling the release of nitrogen, improves the use of urea due to a better synchronization during the degradation of these ingredients.…”

Extruded urea could replace true protein source in supplements for lambs finished in tropical pastures

“…Extruded urea is the product resulting from the extrusion of a mixture of starch, urea (200% crude protein) and sulfur (3.2% S) by means of high temperature and pressure, leading to the gelatinization of starch (Kozerski et al, 2021a). In this type of processing, the starch granules are gelatinized, and the urea modified from a crystalline structure to a non-crystalline form, with most of the non-crystalline structures found within the gelatinized portion, making it more palatable than grain mixtures of unprocessed urea, allowing the food to be better accepted by animals (Kozerski et al, 2021a).…”

Changes in the skin characteristics of Nellore steers during the rearing phase in hot climate pasture supplemented with protein sources

“…Extruded urea is a product obtained by subjecting a mixture of starch (22% total digestible nutrients, TDN), urea (200% crude protein), and sulfur (3.2% S) to high temperature and pressure, resulting in starch gelatinization 11 . This processing method facilitates a gradual release of nitrogen in the rumen 11 . Moreover, it synchronizes nitrogen release with starch, promoting increased microbial protein production.…”