Extruded urea could reduce true protein source in beef cattle diets

Abstract

Rumen micro‐organisms are capable of producing microbial protein from ammonia and carbon skeleton, and non‐protein nitrogen (NPN) may be one of the sources of ammonia. Alternative source of NPN is the slow release of ammonia sources in which the product is the extrusion of starch with urea. This work aimed to determine the effects on nutrient intake, ingestive behaviour, digestibility, nitrogen balance, ruminal pH, rumen ammonia nitrogen, volatile fatty acids (VFA) and blood parameters with increased levels of extruded urea (50, 60, 70 and 80 g/100 kg of body weight [BW]) in beef cattle diet. Four rumen cannulated crossbred steers with initial mean weight of 336 ± 47 kg in a 4 × 4 Latin square design were distributed. Diets were formulated with 400:600 g/kg roughage:concentrate ratio on dry matter based and provided once per day, being used whole corn silage as roughage. There were no effects on nutrient intake (kg/day), ingestive behaviour, apparent digestibility, nitrogen balance, volatile fatty acid (VFA) and blood parameters in extruded urea treatment groups. Similar results were observed on time spent on feeding, rumination and idleness. There were positive linear effects (p = 0.022) on rumen pH in the time of 8 hr after feeding and also on plasma concentration of the extruded urea levels (p = 0.039); whereas a linear negative effect (p = 0.030) was observed on ammonia nitrogen for the collection time of 2 hr after feeding. Increased levels of extruded urea could maintain nutrient intake, digestibility, ingestive behaviour, rumen pH and blood parameters in normal conditions. In conclusion, we recommend the extruded urea use with values up to 80 g/100 kg BW in confined beef cattle that receive balanced diets with 140 g/kg of crude protein.

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 .…”

Calorimetry, physicochemical characteristics and nitrogen release from extruded urea

“…Protein utilization efficiency in ruminants can be improved by maintaining adequate NNP amounts and feeding management with the use of extruded urea in cattle diets. Up to the level of supplementation of 80 g/100 kg body weight of extruded urea (starea with protein equivalent 200% CP) there are no negative influences on the rumen environment 13 .…”

Extruded urea levels in lamb supplementation in rainy tropical savanna conditions: the triad host-gastrointestinal nematodes-environment

“…There are studies that prove the bene cial effects of the EU on beef and dairy cattle (Moraes et al, 2019;Ítavo et al, 2016;Miranda et al, 2015;Mendes et al, 2010). However, in sheep farming, the introduction of this nitrogen source in supplementation has been little studied, since it is not known what level of EU is recommended for partial replacement of SF and also the maintenance of animal performance, especially associated with NGIs.…”