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Extruded urea could reduce true protein source in beef cattle diets
Author(s) -
Moraes Gabriella J.,
Ítavo Luís Carlos V.,
Ítavo Camila Celeste B. F.,
Dias Alexandre M.,
Niwa Marcus Vinicius G.,
Leal Eduardo S.,
Kozerski Noemila Debora,
Costa Marlova Cristina Mioto,
Mata Debora Gabriela,
Inada Aline C.
Publication year - 2019
Publication title -
journal of animal physiology and animal nutrition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.651
H-Index - 56
eISSN - 1439-0396
pISSN - 0931-2439
DOI - 10.1111/jpn.13140
Subject(s) - rumen , latin square , urea , dry matter , chemistry , silage , ammonia , zoology , nitrogen balance , nutrient , ruminant , starch , forage , food science , nitrogen , agronomy , fermentation , biochemistry , biology , pasture , organic chemistry
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.