Abstract
The effects of urea levels on feed intake, digestibility and carcass traits of 27 confined cross bred steers weighing 303.25 ± 60.8kg, were evaluated. After weighing, castrating, vaccinating and a period of seven days, three steers were slaughtered at the beginning of the experiment and the remaining 24 were allotted in a completely randomized design to four isonitogenous experimental diets (12% of crude protein) and increasing level of urea on the dry matter-basis (0.0; 0.65; 1.30 and 1.65%) to replace soybean meal, so that the final content of the experimental diets were approximately 22, 37, 50 and 63% of crude protein in the form of NPN. Corn and elephant grass silages were supplied at a 70:30 ratio and the total diet had a 65:35, forage: concentrate ratio on a DM-basis. The urea level did not affect nutrient intake, except for rumen degradable protein (RDP) and total digestible nutrients (TDN) linearly increased in function of diet urea level. The nutrient digestibilities linearly increased except for ether extract and non fiber carbohydrate (NFC). A quadratic effect of diet urea level on daily weight gain and no effect of urea level on carcass traits were observed. Urea can totally replace soybean meal in diets for confined crossed dairy steers allowing gains of 1kg/day. Urea can enhance nutrient digestibility of diets.
Highlights
The increasing demand for consistently high quality beef has caused changes in Brazilian cattle-raising
Twenty-four animals were assigned to four treatments in a completely randomized design with six steers per treatment
No differences occurred among treatments for DM, organic matter (OM), CP, ether extract (EE), Neutral detergent fiber (NDF) and non fiber carbohydrate (NFC) intake (Table 2)
Summary
The increasing demand for consistently high quality beef has caused changes in Brazilian cattle-raising. Nutritional management is one of the main factors in beef cattle production and adoption of feedlots as the major feeding strategy for the finishing phase in Brazil, has allowed an increase in productivity of beef cattle finishing. The protein fractions in cattle feeds are important because their relative cost. Research has focused on partial or total substitution of true protein sources by non-protein nitrogen (NPN). Urea has been the most widely used NPN compound in cattle diets because of its low cost per nitrogen unit, market availability, easy of use (Santos et al, 2001) and because it does not decrease yield or cause health problems in the animals (Huber, 1984)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Arquivo Brasileiro de Medicina Veterinária e Zootecnia
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
