Relationship between different sources of non-protein nitrogen and supplementation times on performance and metabolism of grazing Nellore cattle during the dry season

Author(s)

Mota, Veronica A. C. ; Prados, Laura F. ; Nascimento, Keuven S. ; Fernandes, Rodolfo M. ; Silva, Luiz F. Costa E. ; Holder, Vaughn B. ; Pettigrew, James E. ; Resende, Flavio D. ; Siqueira, Gustavo R.

• Document type: Journal article
• Source: TROPICAL ANIMAL HEALTH AND PRODUCTION; v. 54, n. 6, p. 12-pg., 2022-12-01.

Abstract

Two experiments were conducted to evaluate the effect of supplementation with two sources of non-protein nitrogen at different feeding times on the performance, ingestive behavior, and rumen metabolism of growing Nellore bulls during the dry season. Exp. 1: One hundred and twenty Nellore bulls, weighing 206 +/- 39 kg of initial body weight (BW) and 12 months of age, were divided into 20 paddocks, and they were used in randomized block design in a 2 x 2 factorial arrangement to evaluate performance and ingestive behavior. Exp. 2: 12 rumen cannulated animals with 509 +/- 59 BW, divided into 4 paddocks, were used in a triple Latin square 4 x 4 in a 2 x 2 factorial arrangement to evaluate metabolism. The factors were 2 non-protein nitrogen sources (urea or slow-release urea) and 2 feeding times (07:00 or 13:00 at 4 g/kg BW of supplement). There was no influence of non-protein sources, supplementation time, or their interaction on the grazing time or the trough time during daytime, nighttime, or total (P >= 0.16). There were no interactions or factor effects on ADG (P >= 0.45) or final body weight (P >= 0.39). There was an interaction between supplementation time and collection time (P < 0.01) on ruminal pH. Animals supplemented in the morning had greater total SCFA at 18 h after supplementation (P = 0.03). The supplementation time and the non-protein nitrogen sources did not alter the ingestive behavior or animal performance of young Nellore cattle. (AU)

• FAPESP's process: 16/05131-4 - Strategies for increasing nitrogen use efficiency in cattle growth phase pastures in Nellore
• Grantee: Verônica Aparecida Costa Mota
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 17/50339-5 - Institutional research development plan of the Animal Science Institute (PDIp)
• Grantee: Lenira El Faro Zadra
• Support Opportunities: Research Grants - State Research Institutes Modernization Program
• FAPESP's process: 18/20176-0 - Impact of different supplementation strategies on Nellore heifers on nutritional and reproductive performance
• Grantee: Laura Franco Prados
• Support Opportunities: Scholarships in Brazil - Post-Doctoral