首页 | 本学科首页   官方微博 | 高级检索  
   检索      


Fecal nitrogen to estimate intake and digestibility in grazing ruminants
Authors:Vanessa Peripolli  Ênio Rosa Prates  Júlio Otávio Jardim Barcellos  José Braccini Neto
Institution:1. Bolsista do CNPq, estudante do Programa de Pós-graduação em Zootecnia, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, CEP 91540-000, Brazil;2. Curso de Pós-graduação em Produção Animal, Departamento de Zootecnia, Faculdade de Agronomia da UFRGS, Brazil;3. Bolsista do CNPq, Brazil
Abstract:This study aimed at evaluating forage intake and digestibility in ruminants using fecal nitrogen content, as well as validating a non-linear model to estimate digestibility in ruminants. A total of 58 conventional metabolism trials, carried out with sheep fed 27 forages (offered pure or in mixture) used in Rio Grande do Sul (RS) during the period 1969–1989 was analyzed. OM intake and OM digestibility (OMD) results were regressed linearly against fecal N, and OMD was also estimated from fecal crude protein (N × 6.25) content by a non-linear regression model. Fecal nitrogen excretion estimated forage intake in sheep with an R2 = 0.73, whereas a low R2 value of 0.36 was observed for OMD estimates. The equation obtained using the non-linear model was OMD = 0.7326 ? 0.3598 exp (?0.9052 CP (g/kg OM))/100]. The parameters a (0.7326) and b (0.3598) estimated by the equation for all forages were significant (P<0.00001) and there was no effect of type of forage (P=0.38). The mean prediction error (MSPE), was 0.2379, indicating that the equation fit well to the data. The difference between estimated and observed organic matter digestibility was mainly caused by random variation (0.9765). The results indicated that the equation using the non-linear model developed with all forages can be used with enough precision to estimate the OM digestibility of forage consumed by sheep in Rio Grande do Sul.
Keywords:
本文献已被 ScienceDirect 等数据库收录!
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号