Abstract

MARTINEZ-TREJO, Guillermina et al. Productive performance and ruminal variables of lambs fed urea-treated maize stover. Rev. Mex. Cienc. Agríc [online]. 2012, vol.3, n.6, pp.1157-1170. ISSN 2007-0934.

The objective of this study was to investigate the effect of feeding lambs with maize stover treated with urea or supplemented with urea diluted or mixed in the feed. Daily feed intake (DFI), daily weight gain (DWG), and feed conversion (FC) were determined, as well as dry matter (DM), organic matter (OM), crude protein (CP), cell wall (CW), cell content (CC), cellulose (CEL) and hemicellulose (HEM) in vivo digestibility, rumen pH (pH), rumen ammonia (CRA), volatile fatty acids concentration (VFA), and in vitro degradability of dry matter (DDM). Four treatments were randomly assigned to 20 male Criollo sheep (20 ± 5 kg) in a completely randomized design. Diets fed to animals contained 30% concentrate and 70.0% of either untreated maize stover (UM); treated with urea (TM) (4 kg of diluted urea in 20 L of H₂O 100^-1 kg of maize stover, treated for 30 days); supplemented with diluted urea (SM) (38g de urea 50 mL¹ H₂O), or urea mixed in the feed (MM) (38g animaHday^-1) at the moment lambs were fed. The addition of urea did not affect DFI, DWG, or FC. In vivo digestibility of DM, OM, CW, HEM and CEL was higher (p<0.05) in TM, whilst CP and CC was higher in SM. There were no differences due to treatment (p> 0.05) for rumen pH and VFA concentration. CRA and in vitro degradability at 24, 48, and 72 h, were higher in the diets containing urea.

Keywords : lambs; maize stover; urea.

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