02231naa a2200217 a 450000100080000000500110000800800410001902200140006010000170007424501480009126000090023930000140024849000060026252015800026865000120184865000260186065000200188665000130190670000180191977300760193710500292018-10-31       2012    bl uuuu     u00u1 u    #d  a2228-77011 aROVIRA, P.J.  aAddition of protein sources for calves supplemented with high moisture grain sorghum silage grazing low quality pasturesh[electronic resource]  c2012  a283-287 2  v2  aThree experiments were conducted to determine the effect of protein addition to high moisture sorghum grain silage (HMS) daily supplemented to calves at a rate of 1% of body weight (BW) grazing low-quality pastures. In exp. 1 addition of sunflower expeller or a protein ration to increase crude protein (CP) of HMS from 7.1% to 12% increased average daily gain 56% compared with calves fed only HMS (0.39 and 0.25 kg/a/d, respectively). Calves supplemented with protein sources were more efficient than calves supplemented only with HMS as feed conversion numerically decreased from 6.0 (HMS) to 4.5 (HMS + sunflower expeller) and 4.1 (HMS + protein ration). In exp. 2 CP of HMS (9.1%) was increased to 15.5% by adding sunflower expeller, urea or combination of both. Protein supplementation increased ADG and final BW (0.20 kg/a/d and 196 kg) compared with only HMS (0.03 kg/a/d and 176 kg). Protein source had no effect on animal performance. In exp. 3 CP concentrations in the supplement had a significant effect on ADG when increased from 8.9 to 16.1% (0.32 and 0.50 kg/a/d). Performance of calves fed either 16.1% or 20.8% CP supplements did not differ possibly because energy was becoming the limiting factor at the highest CP concentration level. Rib eye area and fat thickness were not affected by treatment although supplemented calves registered 7% and 10% greater values in those variables, respectively, than un-supplemented animals at the end of the experiment. The addition of protein sources to HMS increased performance of calves grazing low-quality pastures.  aBOVINOS  aGRANO HUMEDO DE SORGO  aSUPLEMENTACIÒN  aTERNEROS1 aVELAZCO, J.I.  tOnline Journal of Animal and Feed Research, 2012gv. 2, no.3 p. 283-287