title: Effect of concentrate supplementation on nutrient digestibility and growth of Brahman crossbred cattle fed a basal diet of grass and rice straw.
abstract: BACKGROUND
  An experiment was conducted in Vietnam to test the hypothesis that total dry matter (DM) intake and liveweight (LW) gain would increase in a curvilinear manner with increasing amounts of concentrate offered.
  
  
  METHODS
  There were five treatments: a basal diet of Guinea grass fed at 1 % of LW and rice straw fed ad libitum (T0), or this diet supplemented with concentrate at 0.6 (T1), 1.2 (T2), 1.8 (T3), or 2.4 % of LW (T4). The concentrate comprised locally available ingredients, namely cassava chips, rice bran, crushed rice grain, fishmeal, salt, and urea, mixed manually.
  
  
  RESULTS
  Concentrate intake increased from T0 to T3, but there was no difference in concentrate intake between T3 and T4. Total feed intake increased in a curvilinear manner from 4.0 to 6.4 kg DM/d as the quantity of concentrate consumed increased. The substitution of concentrate for grass and rice straw increased with increasing consumption of concentrate and was as high as 0.49 kg DM reduction per kg of concentrate consumed. LW gain increased curvilinearly, with significant differences between T0 (0.092 kg/d), T1 (0.58 kg/d) and T2 (0.79 kg/d); but there were no significant differences in LW gain between T2, T3 (0.83 kg/d) and T4 (0.94 kg/d).With increasing amount of concentrate in the diet, the digestibilities of dry matter, organic matter, crude protein, and crude fat increased, but NDF digestibility decreased.
  
  
  CONCLUSIONS
  Based on these results, young Vietnamese Brahman-cross growing cattle will respond to a locally-sourced concentrate mix offered at a level of up to 1.2 % of LW.
authors.affiliation: Institute of Animal Science Southern Vietnam, Ho Chi Minh, Vietnam.
authors.forename: Do Van
authors.initials: do V
authors.lastname: Quang
authors.affiliation: Faculty of Animal Sciences, Hue University of Agriculture and Forestry, Hue City, Vietnam.
authors.forename: Nguyen Xuan
authors.initials: NX
authors.lastname: Ba
authors.affiliation: Peter Doyle Consulting, 4 Red Bean Close, Byron Bay, NSW 2481 Australia.
authors.forename: Peter T
authors.initials: PT
authors.lastname: Doyle
authors.affiliation: Institute of Animal Science Southern Vietnam, Ho Chi Minh, Vietnam.
authors.forename: Dau Van
authors.initials: DV
authors.lastname: Hai
authors.affiliation: Tasmanian Institute of Agriculture and School of Land and Food, University of Tasmania, Sandy Bay, 7001 Australia.
authors.forename: Peter A
authors.initials: PA
authors.lastname: Lane
authors.affiliation: Tasmanian Institute of Agriculture and School of Land and Food, University of Tasmania, Sandy Bay, 7001 Australia.
authors.forename: Aduli Eo
authors.initials: AE
authors.lastname: Malau-Aduli
authors.affiliation: Faculty of Animal Sciences, Hue University of Agriculture and Forestry, Hue City, Vietnam.
authors.forename: Nguyen Huu
authors.initials: NH
authors.lastname: Van
authors.affiliation: Tasmanian Institute of Agriculture and School of Land and Food, University of Tasmania, Sandy Bay, 7001 Australia.
authors.forename: David
authors.initials: D
authors.lastname: Parsons
keywords: Bos indicus; Concentrate; Crossbred; Digestibility; Rice Straw; Vietnam; Yellow cattle