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چکیده
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The objective of this study was to investigate the effectsof the physical forms of starter and forage sourceson feed intake, growth performance, rumen pH, andblood metabolites of dairy calves. Forty male Holsteincalves (41.3 ± 3.5 kg of body weight) were used (n= 10 calves per treatment) in a 2 × 2 factorial arrangementof treatments with the factors being physicalforms of starter (coarse mash and texturized) andforage source [alfalfa hay (AH) and wheat straw (WS)].Individually housed calves were randomly assigned to1 of the 4 dietary treatments, including (1) coarselymashed (CM; coarse ground grains combined with amash supplement) starter feed with AH (CM-AH), (2)coarsely mashed starter feed with WS (CM-WS), (3)texturized feed starter (TF; includes steam-flaked corn,steam-rolled barley combined with a pelleted supplement)with AH (TF-AH), and (4) TF with WS (TFWS).Both starters had the same ingredients and nutrientcompositions but differed in their physical forms.Calves were weaned on d 56 and remained in the studyuntil d 70. All calves had free access to drinking waterand the starter feeding at all times. No interaction wasdetected between the physical forms of starter feedsand forage source concerning starter intake, dry matterintake, metabolizable energy (ME) intake, averagedaily gain (ADG)/ME intake, ADG, and feed efficiency(FE). The preweaning and overall starter feed intake,dry matter intake, and ME intake were greater forcalves fed TF starter diets than those fed CM starterdiets. The ADG/ME intake was greater for calves fedTF starter diets than that fed CM starter. The FE wasgreater for calves fed TF starter diets compared withthose fed CM starter during the preweaning, postweaning,and overall periods. The WS improved FE duringthe postweaning period compared with AH. The physicalform of starter, forage source, and their interactiondid not affect plasma glucose, triglycerides, and verylow-density lipoprotein concentrations. Ruminal pHwas greater for calves fed
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