The objective of this study was to investigate the effects of the physical forms of starter and forage sources on feed intake, growth performance, rumen pH, and blood metabolites of dairy calves. Forty male Holstein calves (41.3 ± 3.5 kg of body weight) were used (n = 10 calves per treatment) in a 2 × 2 factorial arrangement of treatments with the factors being physical forms of starter (coarse mash and texturized) and forage source [alfalfa hay (AH) and wheat straw (WS)]. Individually housed calves were randomly assigned to 1 of the 4 dietary treatments, including (1) coarsely mashed (CM; coarse ground grains combined with a mash 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 (TF-WS). Both starters had the same ingredients and nutrient compositions but differed in their physical forms. Calves were weaned on d 56 and remained in the study until d 70. All calves had free access to drinking water and the starter feeding at all times. No interaction was detected between the physical forms of starter feeds and forage source concerning starter intake, dry matter intake, metabolizable energy (ME) intake, average daily gain (ADG)/ME intake, ADG, and feed efficiency (FE). The preweaning and overall starter feed intake, dry matter intake, and ME intake were greater for calves fed TF starter diets than those fed CM starter diets. The ADG/ME intake was greater for calves fed TF starter diets than that fed CM starter. The FE was greater for calves fed TF starter diets compared with those fed CM starter during the preweaning, postweaning, and overall periods. The WS improved FE during the postweaning period compared with AH. The physical form of starter, forage source, and their interaction did not affect plasma glucose, triglycerides, and very low-density lipoprotein concentrations. Ruminal pH was greater for calves fed TF starter diets than those fed CM starter on d 30 of life. An interaction was observed between the physical forms of starter diets and forage source for β-hydroxybutyrate on d 28. These results showed that when starter diets contained similar ingredients and nutrient contents, processing calf starters to reduce the number of fine particles can improve the growth performance in dairy calves. Furthermore, the provision of WS improved FE and ADG of calves during the postweaning period.

这项研究的目的是研究发酵剂和饲料来源的物理形式对奶牛采食量，生长性能，瘤胃pH值和血液代谢产物的影响。以2×2因子处理方式使用40只雄性荷斯坦犊牛（41.3±3.5千克体重）（每处理n = 10头犊牛），其中因素包括发酵剂的物理形式（粗和膨化）和饲料来源[苜蓿干草（AH）和麦秸（WS）]。将单独饲养的犊牛随机分配到4种饮食处理中的一种，包括（1）AH粗饲料（CM;粗磨碎的谷物与麦芽补充剂结合）AH（CM-AH）初学者饲料，（2）AH粗饲料WS（CM-WS），（3）膨化饲料起子（TF；包括片状玉米，蒸汽轧制的大麦，加上颗粒状补品）和AH（TF-AH），以及（4）TF和WS（TF-WS）。两种发酵剂的成分和营养成分相同，但物理形式不同。在第56天，给小牛断奶，直到第70天都留在研究中。所有小牛在任何时候都可以自由获得饮用水和开胃饲料。在发酵剂饲料和饲料来源的物理形式之间未检测到相互作用，涉及发酵剂摄入，干物质摄入，代谢能（ME）摄入，日平均增重（ADG）/ ME摄入，ADG和饲料效率（FE）。饲喂TF起始日粮的犊牛的断奶前和总体发酵剂摄入量，干物质摄入量和ME摄入量高于CM起始日粮的犊牛。饲喂TF起始日粮的犊牛的ADG / ME摄入量高于CM起始日粮。在断奶前，断奶后和整个断奶期间，饲喂TF起动剂日粮的犊牛的FE比饲喂CM起动器日粮的犊牛的FE高。与AH相比，WS在断奶后期提高了FE。发酵剂，饲料来源及其相互作用的物理形式不影响血浆葡萄糖，甘油三酸酯和极低密度脂蛋白的浓度。在出生后第30天，饲喂TF起始日粮的小牛的瘤胃pH值大于饲喂CM起始日粮的小牛。在第28天时，观察到发酵剂日粮的物理形式与β-羟基丁酸酯的饲料来源之间存在相互作用。这些结果表明，当发酵剂日粮中含有相似的成分和营养成分时，加工小牛发酵剂以减少细颗粒的数量可以改善生长。牛犊的性能。此外，