Hutcheson D P, Cole N A, McLaren J B
J Anim Sci. 1984 Mar;58(3):700-7. doi: 10.2527/jas1984.583700x.
Two trails were conducted to study effects of K addition to receiving diets and the effects of feeding either a 55% concentrate diet or hay before shipment on the health, performance and blood chemistry of transported calves. One-hundred seven steer calves were used in trial 1 and 160 steer calves in trial 2. Postshipment diets for trial 1 contained .9 or 1.4% K and for trial 2 were .7, 1.3, 2.2 or 3.1% K. The preshipment diets were fed 3 d before shipment and the receiving diets were fed for 2 wk after feedlot arrival. Performance data were collected for 28 and 49 d for trials 1 and 2, respectively. Feeding a 55% concentrate diet before shipment significantly reduced mortality of transported calves. Potassium additions to the diet after arrival improved performance of transported calves. Upon arrival at the feedlot, calves fed the 55% concentrate diet preshipment had lower (P less than .05) plasma urea-nitrogen (PUN) values than calves fed hay preshipment. Blood packed cell volume (PCV) increased (P less than .05) as the receiving diet K level increased from .7 to 2.2%. The K recommended for transported calves was calculated to be 24.7 g/100 kg of body weight for the first 2 wk after arrival, 20% more than the requirement for nontransported calves.
进行了两项试验，以研究在育肥牛日粮中添加钾的效果，以及在运输前饲喂55%精料日粮或干草对运输犊牛的健康、性能和血液生化指标的影响。试验1使用了107头阉公牛犊牛，试验2使用了160头阉公牛犊牛。试验1运输后的日粮含钾量为0.9%或1.4%，试验2为0.7%、1.3%、2.2%或3.1%。运输前的日粮在运输前3天饲喂，到达饲养场后的日粮在到达后饲喂2周。试验1和试验2分别收集了28天和49天的性能数据。运输前饲喂55%精料日粮显著降低了运输犊牛的死亡率。到达后在日粮中添加钾提高了运输犊牛的性能。到达饲养场时，运输前饲喂55%精料日粮的犊牛血浆尿素氮（PUN）值低于（P<0.05）运输前饲喂干草的犊牛。随着到达后日粮钾水平从0.7%提高到2.2%，血液红细胞压积（PCV）增加（P<0.05）。计算得出，运输犊牛到达后的前2周，推荐的钾摄入量为24.7克/100千克体重，比未运输犊牛的需求量高20%。
