Department of Animal Sciences, Colorado State University, Fort Collins 80523, USA.
J Anim Sci. 2010 Dec;88(12):4068-77. doi: 10.2527/jas.2009-2139. Epub 2010 Jul 23.
Increasing dietary electrolyte balance (dEB) has previously been shown to reduce the incidence of nonambulatory and noninjured swine, improve meat quality, and reduce the incidence of gastric ulcers. The objective of this study was to evaluate the effect of dEB under commercial conditions. Due to the variability in feed withdrawal, transport, and lairage conditions in the swine industry, it was necessary to determine first the persistence of blood changes during the marketing process after alteration of dEB. Sixteen pens of 8 crossbred barrows were assigned to a low (121 mEq/kg) or high (375 mEq/kg) dEB diet, calculated as Na(+) + K(+) - Cl(-), to determine the persistence of blood changes associated with the alteration of dEB. Diets were formulated to meet or exceed NRC (1998) requirements for energy, protein, vitamins, and minerals. Dietary treatments were provided for ad libitum intake for 3 d before slaughter. Before transport, animals were fasted in the barn for approximately 10 h. After fasting, animals were shipped to the packing plant, rested for 8 h, and subsequently slaughtered. Initial and final BW of the animals were obtained. Blood was sampled at baseline (2 d before administration of diets), before feed withdrawal (0 h), after feed withdrawal (10 h), and at exsanguination (20 h). Consumption of the high dEB diet for 3 d resulted in an increase in blood TCO(2) (P = 0.001), HCO(3)(-) (P = 0.001), and base excess (P = 0.0003) and a decrease in Cl(-) (P = 0.0002) and anion gap (P = 0.01). These differences, however, were not maintained for any of the blood components after the 10-h feed withdrawal (P > 0.22). Increasing dEB had no adverse effects (P > 0.18) on growth performance, meat quality, or carcass yield and did not decrease pars esophageal ulcer scores. This study demonstrated that the effect of dEB on blood components was not maintained after a 10-h feed withdrawal. Therefore, it is likely that the ability of the animal to withstand any increased metabolic acid load associated with the stress of transport was lost after feed withdrawal. Further research is needed to determine the effects of dEB alteration in animals that have not been fasted before shipment and using diets with a larger difference in dEB.
增加日粮电解质平衡（dEB）已被证明可降低非走动和非受伤猪的发病率，改善肉质，并减少胃溃疡的发病率。本研究的目的是评估商业条件下 dEB 的效果。由于猪业中饲料撤出、运输和圈养条件的可变性，因此有必要首先确定在改变 dEB 后，在市场营销过程中血液变化的持续时间。将 16 个 8 头杂交公猪栏分配到低（121mEq/kg）或高（375mEq/kg）dEB 饮食中，以计算 Na(+) + K(+) - Cl(-)，以确定与 dEB 改变相关的血液变化的持续时间。日粮的配制符合或超过 NRC（1998 年）对能量、蛋白质、维生素和矿物质的要求。在屠宰前，动物自由采食日粮 3d。在运输前，动物在畜舍中禁食约 10h。禁食后，动物被运送到加工厂，休息 8h，然后进行屠宰。获得动物的初始和最终 BW。在基础（日粮管理前 2d）、饲料撤出前（0h）、饲料撤出后（10h）和放血时（20h）采集血液样本。连续 3d 饲喂高 dEB 日粮可使血液 TCO(2)（P = 0.001）、HCO(3)(-)（P = 0.001）和碱剩余（P = 0.0003）增加，Cl(-)（P = 0.0002）和阴离子间隙（P = 0.01）减少。然而，在 10h 饲料撤出后，所有血液成分的这些差异均不再维持（P > 0.22）。增加 dEB 对生长性能、肉质或胴体产率没有不利影响（P > 0.18），也不会降低食管下段溃疡评分。本研究表明，在 10h 饲料撤出后，dEB 对血液成分的影响不再维持。因此，动物在饲料撤出后可能会失去承受与运输应激相关的任何代谢性酸中毒负荷增加的能力。需要进一步研究来确定在运输前未禁食的动物中改变 dEB 的影响，以及使用 dEB 差异较大的日粮。
