Ange K D, Eisemann J H, Argenzio R A, Almond G W, Blikslager A T
Department of Animal Science, North Carolina State University, Raleigh 27695, USA.
J Anim Sci. 2000 Sep;78(9):2344-52. doi: 10.2527/2000.7892344x.
The effects of the physical form of feed on water disappearance and the effects of buffered water on proximal stomach pH in swine were determined in two experiments. In Exp. 1, 32 barrows were used to evaluate the water disappearance in pigs fed a finely ground and pelleted diet vs those fed a coarsely ground and mashed diet for ad libitum consumption over a 2-wk interval. There were four replicates with eight pigs per replicate. Average daily water and feed disappearance did not differ (P = 0.06 and P = 0.10, respectively). However, average daily water to feed ratio was higher for pigs on the pelleted diet (4.21+/-0.31 L/kg vs 3.04+/-0.33 L/kg; P = 0.02). The higher ratio for the pelleted diet indicated that this may be the cause of a more fluid digesta allowing reflux of irritants from the distal stomach to damage the pars esophageal region of the proximal stomach. In Exp. 2, four barrows (25+/-2 kg) had gastric cannulas surgically implanted into the proximal region of the stomach. Pigs were given ad libitum access to a finely ground and pelleted diet. The experimental design was a Latin square. Water treatments included water (control), 200 mOsm NaHCO3, 250 mOsm NaHCO3, and 250 mOsm mono-dibasic sodium phosphate. Pigs were given a 4-d adjustment period, and pH measurements began on the morning of the 5th d and continued for 24 h under normal feeding conditions. Feed was removed and measurements were continued for 16 h. Buffered water raised the pH of the proximal region of the stomach compared to the control (P < 0.001). Average pH while consuming the water treatments was 3.65+/-0.11 (n = 4) for water control, 4.86+/-0.11 (n = 4) for the 200 mOsm NaHCO3, 4.63+/-0.11 (n = 4) for the 250 mOsm NaHCO3, and 4.59+/-0.14 (n = 3) for the 250 mOsm mono-dibasic sodium phosphate. Buffers also raised the pH of the proximal region of the stomach for the fed (P < 0.001) and the feed restriction (P < 0.01) phases of the trial. Water disappearance rates in pigs given NaHCO3 were higher than in the control (P < 0.01). Average daily water disappearance for the treatments was 9.13+/-0.74 L for the control, 13.56+/-0.74 L for 200 mOsm NaHCO3, 13.77+/-0.74 L for the 250 mOsm NaHCO3, and 10.33+/-0.95 L for the phosphate buffer. The proximal pH of the stomach was increased by adding buffers to the water supply. Addition of NaHCO3 buffers also caused increased water disappearance.
在两项试验中测定了饲料物理形态对猪水分消失的影响以及缓冲水对猪近端胃pH值的影响。在试验1中，选用32头公猪，评估自由采食精细粉碎颗粒饲料的猪与自由采食粗粉碎糊状饲料的猪在2周期间的水分消失情况。共4个重复，每个重复8头猪。平均每日水分和饲料消失量无差异（分别为P = 0.06和P = 0.10）。然而，颗粒饲料组猪的平均每日水料比更高（4.21±0.31 L/kg对3.04±0.33 L/kg；P = 0.02）。颗粒饲料组的水料比更高，这表明这可能是消化物更稀从而使刺激性物质从远端胃反流至近端胃食管区造成损伤的原因。在试验2中，4头公猪（体重25±2 kg）手术植入胃近端套管。猪自由采食精细粉碎颗粒饲料。试验设计为拉丁方。水分处理包括水（对照）、200 mOsm碳酸氢钠、250 mOsm碳酸氢钠和250 mOsm磷酸二氢钠-磷酸氢二钠。猪有4天的适应期，pH值测量从第5天上午开始，在正常饲喂条件下持续24小时。然后撤走饲料并继续测量16小时。与对照组相比，缓冲水提高了近端胃的pH值（P < 0.001）。饮水处理期间的平均pH值，水对照组为3.65±0.11（n = 4），200 mOsm碳酸氢钠组为4.86±0.11（n = 4），250 mOsm碳酸氢钠组为4.63±0.11（n = 4），250 mOsm磷酸二氢钠-磷酸氢二钠组为4.59±0.14（n = 3）。缓冲剂在试验的采食期（P < 0.001）和限饲期（P < 0.01）也提高了近端胃的pH值。给予碳酸氢钠的猪的水分消失率高于对照组（P < 0.01）。各处理的平均每日水分消失量，对照组为9.13±0.74 L，200 mOsm碳酸氢钠组为13.56±0.74 L，250 mOsm碳酸氢钠组为13.77±0.74 L，磷酸盐缓冲剂组为10.33±0.95 L。向供水添加缓冲剂可提高胃近端的pH值。添加碳酸氢钠缓冲剂也导致水分消失增加。
