Schmitz Rolf, Schnabel Karina, von Soosten Dirk, Meyer Ulrich, Hüther Liane, Spiekers Hubert, Rehage Jürgen, Dänicke Sven
a Institute of Animal Nutrition, Friedrich-Loeffler-Institut (FLI), Federal Research Institute for Animal Health , Braunschweig , Germany.
b Institute of Animal Nutrition and Feed Management, Bavarian State Research Center of Agriculture (LfL) , Poing-Grub , Germany.
Arch Anim Nutr. 2018 Dec;72(6):458-477. doi: 10.1080/1745039X.2018.1526535. Epub 2018 Oct 8.
The aim of this study was to assess differences of ruminal pH and rumination activity between the prepartal and postpartal period of cows and to investigate changes of feeding behaviour and ruminal fermentation depending on postpartal rations with slight differences in roughage energy and fibre concentration. Therefore, 11 rumen-cannulated German Holstein cows were used from 3 weeks antepartum until 16 weeks postpartum. During the dry period, all cows received the same diet. After calving cows were assigned to two groups receiving partial mixed rations with different energy concentrations (6.1 MJ NE/kg DM [moderate], with 18% straw on dry matter [DM] basis, group MR) or 6.5 MJ NE/kg DM [high], with 6% straw on DM basis, group HR). In both groups, concentrates were supplied on average at 45% of total DM intake. Circadian measurements of ruminal pH, ruminal temperature and rumination activity were conducted weekly during the transition period and bi-weekly after week 4 postpartum. Throughout the postpartal period, feed intake behaviour was measured, and twice during the experiment, rumen fluid composition and net-acid-base excretion in urine were determined. Mean ruminal pH, feeding behaviour, rumination activity and rumen fluid composition did not differ between the groups, whereas group HR exhibited higher diurnal variations of pH and had a lower rumen temperature than group MR postpartum. However, these differences also occurred during the prepartal period when groups received equal rations. It was observed that ruminal pH values and the risk for subacute ruminal acidosis (SARA) were increased during postpartal period, whereby the circadian pH values showed high cow-individual variations. Overall, differences of energy and fibre concentrations in roughage did not affect the observed variables, whereby it should be noted that the number of cows was quite low in this study. Our results suggest that the ruminal pH characteristics are rather cow individual, indicating that cows presumably differ in their susceptibility to develop SARA.
本研究的目的是评估奶牛产前和产后瘤胃pH值及反刍活动的差异，并研究根据产后日粮中粗饲料能量和纤维浓度略有差异的情况下，采食行为和瘤胃发酵的变化。因此，选用了11头安装了瘤胃瘘管的德国荷斯坦奶牛，从产前3周直至产后16周。在干奶期，所有奶牛都采食相同的日粮。产犊后，奶牛被分为两组，分别采食能量浓度不同的部分混合日粮（6.1兆焦代谢能/千克干物质[中等]，以干物质[DM]计含18%的秸秆，MR组）或6.5兆焦代谢能/千克干物质[高]，以干物质计含6%的秸秆，HR组）。两组中，精饲料平均供应量均占总干物质摄入量的45%。在过渡期每周进行瘤胃pH值、瘤胃温度和反刍活动的昼夜测量，产后第4周后每两周测量一次。在整个产后期间，测定采食行为，并且在实验期间两次测定瘤胃液成分和尿液中的净酸碱排泄量。两组之间的平均瘤胃pH值、采食行为、反刍活动和瘤胃液成分没有差异，然而，产后HR组的pH值昼夜变化较大，且瘤胃温度低于MR组。不过，在产前两组采食等量日粮时也出现了这些差异。观察到产后瘤胃pH值和亚急性瘤胃酸中毒（SARA）风险增加，昼夜pH值显示出较高的个体差异。总体而言，粗饲料中能量和纤维浓度的差异并未影响所观察到的变量，不过应该指出的是，本研究中的奶牛数量相当少。我们的结果表明，瘤胃pH值特征具有相当大的个体差异，这表明奶牛在发生SARA的易感性方面可能存在差异。
