Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton T6G 2P5, Canada.
J Anim Sci. 2012 Sep;90(9):3143-52. doi: 10.2527/jas.2011-3983. Epub 2012 Jun 4.
This study investigated the effects of feeding barley grain treated with lactic acid (LA) and heat on the profile of plasma metabolites related to carbohydrate and lipid metabolism and variables related to rumen health and acute phase response. Eight primiparous rumen-fistulated lactating Holstein cows were randomly assigned, in a crossover design, to 1 of the 2 dietary treatments consisting of 32% (DM basis) rolled barley grain steeped in an equal quantity of either tap water alone (CTR) or a 1.0% LA solution and heated at 55°C for 48 h (LAH). Each experimental period was 21 d, with the last 10 d used for measurements. Blood samples were collected on d 1, 3, 5, 7, 9, and 11 before the morning feeding and on the last day of each period at 0, 2, 4, 6, 8, 10, and 12 h postfeeding to measure glucose, lactate, cholesterol, beta-hydroxybutyrate (BHBA), NEFA, haptoglobin (Hp), serum amyloid A (SAA), and tumor necrosis factor-alpha (TNF-α). Also, rumen samples were collected on d 1, 5, and 11 as well as at 0, 4, 8, and 12 h postfeeding on the last day of each period for measuring the concentration of rumen endotoxin. Results of the day-to-day analysis indicated that cows fed the LAH diet had reduced preprandial concentrations of rumen endotoxin (472 vs. 793 ng/mL; P < 0.01) and cholesterol and greater lactate in the plasma; however, treatment had no effect on plasma Hp and TNF-α (P > 0.10). Postprandial responses showed that the LAH diet tended to decrease the concentration of SAA (4.67 vs. 8.50 μg/mL; P = 0.06). Also, there was a treatment by time interaction for rumen endotoxin (P < 0.01), suggesting a role for both the treatment and the time of sampling on this variable. Furthermore, greater concentration of BHBA and a tendency for greater NEFA and reduced concentrations of plasma glucose were observed in cows fed the LAH diet. In conclusion, results indicated that feeding dairy cows barley grain steeped in 1.0% LA and treated with heat modulated the profile of plasma metabolites and acute phase response.
本研究旨在探讨用乳酸（LA）和热处理大麦粒喂养对与碳水化合物和脂质代谢相关的血浆代谢物谱以及与瘤胃健康和急性期反应相关的变量的影响。将 8 头初产、瘤胃瘘管的泌乳荷斯坦奶牛随机分配到 2 种饮食处理中的 1 种，采用交叉设计，这 2 种处理由 32%（DM 基础）的轧碎大麦粒组成，分别用等量的自来水（CTR）或 1.0%的 LA 溶液浸泡，在 55°C 下加热 48 小时（LAH）。每个实验期为 21 天，最后 10 天用于测量。在第 1、3、5、7、9 和 11 天的早上喂料前采集血液样本，并在每个时期的最后一天在 0、2、4、6、8、10 和 12 小时时采集样本，以测量葡萄糖、乳酸、胆固醇、β-羟丁酸（BHBA）、非酯化脂肪酸（NEFA）、触珠蛋白（Hp）、血清淀粉样蛋白 A（SAA）和肿瘤坏死因子-α（TNF-α）。此外，在每个时期的最后一天的 0、4、8 和 12 小时时还采集瘤胃液样本，以测量瘤胃内毒素的浓度。日常分析的结果表明，饲喂 LAH 日粮的奶牛瘤胃内毒素的预饲前浓度降低（472 对 793ng/ml；P<0.01），血浆中乳酸和胆固醇增加，但处理对血浆 Hp 和 TNF-α没有影响（P>0.10）。餐后反应表明，LAH 日粮倾向于降低 SAA 的浓度（4.67 对 8.50μg/ml；P=0.06）。此外，瘤胃内毒素存在处理和采样时间的互作（P<0.01），这表明处理和采样时间都对该变量有影响。此外，饲喂 LAH 日粮的奶牛 BHBA 浓度增加，NEFA 有增加的趋势，血浆葡萄糖浓度降低。总之，结果表明，用 1.0%LA 浸泡并热处理大麦粒喂养奶牛可以调节血浆代谢物和急性期反应的模式。
