Effects of Lactobacillus buchneri inoculation or 1-propanol supplementation to corn silage on the performance of lactating Holstein cows

ABSTRACT The objective was to evaluate the effects of corn silage supplemented with 1-propanol or inoculated with L. buchneri on the ruminal fermentation profile, digestibility, and production traits of lactating Holstein cows. Whole-corn plants were harvested at 350 g/kg dry matter (DM) and packed in nine bag silos (13 t/silo). At ensiling, two treatments were applied: control (no additive; six silos) and L. buchneri inoculation with 1 × 105 cfu/g (three silos). Feeding started after 247 days of storage; one L. buchneri and two control silos were opened in each experimental period. Twenty-one multiparous Holstein cows (~33 kg/day of milk) were allocated to seven balanced 3 × 3 Latin squares with 21-day periods (14 days of adaptation). The experimental diets contained (DM basis): 80 g/kg cottonseed, 95 g/kg citrus pulp, 180 g/kg soybean meal, 90 g/kg corn grain (ground), 25 g/kg minerals and vitamins premix, and 530 g/kg of corn silage. Source of corn silage was the only difference between experimental treatments: control, L. buchneri, or control silage supplemented with 1-propanol (10 g/kg of diet DM). The 1-propanol was dissolved in water (1:1) and sprinkled onto the ration during mixing, immediately before each feeding. Dry matter intake, nutrient digestibility, milk yield, and composition were not affected by treatments. Cows fed 1-propanol had greater concentrations of 1-propanol in the rumen fluid, higher concentration of glucose, and lower concentration of non-esterified fatty acids in blood plasma. Corn silage inoculated with L. buchneri at 1 × 105 cfu/g does not affect silage fermentation, ruminal fermentation profile, or milk production. Supplementation of 1-propanol at 10 g/kg affects the ruminal fermentation profile without affecting feed intake and milk production of mid-lactating dairy cows.

摘要 本研究旨在评估添加1-丙醇或接种布氏乳杆菌（L. buchneri）的玉米青贮对泌乳荷斯坦奶牛瘤胃发酵特性、养分消化率及生产性能的影响。整株玉米于干物质（Dry Matter, DM）含量为350 g/kg时收获，分装至9个袋式青贮窖（每窖13吨）。青贮制作时设置两组处理：对照组（无添加剂，共6个青贮窖）和接种1×10^5 cfu/g布氏乳杆菌组（共3个青贮窖）。青贮储存247天后开始饲喂；每个试验周期内打开1个布氏乳杆菌组青贮窖与2个对照组青贮窖。选取21头经产荷斯坦奶牛（日均产奶量约33 kg），采用7个平衡的3×3拉丁方试验设计，试验周期为21天（其中14天为适应期）。试验日粮以干物质计组成如下：棉籽80 g/kg、柑橘粕95 g/kg、豆粕180 g/kg、粉碎玉米籽粒90 g/kg、矿物维生素预混料25 g/kg，以及玉米青贮530 g/kg。各试验组间唯一差异为玉米青贮来源：对照组青贮、布氏乳杆菌接种青贮，或添加1-丙醇的对照组青贮（添加量为日粮干物质的10 g/kg）。1-丙醇以1:1比例溶于水，于每次饲喂前混合日粮时喷淋至饲粮中。试验结果显示，各处理对干物质采食量、养分消化率、产奶量及乳成分均无显著影响。饲喂1-丙醇组奶牛的瘤胃液中1-丙醇浓度更高，血浆葡萄糖浓度升高，而非酯化脂肪酸浓度降低。以1×10^5 cfu/g剂量接种布氏乳杆菌的玉米青贮，对青贮发酵、瘤胃发酵特性及产奶性能均无影响。以日粮干物质10 g/kg的剂量添加1-丙醇，可改变泌乳中期奶牛的瘤胃发酵特性，但不影响采食量与产奶性能。