Mahan D C, Carter S D, Cline T R, Hill G M, Kim S W, Miller P S, Nelssen J L, Stein H H, Veum T L
The Ohio State University, Columbus 43210, USA.
J Anim Sci. 2007 Sep;85(9):2190-7. doi: 10.2527/jas.2007-0118. Epub 2007 Apr 27.
Two experiments were conducted to evaluate dietary fortification levels of a B vitamin pre-mix for starter and grower-finisher pigs on subsequent performance responses. The objective was to determine whether the modern pig requires higher dietary levels of B vitamins than estimated by the NRC (1998). Both experiments added fat-soluble vitamins at the requirement levels (NRC, 1998) in all diets, whereas the B vitamins were added at 0, 100, 200, or 400% of the total NRC (1998) requirement levels for the starter and grower pig. Indigenous vitamin contributions from the feed grains were not included in the estimates. Each station used the same vitamin premixes but incorporated its own grain sources in the diets. The first experiment was conducted across 7 stations (Indiana, Ohio, Oklahoma, Michigan, Missouri, Nebraska, Texas) and involved 660 pigs in a randomized complete block design in 30 replicates. Complex nursery diets were fed in 2 phases. The first phase (0 to 14 d postweaning) and second phase (15 to 35 d postweaning) diets were formulated to Lys (total) levels of 1.50 and 1.30%, respectively. The results demonstrated no performance response to addition of B vitamins from 0 to 14 d post-weaning, but performances increased quadratically (P < 0.01) to the 100% NRC level from 14 to 35 d postweaning and for the overall 35-d period. The second experiment was conducted across 3 stations (Ohio, Nebraska, and South Dakota) and involved 216 pigs in a randomized complete block design in 10 replicates. Corn-soybean meal mixtures were fed in 3 phases formulated to total Lys levels of 1.30% (23 to 55 kg of BW), 1.00% (55 to 85 kg of BW), and 0.78% (85 to 120 kg of BW). Pig performances increased (P < 0.01) to the 100% B vitamin level from 23 to 85 kg of BW, but there was no response to any level from 85 to 120 kg of BW. Carcass measurements demonstrated a greater LM area (P < 0.01) and a lower backfat depth (P < 0.01) to the 100% B vitamin level. One station evaluated an additional treatment (3 replicates) in which each replicate was fed a fifth diet containing the 100% dietary level of B vitamins from 23 to 85 kg of BW whereupon the B vitamins were removed from 85 to 120 kg of BW. This removal did not reduce pig performance responses for the final period or for the overall period. The results demonstrated that supplementation of B vitamins at the 100% total NRC levels for starter and grower pigs was sufficient to meet their needs, and there was no further improvement to or deleterious effect to greater dietary levels.
进行了两项试验，以评估预混B族维生素对仔猪和生长育肥猪的日粮强化水平及其后续生产性能反应。目的是确定现代猪是否需要比NRC（1998）估计的更高的日粮B族维生素水平。两项试验在所有日粮中均按需求水平（NRC，1998）添加了脂溶性维生素，而B族维生素则按仔猪和生长猪NRC（1998）总需求水平的0、100、200或400%添加。估计中未包括谷物饲料中天然维生素的贡献。每个试验站使用相同的维生素预混料，但日粮中使用各自的谷物来源。第一项试验在7个试验站（印第安纳州、俄亥俄州、俄克拉何马州、密歇根州、密苏里州、内布拉斯加州、得克萨斯州）进行，采用随机完全区组设计，涉及660头猪，共30个重复。复杂的保育日粮分两阶段饲喂。第一阶段（断奶后0至14天）和第二阶段（断奶后15至35天）日粮的赖氨酸（总）水平分别配制为1.50%和1.30%。结果表明，断奶后0至14天添加B族维生素对生产性能无影响，但断奶后14至35天以及整个35天期间，生产性能随B族维生素添加量增加呈二次曲线上升（P<0.01），至100%NRC水平时达到最高。第二项试验在3个试验站（俄亥俄州、内布拉斯加州和南达科他州）进行，采用随机完全区组设计，涉及216头猪，共10个重复。玉米-豆粕型日粮分三个阶段饲喂，赖氨酸总水平分别为1.30%（体重23至55千克）、1.00%（体重55至85千克）和0.78%（体重85至120千克）。体重23至85千克阶段，猪的生产性能随B族维生素添加量增加而提高（P<0.01），至100%B族维生素水平时达到最高，但体重85至120千克阶段，对任何添加水平均无反应。胴体测量结果表明，100%B族维生素水平组的背最长肌面积更大（P<0.01），背膘厚更低（P<0.01）。一个试验站评估了一项额外处理（3个重复），即每个重复从体重23至85千克阶段开始饲喂含100%日粮水平B族维生素的第五种日粮，然后从体重85至120千克阶段开始不再添加B族维生素。这种处理对最后阶段或整个期间的猪生产性能反应没有降低作用。结果表明，仔猪和生长猪日粮中添加100%NRC总水平的B族维生素足以满足其需求，更高的日粮水平对生产性能没有进一步改善作用，也没有有害影响。
