Heemstra J M, Kronberg S L, Neiger R D, Pruitt R J
Department of Animal and Range Sciences, South Dakota State University, Brookings 57007-0392, USA.
J Anim Sci. 1999 Mar;77(3):600-10. doi: 10.2527/1999.773600x.
Yearling cattle (n = 25; 416.1 +/- 25.9 kg) were stratified by weight and gender across five groups. Group 1 (OAT) was offered oat/rape haylage (ORH) for ad libitum consumption during two daily feeding periods. Group 2 (SPURGE) was offered leafy spurge/grass haylage (LSGH) for ad libitum consumption during the same feeding periods. Group 3 was offered ORH in an amount equal to the average amount of LSGH consumed by SPURGE at the previous feeding. Group 4 (MIX) was offered LSGH mixed with ORH for ad libitum consumption during the two feeding periods. Group 5 (PAIR) received the equivalent amount of ORH consumed by MIX at the previous feeding. The DMI for OAT, SPURGE, and MIX were similar at the first feeding (P = .52). The SPURGE group consumed very little LSGH thereafter and was removed from the trial. The OAT and MIX groups consumed similar amounts of DM daily on d 1 to 4 when the ration offered to MIX was only 7% LSGH (P = .33). When LSGH made up > or = 21% of the mixture (d 7 to 32), the OAT group consumed more daily DM than did MIX (P < .05). The spurge/oatlage ration offered to MIX was less digestible than the oatlage-only ration offered to PAIR (P < or = .01). Even though blood chemistry did not indicate that LSGH consumption caused organ damage, its intake caused minor alterations (P < or = .05) in serum albumin, calcium, gamma glutamyltransferase, P, K, and urea nitrogen. No gross or microscopic lesions, infectious agents, or significant numbers of parasites were detected in any of the carcasses or tissues examined. The MIX group had diarrhea for much of the trial. In Trial 2, five yearling cattle were adapted to a mixture of 21% LSGH and 79% ORH. Then they were simultaneously offered three mixtures of spurge and oat haylages: 1) spurge ensiled with a microbial inoculant (LSGH); 2) spurge ensiled with the same inoculant and a cellulolytic/hemicellulolytic enzyme (ENZ); and 3) spurge ensiled with the same inoculant and molasses (MOL). The mixture with ENZ was preferred over those with MOL or LSGH (P < .001), but the amounts consumed were low and similar to those for LSGH-ORH in Trial 1 when amounts of ENZ and LSGH in the mixtures were similar. The ENZ mixture may have been more palatable than LSGH and MOL because it had less (P < .05) lactic acid, but intake of ENZ indicates that it had aversive characteristics, like LSGH. Ensiling leafy spurge did little, if anything, to improve its palatability to cattle.
一岁龄牛（n = 25；体重416.1±25.9千克）按体重和性别分为五组。第1组（燕麦组）在每日两次的喂食期间提供燕麦/油菜青贮料（ORH），任其自由采食。第2组（大戟组）在相同的喂食期间提供叶状大戟/禾本科青贮料（LSGH），任其自由采食。第3组提供的ORH量与大戟组在前一次喂食时消耗的LSGH平均量相等。第4组（混合组）在两次喂食期间提供混合了LSGH和ORH的饲料，任其自由采食。第5组（配对组）在前一次喂食时接受与混合组消耗的ORH等量的饲料。第一次喂食时，燕麦组、大戟组和混合组的干物质采食量相似（P = 0.52）。此后大戟组消耗的LSGH很少，因此退出试验。当提供给混合组的日粮中LSGH仅占7%时，燕麦组和混合组在第1至4天的每日干物质消耗量相似（P = 0.33）。当LSGH占混合物的比例≥2l%时（第7至32天），燕麦组每日消耗的干物质比混合组多（P < 0.05）。提供给混合组的大戟/燕麦青贮料日粮的消化率低于提供给配对组的仅燕麦青贮料日粮（P≤0.01）。尽管血液生化指标未表明消耗LSGH会导致器官损伤，但它的摄入导致血清白蛋白、钙、γ-谷氨酰转移酶、磷、钾和尿素氮出现轻微变化（P≤0.05）。在检查的任何胴体或组织中均未检测到肉眼可见或微观的病变、传染因子或大量寄生虫。混合组在试验的大部分时间里都有腹泻症状。在试验2中，五头一岁龄牛适应了含21% LSGH和79% ORH的混合物。然后同时给它们提供三种大戟和燕麦青贮料的混合物：1）用微生物接种剂青贮的大戟（LSGH）；2）用相同接种剂和纤维素/半纤维素酶青贮的大戟（ENZ）；3）用相同接种剂和糖蜜青贮的大戟（MOL）。与含MOL或LSGH的混合物相比，含ENZ的混合物更受青睐（P < 0.001），但消耗量较低，且当混合物中ENZ和LSGH的量相似时，与试验1中含LSGH - ORH的情况相似。含ENZ的混合物可能比LSGH和MOL更可口，因为它的乳酸含量较少（P < 0.05），但ENZ的摄入量表明它具有与LSGH类似的令人厌恶的特性。青贮叶状大戟对提高其对牛的适口性作用甚微。
