Farran T B, Reinhardt C D, Blasi D A, Minton J E, Elsasser T H, Higgins J J, Drouillard J S
Department of Animal Sciences and Industry, Kansas State University, Manhattan 66506-1600, USA.
J Anim Sci. 2008 Jun;86(6):1382-94. doi: 10.2527/jas.2007-0116. Epub 2008 Mar 14.
Five studies were conducted to evaluate the effects of lipid source on performance and health of stressed feeder cattle. A total of 332 heifers (195 +/- 2.37 kg initial BW) in trial 1 and 336 heifers (206 +/- 1.70 kg initial BW) in trial 2 were fed diets containing ground flaxseed (FLAX), rolled full-fat soybeans (SOY), or tallow (TAL) at 13, 20, or 4%, respectively (DM basis). All diets were formulated to be isonitrogenous and isocaloric. The ADG and G:F for the first 7 d and for the entire feeding period were greater (P < 0.05) for TAL and FLAX than for SOY. Percentage of animals treated and retreated for bovine respiratory disease did not differ among dietary treatments. The FLAX treatment increased (P < 0.05) total n-3 PUFA concentrations in the plasma, whereas SOY increased (P < 0.05) plasma concentrations of total n-6 PUFA. In trial 3, 18 steers were individually fed diets containing TAL and 18 steers were fed a diet containing SOY (20% of DM). In trials 4 and 5, 18 steers were individually fed diets containing TAL and 18 steers were fed diets containing FLAX (12.9% of DM). On d 14 and 17 of study 3, 4, and 5, 16 steers from each dietary treatment were injected i.v. with Escherichia coli O55:B5 lipopolysaccharide (LPS), and 2 steers from each diet were injected with saline. Rectal temperatures after LPS challenge were lower (P < 0.05) for SOY and FLAX than for TAL, and plasma TNF was greater (P < 0.05) for SOY than for TAL. Serum haptoglobin and blood fibrinogen increased and white blood cell count decreased in response to LPS, but none of these variables was affected by treatment. Although this research failed to measure an effect of lipid source on feedlot morbidity or mortality, these studies indicate that altering the source and type of dietary fatty acids may modify the immune response in stressed feeder cattle and that performance may be hindered by feeding full-fat soybeans to receiving cattle.
开展了五项研究，以评估脂肪来源对处于应激状态的育肥牛生长性能和健康状况的影响。试验1中共有332头小母牛（初始体重195±2.37千克），试验2中有336头小母牛（初始体重206±1.70千克），分别饲喂含13%、20%或4%（干物质基础）的磨碎亚麻籽（FLAX）、全脂大豆（SOY）或牛脂（TAL）的日粮。所有日粮均配制为等氮和等热的。在前7天和整个饲养期，TAL和FLAX组的平均日增重（ADG）和料重比（G:F）均高于SOY组（P<0.05）。不同日粮处理间，接受治疗和再次治疗的牛呼吸道疾病动物百分比无差异。FLAX处理使血浆中总n-3多不饱和脂肪酸（PUFA）浓度升高（P<0.05），而SOY使血浆中总n-6 PUFA浓度升高（P<0.05）。在试验3中，18头阉牛单独饲喂含TAL的日粮，18头阉牛饲喂含SOY（占干物质的20%）的日粮。在试验4和5中，18头阉牛单独饲喂含TAL的日粮，18头阉牛饲喂含FLAX（占干物质的12.9%）的日粮。在研究3、4和5的第14天和第17天，每种日粮处理的16头阉牛静脉注射大肠杆菌O55:B5脂多糖（LPS），每种日粮的2头阉牛注射生理盐水。LPS攻击后，SOY和FLAX组的直肠温度低于TAL组（P<0.05），SOY组的血浆肿瘤坏死因子（TNF）高于TAL组（P<0.05）。LPS刺激后，血清触珠蛋白和血纤维蛋白原增加，白细胞计数减少，但这些变量均不受处理的影响。尽管本研究未能测定脂肪来源对饲养场发病率或死亡率的影响，但这些研究表明，改变日粮脂肪酸的来源和类型可能会改变处于应激状态的育肥牛的免疫反应，并且给育肥牛饲喂全脂大豆可能会阻碍其生长性能。
