Ebert-Allen R A, Willis G M, Drackley J K
Department of Animal Sciences, University of Illinois Urbana-Champaign, Urbana 61801.
Milk Specialties Global, Eden Prairie, MN 55344.
JDS Commun. 2022 Feb 10;3(2):110-113. doi: 10.3168/jdsc.2021-0180. eCollection 2022 Mar.
Glycerol (glycerin) is increasingly available from biodiesel manufacture and edible oil refining and it has been used successfully in diets for chickens, pigs, and adult cattle; however, less information is available on its nutritional value in young calves. Our objective was to determine the effects on calf growth and health when glycerol replaced a portion of lactose in milk replacer. Holstein calves (12 male, 12 female) born at the University of Illinois dairy unit were assigned alternately to 1 of 2 treatments (24 calves total): control milk replacer or milk replacer supplemented with 15% glycerol in replacement of lactose. The experimental base milk replacer contained greater protein, fat, minerals, and vitamins so that when glycerol was added, the composition would be the same as that of the control, except that glycerol replaced some lactose. Calves were housed in individual hutches bedded with straw, and water was freely available. Starter was offered beginning on d 36. The amount of milk replacer offered was reduced by half on d 43, and calves were weaned at d 49. Calves were fed milk replacers twice daily from d 3 of life. Milk replacers contained 28% protein (all from whey proteins), 2.6% lysine, and 15% fat. Control milk replacer contained 40% lactose, and the glycerol milk replacer contained 25% lactose. Both replacers were reconstituted to 15% solids. Glycerol (liquid) was added to reconstituted base milk replacer at each feeding. During wk 1, milk replacers were fed at a rate of 0.25 Mcal/kg of metabolic body weight (BW) (about 1.5% of BW daily as powder, or approximately 675 g/d) and from wk 2 to 6 at 0.30 Mcal/kg of metabolic BW (about 2% of BW daily, or approximately 900 to 1,200 g/d). Measurements of BW and stature were made weekly through d 56. Calf BW and average daily gain through d 35 (0.66 vs. 0.65 kg/d for controls and glycerol, respectively) did not differ significantly between treatments. Stature measurements (withers height, body length, heart girth) and measures of health (fecal scores, medical treatments) did not differ between treatments. Under the conditions of this experiment, glycerol was an acceptable replacement for at least 37.5% of the total lactose in milk replacer (15% of the formula) if economically favorable.
甘油（丙三醇）在生物柴油生产和食用油精炼过程中的产量日益增加，并且已成功应用于鸡、猪和成年牛的日粮中；然而，关于其在犊牛幼崽中的营养价值的信息较少。我们的目标是确定用甘油替代代乳粉中一部分乳糖对犊牛生长和健康的影响。伊利诺伊大学奶牛场出生的荷斯坦犊牛（12头雄性，12头雌性）被交替分配到两种处理方式中的一种（共24头犊牛）：对照代乳粉或添加15%甘油以替代乳糖的代乳粉。实验用的基础代乳粉含有更高的蛋白质、脂肪、矿物质和维生素，因此添加甘油后，其成分与对照代乳粉相同，只是甘油替代了一些乳糖。犊牛被安置在铺有稻草的单独畜栏中，可自由饮水。从第36天开始提供开食料。第43天，代乳粉的供应量减少一半，犊牛在第49天断奶。从出生第3天起，犊牛每天喂两次代乳粉。代乳粉含有28%的蛋白质（全部来自乳清蛋白）、2.6%的赖氨酸和15%的脂肪。对照代乳粉含有40%的乳糖，甘油代乳粉含有25%的乳糖。两种代乳粉均调配成15%的固形物含量。每次喂食时，将甘油（液体）添加到调配好的基础代乳粉中。在第1周，代乳粉的喂食量为0.25兆卡/千克代谢体重（BW）（约为体重的1.5%，以粉末形式计，即约675克/天），从第2周到第6周为0.30兆卡/千克代谢体重（约为体重的2%，即约900至1200克/天）。在第56天前每周测量体重和体高。在第35天前，犊牛的体重和平均日增重（对照和甘油组分别为0.66和0.65千克/天）在两种处理方式之间没有显著差异。体高测量值（鬐甲高、体长、胸围）和健康指标（粪便评分、医疗处理）在两种处理方式之间也没有差异。在本实验条件下，如果经济上可行，甘油可作为代乳粉中至少37.5%的总乳糖（配方的15%）的可接受替代品。
