Aldrich C G, Merchen N R, Drackley J K, Fahey G C, Berger L L
Department of Animal Sciences, University of Illinois, Urbana 61801, USA.
J Anim Sci. 1997 Feb;75(2):512-21. doi: 10.2527/1997.752512x.
To determine the effect of alkaline hydrogen peroxide treatment of whole canola seed on milk fatty acid composition, 12 multiparous lactating Holstein cows (618 kg, 47 d in milk) were fed total mixed rations in a replicated (3) 4 x 4 Latin square designed experiment. The control diet contained no supplemental fat source. Canola seed (11.2%), either crushed or treated with alkaline hydrogen peroxide or Megalac (5.6%) were supplemental fat sources in the crushed, treated, and calcium salts of long-chain fatty acids (Ca-LCFA) dietary treatments. Experimental periods consisted of 28 d, with 21 d of adaptation to diets and 7 d for data collection. Cows were offered ad libitum access to feed. Intakes, ruminal characteristics, and total tract apparent digestibilities were measured and are discussed. Production of milk and 4% fat-corrected milk were not different among treatment groups (average 35.0 and 32.8 kg/d, respectively). Milk fat percentages were greater (P = .02) for cows fed treated canola seed or Ca-LCFA than for cows fed crushed canola seed (average 3.71 vs 3.43%, respectively), but milk fat yield (kg/d) was unaffected. Cows fed fat-supplemented diets had lower milk protein percentages than cows fed the control diet. Within the fat-supplemented diet groups, cows fed crushed canola seed had greater milk protein percentages (P = .01) and yields (P < .01) than cows fed treated canola or Ca-LCFA. Milk fat from cows fed diets supplemented with canola seed (treated or crushed) had lower proportions of 14:0 and 16:0 and greater proportions of 18:0 and 18:1 than milk fat from cows fed the control or Ca-LCFA diets. Intakes, milk production, milk composition, and milk fatty acid profiles substantiate that treated canola seed was utilized by cows to an extent similar to that of crushed canola seed. Further definition of the method for treatment of canola seed may provide a strategy for adding higher levels of monounsaturated fatty acids to lactation diets to produce favorable alterations in milk fat composition.
为了确定碱性过氧化氢处理全油菜籽对牛奶脂肪酸组成的影响，在一项重复（3次）的4×4拉丁方设计实验中，给12头经产泌乳荷斯坦奶牛（体重618千克，产奶47天）投喂全混合日粮。对照日粮不含补充脂肪源。在粉碎、处理和长链脂肪酸钙盐（Ca-LCFA）日粮处理中，油菜籽（11.2%），无论是粉碎的、经碱性过氧化氢处理的还是添加了美加力（5.6%）的，均作为补充脂肪源。实验期为28天，其中21天用于适应日粮，7天用于数据收集。给奶牛提供不限量的饲料。测量并讨论了采食量、瘤胃特征和全消化道表观消化率。各处理组间的牛奶和4%脂肪校正乳产量无差异（平均分别为35.0和32.8千克/天）。饲喂经处理油菜籽或Ca-LCFA的奶牛的乳脂率高于饲喂粉碎油菜籽的奶牛（P = 0.02）（平均分别为3.71%和3.43%），但乳脂产量（千克/天）不受影响。饲喂补充脂肪日粮的奶牛的乳蛋白率低于饲喂对照日粮的奶牛。在补充脂肪的日粮组中，饲喂粉碎油菜籽的奶牛的乳蛋白率（P = 0.01）和产量（P < 0.01）高于饲喂经处理油菜籽或Ca-LCFA的奶牛。与饲喂对照或Ca-LCFA日粮的奶牛的乳脂相比，饲喂补充油菜籽（处理的或粉碎的）日粮的奶牛的乳脂中14:0和16:0的比例较低，18:0和18:1的比例较高。采食量、产奶量、乳成分和乳脂肪酸谱证实，奶牛对经处理油菜籽的利用率与粉碎油菜籽的利用率相似。对油菜籽处理方法的进一步明确可能为在泌乳日粮中添加更高水平的单不饱和脂肪酸以改善乳脂成分提供一种策略。
