PDF(Pubmed)
Abstract：
This study investigated the effect of feeding seaweed (Ascophyllum nodosum) to dairy cows on milk mineral concentrations, feed-to-milk mineral transfer efficiencies, and hematological parameters. Lactating Holstein cows (n = 46) were allocated to 1 of 2 diets (n = 23 each): (1) control (CON; without seaweed) and (2) seaweed (SWD; replacing 330 g/d of dried corn meal in CON with 330 g/d dried A. nodosum). All cows were fed the CON diet for 4 wk before the experiment (adaptation period), and animals were then fed the experimental diets for 9 wk. Samples included sequential 3-wk composite feed samples, a composite milk sample on the last day of each week, and a blood sample at the end of the study. Data were statistically analyzed using a linear mixed effects model with diet, week, and their interaction as fixed factors; cow (nested within diet) as a random factor; and data collected on the last day of the adaptation period as covariates. Feeding SWD increased milk concentrations of Mg (+6.6 mg/kg), P (+56 mg/kg), and I (+1,720 μg/kg). It also reduced transfer efficiency of Ca, Mg, P, K, Mn, and Zn, and increased transfer efficiency of Mo. Feeding SWD marginally reduced milk protein concentrations, whereas there was no effect of SWD feeding on cows\' hematological parameters. Feeding A. nodosum increased milk I concentrations, which can be beneficial when feed I concentration is limited or in demographics or populations with increased risk of I deficiency (e.g., female adolescents, pregnant women, nursing mothers). However, care should also be taken when feeding SWD to dairy cows because, in the present study, milk I concentrations were particularly high and could result in I intakes that pose a health risk for children consuming milk.
摘要：
这项研究调查了向奶牛饲喂海藻（结鞘草）对牛奶矿物质浓度的影响，饲料到牛奶的矿物质转移效率和血液学参数。将泌乳的荷斯坦奶牛（n=46）分配给2种饮食之一（每个n=23）：（i）对照（CON；无海藻），和（ii）海藻（SWD；用330g/d干燥的结节A.nodosum代替CON中的330g/d干燥的玉米粉）。在实验之前(适应期),将所有母牛饲喂CON饮食4周;然后将动物饲喂实验饮食9周。样品包括连续3周的复合饲料样品，每周最后一天的复合牛奶样本，研究结束时的血液样本。使用饮食的线性混合效应模型对数据进行统计分析，week,以及它们作为固定因素的相互作用；牛（嵌套在饮食中）作为随机因素，在适应期的最后一天收集的数据作为协变量。饲喂SWD增加了Mg的牛奶浓度（6.6mg/kg），P（+56mg/kg），和I(+1720μg/kg)。它也降低了Ca的转移效率，Mg,P,K,Mn,Zn,提高了Mo的转移效率。饲喂SWD略微降低了牛奶蛋白浓度，而SWD饲喂对奶牛血液学参数没有影响。饲喂A.nodosum增加了牛奶的浓度，当饲料I浓度有限或在人口统计或I缺乏风险增加的人群中(例如，青少年女性,孕妇,哺乳母亲)。然而,在给奶牛喂食SWD时也应该小心，因为，在本研究中，牛奶I浓度特别高，可能导致I摄入量对食用牛奶的儿童构成健康风险。
