Hachemi Mohammed A, Sexton Jessica R, Briens Mickael, Whitehouse Nancy L
Adisseo France S.A.S., 10, Place du Général de Gaulle, 92160 Antony, France.
Department of Agriculture, Nutrition, and Food Systems, University of New Hampshire, Durham 038224.
J Dairy Sci. 2023 Apr;106(4):2374-2385. doi: 10.3168/jds.2022-22323. Epub 2023 Mar 7.
In this study, we aimed to determine the amount of Se transferred to milk and blood of mid- to late-lactation dairy cows when supplemental Se from hydroxy-selenomethionine (OH-SeMet) was fed compared with an unsupplemented group and a group supplemented with a seleno-yeast (SY). Twenty-four lactating Holstein cows (178 ± 43 d in milk) were used in a complete randomized block design for 91 d (7-d covariate period and 84-d treatment period). Treatments were (1) basal diet with an analyzed Se background of 0.2 mg of Se per kg as-fed (control); (2) basal diet + 0.3 mg of Se/kg as-fed from SY (SY-0.3); (3) basal diet + 0.1 mg of Se/kg as-fed from OH-SeMet (OH-SeMet-0.1); and (4) basal diet + 0.3 mg of Se/kg as-fed from OH-SeMet (OH-SeMet-0.3). During the trial, plasma and milk were analyzed for total Se, and plasma was analyzed for glutathione peroxidase activity. The mean plasma and milk Se concentrations exhibited the same relationship, where OH-SeMet-0.3 resulted in the highest values (142 µg/L of plasma and 104 µg/kg of milk), followed by SY-0.3 (134 µg/L and 85 µg/kg), OH-SeMet-0.1 (122 µg/L and 67 µg/kg), and the control group had the lowest values (120 µg/L and 50 µg/kg). The increment of Se in milk induced by OH-SeMet-0.3 (+54 µg/kg) was 54% higher than that induced by SY-0.3 (+35 µg/kg). Additionally, dietary supplementation of 0.2 mg/kg Se from OH-SeMet in the total mixed ration was estimated to be similar to 0.3 mg/kg Se from SY in the total mixed ration when considering the level of Se in the milk. There was no difference in plasma glutathione peroxidase activity between groups; however, OH-SeMet-0.3 significantly decreased somatic cell count. The results confirmed that supplementation with organic Se increases milk and plasma Se concentrations. Moreover, when administered at the same level of supplementation, OH-SeMet was shown to be more efficient than SY in improving milk quality by increasing Se content and decreasing milk somatic cell count.
在本研究中，我们旨在确定与未补充组和补充硒酵母（SY）的组相比，给泌乳中期至后期的奶牛饲喂羟基硒代蛋氨酸（OH-SeMet）补充硒时，转移到牛奶和血液中的硒量。24头泌乳荷斯坦奶牛（产奶178±43天）采用完全随机区组设计，为期91天（7天协变量期和84天治疗期）。处理方式为：（1）基础日粮，实测硒背景为每千克风干日粮含0.2毫克硒（对照组）；（2）基础日粮+每千克风干日粮添加0.3毫克硒的SY（SY-0.3）；（3）基础日粮+每千克风干日粮添加0.1毫克硒的OH-SeMet（OH-SeMet-0.1）；（4）基础日粮+每千克风干日粮添加0.3毫克硒的OH-SeMet（OH-SeMet-0.3）。在试验期间，分析血浆和牛奶中的总硒含量，并分析血浆中的谷胱甘肽过氧化物酶活性。血浆和牛奶中硒的平均浓度呈现相同的关系，其中OH-SeMet-0.3组的值最高（血浆中142微克/升，牛奶中104微克/千克），其次是SY-0.3组（134微克/升和85微克/千克），OH-SeMet-0.1组（122微克/升和67微克/千克），对照组的值最低（120微克/升和50微克/千克）。OH-SeMet-0.3组使牛奶中硒增加量（+54微克/千克）比SY-0.3组（+35微克/千克）高54%。此外，考虑到牛奶中的硒水平，在全混合日粮中添加0.2毫克/千克硒的OH-SeMet估计与添加0.3毫克/千克硒的SY效果相似。各组之间血浆谷胱甘肽过氧化物酶活性没有差异；然而，OH-SeMet-0.3组显著降低了体细胞计数。结果证实，补充有机硒可提高牛奶和血浆中的硒浓度。此外，在相同补充水平下，OH-SeMet在增加硒含量和降低牛奶体细胞计数方面比SY更有效地改善了牛奶质量。
