Kommisrud E, Osterås O, Vatn T
Geno Breeding and AI Association, Hamar, Norway.
Acta Vet Scand. 2005;46(4):229-40. doi: 10.1186/1751-0147-46-229.
A survey of blood selenium (Se) concentrations in Norwegian Red heifers and dry period cows was conducted to reveal possible association to management, feeding, health and fertility. Selenium contents were determined in 254 herd blood samples consisting of pooled samples from individual non-lactating animals from herds in 5 counties. The Se concentrations showed a normal distribution with mean 0.09 microg Se/g blood, with a standard deviation (SD) of 0.05, and ranged from 0.02 to 0.23 microg/g, with 50 % of the samples being between 0.06 and 0.11 microg/g. The herds with Se concentrations below 0.06 microg/g were smaller (21.4 +/- 8.7 cow-years) than those with Se levels above 0.11 microg/g (27.5 +/- 14.1 cow-years) (P<0.01), but there were no differences in milk yield, incidence of replacement, proportion of animal culling, amount of concentrate or grass silage as percentage of energy consumption between the groups. Treatment registration records showed a tendency that more animals in the low Se herds were treated for all the diseases included in this investigation (64.8 animals per 100 cow-years) than those in the high Se herds (57.5 per 100 cow-years), while no such differences were revealed for individual disorders. There was, however, a significant difference in bulk milk somatic cell counts (BMSCC) between low and high Se herds, their values being 137 000 and 155 000 cells/ml, respectively. This difference was significantly influenced by herd size. Furthermore, a total of 4916 lactations were analyzed from individual health and fertility recordings, including 2 934 first lactations and 1 982 later lactations. The present study revealed a reduced incidence of disease treatment with increased Se concentrations from 0.02 to 0.23 microg Se/g blood. In this regard, there seemed to be an optimum of 0.10 to 0.15 microg Se/g for all types of mastitis treatments summarized, and for treatment of retained placenta. Thus, herd Se concentrations below and above these values was connected with increased probability for sum mastitis and retained placenta, reflecting the effect of the quadratic term of Se. The cow (composite) milk somatic cell count (SCC) was lower in lactations from low Se herds than in high Se herds with a marked SCC increase in the Se concentration interval from 0.11-0.13 microg/g blood. In conclusion, heifers and dry period cows in Norway are low in blood Se content and there seems to be a positive association between increased blood Se concentration pre partum and decreased incidence of mastitis, ovarian cysts and anoestrus/silent oestrus post partum.
对挪威红牛小母牛和干奶期奶牛的血液硒（Se）浓度进行了一项调查，以揭示其与管理、饲养、健康和繁殖力之间可能存在的关联。测定了来自5个县各牛群中个体非泌乳动物的混合样本组成的254份牛群血液样本中的硒含量。硒浓度呈正态分布，平均为0.09微克硒/克血液，标准差（SD）为0.05，范围为0.02至0.23微克/克，50%的样本在0.06至0.11微克/克之间。硒浓度低于0.06微克/克的牛群规模较小（21.4±8.7母牛年），低于硒水平高于0.11微克/克的牛群（27.5±14.1母牛年）（P<0.01），但两组之间在产奶量、更替发生率、动物淘汰比例、精饲料量或青贮草占能量消耗的百分比方面没有差异。治疗登记记录显示，低硒牛群中因本研究涵盖的所有疾病接受治疗的动物似乎比高硒牛群更多（每100母牛年64.8头）（每100母牛年57.5头），而个别疾病未显示出此类差异。然而，低硒和高硒牛群之间的全脂牛奶体细胞计数（BMSCC）存在显著差异，其值分别为137000和155000个细胞/毫升。这种差异受牛群规模的显著影响。此外，从个体健康和繁殖记录中分析了总共4916次泌乳，包括2934次一胎泌乳和1982次后续泌乳。本研究表明，随着血液硒浓度从0.02微克硒/克增加到0.23微克硒/克，疾病治疗发生率降低。在这方面，对于总结的所有类型的乳腺炎治疗以及胎盘滞留的治疗，似乎存在0.10至0.15微克/克的最佳值。因此，低于和高于这些值的牛群硒浓度与乳腺炎总和和胎盘滞留的概率增加有关，反映了硒二次项的影响。低硒牛群泌乳期的奶牛（综合）牛奶体细胞计数（SCC）低于高硒牛群，在血液硒浓度区间0.11 - 0.13微克/克时SCC显著增加。总之，挪威的小母牛和干奶期奶牛血液硒含量较低，产前血液硒浓度升高与产后乳腺炎、卵巢囊肿和发情异常/安静发情发生率降低之间似乎存在正相关。
