Variation of serum selenium concentrations in German sheep flocks and implications for herd health management consultancy

Abstract

BackgroundThis study was performed to demonstrate the widespread distribution and severity of selenium (Se) deficiency in sheep flocks and to evaluate the impact of influencing factors. In 150 flocks, ten serum samples of adult ewes were analysed for Se concentration. The farmers were interviewed concerning flock size, provision of mineral supplement, predominant form of husbandry (stationary fenced pasture/transhumance), predominant form of water provision (tap water/well/surface water) and predominant soil (sandy, silty/loamy, clay) in the area. The location of the flock was recorded as well as the production stage/season at the time of sampling. Intra-group variation and the validity to analyse pooled samples were tested.ResultsPools of five samples correlated well with the mean of individually analysed samples. The intra-group range of serum Se concentration varied enormously (mean 45.4 ± 18.8 μg Se/l). About 60% of the flocks showed mean serum Se concentrations below 80 μg/l, 37.4% were below 60 μg Se/l, representing a Se deficient stage. Using mineral supplement in general was no key factor for Se status. Stationary flocks on fenced pasture had constantly higher mean serum Se concentrations during breeding (outdoors, August-November), lambing (mainly indoors, December-March) and lactation (outdoors, April-July), whereas flocks practising transhumance had significantly lower Se status, except during lambing. There was no significant correlation between the soil type and the Se status, but flocks in Southern Germany tend to show a lower Se status compared to Central and Northern Germany. Increasing flock size was associated with lower mean serum Se concentrations. In stationary flocks only, the use of surface water was accompanied by significantly lower Se status.ConclusionSe deficiency is widespread in German sheep flocks. More than one third of the flocks showed Se deficiency, indicating the need to optimise the nutritional management. Factors raising suspicion of Se deficiency are large flocks, transhumance during lactation and the breeding season as well as surface water provision in stationary flocks.

The effect of organic selenium in feeding of ewes in late pregnancy on selenium transfer to progeny

“…Similar results were reported by Kurt et al (2001), who observed that blood Se levels of Akkaraman sheep in the Diyarbakır region (southeast of Anatolia) were 46-65 ng/mL. These results are similar to the findings reported by Kurt et al (2001) in the current trial, although the results of these authors were higher than those seen in a Polish research, in which the serum Se level of sheep was 31 ng/mL (Pılarczyk et al, 2004), or the Iranian trial with 28 ng/mL (Karimi-Poor et al, 2011), or the German trial, which showed 45 ng/mL (Humann-Ziehank et al, 2013). Øvernes et al (1985) reported that plasma Se concentration of sheep should be 150-350 ng/mL, as white muscle disease is seen when it is below 100 ng/mL.…”

Effect of Long-Acting Selenium Preparation on Health and Productivity of Sheep

“…Serum Se levels of 25–50 μg/L are considered insufficient, while the optimal value falls between 120 and 150 μg/L [ 39 ]. Low concentrations of this microelement were also noted in sheep by Humann-Ziehank et al [ 40 ] and Milewski et al [ 30 ], who reported an average serum Se level of 45.4 and 48.70 µg/L, respectively. Much lower results were obtained by Pilarczyk et al [ 41 ] and Karimi-Poor et al [ 42 ], 13 µg/L and 28 µg/L, respectively.…”

Selenium, copper and iron in veterinary medicine—From clinical implications to scientific models

“…Subsequently, a nation-wide survey on farmed sheep revealed more than one third of the German sheep flocks showing Se deficiency. The intra-group range of serum Se concentration varied enormously, the main factors for low Se status were large flocks, shepherding/transhumance and outdoor seasons leading to the suspicion of a high impact of the nutritional management to ensure mineral supplementation of all individuals consistently [95].…”