Robert Pieper

• PD Dr
• Head of Department (provisional) at Bundesinstitut für Risikobewertung

The study examined the vitamin A status in commercially managed suckler cows and lactating dairy cows and identified primary influencing factors. Liver retinyl ester concentrations were higher in multiparous than primiparous cows (p < 0.01). Pasture availability was associated with higher β-carotene concentrations (p < 0.001). In dairy cows, pastur...

Little is known about knowledge and perceptions of the public and farmers on livestock feed. However, it is important to know their perspectives to find widely accepted and sustainable solutions in agriculture, which account for animal welfare, societal expectations, economy and the environment alike. Therefore, the objective of the present study w...

The use of lead-based rifle bullets in hunting poses a risk to human and animal health when bullet fragments remain in the game meat. The objective of this study was to assess, for the first time, the number, size and spatial distribution of bullet fragments in game animals collectively and in three dimensions. Four roe deer (Capreolus capreolus) h...

The industrial hemp sector is growing and, in recent years, has launched many novel hemp-derived products, including animal feed. It is, however, unclear to what extent individual cannabinoids from industrial hemp transfer from the feed into products of animal origin and whether they pose a risk for the consumer. Here we present the results of a fe...

Per- and polyfluoroalkyl substances (PFAS) constitute a group of anthropogenic compounds that are ubiquitously distributed in the environment due to their widespread use in various industrial processes and consumer products. Among foodstuffs of animal origin, wild boar (Sus scrofa) livers may contain particularly high levels of PFAS. Additionally,...

The transformation of hypoglycin A (HGA), hypoglycin B (HGB), and methylene cyclopropyl glycine (MCPrG) in ruminal fluid batch cultures was investigated, and the effect of these toxins on the batch culture microorganisms using microbial metabolites was measured. An experiment was conducted using ovine ruminal fluid batch cultures and the ANKOM RF G...

Tansy ragwort (Senecio jacobaea L.) growing in animal pasture may pose a risk to humans due to the potential transfer of pyrrolizidine alkaloids (PAs) into food of animal origin. Here, we investigated what amount of PAs corresponds to the amount of ragwort consumed by sheep on a pasture and whether the ingested PAs are transferred into edible tissu...

Background: Methionine (Met) is a popular nutritional supplement in humans and animals. It is routinely supplemented to pigs as L-Met, DL-Met, or DL-2-hydroxy-4-(methylthio) butanoic acid (DL-HMTBA). Methods: We investigated the effect of these Met supplements on jejunal amino acid (AA) transport in male castrated Piétrain × Danbred pigs, also incl...

Hemp (Cannabis sativa L.) is an important source of fibre and seed oil and protein. By-products of industrial hemp fibre production, like hemp seeds and cakes, can be used as feed for all animal species as fat and protein source and the whole hemp plant (including stalk and leaves) might be a suitable fibre source for ruminants. However, a previous...

The microbiome of wild animals is believed to be co-evolved with host species, which may play an important role in host physiology. It has been hypothesized that the rigorous hygienic practices in combination with antibiotics and diets with simplified formulas used in the modern swine industry may negatively affect the establishment and development...

The microbiome of wild animals is believed to be co-evolved with host species, which may play an important role in host physiology. It has been hypothesized that the rigorous hygienic practice in combination with antibiotics and diets with simplified formulas used in the modern swine industry may negatively affect the establishment and development...

Dioxin-like polychlorinated biphenyls (dl-PCBs) as well as polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) are a major concern for food safety, especially in fat-containing foods of animal origin, such as milk. Due to the lipophilic character of PCDD/Fs and PCBs, it is of special interest to explore whether the metabolic state o...

Hypoglycin A (HGA), methylenecyclopropylglycine (MCPrG), hypoglycin B (HGB), and γ-glutamyl-α-(methylenecyclopropyl) glycine (γ-glutamyl-MCPrG) are secondary plant metabolites occurring in sycamore maple (Acer pseudoplatanus) as well as several other Sapindaceae (e.g., Blighia sapida). By interfering with energy metabolism, they may cause severe in...

Non-dioxin-like polychlorinated biphenyls (ndl-PCBs) are persistent environmental pollutants that accumulate in the tissues of exposed animals and humans. Contaminated feed can lead to ndl-PCB contaminated foods of animal origin; such foods are the main route of human exposure. Therefore, predicting ndl-PCB transfer from feed into animal products i...

Zusammenfassung Die ganzheitliche Betrachtung der Lebens- und Futtermittelsicherheit unter Einbeziehung der Tiergesundheit und der Umweltbedingungen ist eine wichtige Säule des One-Health-Ansatzes. Die Begrifflichkeit geht damit deutlich über die häufig darunter verstandene Vermeidung der Verbreitung von übertragbaren mikrobiologischen Krankheiten...

The use of enrichment and bedding materials in pig husbandry intends to comply with the animals' behavioural needs to perform natural exploratory behaviour, which is strongly connected to foraging behaviour. It can thus be assumed that pigs will ingest a certain material quantity possibly posing a risk to animal health and food safety as previous s...

Zusammenfassung Gegenstand und Ziel Die Körpertemperatur ist ein wichtiger Befund in der Beurteilung der Allgemeingesundheit von Tieren. Als „Goldstandard“ wird die Körperinnentemperatur rektal gemessen, was eine Fixierung der Tiere erfordert. Dies kann bei Tieren Stress erzeugen. Stress wird als Belastung der Tiere bewertet und kann zudem zu einer...

The German Total Diet Study (BfR MEAL Study) measured copper in 356 foods. In 105 of these foods copper was determined separately for conventionally and organically pooled samples. Mammalian liver, nuts, oilseeds, cocoa powder and chia seeds contained the highest copper levels. Organically produced foods tended to have higher levels compared to con...

Background Domestic pigs have an evolutionary conserved exploratory behaviour. To comply with this requirement, the European Union aims at setting standards for appropriate enrichment materials for pigs (Council Directive 2008/120/EC). As recommended characteristics include ‘chewable’ and ‘edible’, pigs might also consume these materials (Commissio...

Understanding the transfer of polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) as well as polychlorinated biphenyls (PCBs) from oral exposure into cow's milk is not purely an experimental endeavour, as it has produced a large corpus of theoretical work. This work consists of a variety of predictive toxicokinetic models in the rea...

Non-dioxin-like polychlorinated biphenyls (ndl-PCBs) are a subclass of persistent bioaccumulative pollutants able to enter the food chain. Toxicokinetic models for the transfer of the six ndl-PCB congeners (PCBs 28, 52, 101, 138, 153, and 180) from contaminated feed and soil into chicken eggs and meat are presented. Three independent controlled fee...

Polychlorinated dibenzo- p -dioxins (PCDDs) and dibenzofurans (PCDFs) (collectively and colloquially referred to as “dioxins”) as well as polychlorinated biphenyls (PCBs) are persistent and ubiquitous environmental contaminants that may unintentionally enter and accumulate along the food chain. Due to their chronic toxic effects in humans and bioac...

Currently, the authorisation procedure of trace elements as feed additives in the European Union according to Regulation (EC) No. 1831/2003 does not consider the bioavailability of trace element sources. This manuscript provides framework conditions for in vivo experiments that aim to estimate differences in the relative bioavailability between sup...

Understanding the transfer of non-dioxin-like polychlorinated biphenyls (ndl-PCBs) into foods of animal origin is crucial for human health risk assessment. In two experiments, we investigated the transfer of ndl-PCBs from contaminated feed and soil into eggs and meat of laying hens. The transfer from the feed was investigated with 30 laying hens. T...

Pyrrolizidine alkaloid (PA) producing plants like Senecio jacobaea or Senecio vernalis are undesirable in fields for forage production, since PA are toxic to animals and humans. Previous studies have shown that ensiling can decrease the PA content in forages; however, no direct comparison of diverse PA from different Senecio spp. under various ensi...

Methionine (Met) as an essential amino acid has key importance in a variety of metabolic pathways. This study investigated the influence of three dietary Met supplements (0.21% L-Met, 0.21% DL-Met and 0.31% DL-2-hydroxy-4-(methylthio)butanoic acid (DL-HMTBA)) on the metabolome and inflammatory status in the small intestine of pigs. Epithelia from d...

Background Given the key role of methionine (Met) in biological processes like protein translation, methylation, and antioxidant defense, inadequate Met supply can limit performance. This study investigated the effect of different dietary Met sources on the expression profile of various Met transporters along the gastrointestinal tract (GIT) of pig...

Bedding, environmental enrichment materials and disinfectant powders in pig farming are meant to ensure a hygienic bedding environment or allow pigs to perform explorative behaviour. To our knowledge, no legal regulation exists, that established maximum contents for undesirable substances, such as toxic metals, dioxins or trace elements in these ma...

Background Microbial colonization and immune cell maturation coincide at mucosal sites and are decisive for postnatal lung development. How external factors influence neonatal pulmonary immune development is poorly understood. Objective To elucidate the impact of key determinants in early life, nutrition, and maternal bonding, on postnatal lung ma...

Non-dioxin-like polychlorinated biphenyls (ndl-PCBs) are a subclass of persistent bioaccumulative pollutants able to enter the food chain. We investigated the transfer of ndl-PCBs from contaminated feed into meat and liver of fattening chickens. A total of 48 chicks were divided into five treatment and one control groups. Treated animals were fed w...

Background During food or feed contamination events, it is of utmost importance to ensure their rapid resolution to minimize impact on human health, animal health and finances. The existing Rapid Alert System for Food and Feed (RASFF) is used by the European Commission, national competent authorities of member countries and the European Food Safety...

Certain undesirable substances in feed can transfer into foods of animal origin after ingestion by livestock animals. They become contaminants in food that may threaten the consumers' health. Commonly, feeding trials with animals are conducted to assess the transfer of undesirable substances into animal tissues or milk. Such feeding trials explore...

Zusammenfassung Chronische Überversorgungen oder Intoxikationen mit Kupfer (Cu) treten beim Rind seltener auf als beim Schaf. Dieser Fallbericht beschreibt eine chronisch erhöhte Cu-Exposition durch übermäßige Supplementierung von Mineralfutter als Bestandsproblem in einer Deutsche-Holstein-Herde. Zur Diagnostik auf Bestandsebene wurden bei jeweils...

As a consequence of the toxicological lead characteristics, a reduction of its exposure should consider all sources. Game meat might contain elevated levels of lead due to the use of lead ammunition. The aim of the present study was to investigate the effects of acidic marination on the bioavailability of ammunition-derived lead in game meat (Roe d...

Zusammenfassung Nach versehentlicher Verfütterung eines mit dem Kokzidiostatikum Nicarbazin kontaminierten Mischfutters in einem Legehennen-Elterntier-Betrieb (Lohmann Brown Classic) zeigten die Tiere wenige Stunden später ausgeprägte klinische Symptome. Die Mortalitätsrate stieg innerhalb von 5 Tagen an, während im gleichen Zeitraum die Legeleistu...

Background Clostridioides difficile infection (CDI) is an increasing zoonotic health threat and has also been documented as a cause of enteritis outbreaks in neonatal pigs. Furthermore, CDI in neonatal piglets cause changes in microbial gut colonization. We hypothesized that an imbalanced microbial colonization in piglets with CDI could be associat...

Despite a well-documented effect of high dietary zinc oxide on the pig intestinal microbiota composition less is it yet known about changes in microbial functional properties or the effect of organic zinc sources. Forty weaning piglets in four groups were fed diets supplemented with 40 or 110 ppm zinc as zinc oxide, 110 ppm as Zn-Lysinate, or 2500...

Non-communicable diseases, such as the metabolic syndrome and inflammatory bowel disease, constitute serious public health threats in developed countries. Besides environmental factors, genetic predispositions contribute to the onset and progression of the disease. State-of-the-art mouse models recently highlight the involvement of Toll-like recept...

Characteristics of wheat and barley inoculated with a homo-fermentative (HO) or hetero-fermentative (HE) lactic acid bacteria (LAB) were investigated in separate 97 d studies conducted using a 3 × 2 factorial arrangement comparing inoculants (no inoculant, HO or HE) and multi-enzyme (no or yes) addition. The pH declined (P < 0.05) to below 4.5 by d...

In 2017-2018, a fipronil contamination occurred in the European chicken egg supply chain due to its illegal use as insecticide to control red lice infestations. Fipronil has the potential to be transferred into eggs of laying hens, thereby entering the food chain. Here, we present a toxicokinetic model to predict the transfer of fipronil in laying...

Background: Methionine is an essential amino acid (AA) with many fundamental roles. Humans often supplement l-Met, whereas dl-Met and dl-2-hydroxy-4-(methylthio)butanoic acid (dl-HMTBA) are more frequently used to supplement livestock. Objectives: The study aimed to investigate whether dietary Met source alters the absorptive capacity for Met is...

Background: Clostridium difficile infection (CDI) is an increasing zoonotic health threat and has also been documented as a cause of enteritis outbreaks in neonatal pigs. Furthermore, CDI in neonatal piglets cause changes in microbial gut colonization. We hypothesized that an imbalanced microbial colonization in piglets with CDI could be associated...

Zinc treatment is beneficial for infectious diarrhea or colitis. This study aims to characterize the pathomechanisms of the epithelial barrier dysfunction caused by alpha-hemolysin (HlyA)-expressing Escherichia coli in the colon mucosa and the mitigating effects of zinc ions. We performed Ussing chamber experiments on porcine colon epithelium and i...

Clostridioides difficile toxins are one of the main causative agents for the clinical symptoms observed during C. difficile infection in piglets. Porcine milk has been shown to strengthen the epithelial barrier function in the piglet’s intestine and may have the potential to neutralise clostridial toxins. We hypothesised that porcine colostrum exer...

Tetrachlorodibenzo-p-dioxin (TCDD) is a ubiquitous, toxic, persistent and bioaccumulative organic pollutant. TCDD can potentially enter the food chain through contaminated food of animal origin as a consequence of feed contamination. Prediction of the TCDD transfer from feed into animal products is thus important for human health risk assessment. H...

Background: The present study aimed at investigating the influence of 90% menthol-containing plant bioactive lipid compounds (PBLC, essential oils) on growth performance, blood haematological and biochemical profile, and nutrient absorption in sheep. Twenty-four growing Suffolk sheep were allotted into three dietary treatments: Control (without PB...

This study aimed to investigate the effects of two practically relevant doses of menthol-rich plant bioactive lipid compounds (PBLC) on fermentation, microbial community composition, and their interactions in sheep rumen. Twenty-four growing Suffolk sheep were divided into three treatments and were fed hay ad libitum plus 600 g/d of concentrate con...

Background This study evaluated the degradation of pyrrolizidine alkaloids (PAs) from eastern groundsel (Senecio vernalis) in grass silage prepared with different inoculants. Silages were produced from ryegrass with 230 g kg⁻¹ dry matter (DM) content and mixed with eastern groundsel (9:1; w/w fresh matter basis) containing 5.5 g kg⁻¹ DM PA. Treatme...

Zn serves as a powerful feed additive to reduce post-weaning diarrhoea in pigs. However, the mechanisms responsible for Zn-associated effects on the adaptive immune responses following feeding of a very high dosage of Zn remain elusive. In this study, we examined the T-cell response in gut-associated lymphatic tissues of seventy-two weaned piglets....

This study examined gut colonization patterns and host responses to fecal microbiota transplantation (FMT) by different administration routes after preterm birth. In two separate experiments, cesarean-delivered, preterm pigs were administered combined oral + rectal, or exclusively rectal donor feces, and compared with saline controls. After 5 days,...

Clostridium difficile has been documented as a major cause of uncontrolled outbreaks of enteritis in neonatal pigs and antibiotic-associated infections in clinical settings. It belongs to the natural cohort of early colonisers of the gastrointestinal tract of pigs and can be detected in faeces up to two weeks post-partum. In older pigs, it often re...

A feeding trial was conducted to investigate the effects of differently processed yeast products (hydrolyzed or non-hydrolyzed) derived from Kluyveromyces fragilis on immunological parameters of piglets in an early phase post weaning (d 1–14). A total of 48 male and female piglets (6.17 ± 0.32 kg BW, weaned at d 25) were allocated to three dietary...

Zusammenfassung Der Fallbericht beschreibt die Abklärung von Bewegungsstörungen bei drei männlichen Wasserbüffeln (1–2 Jahre) aus extensiver Freilandhaltung. Die drei aufgrund von Mattigkeit und vermehrtem Liegen vorgestellten Jungbullen konnten nur mühsam aufstehen und zeigten staksigen Gang, teilweise mit Muskeltremor im Bereich der Gliedmaßen. D...

Two feeding trials were conducted to investigate the effects of hydrolyzed (HY) or non-hydrolyzed (NHY) yeast (Kluyveromyces fragilis) in isoenergetic and isonitrogeneous diets in the post-weaning period. In Exp. 1, a total of 550 unsexed pigs (6.5 ± 0.5 kg BW), weaned at 24 ± 2 d of age, were allocated to 5 treatment groups, receiving either a con...

High levels of zinc oxide are used frequently as feed additive in pigs to improve gut health and growth performance and are still suggested as an alternative to antimicrobial growth promoters. However, we have recently described an increase of multi-resistant E. coli in association to zinc feeding in piglets. This previous study focused on clonal d...

Data of the antimicrobial resistance screening of the zinc pig feeding trial. (XLSX)

Quantitative E. coli data of the zinc pig feeding trial. (XLSX)

Spontaneous Clostridium difficile (CD) outbreaks occur in neonatal piglets but the predisposing factors are largely not known. To study the conditions for CD colonisation and infection development, neonatal piglets (n=48) were moved into isolators, fed bovine milk-based formula and infected with CD 078. Analyses included: clinical scoring; faecal C...

The aim of the present study was to investigate systematically the expression of inflammasome components in pig intestine and to analyze the influence of age and long-term supplementation with the probiotic Enterococcus faecium NCIMB 10415 (E. faecium). In order to examine probiotic effects on the inflammasomes during a challenge with pathogens, en...

Probiotics are live microorganisms that can confer a health benefit on the host, and amongst various mechanisms probiotics are believed to exert their effects by production of antimicrobial substances, competition with pathogens for adhesion sites and nutrients, enhancement of mucosal barrier integrity and immune modulation. Through these activitie...

During the prenatal, neonatal and post-weaning periods, the mammalian gastrointestinal tract undergoes various morphological and physiological changes alongside with an expansion of the immune system and microbial ecosystem. This review focuses on the time period before weaning and summarizes the current knowledge regarding i) structural and functi...

There is growing interest in studying host–pathogen interactions in human-relevant large animal models such as the pig. Despite the progress in developing immunological reagents for porcine T cell research, there is an urgent need to directly assess pathogen-specific T cells—an extremely rare population of cells, but of upmost importance in orchest...

Background and AimEnterotoxigenic Escherichia coli (ETEC) strains are involved in piglet post-weaning diarrhea. Prophylactic measures including probiotics have been examined in infection experiments with live piglets. In the present study, we have tested whether the early effects of ETEC infection can also be evoked and studied in a model in which...

Milk contains a variety of components that have been shown to affect the expression and localization of epithelial tight junction proteins and therefore the intestinal barrier. Thus, we hypothesized that milk would have an effect on intestinal barrier properties, owing to effects on the tight junction in an intraspecies porcine intestinal in vitro...

Zinc homoeostasis exerts protective effects in inflammatory intestinal diseases and zinc supplementation has been successfully used for treating infectious diarrhoea. This study aimed at a characterisation of zinc effects on focal leak induction by ?-haemolysin (HlyA)-producing Escherichia coli (E. coli) as protective mechanism for colitis. We cond...

Einfluss einer Formula-Fütterung auf die Anfälligkeit neugeborener Ferkel gegenüber einer Clostridium difficile-Infektion

The negative energy balance during early lactation often leads to excessive mobilization of body reserves and increases the risk for ketosis. The present study proceeded from the hypothesis that combined supplementation of a commercial blend of plant bioactive lipid compounds (essential oils) plus biotin throughout the transition period could have...

Hyperprolificacy in modern pig breeds has led to increased use of artificial rearing and formula feeding of neonatal piglets, which may change their intestinal bacterial ecophysiology. Here, newborn piglets ( = 8 per group) were fed a bovine milk-based formula (FO) or allowed to suckle their mothers (sow milk [SM]) for 2 wk, and digesta samples fro...

Hyperprolificacy in modern pig breeds has led to increased use of artificial rearing and formula feeding of neonatal piglets, which may change their intestinal bacterial ecophysiology. Here, newborn piglets (n = 8 per group) were fed a bovine milk-based formula (FO) or allowed to suckle their mothers (sow milk [SM]) for 2 wk, and digesta samples fr...

The physiological role of the gastrointestinal microbiota has become an important subject of nutrition research in pigs in the past years, and the importance of intestinal microbial activity in the etiology of disease is doubtless. This review summarizes the recent knowledge related to the microbial ecology of protein fermentation and the appearanc...

The current study aimed at determining the influence of both grinding intensity and expanding of blue sweet lupin (BSL) on the nutritive value of complex diets for growing pigs as compared with soybean meal-based diet. Four diets were formulated based on soybean meal (SBM, 21% in the diet) or differentially treated BSL (31% in the diet). Treatments...

Artificial rearing and formula feeding is coming more into the focus due to increasing litter sizes and limited nursing capacity of sows. The formula composition is important to effectively support the development of the gut and prevent intestinal dysfunction in neonatal piglets. In this study, newborn piglets ( = 8 per group) were fed a bovine mil...

Artificial rearing and formula feeding is coming more into the focus due to increasing litter sizes and limited nursing capacity of sows. The formula composition is important to effectively support the development of the gut and prevent intestinal dysfunction in neonatal piglets. In this study, newborn piglets (n = 8 per group) were fed a bovine mi...

Medium-chain fatty acids (MCFA) and short-chain organic acids (SOA) are often used as feed additives in piglet diets. There are limited studies in pigs describing the impact of MCFA or SOA on gut morphology and the local immune system. The aim of this study was to investigate whether the supplementation of SOA (0.41% fumaric acid and 0.32% lactic a...

A study was conducted to determine the effect of high dietary zinc (Zn) oxide on trace element accumulation in various organs with special emphasis on the kidney. A total of 40 weaned piglets were allocated into two groups with 16 and 24 piglets each receiving a diet containing normal (NZn; 100 mg Zn/kg) or high (HZn; 2,100 mg Zn/kg) Zn concentrati...

The aim of the study was to identify the effect of high dietary zinc oxide (ZnO) levels on the histamine-induced secretory-type response and histamine metabolism in the porcine proximal colon. After weaning at d 26, 3 diets with low (LZn), normal (NZn), and high (HZn) concentrations of zinc (57, 164, or 2,425 mg/kg) were fed to a total of 120 pigle...

High doses of zinc oxide are commonly used in weaned pig diets to improve performance and health. Recent reports show that this may also lead to an imbalanced zinc homeostasis in the animal. For a better understanding of the regulatory mechanisms of different zinc intakes, we performed a feeding experiment to assess potential epigenetic regulation...