Review: Bioavailability of trace elements in farm animals: definition and practical considerations for improved assessment of efficacy and safety.

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 supplements of essential trace elements. Framework conditions encompass necessary technical information on the test substance, the experimental design and diet composition as well as the suitability of status parameters that allow for relative comparisons of regression variables. This manuscript evolves recommendations for researchers to conduct solid and reliable experiments on the matter as well as decision makers to interpret the value of studies submitted with authorisation applications regarding a certain trace element supplement.

Effects of supplementing a CP-reduced diet with rumen-protected methionine on Fleckvieh bull fattening.

The objective of this study was to evaluate the effect of supplementing a CP-reduced diet with rumen-protected methionine on growth performance of Fleckvieh bulls. A total of 69 bulls (367 ±â€¯25 kg BW) were assigned to three feeding groups (n = 23 per group). The control (CON) diet contained 13.7% CP and 2.11 g methionine/kg diet (both DM basis) and was set as positive control. The diet reduced in CP (nitrogen) (RED) diet as negative control and the experimental RED + rumen-protected methionine (MET) diet were characterised by deficient CP concentrations (both 9.04% CP). The RED + MET diet differed from the RED diet in methionine concentration (2.54 g/kg DM vs. 1.56 g/kg DM, respectively) due to supplementation of rumen-protected methionine. Rumen-protected lysine was added to both RED and RED + MET at 2.7 g/kg DM to ensure a sufficient lysine supply relative to total and metabolisable protein intake. Metabolisable energy (ME) and nutrient composition were similar for CON, RED, and RED + MET. Bulls were fed for 105 days (d) on average. Individual feed intake was recorded daily; individual BW was recorded at the beginning of the experiment, once per month, and directly before slaughter. At slaughter, blood samples were collected and carcass traits were assessed. Reduction in dietary CP concentration reduced feed intake, and in combination with lower dietary CP concentration, daily intake of CP for RED and RED + MET was lower compared with CON (P < 0.01). Daily ME intake was reduced in RED and RED + MET compared with CON (P < 0.01). Consequently growth performance and carcass weights were reduced (both P < 0.01) in both RED and RED + MET compared with CON. Supplemental rumen-protected methionine was reflected in increased serum methionine concentration in RED + MET (P < 0.05) as compared to RED but it did not affect growth performance, carcass traits and serum amino acid (AA) concentrations, except for lysine which was reduced (P < 0.01) compared to CON and RED. In conclusion, bulls fed RED or RED + MET diets were exposed to a ruminal CP deficit and subsequently a deficit of prececal digestible protein, but methionine did not appear to be the first-limiting essential AA for growth under the respective experimental conditions.

[Ten Years of Smoking Ban - Effects of the Federal Nonsmoker Protection Act Exemplified by the Traditional Pub District of Cologne's Südstadt]. / Zehn Jahre Rauchverbot − Auswirkungen des Nichtraucherschutzgesetzes am Beispiel des traditionellen Kneipenviertels der Kölner Südstadt.

BACKGROUND: Since September 2007, the Federal Nonsmoker Protection Act regulates a general legal ban on smoking in federal facilities, public transport vehicles and passenger stations. Other smoking bans are not uniformly regulated and vary from state to state. In addition to places of public interest, sports venues and the workplace, particular attention in political debates has always been paid to bars and restaurants, where smoking has always been part of the picture. The situation of the Südstadt pubs in Cologne considered in this paper is governed by the expanded law for the protection of non-smokers in North Rhine Westphalia (NRW) of December 20, 2007. METHODS: A survey using a specifically created questionnaire comprising 24 items was carried out. Persons over 26 years of age visiting selected bars were interviewed in order to ensure that at the time the Nonsmoker Protection Act was introduced, participants had reached the legal age for smoking. Data acquisition was carried out both by direct surveys of participants in selected pubs in Cologne's Südstadt and by means of online surveys, attention to which had been drawn in the press, television and through social media. RESULTS: A total of 1318 completed questionnaires were evaluated. Participants were on average 49 years old (±â€Š12.1). Of the 1318 respondents, 726 were active smokers in 2007 (55.1 %). In 2018, 518 (39.3 %) (p: < 0.001) respondents stated that they were still active smokers. Of the 726 active smokers, 289 (39.8 %) had been consuming more than 20 cigarettes a day in 2007. In 2018, 179 of 518 (34.6 %) (p: < 0.001) were heavy smokers. In 2007, 303 persons (41.7 % of smokers) fell into the group of medium smokers with 10 - 19 cigarettes per day, in 2018 there were 227 (43.8 %) (p: < 0.001). The group of people who smoked less and consumed 1 - 9 cigarettes per day included a total of 134 persons (18.5 %) in 2007 and 112 (21.6 %) in 2018 (p: < 0.001). Among active smokers, the smoking ban was the most relevant cause for a change in smoking behaviour in this survey. Among non-smokers or former smokers, health aspects as well as family and friends were the decisive factors in rejecting tobacco products. SUMMARY: Based on a sample of 1318 participants among pub visitors, the study showed that the number of active smokers had significantly and distinctly decreased since the introduction of the Nonsmoker Protection Act in 2007. Furthermore, the number of people with rather low cigarette consumption showed a significant increase.

Effects of supplementing rumen-protected niacin on fiber composition and metabolism of skeletal muscle in dairy cows during early lactation.

Nicotinic acid (NA) has been shown to induce muscle fiber switching toward oxidative type I fibers and a muscle metabolic phenotype that favors fatty acid (FA) utilization in growing rats, pigs, and lambs. The hypothesis of the present study was that supplementation of NA in cows during the periparturient phase also induces muscle fiber switching from type II to type I fibers in skeletal muscle and increases the capacity of the muscle to use free FA, which may help to reduce nonesterified fatty acid (NEFA) flow to the liver, liver triglyceride (TG) accumulation, and ketogenesis. Thirty multiparous Holstein dairy cows were allocated to 2 groups and fed a total mixed ration without (control group) or with ∼55 g of rumen-protected NA per cow per day (NA group) from 21 d before expected calving until 3 wk postpartum (p.p.). Blood samples were collected on d -21, -14, -7, 7, 14, 21, 35, and 63 relative to parturition for analysis of TG, NEFA, and ß-hydroxybutyrate. Muscle and liver biopsies were collected on d 7 and 21 for gene expression analysis and to determine muscle fiber composition in the musculus semitendinosus, semimembranosus, and longissimus lumborum by immunohistochemistry, and liver TG concentrations. Supplementation of NA did not affect the proportions of type I (oxidative) or the type II:type I ratio in the 3 muscles considered. A slight shift from glycolytic IIx fibers toward oxidative-glycolytic fast-twitch IIa fibers was found in the semitendinosus, and a tendency in the longissimus lumborum, but not in the semimembranosus. The transcript levels of the genes encoding the muscle fiber type isoforms and involved in FA uptake and oxidation, carnitine transport, tricarboxylic acid cycle, oxidative phosphorylation, and glucose utilization were largely unaffected by NA supplementation in all 3 muscles. Supplementation of NA had no effect on plasma TG and NEFA concentrations, liver TG concentrations, and hepatic expression of genes involved in hepatic FA utilization and lipogenesis. However, it reduced plasma ß-hydroxybutyrate concentrations in wk 2 and 3 p.p. by 18 and 26% and reduced hepatic gene expression of fibroblast growth factor 21, a stress hormone involved in the regulation of ketogenesis, by 74 and 56%. In conclusion, a high dosage of rumen-protected NA reduced plasma ß-hydroxybutyrate concentrations in cows during early lactation, but failed to cause an alteration in muscle fiber composition and muscle metabolic phenotype.

Gender-specific effects of a phytogenic feed additive on performance, intestinal physiology and morphology in broiler chickens.

To date, most studies published were carried out on broilers of the same sex, and possible gender-specific effects of phytogenic substances have not been investigated so far. A 3 × 2 factorial study was performed to examine gender-specific effects of a PFA at two dietary levels (150, 1500 ppm) on growth performance, carcass traits and gastrointestinal attributes in broiler chickens versus an untreated control group. The addition of 150 ppm of the PFA led to a downregulation of trypsinogen mRNA in pancreas compared with the control group (p < 0.05). The number of goblet cells decreased in jejunum compared with the unsupplemented group, whereby this effect was more pronounced in male birds (p < 0.05). Furthermore, higher methylamine contents compared with the control group were measured (p < 0.01). In proximal ileum, female birds, supplemented with 150 ppm PFA, had lower crypt depths than their litters in the 1500 ppm treatment (p < 0.05). In distal ileum, villus height:crypt depth ratio was higher in birds fed the PFA at 150 ppm than in the control group (p < 0.05). The 1500 ppm dosage of the PFA increased jejunal histamine concentration compared with the negative control group (p < 0.05). Jejunal histamine concentration was also affected by the interaction PFA × sex (p < 0.05). Regardless of inclusion level, total amount of biogenic amines and other microbial metabolites in digesta samples was not affected by the PFA. These results demonstrate variable, partially gender-specific effects of the tested PFA. Although the supplementation of 150 ppm showed little effect on mRNA expression level of selected marker genes for nutrient digestion, beneficial effects on gut morphology were observed. The 10-fold higher dosage of the PFA did not adversely affect growth performance as well as most investigated parameters compared with the control group.

Effects of a rumen-protected mixture of conjugated linoleic acids on hepatic expression of genes involved in lipid metabolism in dairy cows.

Supplementation of conjugated linoleic acids (CLA) reduces milk fat content in dairy cows and, thus, may be a useful dietary strategy to improve energy balance during early lactation. The present study was performed to investigate whether supplementation of CLA could have adverse effects on hepatic lipid metabolism such as observed in rodents. For this aim, 40 Holstein cows were allotted to 2 groups, which were fed daily 172 g of either a CLA-free, rumen-protected control fat (control group) or a rumen-protected CLA fat supplying 4.3g of cis-9,trans-11 CLA and 3.8 g of trans-10,cis-12 CLA per day (CLA group). To identify potential changes of lipid metabolism, expression of several genes involved in lipid metabolism was determined in liver biopsy samples taken at wk 5 of lactation, using a whole-genome gene chip. In the CLA group, milk fat content and daily milk fat yield were lower than in the control group. Milk yield was higher, whereas fat-corrected milk and energy-corrected milk were lower in the CLA group than in the control group. The CLA group, moreover, had an improved energy balance. To study potential effects of CLA on hepatic lipid metabolism, we considered 6 genes encoding fatty acid transporters, 7 genes involved in intracellular fatty acid transport, 21 and 7 genes, respectively, involved in mitochondrial and peroxisomal ß-oxidation, 6 genes of carnitine metabolism, 3 genes of ketogenesis, 21 genes involved in fatty acid and triacylglycerol synthesis, 17 genes involved in cholesterol metabolism, and 20 genes involved in lipoprotein metabolism. None of these genes was differentially regulated between the CLA group and the control group. Gene chip data were confirmed by quantitative PCR analysis, which revealed no difference in the expression of key enzymes of various pathways such as lipogenesis, ß-oxidation, and ketogenesis between the 2 groups of cows. In line with those findings, concentrations of triacylglycerols and cholesterol in liver and plasma were not different between the 2 groups of cows. In conclusion, the present study shows that CLA supplementation at a dose effective for milk fat depression does not induce adverse effects on hepatic lipid metabolism in dairy cows.

Bioavailability of zinc from different sources in pigs.

In contrast to inorganic Zn, organic Zn sources are absorbed via peptide or AA transport systems resulting in a higher digestibility and availability. Bioavailability of organically bound Zn seems also to be influenced by the type of complex being used. Forty-two gilts (Large white × Landrace) with initial BW of 24 ± 1.4 kg were allotted to 6 treatments of 7 pigs each. Pigs were fed diets based on corn (Zea mays), barley (Hordeum vulgare), and soybean (Glycine max) meal containing either low or high Zn supplementation with ZnO, Zn-Met 1:2 complex, Zn-Gly, Zn proteinate (Zn-Prot), or Zn-yeast. Diets were fed during a 10-d adaptation followed by a 4-d quantitative collection. Daily feed allowance was restricted to 1400 g/pig. Pigs were weighed at the start and end of adaptation and collection and feed consumption was monitored daily. Dietary Zn addition was 10 and 100 mg/kg feed for ZnO and 10 mg/kg feed for other Zn sources. Corresponding ADG ranged from 437 to 587 g with the lowest (P < 0.05) ADG for 10 ppm ZnO. Only Zn-Met addition increased (P < 0.02) Zn digestibility and retention (P < 0.05). Organically bound Zn, in particular Zn from Zn-Met 1:2 and Zn-yeast, can replace higher dosages of ZnO due to better bioavailability indicating that type of chelate is important for Zn retention. Organically bound Zn may reduce Zn excretion, which consequently may lower the environmental impact.

[Chronic respiratory failure: the role of home mechanical ventilation]. / Chronische respiratorische Insuffizienz: Rolle der ausserklinischen Beatmung.

While negative pressure ventilation using cuirass respirators or iron-lung machines was prevailing in the first part of the 20th century, the polio epidemic in Copenhagen 1952 marks the turning point at which positive pressure ventilation following tracheotomy was started. Furthermore, following the introduction of facial masks and starting 1985 in Germany non-invasive positive pressure ventilation has meanwhile been developed as a routine procedure for the long-term treatment of patients with chronic ventilatory failure today. The current article provides an overview of these developments and also outlines the role of two particular national societies: "Deutsche Gesellschaft für Pneumologie und Beatmungsmedizin (DGP) e. V." (German Medical Association of Pneumology and Ventilatory Support) and "Deutsche Interdisziplinäre Gesellschaft für außerklinische Beatmung (DIGAB) e. V." (German Interdisciplinary Society for Home Mechanical Ventilation).

Impact of inulin and a multispecies probiotic formulation on performance, microbial ecology and concomitant fermentation patterns in newly weaned piglets.

The effect of inulin and a multispecies probiotic formulation on performance and microbial parameters in a 28 days feeding trial with newly weaned piglets was assessed. Forty-eight piglets were allocated to a 2 × 2 factorial experiment involving two levels of inulin supplementation (0% or 0.4%) and two levels of probiotics (0 or 1 × 10(9) CFU/kg as fed, comprising enterococci, lactobacilli and bifidobacteria). In digesta samples obtained at slaughter (stomach, jejunum, ileum and colon), selected bacterial groups were enumerated and lactic acid, short chain fatty acids and ammonia concentrations analysed. The overall performance of piglets was unaffected by treatment. Inulin increased total aerobes in stomach and jejunum (p < 0.05), whereas enterococci declined in colon of the inulin group (p < 0.05). Furthermore decreasing colonic acetic acid (p < 0.01) and increasing lactic acid (p < 0.05) was observed for inulin. Probiotics increased total aerobes (p < 0.05) and enterococci (p < 0.01) in ileum and lactobacilli (p < 0.05), enterococci and gram-negative anaerobes (p < 0.01) in colon. Moreover, dry matter content in stomach and colon was lower and acetic acid in colon increased (p < 0.05). A decrease in ileal pH value was noted symbiotically for both additives. However, several parameters showed no synbiotic, but distinct individual effects of inulin and probiotics. Effects occurred along the entire gastrointestinal tract without restriction to the colon.

Bioavailability of zinc glycinate in comparison with zinc sulphate in the presence of dietary phytate in an animal model with Zn labelled rats.

The objective of this study was to quantify the bioavailability of zinc (Zn) from sulphate and glycinate as representatives of inorganic and organic zinc sources. The semi-synthetic basal diet contained 2 microg/g of native Zn and was fortified with pure sodium-phytate (8 g/kg) in order to simulate conditions of common cereal-based meals. The basal diet was supplemented with either 53 microg/g of Zn from sulphate (control) or 10 microg/g of Zn from either sulphate (ZnSulphate) or glycinate (ZnGly). Twenty-four (65)Zn-labelled, growing rats weighing 133 g were allotted to the three diets (eight animals per treatment) and were kept pair-fed to ZnSulphate for 15 days. Zn contents in blood plasma, femur and whole body, as well as, plasma alkaline phosphatase activities were reduced compared with control indicating a zinc deficiency in ZnSulphate and ZnGly treatment. This allowed their differentiation in zinc bioavailability. True absorption of dietary Zn was significantly higher in ZnGly than in ZnSulphate (51% vs. 44%) while losses of endogenous faecal Zn and urinary Zn were not affected to a quantitatively relevant extent (mean: 17% and 2% of intake). This resulted in a +30% significantly improved Zn retention for ZnGly (33% vs. 25%) and a lower severity on Zn deficiency symptoms compared with ZnSulphate. Metabolic utilization accounted for 95% of absorbed dietary Zn for both Zn sources. Overall, the bioavailability of zinc glycinate was significantly superior by 16% to zinc sulphate (49% vs. 42%), mainly because of a higher absorptive potential at presence of a strong anti-nutritive component (phytate) in the diet.

Effect of potassium diformate in combination with different amounts and sources of excessive dietary copper on production performance in weaning piglets.

Three studies with each 96 weaning piglets were conducted to evaluate the combinatory effect of potassium diformate and high dietary doses of Cu on production performance. In Exp. 1, increasing dietary Cu (25, 75, 125, 175 ppm Cu) were tested at either no or 1.8% potassium diformate. In Exp. 2, rising dietary levels of potassium diformate (0%, 0.6%, 1.2% and 1.8%) were tested at either 25 or 175 ppm Cu. In Exp. 3, a basal dietary Cu content of 15 ppm was compared with dietary Cu levels of 95 or 175 ppm, each of them added as either Cu sulphate or Cu amino acid chelate or Cu formate. Rising dietary additions of potassium diformate and Cu improved weight gain, feed intake and feed conversion rate of piglets. The combination of potassium diformate and Cu failed to act additively at highest dose levels of the two supplements. Cu sulphate was efficient as growth stimulating additive in all 3 experiments, Cu formate failed to stimulate production performance. Cu chelate tended to depress production performance and to increase blood plasma Cu compared to equivalent amounts of Cu from Cu sulphate.

A study on the nutritive value of pollen from the Chinese Masson Pine (Pinus massoniana) and its effect on fecal characteristics in rats.

A digestion experiment with growing rats was conducted to study the effect of native and broken pollen of Chinese Masson Pine (Pinus massoniana) on fecal composition and digestibilities of dry matter, crude protein and crude ash. For that issue each 10 of 30 animals were fed a semisynthetic diet containing either no pollen or and addition of 6% native or broken pollen for 17 days at restricted amounts. In a second experiment each 6 of 12 growing rats received a semisynthetic diet containing either no or 5% broken pollen. At day 4, 11 and 18 samples of the feces were collected and analyzed for mesophilic aerobic bacteria. The pollen contained large amounts of cell wall constituents (26-30% lignin and 10-15% cellulose, 2-13% hemicellulose) with higher values found in native pollen. The contents of crude protein, crude fat, total lipids, available carbohydrates (starch and sugars), crude ash, gross energy and metabolizable energy were 13%, 2-10%, 8-10%, 17-18%, 3.1-3.5%, 21-22 kJ/g and 5.7-9.0 kJ/g. The addition of native pollen to the diet increased the total amount of feces by 71% as compared to the control level. The fecal contents of dry matter and of crude protein and crude ash in fecal dry matter changed by -5, +4 and -5 percentage units. The apparent digestibilites of dry matter and crude protein decreased by 3 and 5 percentage units, respectively, while the apparent digestibility of crude ash remained unchanged. Broken pollen acted in the same direction, however the effects were about 20% less pronounced as compared to native pollen. The pollen feeding reduced the fecal germ contents of Proteus mirabilis and Escherichia coli, while the amounts of alpha-hemolysing streptococci was increased. In total, the observed effects of an addition of native broken or pollen to the diet seemed to be based mainly on the increased intake of cell wall constituents.

[The effect of avilamycin and tylosin on the apparent digestibility of iron, zinc, copper, manganese and selenium in the beginning and ending performance of swine]. / Zum Effekt von Avilamycin und Tylosin auf die scheinbare Verdaulichkeit von Eisen, Zink, Kupfer, Mangan und Selen in der Anfangs-und Endmast von Schweinen.

In two metabolism trials with growing and finishing pigs the effect of the antibiotic feed additives Avilamycin and Tylosin on the apparent digestibility of Fe, Zn, Cu, Mn and Se was investigated. The feed additives were supplied to the diet in levels of 40 ppm (growing pigs) and 20 ppm (finishing pigs) each. Dietary contents of Fe, Zn, Cu, Mn and Se covered the requirements of all treatment groups. Avilamycin and Tylosin increased the apparent digestibility by 4 (Fe), 4 (Zn), 5 (Cu), 2 (Mn) and 2 (Se) percentage units on an average.