Pharmacokinetics of tapentadol in laying hens and its residues in eggs after multiple oral dose administration

1. The aim of the study was to evaluate the pharmacokinetics (PKs) of tapentadol (TAP), a novel opioid analgesic, in laying hens after intravenous (IV) and oral (PO) administration and to quantify the concentrations of TAP residues in eggs. 2. Twenty healthy laying hens were divided into three groups: A (n = 6), B (n = 6) and C (n = 8). The study was conducted in two phases. Groups A and B received TAP by IV and PO routes at the dose of 1 and 5 mg/kg, respectively. 3. No visible adverse effects were observed after administration of the drug. TAP plasma concentrations were detectable up to 4 h following administration. Following IV administration, TAP plasma concentrations were only higher than the minimal effective concentration (148 ng/ml) reported for humans for 1 h. After single PO administration, plasma concentrations of TAP would not conform to software algorithms and the PK parameters were not calculated. TAP concentration following multiple PO doses at 5 mg/kg for 5 d was found to be higher and more persistent (12 h vs. 7 h) in yolk compared with albumen. 4. This is the first PK study on the novel atypical opioid TAP in laying hens. Further studies are required to investigate the analgesic efficacy and actual effective plasma concentration of TAP in this species.

Dietary lipid sources and vitamin E affect fatty acid composition or lipid stability of breast meat from Muscovy duck

A trial was conducted in order to assess the fatty acid composition and lipid stability of breast meat from Muscovy ducks (Cairina moschata domestica L.) fed a basal diet supplemented with 20 g kg-1 of soybean oil or fish oil and 30 or 230 mg kg-1 α-tocopheryl acetate (α-TA). A total of 120 one-day-old female muscovy ducklings were distributed over 12 pens (10 birds/pen). Growth performance traits were measured through the study. Each dietary treatment was randomly administered to three replicates when birds were 43 d until the slaughtering age of 66 d. Dietary treatments did not induce differences in growth performances and slaughter traits. Similarly, proximate composition and pH of breast muscle were not influenced by the diets. Significant increases in eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) contents in breast meat of ducks fed fish-oil-supplemented diets was observed. Lipid oxidation, expressed as thiobarbituric acid reactive substances (TBARS), of breast meat from birds fed 230 mg kg-1 α-TA-supplemented diets was significantly lower, compared with those fed diets supplemented with 30 mg kg-1 α-TA, both 1 and 7 d after slaughter.Key words: Duck, meat, fatty acid, vitamin E, thiobarbituric acid reactive substances

Influence of dietary lipid source and strain on fatty acid composition of Muscovy duck meat

A trial was conducted to study the effect of dietary 2% soya bean oil and dietary 2% fish oil (FO) on fatty acid composition of breast meat of two different Muscovy duck (Cairina moschata domestica L.) strains. The two strains were a broiler strain selected for meat production and an unselected rural strain. Fatty acid composition of breast muscle was deeply influenced by lipid source. Dietary FO improved the long chain polyunsaturated fatty acids (LC-PUFAs) of omega 3 series content, while the content of LC-PUFAs of omega 6 series was reduced. Differences in susceptibility in lipid manipulation were found between the two groups of animals suggesting the highest capability of animals belonging to the rural strain in stocking arachidonic acid in breast muscle. As the fatty acid profile of Muscovy duck meat can be considerably modified by changing the fatty acid composition of the diet, and dietary FO represents an easy way to reach this goal, human intake of healthy n-3 LC-PUFAs could be enhanced using this enriched poultry meat, even if the influence of FO on organoleptic characteristics (i.e. off-flavours) must be evaluated.