Luka Cvetnić

Distribution of sulfamonomethoxine and trimethoprim in egg yolk and white

The distribution of sulfamonomethoxine (SMM) and trimethoprim (TMP) in egg yolk and white was measured during and after administration of a SMM/TMP combination in laying hens in doses of 8 g l(-)(1) and 12 g l(-)(1) in drinking water for 7 days. The SMM concentration reached maximal levels on day 2 of the post-treatment period for both doses (μg kg(-)(1)): 5920 and 9453 in yolk; 4831 and 6050 in white, in doses 1 and 2, respectively. Significant differences in the SMM and TMP concentrations between yolk and white in post treatment period were found. SMM dropped below the LOD (1.9 μg kg(-1)) in yolk after day 16 and 19 for doses 1 and 2. TMP reached maximal levels on day 3 after drug administration for doses 1 and 2 (μg kg(-)(1)): 6521 and 7329 in yolk, 1370 and 1539 in white. TMP residues were measured above LOD (0.3 μg kg(-)(1)) in yolk for both doses on day 37 post-treatment.

Deposition and depletion of maduramicin residues in eggs after oral administration to laying hens determined by LC-MS

The coccidiostat maduramicin has been approved as a feed additive for chickens and turkeys, although it is prohibited for use in laying hens. In the present study, laying hens were divided into three groups and fed for 14 days with medicated feed containing maduramicin, at three different concentrations: 50, 100 and 500 µg kg−1. Eggs were collected during treatment and for 26 days after the end of feeding with medicated feed. Maduramicin residues were found exclusively in egg yolk, with the highest concentration in egg yolk of 459 µg kg−1 for the highest dose. The maximum concentration of maduramicin in whole egg was 16.6 µg kg−1 for the group receiving feed containing the maximum permitted level of maduramicin in feed (50 µg kg−1). The half-life of elimination of maduramicin, calculated for post-treatment days 1–10, was 6.5 days. Twelve days after drug administration, the concentration of the maduramicin in egg yolk for Group 3 (fed with 500 µg kg−1 maduramicin) still exceeded 20 µg kg−1, while the concentrations for Groups 1 and 2 were 1.2 and 2.7 µg kg−1, respectively. Graphical Abstract

MODULATION OF SYSTEMIC INNATE AND ADAPTIVE IMMUNE PARAMETERS IN WEANED PIGS BY SINGLE ORAL APPLICATION OF IMMUNOBIOTICS

The aims of this study were to evaluate the effects of peroral treatment of 4-week old pigs at weaning (Day 0) with a single dose of levamisole (LEVA) or polyoxyethyle-polyoxypropylene (POE-POP), well known immunobiotics (IBC) and promising alternatives to dietary antibiotic growth promoters (AGP), on systemic innate and adaptive immunity by determining phagocytosis (PHC) and microbicidity (MBC) efficiency of their monocytes (MO) and granulocytes (GR), changes of serum C-reactive protein (CRP) and haptoglobin (HpG) profiles and kinetics of CD4+ CD8+ T cells expression during 5 weeks following the treatments. Levels of CRP were decreased by either POE-POP or LEVA (P<0.05) at Day 7 and 21, respectively. LEVA-treated pigs had increased levels of HpG (P<0.05) at Day 14 and 21, whereas POE-POP-treated pigs had decreased and increased levels (P<0.05) at Day 7 and 21, respectively. Both IBC stimulated in vitro PHC of GR (from Day 7 to 35) and MBC of MO (at Day 35) from treated pigs (P<0.05). MO from POE-POP-treated pigs exhibited increased PHC (P<0.05) at Day 35, whereas GR from LEVA- or POE-POP-treated pigs showed increased MBC (P<0.05) at Day 7 and 35, respectively. The pigs treated by LEVA or POE-POP had higher proportions of CD4+ CD8+ T cells (P<0.05) from Day 14 to 35 or Day 28 to 35, respectively. Tested IBC showed capability of stimulating particularly cellular components of nonspecific and specific immunity during early postweaning period before pigs reach adult immunocompetence values, and thus could be considered as potent immunostimulators in swine production. Key words: synthetic immunobiotics; innate/adaptive immunity; weaned pig VPLIV NA SISTEMSKO PRIROJENO IN PRIDOBLJENO IMUNOST PRI ODSTAVLJENIH PUJSKIH PO ENKRATNEM DODATKU IMUNOBIOTIKOV PREKO PREBAVNEGA TRAKTA Namen raziskave je bil ugotoviti vpliv lavamisola (LEVA) in polyoxyethylen-polyoxypropylena (POE-POP), znanih imunobiotikov, ki bi jih lahko uporabljali v prasicereji za boljsi prirast namesto antibiotikov, na sistemsko prirojeno in pridobljeno imunost pri odstavljenih, 4 tedne starih pujskih. Vsem živalim smo LEVA in POE-POP dajali preko ust (peroralno) in tedensko v odobju petih tednov dodajanja imunobiotikov ugotavljali stopnjo fagocitoze in protimikrobno aktivnost monocitov in granulocitov, raven serumskega C-reaktivnega proteina (CRP), profil haptoglobina (HpG) ter raven prisotnosti limfocitov T, ki izražajo gena CD4 in CD8 v krvi. Rezultati so pokazali, da je bila raven serumskega CRP znižana pri pujskih, ki so prejemali tako LEVA kot POE-POP 7. in 21. dan raziskave (p < 0,05). Pujski, ki so prejemali LEVA, so imeli zvisan HpG 14. in 21. dan raziskave (p < 0,05), medtem ko so imeli pujski, ki so prejemali POE-POP, 7. dan raziskave HpG znižan, 21. dan pa zvisan (p < 0,05). Oba imunobiotika sta v pogojih in vitro dvignila stopnjo fagocitoze pri granulocitih in protimikrobno aktivnost monocitov na 35. dan raziskave (p < 0,05). Pujski, ki so prejemali en ali drugi imunobiotik, so imeli 35. dan raziskave visje vrednosti limfocitov T, ki so izražali CD4 in CD8, od vrednosti na 14. ali 28. dan raziskave (p < 0,05). Rezultati raziskave torej kažejo, da sta oba imunobiotika pozitivno vplivala na izbrane kazalce delovanja imunskega sistema in sta potencialno zanimiva za uporabo v prasicereji za spodbujanje delovanja imunskega sistema in s tem boljsi prirast prasicev. Kljucne besede: odstavljeni pujski; umetni imunobiotiki; prirojena imunost; pridobljena imunost;

Estimation of the Withdrawal Time of Levamisole in Eggs after Oral Administration to Laying Hens

This study was conducted to evaluate withdrawal time of levamisole in eggs after oral administration in laying hens at different doses. Sampling of eggs was conducted for 37 days after the end of treatment, and levamisole concentrations were measured by liquid chromatography-tandem mass spectrometry validated according to the Commission Decision 2002/657/EC. Estimated validation parameters were as follows: decision limit, 0.54 μg/kg; detection capability, 0.56 μg/kg; limit of detection, 0.04 μg/kg; limit of quantification, 0.15 μg/kg; accuracy (recovery), between 92.9 and 102.3%; precision (relative standard deviation), ≤4.62%; and within-laboratory precision (relative standard deviation), ≤5.19%. Levamisole residue levels were significantly higher in egg yolks than in egg whites. The highest levels of levamisole were detected on day 2 posttreatment in groups receiving 50 mg/kg of body weight (556.2 μg/kg in egg yolks and 166.5 μg/kg in egg whites). Significant elimination occurred within 5 days after the cessation of treatment in all groups, with an elimination half-life of 1.3 days. Levamisole was still detectable on day 30 after the end of treatment in egg whites (0.06 μg/kg) and on day 37 in egg yolks (0.06 μg/kg). The longest withdrawal time for levamisole in eggs (14.9 days) was determined in a group treated with 25 mg of levamisole per kg of body weight for two consecutive days. According to the results, oral treatment of laying hens with levamisole may result in noncompliant egg samples even 14 days after treatment.

Occurrence of aflatoxin M1 in raw cow, goat and sheep milk during spring and autumn in Croatia during 2016

Abstract Raw cow, goat and sheep milk samples were collected in different regions of Croatia during spring and autumn 2016. Aflatoxin M1 (AFM1) concentrations were measured in the following ranges (ng/kg): cow milk 0.93–85.4; goat milk 2.0–18.6; sheep milk 2.27–11.2. AFM1 levels exceeding the European Union maximum residue levels of 50 ng/kg were found in two cow milk samples in spring and 10 cow milk samples in autumn. The probable daily intakes (PDIs) for all three dairy species were from 0.0108 to 0.0165 ng/kg b.w./day and contributing 1.08–1.65% to the proposed provisional maximum tolerable daily intake (PMTDI; 1 ng/kg b.w./day), indicating low risk exposure for consumers. The mean positive cow milk PDI was 0.15 ng/kg b.w./day, contributing 15.2% to the PMTDI.