# Determination of Eleven Veterinary Drugs in Chicken Meat and Liver
## 3 Results and Discussion
### Feed Additives
\begin{table}
\begin{tabular}{c c c c c c c c c c c} \hline \hline \multicolumn{1}{c}{\multirow{2}{*}{**Compound**}} & \multicolumn{3}{c}{**This Study**} & \multicolumn{6}{c}{**MRL in Meat (ug/kg)**} \\ \cline{2-11}  & **Residues (ug/kg)\({}^{*}\)** & **Number of Samples\({}^{**}\)** & & **Brazil \({}^{*}\)** & & **Middle East\({}^{*}\)** & **EU \({}^{*}\)** & **China \({}^{a}\)** & **Canada \({}^{*}\)** & **USA \({}^{f}\)** & **CODEX \({}^{*}\)** \\ \hline  & & & **Matrix** & \
\begin{tabular}{c} **Number** \\ **of Samples** \\ \end{tabular} & **MRL** & & & & & & & & \\ \hline Amoxicillin & \textless{}10 & 300 &
\begin{tabular}{c} Chicken \\ meat \\ \end{tabular} & 600 & 50 & 10 & 50 & 50 & 10 & 10 & 50 \\ \hline Bacitracin & \textless{}75 & 300 & Egg & 300 & 500 & 150 & 500 & 500 & 500 & - \\ \hline Colistin & \textless{}75 & 300 & Egg & 300 & 300 & 150 & 150 & 150 & - & - & 150 \\ \hline Diminlomide & \textless{}5 & 60 & - & - & - & 3000 & - & 3000 & 3000 & - \\ \hline Spectiomycin & \textless{}50 & 300 & Kidney & 600 & 5000 & 100 & 300 & 500 & 100 & 100 & 500 \\ \hline Halotyping & \textless{}3 & 60 & - & - & - & 100 & 10 & 10 & 10 & - & - \\ \hline Roxarsone & \textless{}70 & 300 & - & - & - & 500 & - & 500 & - & - & - \\ \hline Taumulin & \textless{}25 & 300 & Egg & 300 & 1000 & 100 & 100 & 100 & - & - \\ \hline Tylosin & \textless{}25 & 300 & *** & 600 & 100 & 200 & 100 & 200 & 200 & 100 \\ \hline
17-\(\upalpha\)-Trenolone & \textless{}2 & 60 &
\begin{tabular}{c} Swine \\ urine \\ \end{tabular} & 60 & 2 & 2000 & - & - & 2 & - & 2 \\ \hline Virginiamycin & \textless{}20 & 300 & - & - & - & 200 & 10 & 100 & 100 & - \\ \hline \hline \end{tabular}  
* BRASAL [6]; \({}^{b}\) Gulf Technical Regulation [7]; \({}^{c}\) EU [8]; \({}^{d}\) MOA [9]; \({}^{e}\) Health Canada [10]: \({}^{f}\) Code of Federal Regulation [11]; \({}^{g}\) Codex Alimentarius [12]; \({}^{*}\) Residues found in this study refer to LQ, while LD where half the concentration of LQ for all compounds, except for backtracin (LD = 20 \(\upmu\)g/kg) and colistin (LD = 35 \(\upmu\)g/kg); the recovery rates for all compounds were between 80 and 110%; \({}^{m}\) all samples evaluated herein were from chicken meat, except for halofuginone hydrochloride, which was analyzed in liver; *** Tylosin has MRL for chicken meat, kidney, egg, milk, and honey.  
\end{table} 
Table 1: Results of the eleven compounds analyzed in chicken meat and liver, number of samples evaluated for each matrix; Brazilian legislation (matrix, number of samples, MRL) compared to worldwide MRL legislation regarding these same residues in meat. Regarding tianulin, all 300 samples showed residue levels below LQ (25 \(\upmu\)g/kg) in chicken meat. Although MAPA only analyzes this residue in eggs (MRL = 1000 \(\upmu\)g/kg), the amount allowed by other legislations in meat, as displayed in Table 1, is 100 \(\upmu\)g/kg for this type of residue. Tianulin is approved to be used in chicken and turkey production to reduce the severity of disease caused by mycoplasma, while in swine tianulin is FDA-approved to treat pneumonia and dysentery [15]. Bacitracin residues in this study showed concentration values below 75 \(\upmu\)g/kg in chicken meat, while MAPA has in its PNCRC scope that 300 samples need to be analyzed in eggs (MRL = 500 \(\upmu\)g/kg). In other legislations, bactracin residues vary from 150 to 500 \(\upmu\)g/kg for this type of residue. Bactracin is indicated for the prevention of necrotic enteritis caused, for instance, by _Clostridium_ spp. [16]. Spectinomycin residues determined in 300 samples of chicken meat were found to be below LQ < 50 \(\upmu\)g/kg. MAPA scope foresees spectinomycin determination only in chicken kidneys with MRL = 5000 \(\upmu\)g/kg in 600 samples collected annually. Other legislations demand MRL values varying from 100 to 500 \(\upmu\)g/kg in chicken meat.