Industrial egg residue as a calcium source in broiler feed: digestibility and growth performance.

Industrial egg residue (IER) possesses substantial concentrations of calcium and crude protein. The objective of this study was to measure the digestibility and performance of broilers when IER was added to the feed. Four treatments were tested, which caused increasing replacement of calcitic limestone by IER (0, 35, 70 and 100%) during a 42-day production cycle. First, total bird excreta were collected from broilers with and without IER, and we determined dry matter digestibility, apparent metabolizable energy (AME), calcium, and nitrogen retention. The IER presented 7.5% of crude protein, 31% of calcium, 209 kcal/kg of AME and the digestibility coefficients for dry matter, crude protein, and calcium were calculated at 83.95%, 86.20%, and 67%, respectively. After the digestibility test, the effects of IER on performance, carcass and meat yield were evaluated. No significant differences between the treatments were found in terms of performance (weight gain, feed conversion, consumption, and mortality), and no differences were found in terms of carcass or meat yield. A linear decrease in the percentage of abdominal fat was observed with increasing inclusion of IER in feed. These findings suggest that IER can totally replace limestone (calcium carbonate) in broiler diets.

Development of a readily applied method to quantify ractopamine residue in meat and bone meal by QuEChERS-LC-MS/MS.

A QuEChERS method of ractopamine (RCT) residue detection in swine meat and bone meal (MBM) samples was demonstrated. Samples were hydrolyzed with protease and ß-glucuronidase prior to QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) extraction and clean-up. Samples were analyzed in a Liquid Chromatography (equipped with ACE 5 C18 column under gradient elution) coupled with a triple quadrupole mass spectrometer operating in positive electrospray ionization mode (using multiple reaction monitoring, MRM). The method was validated for its specificity, decision limit (CCα), detection capability (CCß), recovery, repeatability, reproducibility, linearity, limits of detection (LODs), quantification (LOQs), and stability according to international guidelines (European Commission Decision 2002/657/EC). Recoveries ranged from 96.3 to 107.0%. Repeatability and reproducibility showed both RSD<5.7% and 3.1%, respectively. LODs and LOQs were 1.91 and 6.36 ppb, respectively. CCα and CCß values were 1.91 and 2.37 ppb, respectively. RCT showed good stability for spiked samples and real samples when the concentration was higher, otherwise at lower concentration stability was lower. The proposed method can be successfully applied on a regular basis for the determination of RCT in MBM, demonstrating the usefulness of the method as a tool for compliance monitoring in regulatory laboratories.