Determination of biogenic amines in aerobically stored beef using high-performance thin-layer chromatography densitometry

The aim of this study was to develop a high-performance thin-layer chromatography densitometry method to simultaneously evaluate levels of different biogenic amines (BAs) in beef stored aerobically at 4°C. Steaks from M. longissimus thoracis et lumborum muscles were overwrapped with polyvinyl chloride film and stored for 0, 4, 7, and 10 days. For this purpose, the solvent system and pH for the derivatization of BAs with dansyl chloride were optimized. Moreover, this method was also validated for linearity, limits of detection and quantification, precision, and recovery. As found using this method in beef samples, spermine content decreased significantly after 7 days of storage, and tyramine and cadaverine were not detected until day 10.     

Use of thermal imaging for identification of foot lesions in dairy cattle

The objective of this study was to investigate the use of infrared thermography (IRT) for detection of foot lesions in dairy cattle. Thermal images of the rear feet of 139 lactating dairy cows were taken with a thermal camera and evaluated using imaging software. Foot lesions identified in the study included white line disease (WLD), sole ulcer (SU) and digital dermatitis (DD). Temperatures at the coronary band (CBT) and the skin (ST) were recorded. Cows were scored for locomotion on a scale of 1–5 (1?=?normal and 5?=?severely lame). CBT was higher for all types of foot lesion (34.1?±?2.3, 33.8?±?1.6 and 33.1?±?1.6°C for WLD, SU and DD, respectively) than for healthy (32.6?±?1.9°C) feet. ST was higher only for WLD (33.2?±?2.0°C) compared to healthy feet (31.5?±?1.7°C). ΔT (temperature difference between CBT and ST) was higher for SU (2.1?±?0.8°C) than healthy feet (1.1?±?0.9°C). Locomotion scores (LSs) were similar between healthy cows (2.2?±?0.7) and DD (2.4?±?0.7) but greater for SU and WLD cows (3.0?±?0.9, 3.0?±?0.8) than healthy cows. The threshold values established for CBT and ST were 33.5°C (sensitivity?=?77.8%, specificity?=?65.2%) and 33.7°C (sensitivity?=?44.4%, specificity?=?92.9%) for SU, and 34.4^oC (sensitivity?=?28.1%, specificity?=?88.6%) and 31.8°C (sensitivity?=?60.7%, specificity?=?55.4%) for overall lesion, respectively. These results indicate that IRT can be a useful tool for detection of SU, but not WLD and DD. In addition, CBT and ΔT were the best indicators for the detection of foot lesions.     

The suitability of some blood gas and biochemical parameters as diagnostic tools or early indicators of ascites syndrome in broiler sire lines

In recent few years, there have been some attempts to find a reliable indicator trait as a selection criterion against susceptibility to ascites syndrome (AS). Blood parameters were of great interest as they could be measured in live animals without implementing an ascites‐inducing challenge (AIC). In this work, the suitability of some blood parameters was evaluated for diagnosing AS‐susceptible chicks in later steps of the disease in trial 1 as well as their early predictive ability in trial 2. In the first trial, one hundred 1‐day‐old chicks from two pure broiler lines namely S₁ and S₂ and, in the second trial, 226 1‐day‐old chicks from line S₂ were subjected to AIC. Saline drinking water (1200 mg/l) and lower‐than‐standard ambient temperatures were the implemented AICs in trials 1 and 2 respectively. The blood parameters including pH, partial pressure of O₂ (pO₂), partial pressure of CO₂ (pCO₂), bicarbonate ion concentration (BIC), percentage of haematocrit (HCT) and saturated haemoglobin (SaO₂) were measured twice per each bird at days 28 and 35 in trial 1 and once in trial 2 at day 21. The results of the first trial revealed that in line S₂ some of the blood parameters differed significantly between the ascitic and non‐ascitic groups following exposure to AIC. In this line, the incidence of AS was accompanied by a lower pO₂, SaO₂ and BIC, while with higher pCO₂ and HCT values. In the second trial, however, although almost all of the parameters showed meaningful differences between the ascitic and non‐ascitic broilers, only mean difference of BIC parameter was statistically significant. The general conclusion of this study is that the blood parameters can somewhat have diagnostic ability in the condition in which the AIC is already present, whereas the results did not approve their usefulness as early predictors of AS.     

Physiological and biochemical changes of females of Piracanjuba,subjected to induced reproduction

The aim of this experiment was to compare the level of fish female stress during induced reproduction with pituitary extract by two different methods, natural and semiextruded. The reproductive efficiency was 62.5% in the seminatural treatment and 100% in the extruded. Obtained egg volume was 5200 ml and 4000 ml, for seminatural and extruded treatments respectively. The mean number of eggs was 46.7 for the seminatural and 52.0 and for the extruded treatment. The percentage of viable eggs was, respectively, 87.2% and 8.17% for the natural treatment and extruded semimethods. Blood samples were collected to quantify cortisol and glucose levels, as well as red cell series and lymphocyte count. Fishes submitted to induction procedures showed elevated cortisol and glucose levels, compared to the control animals. The results for haematocrit, haemoglobin concentration and red blood cell count showed no significant differences among groups. Significant differences found in the number of lymphocytes and monocytes suggest the general adaptation syndrome. Our results suggest the reproductive induction process with extrusion of gametes as a more stressful method than seminatural reproduction process.