Manuel Gascón

Effect of transport time on welfare and meat quality in pigs.

The purpose of this study was to determine the effects of transport duration on some welfare and meat quality parameters. For the study 144 pigs were used. One group of 72 animals was subjected to 15 min and the others to 3 h transport time. Blood from all animals was analysed in order to detect stress-susceptible pigs and assess pre-slaughter stress. Meat quality parameters were analysed from Longissimus thoracis and Semimembranosus muscles. It was concluded that under normal Spanish commercial conditions, pigs subjected to short transport showed a more intense stress response and poorer meat quality than pigs subjected to moderately long transport when they were immediately slaughtered on arrival at the slaughterhouse. Transport of 3 h might have allowed the animals to adapt to transport conditions and then could act as a resting period like a lairage time. The effect of transport time on welfare and meat quality parameters was more important than genotype and sex. Nevertheless, from the point of view of blood enzyme activities, genetically stress susceptible females transported for 3 h were more sensitive to muscle damage.

Variations of clinical biochemical parameters of laying hens and broiler chickens fed aflatoxin-containing feed.

Two groups of 32 laying hens (Hyssex Brown) and two groups of 32 23-day-old (Hybro) broiler chickens were fed 2.5 and 5 parts/10(6) of aflatoxin in their diet for 4, 8, 16 and 32 days; 16 hens and 32 chicks were maintained as control groups (0 parts/10(6)). After the intoxication period, a clearance period was established of 1, 2, 4 and 8 days. Relative weights of liver and kidneys significantly increased in intoxicated hens, but not in broiler chickens. Histological lesions in both types of bird consisted of hepatic cell vacuolation with fatty infiltration. There was a significant decrease (P< 0.001) in egg production in the 5 parts/10(6) group, which started to recover during the clearance period. No morbidity or mortality due to the aflatoxicosis were observed in either type of bird. In intoxicated laying hens, cholesterol levels were not significantly (P> 0.05) different from control values, but triglyceride levels decreased (P< 0.001) in both intoxicated groups. The effect of aflatoxin on calcium and phosphorus levels was important, because on the 4th day their values decreased significantly. Aspartate aminotransferase (AST) serum levels remained normal, whereas alanino aminotransferase (ALT) activity decreased in both intoxicated groups. The activity of serum lactic dehydrogenase (LDH) and gammaglutamil transferase (GGT) increased significantly. In intoxicated broiler chickens, aflatoxins did not alter (P> 0.05) the biochemical parameters studied, except that the serum calcium concentration was lower in the 5 parts/10(6) group. These data indicated that in intoxicated laying hens, a severe clinical biochemical alteration was produced, and that this together with the hepatic lesions observed in hens and broilers may aid disease diagnosis.

CHANGES IN THE PROTHROMBIN TIME, HAEMATOLOGY AND SERUM PROTEINS DURING EXPERIMENTAL AFLATOXICOSIS IN HENS AND BROILER CHICKENS

Two groups of 32 laying hens and two groups of 32, 23-day-old broiler chickens were given 2.5 and 5 mg kg-1 of aflatoxin in their diet for four, eight, 16 and 32 days; 16 hens and 32 broiler chicks served as control groups. In the laying hens, aflatoxicosis was characterised mainly by an increase in prothrombin time, and decreases in total plasma proteins and albumin levels; there were increases in red blood cell (RBC) counts and haematocrit which were greater in the group fed 5 mg kg-1. There was a decrease in beta-globulins and an increase in gamma-globulins. In the broiler chickens, there was only a slight increase in prothrombin time and a decrease in RBC counts. This data proves the good sensitivity and utility of prothrombin time values as an indicator of aflatoxicosis in birds.

The nitroblue tetrazolium reduction test in canine leishmaniosis

The nitroblue tetrazolium reduction test (NBT) is a quick, easy and cheap assay based on the activation percentage of neutrophils in peripheral blood. The aim of this study was to evaluate the NBT on healthy dogs and in dogs affected by different degrees of leishmaniasis (Stages I and IV). Forty healthy dogs, 20 dogs in Stage I and 20 dogs in Stage IV were included in the study. Three millilitres of blood were extracted from all the dogs via jugular venipuncture in tubes with EDTA. Incubation with NBT was performed depositing 0.05 ml of the leukocyte suspension in the same quantity of 0.1% concentration NBT. The results of the test were reported as NBT reduction rate which represents the percentage of the total of neutrophils evaluated that presented cytoplasmatic accumulations of formazan, meaning a positive NBT reduction. The mean NBT reduction rate for the healthy dogs group was 4.57%, 34% for Stage I dogs (mild disease) and 3.7% for dogs in Stage IV (severe disease), showing that dogs affected with leishmaniasis but with no clinical development of disease have a significantly higher neutrophil reactivity (p<0.01). Although more studies evaluating the correlation of NBT with other tests prior to and during treatment are needed, NBT could be a good assay in canine leishmaniasis evaluation.

Foundamentals and Applications of Abdominal Doppler

Since the Doppler effect was firstly described by Christian Doppler in 1842, it has been applied in many different fields. In human medicine has been extremely helpful in monitoring the fetal viability or assessing the carotid flow, and it is currently being used in most of the disciplines. In veterinary medicine, the Doppler effect is a helpful tool in abdominal ultrasound, and essential in the echocardiography exam. Its principle can be defined as the apparent shift in transmitted frequency, reflected back to the source off a target, which occurs as a result of the movement of this target. When this effect is applied in ultrasonography, the red blood cells (RBC’s) are the moving targets, and the apparent shift in the frequency of the sound reflected back to the transducer is proportional to their velocity and direction of the movement. The software of the ultrasound machine displays this values in a color code (Color Doppler) or in a graphic, (spectral trace of the Pulsed wave Doppler (PW) or Continuous wave Doppler (CW)). In Color Doppler, a given color is usually assigned to the direction of flow; red is flow toward, and blue is flow away from the transducer (Figure 1). The center of the color bar, displayed in the screen, is black and represents zero flow. In addition to simple direction, velocity information is also displayed. Progressively increasing velocities are encoded in varying ranges of either red or blue. The more dull the hue, the slower the velocity. The brighter the hue, the faster the relative velocity. Color Doppler is also used to display turbulent flow (showing a mosaic of many colors) and allows an operator to discriminate between normal and abnormal flow states. Color Doppler is useful for assessing relatively big areas, whilst PW (Pulsed Wave) and CW (Continous Wave) Doppler are used for assessing smaller areas of interest. Since Color Doppler is a type of pulsed wave Doppler, it suffers from the same limitations. Before explaining the difference between CW and PW, explaining the concept of spectral trace is required. This is the graphic representation of velocity flow profile against time. Depending of the number of cells crossing the amount of signal increases (Figure 2).