Behavioural method to detect marginal neurotoxic effects of ivermectin in DA/Orl rats.

Ivermectin (22, 23-dihydroavermectin B 1) in subtoxic doses was administered subcutaneously to young adult DA rats. Prior to treatment the rats had been trained in a visual discrimination learning programme until their response pattern was stable. The behavioural response data were recorded during continued discrimination testing following the Ivermectin injection and compared with those of a control group. The results showed that the Ivermectin injection reduced the total number of lever presses and reinforcement collections. Further the treatment caused an increase in the total number of erroneous responses.     

Chronic Copper Poisoning in Sheep

Four cases of experimental copper poisoning in sheep were examined. Light microscopical and ultrastructural alterations of erythrocytes were observed a few hours before a significant haemolysis was evident. Heinz body formation in otherwise unchanged red cells was the first morphological alteration observed. The Heinz bodies were predominantly membrane-attached. During the haemolytic crisis severe erythrocytic distortion, structural membrane alteration and Heinz body-containing ghost cells were observed. Erythrophagocytosis was mainly located to the RE cells of the spleen. Intrafollicular necroses were found in all histological sections from the spleen. Pathological changes in liver and kidney were comparable to those of earlier reports, comprising hepatocellular and renal tubular necrosis.     

Impact of two myostatin (MSTN) mutations on weight gain and lamb carcass classification in Norwegian White Sheep (Ovis aries)

Background

Our aim was to estimate the effect of two myostatin (MSTN) mutations in Norwegian White Sheep, one of which is close to fixation in the Texel breed.

Methods

The impact of two known MSTN mutations was examined in a field experiment with Norwegian White Sheep. The joint effect of the two MSTN mutations on live weight gain and weaning weight was studied on 644 lambs. Carcass weight gain from birth to slaughter, carcass weight, carcass conformation and carcass fat classes were calculated in a subset of 508 lambs. All analyses were carried out with a univariate linear animal model.

Results

The most significant impact of both mutations was on conformation and fat classes. The largest difference between the genotype groups was between the wild type for both mutations and the homozygotes for the c.960delG mutation. Compared to the wild types, these mutants obtained a conformation score 5.1 classes higher and a fat score 3.0 classes lower, both on a 15-point scale.

Conclusions

Both mutations reduced fatness and increased muscle mass, although the effect of the frameshift mutation (c.960delG) was more important as compared to the 3''-UTR mutation (c.2360G>A). Lambs homozygous for the c.960delG mutation grew more slowly than those with other MSTN genotypes, but had the least fat and the largest muscle mass. Only c.960delG showed dominance effects.     

Comparative ultrastructural study on merkel cells and dermal basal cells in poultry (Gallus domesticus)

Summary Basal cells of the hard palate epithelium have been examined electronmicroscopically. Secretory granules, morphologically similar to those of the Merkel cells, occur in the groups of basal cells. A comparison concerning the cytoplasmic qualities of the two cell types is given, and the possibility of a cytogenetical or physiological relationship between the Merkel cells and the basal cells is discussed.Supported by the Agricultural Research Council of Norway.     

Teratogenicity and Embryotoxicity of Orally Administered Fenchlorphos in Blue Foxes

Pregnant blue foxes (Alopex lagopus) were administered fenchlorphos (0-0-dimethyl-0-(2,4,5-trichlorophenyl) phos-phorothioate) orally at a dose of 100 mg/kg/day in different periods of gestation. The dose chosen represents the therapeutic dose for the treatment of parasitic lesions. At term the mean number of whelps were recorded, and they were killed and examined for external, visceral and skeletal malformations. Of 19 medicated vixens the mean number of live whelps at term was 1.2 per vixen versus 9.5 in the control group. There was an evident predominance of males in the medicated groups. Several malformations of the head were registered, among them incomplete ossification of the skull bones, cleft palate, hydrocephalus internus and externus. Minor malformations like extra ribs or missing ribs occurred in the medicated groups. Congenital alopecia, hypoplastic kidneys, and hydronephrosis were observed in all the whelps in 1 medicated group. No significant difference in total brain weight, cerebellum weight or the cerebellum-to-total-brain weight was observed. Histological examination of the cerebellum showed a narrowing or absence of the granular and the molecular layers of the cortical zone.     

An electron microscope study on the termination of the perforant path fibres in the hippocampus and the fascia dentata

Summary Morphology and distribution of the perforant path fibres in the hippocampus and the fascia dentata of the rat have been studied in the electron microscope. Investigations were carried out on normal tissue as well as on tissue degenerating after entorhinal damage. The perforant path fibres were relatively thin and the terminals small. Two terminal fields were found to be of quantitative importance, one in the middle third of stratum moleculare of the fascia dentata, the other in stratum lacunosum moleculare of regio inferior of the hippocampus. Some of the observations have been expressed in numerical terms.This study was supported in part by Grant NB 02215 from the National Institute of Neurological Diseases and Blindness, U.S. Public Health Service.     

The Vitamin E-Deficiency Syndrome in Pigs

Four feeding experiments with fat-rich diets were performed to study the gross and histologic pathology of the vitamin E-deficiency syndrome in pigs. The pathologic changes which occurred included skeletal and heart muscle dystrophy with degenerative and micro- thrombotic vessel injury, anaemia, liver necrosis (hepatosis diaetetica) and yellow discoloration of the fat tissue (yellow-fat disease). In some cases clear-cut pathologic changes corresponding to “mulberry heart disease” or hepatosis diaetetica occurred, but there was an obvious tendency for these pathologic conditions, as well as for muscle dystrophy and yellow fat to occur simultaneously. The changes could be counteracted with alphatocopherol, while supplement of selenium or sulphur-containing amino acids did not protect against the lesions under the conditions of these experiments. This may be due to the high content of unsaturated fatty acids in the experimental diets. Contradictory to earlier reports, hepatosis diaetetica developed on diets containing casein as a source of protein, and even when extra supplements of sulphur-containing amino acids were given. In these experiments „mulberry heart disease” was induced experimentally in vitamin E-deficient pigs. The explanation why several of these pigs belonged to groups with extra amino acids or selenium supplement may be a somewhat improved rate of growth in these groups.     

Spatial variation in the evolutionary potential and constraints of basal metabolic rate and body mass in a wild bird

An organism's energy budget is strongly related to resource consumption, performance, and fitness. Hence, understanding the evolution of key energetic traits, such as basal metabolic rate (BMR), in natural populations is central for understanding life-history evolution and ecological processes. Here we used quantitative genetic analyses to study evolutionary potential of BMR in two insular populations of the house sparrow (Passer domesticus). We obtained measurements of BMR and body mass (M_b) from 911 house sparrows on the islands of Leka and Vega along the coast of Norway. These two populations were the source populations for translocations to create an additional third, admixed ‘common garden’ population in 2012. With the use of a novel genetic group animal model concomitant with a genetically determined pedigree, we differentiate genetic and environmental sources of variation, thereby providing insight into the effects of spatial population structure on evolutionary potential. We found that the evolutionary potential of BMR was similar in the two source populations, whereas the Vega population had a somewhat higher evolutionary potential of M_b than the Leka population. BMR was genetically correlated with M_b in both populations, and the conditional evolutionary potential of BMR (independent of body mass) was 41% (Leka) and 53% (Vega) lower than unconditional estimates. Overall, our results show that there is potential for BMR to evolve independently of M_b, but that selection on BMR and/or M_b may have different evolutionary consequences in different populations of the same species.