Review of literature and results from test matings of East Friesian milk sheep affected with brachygnathia inferior

Shortness of the lower jaw (brachygnathia inferior, underbite, overshot, parrot mouth) is an inborn and mostly hereditary malformation often seen in many sheep breeds. Chromosomal anomalies are generally not involved in brachygnathia inferior. Viral infections, teratogenic drugs and alkaloids of plants often lead to craniofacial malformations associated with brachygnathia inferior. A maternal deficiency of iron is discussed as a cause for brachygnathia inferior. We performed a three-year breeding trial using mainly East Friesian milk sheep affected by brachygnathic occlusion. Mating schemes included affected by affected and affected by unaffected matings. In the breeding trial, 60 lambs were born and from these 37 animals had variable degrees of brachygnathia inferior. The brachygnathic condition increased with rising age of the lambs. Extremely affected lambs showed palatine ulcers and growth retardation. Moreover, some animals had abnormal positions of the incisor teeth, distortion of the lower jaw and deformities of the external ear. Analysis of the pedigree did not support a monogenic inheritance pattern. An oligogenic inheritance including a dominant and recessive locus responsible for the major gene effects and possibly further modifying loci appeared much more likely. Other causes for brachygnathia inferior such as viral infections and anemia of the ewes could be ruled out. Chromosomal abnormalities were not evident and thus, large chromosomal defects were not associated with brachygnathia inferior.     

Reproducibility of bovine neonatal pancytopenia (BNP) via the application of colostrum

A haemorrhagic diathesis has been observed in young calves since 2007 which is described as bovine neonatal pancytopenia (BNP) and presents a completely new disease. The objectives of our investigation were to test if BNP could be reproduced using colostrum of cows with a BNP history and pre-colostral calves from farms where BNP has not been observed. In the present experiment, 22 German Holstein calves from BNP-free farms were fed four to six hours after birth 2.5 l colostrum from cows which had been reported to have had at least one calf with BNP in the last lactation. We distinguished three different experimental groups according to the composition of the colostrum. In experimental group I, each of the six calves received colostrum of a single cow, in experimental group II all six calves received colostrum from the same cow and in experimental group III each of the ten calves received a colostrum mix from ten different cows. Clinical signs of BNP were observed in 50% of the calves in experimental group I, 67% of the calves in experimental group II and all calves in experimental group III. The lethality in the three experimental groups was significantly different with rates of 16.7%, 66.7% and 80%, respectively. Calves fed with a colostrum-mix in experimental group III had the highest lethality. Neither the farm nor the amount of the colostrum fed had a significant effect on the occurrence and course of BNP. The profiles for thrombocytes, leucocytes and erythrocytes significantly differed in dependence of the severity of BNP signs. Calves with non-lethal BNP showed thrombocytopenia with values below 100 G/l on the 1th to 3rd and the 7th to 11th day of life. In calves with lethal BNP, thrombocytes decreased under 50 G/l from day 5. In calves with non-lethal BNP, a decrease of the leucocytes under the threshold was present only for a short period of time. In calves with lethal BNP, leucocytes decreased in the first 5 days after birth continuously and increased on the 6th to the 8th day to normal values and then a rapid decrease occurred. Erythrocytes decreased under the normal threshold just in the last two days before the calves died or were euthanized. Thus, the present experiments showed that colostrum of cows with a BNP-history and vaccination with PregSure BVD from Pfizer caused lethal BNP. We can assume that the different reactions of the calves are due to immunogenetic reactions to colostral alloreactive antibodies. The reaction spectrum of calves depends on the presence of antigens which can react with these colostral antibodies. The experimental results can explain the different incidences of BNP within and among farms as well as between breeds.     

Bovine neonatal pancytopenia in German Holstein calves

Profiles of blood cell counts were evaluated for 15 calves from three different farms. These calves showed petechia in the mucous membranes and in the skin and prolonged secondary bleeding after puncture. The clinical course of the disease could be observed in eleven calves. With exception of one case, the blood cell counts indicated a severe anaemia, leukocytopenia and thrombocytopenia. Out of these 15 calves, six calves survived and the other nine calves died or had to be euthanized due to the severity of the disease. Necropsy of these nine calves revealed petechia in the skin, subcutis, muscles, in inner organs and all serous membranes. Pathohistological examination showed a depletion of the bone marrow and lymphatic tissue in eight calves. These findings confirmed the diagnosis of bovine neonatal pancytopenia (BNP) for eight of these nine calves. Bluetongue virus serotype 8 was tested negatively using PCR. Bovine virus diarrhoea virus (BVDV) was negatively tested using immunofluorescence and cell culture and salmonella species were negatively tested in seven dissected calves. A cluster of toxins was negatively tested in one of the dissected calves. All 15 calves had high antibody titres for BVDV. The BVDV-antibody titres from twelve dams with affected calves were positive in six cases and not detectable in the other six cases. In three of the six dams with not detectable BVDV-antibody titres, calves were fed with colostrum of a further dam with high BVDV-antibody titres. In the further three dams without detectable BVDV-antibody titres, we could not ascertain which colostrum has been fed to the calves. BVDV-specific antigen could not be detected in any of the samples from the calves and dams tested. Using the activity of the gamma-glutamyl-transferase, we assumed a sufficient supply with colostrum for the examined calves.The cause for the occurrence of these BNP cases was due to bone marrow depletion.The reason for the bone marrow depletion remained unclear. However, it was obvious that the BNP described here is highly likely caused by colostrum from cows with positive BVDV-antibody titres.     

Arbuscular Mycorrhizal Inoculation of Peanut in Low-Fertile Tropical Soil. II. Alleviation of Drought Stress

The effect of drought stress and inoculation with an indigenous Mozambican and a commercial arbuscular mycorrhizal (AM) inoculant on root colonization and plant growth and yield was studied in two peanut (Arachis hypogaea L.) cultivars—a traditional, low-yielding Mozambican landrace (Local) and a modern, high-yielding cultivar (Falcon)—grown in a non-sterile Mozambican soil. In these cultivars, AM mycorrhizal colonization was not substantially reduced by drought stress. Growth and yield of inoculated plants subjected to drought stress were increased in comparison with non-inoculated ones. The indigenous Mozambique inoculant significantly increased leaf and root growth in both cultivars under drought stress by preventing an increase in root weight ratio (RWR) and maximum root-length to leaf-area ratio (MRLAR). The commercial Hannover inoculant had a positive effect on growth only under well-watered conditions, this result was due most likely to a lesser ability to adapt to drought conditions to which the AM fungal strains in Mozambique inoculant are frequently exposed. Such drought-stress effects on growth could be alleviated by inoculation with Mozambique inoculant, particularly because of its ability to decrease sensitivity of the host plant to reduction in leaf expansion. Therefore, an adequate management of the AM symbiosis may improve peanut productivity, particularly under drought stress and in small-scale farming systems.     

Advances in remote sensing of freshwater fish habitat: A systematic review to identify current approaches,strengths and challenges

Remote sensing technology offers the ability to derive information on freshwater fish habitats across broad geographic areas and has the potential to transform approaches to monitoring. However, the numerous platforms, sensors and analytical software that are available may overwhelm those interested in utilizing this important technology and thus limit its broad application and uptake. Our review is intended to shed light on the capacity of this technology to transform freshwater fish habitat monitoring by examining the fundamental characteristics of the major remote sensing technologies that have been used for characterizing freshwater habitats, conducting a systematic literature review of studies that have used remote sensing technologies to characterize freshwater fish habitats and, highlighting some of the key habitat features, fish species and regions, that have been examined. Lastly, we identify the relative strengths and weaknesses of the various remote sensing technologies that can be used, recommend future research that could help improve the use of these technologies, and, provide a series of important considerations for those who are interested in utilizing these technologies for freshwater fish habitat characterization.     

The comparative pathogenicity of four serovars of Actinobacillus (Haemophilus) pleuropneumoniae

The pathogenicity of 2 isolates of each of serovars 7, 3, 1 and 2 of Actinobacillus pleuropneumoniae was tested by intranasal inoculation into 60, 6-week-old large white pigs. Four dose rates varying from 0.27 to 560 x 10(6) organisms per pig with 10-fold serial dilutions were used. Surviving pigs were necropsied 7 days after inoculation. The proportion of pigs dying and developing gross lesions following infection was significantly greater for pigs given serotype 1 than for each of the other 3 serotypes, which did not differ significantly from each other. Twelve of 16 pigs given either of the 2 isolates of serovar 1 died after acute illness and 1 of 44 pigs given either of the 2 isolates each of serovars 7, 3 and 2 died. Pigs given serovar 1 showed high temperatures, severe respiratory distress, frothy haemorrhagic nasal discharge and weight loss. Lung lesions were produced in all 16 pigs given serovar 1, in 7 of 14 pigs given serovar 7, 7 of 14 pigs receiving serovar 3 and in 5 of 16 pigs given serovar 2. The lethal infections were characterised by a severe acute fibrinohaemorrhagic necrotising pleuropneumonia, whereas non-lethal cases had lung lesions ranging from necrotising purulent pleuropneumonia to abscessation. Significant differences between isolates in proportions of tissues culture positive for A. pleuropneumoniae for serovars 7 and 2, but not for serovars 3 and 1 suggested that isolates may vary in virulence within serovars, but more detailed studies are needed to clarify this point.     

Secondary indigestion as a cause of functional pyloric stenosis in the cow

In 23 cows suffering from a secondary indigestion, in most cases with septicaemia, the syndrome of functional pyloric stenosis or vagal indigestion developed. The signs were anorexia, ruminal distension with fluid material, abomasal reflux into the ruminoreticulum, dehydration, hypochloraemic, hypokalaemic metabolic alkalosis and uraemia. These signs often disappeared after treatment of both the primary causative disease and the secondary indigestion. The importance of recognising this condition is emphasised, because the serious signs of the secondary indigestion may dominate the causative disease. The prognosis depends upon the causative disease and is not necessarily bad.