Effect of a Grain Extract on Certain Digestive Physiological Indicators in Early Weaned Rabbits
ACTA VETERINARIA BRNO
Authors: Kovacs, Melinda; Kosa, Emma; Horn, Peter; Szendro, Zsolt; Milisits, Gabor
Abstract
The effect of a non-medicated diet with or without a grain extract feed additive (benzoquinones as main active ingredients) on the growth of rabbits and certain physiological indicators of the digestive tract was examined. One-day-old rabbits of average birth weight were distributed into litters of eight, and these litters were randomly divided into three groups (21-22 litters/group). The control group (Group C) received a basal diet. The diet fed to rabbits of Group IM, was supplemented with a feed additive containing natural basic ingredients (Immunovet-HBM, 1 kg/t); the diet fed to Group M was medicated (tiamulin, oxytetracycline and diclazuril). Three days prior to kindling and up to weaning at 21 days of age of the pups, the does were fed one of the three diets ad libitum. Young rabbits were allowed to consume the same diets beside their mother's milk before weaning. Significant (p < 0.05) difference in body weight between groups was detected only at the ages of 4 and 8 weeks. The pH of the gastric content remained significantly U) < 0.05) higher in Group IM after weaning. Rabbits in Group IM showed the highest pancreatic enzyme (trypsin, lipase, alpha-amylase) activities throughout the period studied. The composition of microflora of the caecum was only slightly altered by the treatment. The total volatile fatty acid content (tVFA) increased with age and from day 28 it was significantly (p < 0.05) higher in the C and IM group than in M rabbits. The proportion of butyric acid was lower than that of propionic acid even on the 42(nd) day in Group M. From the results of this study it is clear that the early weaning of rabbits can be accomplished by the use of a non-medicated diet without any decrease in weight gain. In our study the grain extract feed additive exerted a beneficial effect by increasing the pancreatic enzyme activity and maintaining a better VFA ratio.
SARCOCYSTIS NEURONA-INDUCED MYELOENCEPHALITIS RELAPSE FOLLOWING ANTICOCCIDIAL TREATMENT
JOURNAL OF PARASITOLOGY
Authors: Hay, Alayna N.; Witonsky, Sharon G.; Lindsay, David S.; LeRoith, Tanya; Zhu, Jing; Kasmark, Leah; Leeth, Caroline M.
Abstract
Sarcocystis neurona is a ubiquitous parasite in the eastern United States, which is the principal causative agent in the neurologic disorder equine protozoal myeloencephalitis (EPM). While much is known about this protozoa's life cycle in its natural host, the opossum (Didelphis virginiana), little is known of how it acts in the aberrant equine host, which displays a high incidence of exposure with a relatively low rate of morbidity. For this study, we employed the popular interferon gamma knockout mouse model to determine the potential for recrudescence of S. neurona infection after treatment with the anticoccidial drug diclazuril. Mice were infected with S. neurona merozoites, and 7-days post-infection (DPI) they were treated with diclazuril for 30 or 60 days or not treated at all. All infected non-treated mice developed neurologic signs consistent with S. neurona infection within 30 DPI. All diclazuril-treated infected mice remained clinically normal while on treatment but developed neurologic signs within 60 days of treatment cessation. Histological examination of cerebella from all infected mice demonstrated characteristic lesions of S. neurona infection, regardless of treatment status. Cerebellar samples collected from infected treated mice, displaying neurologic signs, produced viable S. neurona in culture. However, cerebellar samples collected from infected and neurologically normal mice at the end of a 30-day treatment period did not produce viable S. neurona in culture. Analysis of the humoral immune response in infected mice showed that during treatment IgM antibody production decreased, suggesting the organism was sequestered from immune surveillance. The cessation of treatment and subsequent development of neurologic disease resulted in increased IgM antibody production, suggesting recognition by the immune system at that time. Based on the study results the authors propose that diclazuril was able to inhibit the replication and migration of S. neurona but not fully eliminate the parasite, suggesting recrudescence of infection after treatment is possible.