Forecasting of bovine abomasal worm burden by means of serum pepsinogen measurement. Study on suckling calves and heifers in first and second grazing season.
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Abattoirs↗
Biomedical subjects
D Kerboeuf
Publications and source records attributed to D Kerboeuf.
Repeated anthelmintic treatments and receptivity of mice to experimental infections with Heligmosomoides polygyrus (Nematospiroides dubius).
Two experiments were carried out to define the effect of repeated anthelmintic treatments with or without repeated infections by H. polygyrus on the receptivity of the mouse to subsequent infections by the same parasite. The aim of the first experiment was to show the effect of these interventions on the future development of host resistance. This experiment did not reveal a marked difference in behaviour between treated or non-treated animals. During the second experiment a modification of the acquisition of resistance during the period of infections and multiple treatments was looked for. It was shown that multiple treatments of the host during the period of immunity markedly improved the mechanisms of defense against a new infection. Any direct action of anthelmintics was ruled out in explaining this mechanism. Two drugs were compared: pyrantel tartrate and levamisole. No difference has been shown between these two drugs. It is possible, however, that the multiple treatments act by enabling a more intense renewal of the parasitic population and therefore by increasing the stimulus initiating protection.
Animals↗
[Modifications by Nematoda of the sensitivity of mice to Salmonella abortus ovis administered orally or subcutaneously].
Mice inoculated 6 to 9 days previously with Heligmosomoides polygyrus (=Nematospiroides dubius) become more frequently infected than controls after an oral challenge with a constant dose of Salmonella abortus ovis. But parasitism increases the LD 50 when the subcutaneous route of infection is used, probably by stimulating the immune system of the host.
Administration, Oral↗
Study of gastro-intestinal stronglyosis in a sheep flock on permanent pasture. 1. Sheep parasitism in 1977.
An epidemiological study aimed at defining gastro-intestinal parasitism in sheep qualitatively and quantitatively was carried out in the Limousin area in France. Five lambs were sacrificed regularly every 4 weeks from May till January of the following year. Complete parasite counts were performed on these animals as well as measurements of the plasma level of pepsinogen. In order to define the influence of parasitism on the growth of the animals, the weight gains of lambs treated regularly and untreated lambs were compared. The results of post-mortem examination show that parasitism is mainly linked to the incidence of strongyles. Other observations in the flock have shown that Moniezosis may also play a non-negligeable part. The parasitic level, already high after one month at pasture, reached its maximum in July-August 1977 and was marked by a very high level of parasitism. Among these species found, two played an essential part: Ostertagia circumcincta and Haemonchus contortus. A study of the growth of the lambs showed that within 6 months, the weight gain of the treated animals was twice that of the untreated animals. The effects of parasitism were worsened by the low fodder value of the pasture and the occurrence of overgrazing. The blood pepsinogen measurements confirmed the usefulness of this technique in establishing the mean level of infestation of a flock by parasites of the abomasum. It seems that in some cases it could help to define the succession of peaks of infestation by different species.
Animal Nutritional Physiological Phenomena↗
The effects of time and temperature of storage on the infectivity of third-stage larvae of Heligmosomoides polygyrus (= Nematospiroides dubius). 1. Effects on the development to the adult stage in mice.
The relationship between storage time and temperature on the infectivity of the third-stage larvae of Heligmosomoides polygyrus (= Nematospiroides dubius) was examined. Results showed that third-stage larvae lose their infectivity when they aged. This loss was steeper at 22 degrees C than at 4 degrees C. Results obtained at 15 degrees C seemed to be intermediate. Data also demonstrated that a maturation period was required for maximum infectivity. A longer maturation period was observed at + 4 degrees C than at 22 degrees C and the maximum was maintained for longer at 4 degrees C.
Animals↗
The effects of time and temperature of storage on the infectivity of third-stage larvae of Heligmosomoides polygyrus (= Nematospiroides dubius). 2. Studies on the fecundity of female worms as a function of the infectivity of the third-stage larvae.
In this study we examined the effect of infectivity of third-stage larvae on the fecundity of H. polygyrus female worms. Groups of 10 mice were infected with third-stage larvae which had been stored for different lengths of time at 22 degrees C. Results showed that the number of eggs laid by one female worm increased when the worm burden was smaller and decreased with a greater worm burden. Also, the egg-output of female worms growing in a similar population varied according to the level of infectivity of the larvae, with a low infectivity resulting in greater fecundity and vice versa. These results may explain the variations in egg-output which are recorded at different times of the year from the parasites of grazing animals. If this phenomenon is confirmed in other species of parasites, it will be important for epidemiological studies.
Animals↗
Changes in pepsinogen, proteins and lipids in the serum during experimental haemoncosis in sheep.
To determine the relationship between the course of infection by parasites of the genus Haemoncus and variations in the level of serum pepsinogen, an experiment was done with three groups of five lambs. The first was a non-infested control group. The lambs of the second group were given one dose of 10,000 H. contortus infective larvae. The animals of the third group were given one dose of 50,000 larvae. Fluctuations of the level of serum pepsinogen were determined throughout the experimental period (88 days). Observations also included variations of protein and lipid levels. Our experimental results showed that the development of H. contortus larvae, even when in small numbers, can cause lesions comparable to ostertagiosis in abomasum and produce the same rise in the level of serum pepsinogen. This increase in serum pepsinogen appeared to be related to the amount of larvae which were given. The high level of serum pepsinogen persisted over a long period. Variations of the serum, total protein and albumin levels were the same as described by other authors. There was no decrease in serum lipids.
Animals↗
[Survival of parasitic elements in liquid manure: effect of xylene (author's transl)].
The spreading of liquid manure may play a role in the transmission of parasitism. In this preliminary study, we have investigated the evolutionary and survival capacities of parasitic elements in liquid manure, their development potential after extraction and the destructive action of xylene in concentration of 1 p. 1000. As parasitic models we have retained: the coccidial oocyst (E. tennella), a thick-shelled egg (A. suum), thin-shelled eggs (H. contortus, O. quadrispinulatum), a trematode egg (F. hepatica) and larva III of H. contortus. The studies were carried out in Erlenmeyer with parasite free liquid manure taken from a bovine cowshed. Water was used as control medium. The parasitic models were kept in the liquid manure for a maximum of 17 days excpet for Ascaris suum, 45 days. Only the coccidial oocyst is little affected. The eggs of Trichostrongylides and of Fasciola show a poor resistance to this environment and to a lesser degree the egg of Ascaris. The larvas III are rapidly destroyed and those obtained from eggs that stayed in liquid manure have a greatly diminished viability. The antiparasitic action of xylene varies according to the type of parasitic element. Its action is particularly clear on the eggs of Trichostrongylides and of Fasciola hepatica.
Animals↗
The negative effects of the residues of ivermectin in cattle dung using a sustained-release bolus on Aphodius constans (Duft.) (Coleoptera: Aphodiidae).
This paper reports the findings of two trials into the effects of the treatment of cattle with ivermectin slow-release (SR) bolus on the larval development of the dung beetle Aphodius constans Duft. Rectal faecal samples were collected prior to treatment and every 3 and 2 weeks in a first and second trial, respectively, and up to 156 days post-administration of the SR bolus. Faecal ivermectin concentration reached a peak at 63 days post-treatment (1427 ng g(-1)) and ivermectin was detected up to 147 days post-treatment in the first trial (7.2 ng g(-1)). First stage larvae of A. constans were reared with control or contaminated dung and adult beetles were counted after emergence. In the first trial, the comparison of pairwise samples showed that ivermectin prevented the development of larval A. constans until day 105, while at day 135 the rate of emergence was still significantly lower than the corresponding series of control (p < 0.05). In the second trial, the difference between control and treated series remained significant until 143 days post-treatment, with no emergence until 128 days post-administration of SR bolus to cattle. These results show the negative effect of ivermectin on the development of larval A. constans, even at a low concentration (38.4 ng g(-1)). The administration of ivermectin sustained-release bolus to cattle was highly effective in killing dung beetle larvae for approximately 143 days after treatment. The results were similar when dung was obtained from a single animal kept alone, or from a blending of faecal pats obtained from a group of animals kept in field conditions during the whole trial period.
Animals↗
Identification and cytogenetic analysis of an abnormal pig chromosome for flow cytometry and sorting.
For cytogenetics of pig (Sus scrofa domestica) and the influence of chromosome aberrations on pig production, high interest exists in flow sorted chromosomes for gene mapping, to establish DNA-libraries, or to produce DNA-probes. Flow karyotyping and sorting as well as slit scan flow analysis of metaphase chromosomes of an abnormal cell type carrying a translocation marker chromosome 6/15 are described. Flow sorting of the largest chromosomes of these cells was performed. After sorting the chromosomes still had a well preserved morphology and were identified microscopically by G-banding. The quality of the band pattern of the sorted chromosomes was compatible to that of isolated chromosomes not subjected to flow cytometry. The sorted fraction showed an enrichment of chromosome 6/15 and chromosome 1 which have quantitatively about the same integrated fluorescence intensity. Slit scan flow analysis was performed to discriminate these two chromosomes. Metacentric and submetacentric chromosomes were analyzed according to their bimodal slit scan profiles. Profiles of the largest chromosomes were distinguished by their different centromeric indices. Two groups were interpreted as the normal chromosome 1 and the translocation chromosome 6/15.
Animals↗
Statistical methods of detection of a periodic phenomenon in a short series. Example of application: a density series of nematode eggs - II.
Using the example of the statistical treatment of a series of density of nematode eggs, we give here a survey of the main methods of detection of a periodic phenomenon in a short series. The purpose of these methods, which may be ranked into 3 groups: smoothing methods, regression methods, autocorrelations, is to study non random characteristics of the process. We detected in this series and estimated a rhythm of period 12 h. We concluded that the regression methods are the most resourceful for detecting a deterministic periodic phenomenon but that it is useful to confirm the results using the other methods.
Animals↗
Rhythmic egg release by Heligmosomoides polygyrus (= Nematospiroides dubius), parasitic Trichostrongylida of the murine gut.
Heligmosomoides polygyrus is a strongyle parasite of the murine small intestine. The existence of a daily rhythm of parasite egg production was sought. Two series of measurements were analyzed, one lasting 3 days, the other 4. Variables measured were faecal weight emitted hourly and the density of parasite eggs/h/g faecal matter. Results show a very significant rhythm of egg production, with a 12 h period and variable amplitude. A peak of excretion was recorded between 0500 and 0600 and another between 1700 and 1800, followed by a greater peak corresponding to egg release between 0000 and 0100 or 1200 and 1300. There also exists a negative influence of the phenomenon on itself: a peak of production is followed by a highly reduced excretion 6-h later. The analysis of faecal production showed the existence of a 12-h cycle and of a 24-h cycle independent of the former. As in the case of egg production, the same negative influence of faecal production on itself was observed with a 6-h delay. The peaks of faecal matter and egg excretions do not coincide but there are certain similarities between the two phenomena. Crossed correlations between the faecal production and egg production series show instantaneous relations or those with a 4-5 or 6 h delay. This is consistent with an effect of faecal production, thus intestinal transit, on egg excretion, but this remains to be confirmed by subsequent work.
Animals↗