1,721,044 research outputs found
Age-related differences of Ascaridia galli egg output and worm burden in chickens following a single dose infection
No full textNinety white chickens (Lohmann LSL) were reared under helminth-free conditions and divided into five groups. Four groups were artificially infected with 250 embryonated Ascaridia galli eggs at the age of 6, 12, 18 or 24 weeks. Ten birds were kept as uninfected controls. Six and 10 weeks after infection (p.i.), individual faecal egg counts (FEC) were performed. The birds were slaughtered after the second sampling and their gastrointestinal tracts were examined for the presence of adult A. galli. The FEC increased from the first to the second sampling significantly in all the infected groups. The highest increase was shown in the group infected at 12 weeks of age, whereas the increase in the other groups was relatively moderate. However, the total worm burden and mean FEC at the second sampling were highest (p 0.05) between any of the groups. Thyroxine (T4) was significantly different between the groups infected at 6 and 18 weeks of age (p < 0.05), and those at 6 and 24 weeks of age (p < 0.01). The thyroid hormone levels correlated significantly with the FEC. Age does not seem to play a major role in resistance to A. galli infections in layers, whereas a bird's hormonal and immune status, related to laying activity, seems to have a significant negative impact on resistance. (c) 2004 Elsevier B.V. All rights reserved
Use of FAMACHA (R) Eye-Colour-Chart in the context of breeding for parasite resistance in lambs exposed to an artificial Haemonchus contortus infection.
No full textThe control of gastro-intestinal nematodes in sheep has almost entirely been based on the use of anthelmintics and pasture management. Therefore anthelmintic resistance escalated in the past. One way of reducing this problem may be the limitation of anthelmintic treatment to those animals with clinical symptoms only. The FAMACHA(R) Eye-colour-chart is based on the principle knowledge that the colour of mucous membranes are correlated with the anaemiae situation of an animal. To monitor anaemic animals they are identified and classified in a 1 to 5-color scale based on the colour of the conjunctiva, and anaemic animals can be selectively treated. It helps to reduce treatments and therefore the development of drug resistance. The objective of this study was to estimate the correlation between FAMACHA(R)-scores, haematocrit values, faecal egg counts, plasma albumin level and worm burden following an experimental infection with Haemonchus contortus in lambs. The estimated correlations have been low. This proofs the limits of the FAMACHA(R) system under a situation of low parasite pressure
Use of FAMACHA (R) Eye-Colour-Chart in the context of breeding for parasite resistance in lambs exposed to an artificial Haemonchus contortus infection.
No full textThe control of gastro-intestinal nematodes in sheep has almost entirely been based on the use of anthelmintics and pasture management. Therefore anthelmintic resistance escalated in the past. One way of reducing this problem may be the limitation of anthelmintic treatment to those animals with clinical symptoms only. The FAMACHA(R) Eye-colour-chart is based on the principle knowledge that the colour of mucous membranes are correlated with the anaemiae situation of an animal. To monitor anaemic animals they are identified and classified in a 1 to 5-color scale based on the colour of the conjunctiva, and anaemic animals can be selectively treated. It helps to reduce treatments and therefore the development of drug resistance. The objective of this study was to estimate the correlation between FAMACHA(R)-scores, haematocrit values, faecal egg counts, plasma albumin level and worm burden following an experimental infection with Haemonchus contortus in lambs. The estimated correlations have been low. This proofs the limits of the FAMACHA(R) system under a situation of low parasite pressure
Influence of Ascaridia galli infections and anthelmintic treatments on the behaviour and social ranks of laying hens (Gallus gallus domesticus)
No full textIn the present study, the effects of an experimental Ascaridia galli infection and anthelmintic treatment on the behaviour and social status of laying hens of two different lines were studied. Sixty white (Lohmann LSL; LSL) and 60 brown (Lohmarm Brown; LB) hens were reared under helminth-free conditions. The hens of each line were divided into four groups. The birds in two of the groups were artificially infected with 250 embryonated A. galli eggs at an age of 27 weeks. The other two groups were kept as uninfected controls. One infection and control group was dewormed at 38 weeks of age and slaughtered 4 weeks later, contemporary with the other animals. Individual faecal Ascaridia egg counts (FEC) were performed 11 weeks post-infection (p.i.). Body weights, laying performance and egg weights were recorded regularly. Blood was taken to measure testosterone levels. The worm burdens established in the intestines were counted in the infected not treated group after slaughtering. In addition, 15 behavioural parameters were recorded by focal animal observation (n = 10 per group) of one infection (plus anthelmintic treatment) and one control group, according to the time-sampling method throughout the experiment. All agonistic interactions within the groups were recorded simultaneously on an ongoing basis, thereby allowing the calculation of an individual social rank index. The following results were obtained: Mean FEC and worm burden were higher (p 0.05) from the controls. Infections with A. galli resulted in significant behavioural changes in both lines as the infected birds showed a higher food intake and lower locomotion activity during the prepatent and patent periods. After anthelmintic treatment, food intake decreased and locomotion increased. Behavioural changes were more pervasive in the infected LSL hens, as these hens also showed changes in ground pecking and nesting activity not only during the prepatent and patent periods, but also after anthelmintic treatment. Social rank did not significantly change as a consequence of A. galli infection, but the infection groups of both lines had a tendency to display more agonistic activity than the non-infected controls. Serum testosterone values only increased significantly in the LSL hens during the patent period compared to the controls. No significant correlations were apparent between serum testosterone level, parasitic parameters, social status and/or aggressiveness in any of the groups
Effects of weaning beef cattle in two stages or by abrupt separation on nasal abrasions, behaviour, and weight gain
No full textThe effects of traditional (n = 103) and two-stage weaning (n = 89) on nasal abrasions, behaviour, and weight gain were evaluated in a total of 192 cow-calf pairs. Two-stage calves were prevented from suckling by fitting nose flaps for 7 days before separation from their mothers. Nasal abrasions caused by the devices were assessed by scoring the irritations of the nasal septum at removal and 1 week later. The behaviour of 20 calves was observed for 3 days before and 4 days after weaning and vocalisations of the cows after separation were recorded. Nasal abrasions were found in more than 95% of the animals at removal, whereas 30% of the animals showed heavy bleeding and 10% suffered from even worse injuries. One week later, 45% of the calves still showed irritations. Cows of the traditional group vocalised 19.2 and those of the two-stage group 3.7 times per hour (P < 0.001). Compared with the pre-weaning period, calves spent more time walking on Days 1 and 2 after weaning (P < 0.01). However, the duration was significantly lower in two-stage than in traditionally weaned animals (P < 0.01). After removal of the devices, the time spent for walking increased again for 2 days. An effect on the weight gain of the calves was not noted. In conclusion, two-stage weaning positively influenced the post-weaning behaviour, but the nose flaps caused heavy nasal abrasions in the calves. Therefore, the design of the devices and the period they are fitted should be modified to minimise nasal abrasions
Changes in testicular histology and sperm quality in llamas (Lama glama), following exposure to high ambient temperature
No full textThe aim of the study was to investigate whether a moderately elevated ambient temperature (29 degrees C, 4 weeks, 24 h per day) has an effect on the spermatogenesis in male llamas (Lama glama) and to monitor the recrudescence of spermatogenesis. Thirteen llamas were used. Semen parameters were monitored in four of the llamas and six animals were castrated at different times after the heat treatment. An additional three llamas were used as control animals and were castrated without any treatment. Spermatogenesis was found to be severely impaired due to the high environmental temperature. Sperm concentration declined from 97.5 million to 10 million spermatozoa/ml. Sperm motility declined from 63.1% to 15.0% and the percentage of morphologically abnormal sperm cells increased from 26.3% up to 50.5%. The changes in sperm parameters corresponded to the histological analysis of the testes. We found an increase in destroyed tubules, where no stage of the spermatogenic cycle could be established from 1.8% up to 38.2%, and a reduction of the spermatogonial proliferation rate (Ki-67 histochemistry) represented by tubules with proliferating spermatogonia from 79.5% to 45.7% directly after the heat treatment. Apoptosis TUNEL assay) showed no significant changes during the experiment. The recrudescence of spermatogenesis within 6 weeks after the beat treatment was found to be due to an increase of mitotic proliferation of spermatogonia and not due to a decrease in the apoptotic rate. Our data indicate that in llamas the thermoregulatory ability is not sufficient enough to prevent heat caused damage to the testis at longer acting ambient temperature of 29 degrees C. (c) 2007 Elsevier Inc. All rights reserved
Analysis of association of two SNP in cholecystokinin B receptor gene with behaviour scores in German Angus and German Simmental cattle (Brief Report)
No full textDFG [SFB299
Analysis of association of two SNP in cholecystokinin B receptor gene with behaviour scores in German Angus and German Simmental cattle (Brief Report)
No full textDFG [SFB299
Maternal protective behaviour of German Angus and Simmental beef cattle after parturition and its relation to production traits
No full textA total of 390 German Angus (Aberdeen Angus x German dual-purpose breeds) and Simmental cows were tested in seven consecutive years (2000-2006) for maternal protective behaviour which was assessed by categorising behavioural response of the darns during earmarking their calves. The test was conducted within 24 h after parturition by the same person. Analysis of variance of maternal protective behaviour scores (MBS) was performed using a model including breed, lactation-number and calving month as fixed effects as well as the interaction between breed and lactation-number. The cow was included as a random effect. Breed, lactation-number and the interaction breed x lactation-number highly affected MBS. German Angus was scored higher than Simmental as well as cows with higher lactation-numbers in comparison to younger cows. Heritability was estimated under consideration of the whole relationship matrix and differed between 0.14 (S.E. 0.08) for German Angus and 0.42 (S.E. 0.05) for Simmental. Repeatabilities for MBS were 0.24 (S.E. 0.04) for German Angus and 0.42 (S.E. 0.05) for Simmental, respectively. Weaning weights and average daily weight gains of the calves were not correlated with maternal protective behaviour scores. (C) 2008 Elsevier B.V. All rights reserved.German Research Foundation [DFG-SFB 299
Heterosis analysis of Haemonchus contortus resistance and production traits in Rhoen sheep, Merino Land sheep and crossbred lambs
No full textA crossbreeding program was conducted to evaluate the resistance status to Haemonchus contortus in reciprocal crossbred (F 1) lambs and their Merino Land sheep (Ml) and Rhoen sheep (Rh) purebred counterparts. A total of 406 lambs were included in the study. Faecal egg counts (FEC) and haematocrit values (He) of all the lambs were collected 4 and 8 weeks after an artificial infection with H. contortus. FAMACHA (c) scores were given at the same time. Worm counts of all lambs were obtained after slaughtering at 21 weeks of age. The Ml group consistently showed the highest body weights, daily weight gains and best carcass performances, whereas the Rh group showed the lowest results. Most of the body weight parameters in the F, group fell intermediately between the MI and Rh groups, though the heterosis analysis of body weight and carcass parameters showed a tendency to favour the crossbreeding group Rh x Ml. The Rh group showed, on average, the highest FEC and the lowest He values compared to the MI. However, the nematode counts were not significantly different between the pure breeds. In comparison, the worm counts of the Rh x MI crosses were significantly different from those in the Ml x Rh crosses. A heterosis analysis showed that FEC, Hc and the worm count in the F1 group favoured the crossbreeding group Rh x Ml. These results suggested that crossbreeding Rh to MI sheep may be a suitable way of producing lambs with improved resistance to H. contortus infection without any negative effects on production traits. (c) 2006 Elsevier B.V. All rights reserved
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