Comparative susceptibility of Pyrenean and Brown Swiss calves to gastrointestinal nematodes in subclinical naturally acquired infections

The susceptibility of two common breeds of cattle in the Pyrenees, Brown Swiss and Pyrenean breed, to parasitism by gastrointestinal nematodes was studied. Twenty-two female calves (13 Brown Swiss and 9 Pyrenean), 3 months old with a mean weight of 112.8 +/- 18.33 and 103.3 +/- 17.11 kg respectively at the start of the study, were used. The calves began their first grazing season grazing with 200 cattle following the traditional grazing system for mountainous areas: Stabling during winter (December-April), grazing on harvesting meadows at an elevation of 900 m in the spring (May-June) and autumn (October-November), and grazing areas between 1200-2100 m during the summer (July-September). Faeces, blood samples and calves growth rate were taken at 2-week intervals throughout the grazing season. Faecal egg counts of gastrointestinal nematodes, level of serum pepsinogen, total serum protein and blood parameters were measured. The worm egg counts and Cooperia sp. counts were significantly smaller in the calves of Pyrenean breed than in Brown Swiss throughout the experiment. Numbers of eggs of the other genera of parasites found were smaller in the calves of Pyrenean breed than in calves of Brown Swiss breed, but no statistical differences were found. Blood was compared during two periods: the prepatent and patent periods. During the first period, no differences were found between the breeds for any parameter studied. However, during the patent period, Pyrenean animals had significantly greater numbers of erythrocytes, haemoglobin values and packed cell volume (PCV) values, and smaller numbers of eosinophils than animals of the Brown Swiss breed. No differences were found in the level of serum pepsinogen, total serum protein and live weight gains between the two breeds.     

Effect of chemoprophylaxis with an ivermectin sustained-release bolus on acquired resistance to gastrointestinal parasites in cattle

The influence of chemoprophylaxis with an ivermectin sustained-release bolus in the first grazing season on the resistance of cattle to gastrointestinal nematodes during the following grazing season was investigated. In 1993 and 1994 dairy replacement calves were either given one bolus at the start of their first grazing season or left untreated. The two groups were grazed separately on a pasture that was divided into two similar sized paddocks. Faecal egg counts, serum pepsinogen and antibody levels were measured to evaluate host-parasite contact. Pasture infection levels were estimated by pasture larval counts and worm counts in tracer calves. After winter housing the animals were monitored during their second grazing season on a pasture that was also divided into two similar sized paddocks. Acquired resistance to gastrointestinal nematodes was evaluated by faecal egg counts and weight gains. Again, pasture infection levels were determined and pepsinogen and antibody levels were measured. During the first grazing seasons gastrointestinal nematode infections were controlled very effectively by the bolus, as shown by the greater weight gains, the negligible faecal egg counts and the low serum pepsinogen and antibody levels in the treated calves. In contrast, all parameters showed extensive parasite-host contact in the untreated animals. The efficient prophylaxis in the treated groups resulted in low levels of larval contamination on the paddocks grazed by the treated animals, compared to moderate infection levels at the end of both first grazing seasons on the paddocks grazed by the untreated animals. During the second grazing seasons (1994 and 1995) the faecal egg output was low in all groups. Although in the previously treated animals faecal egg counts were consistently higher, the differences were minimal, resulting in comparable levels of larval contamination on both paddocks. Serum pepsinogen and antibody levels were not significantly different between the groups and indicated a similar level of larval uptake on both paddocks. No negative effect of the previous chemoprophylaxis on the clinical condition and the weight gain of the second season grazing animals was observed.     

Effects of preventive anthelmintic treatment on acquired resistance to gastrointestinal nematodes in naturally infected cattle

This study explores how granddaughters account for the development of their relationships with their maternal grandmothers. The retrospective interviewing technique was used to elicit turning points in their relational histories. Analysis of the turning point content revealed several different types of turning points that reflected both normative and idiosyncratic events. Increases in relational closeness resulted from decreases in geographic separation, engaging in shared activities, deaths or serious illnesses in the family, and family disruptions. Decreases in closeness were associated with negative experiences with the grandmother, increases in geographic separation, and the transition to college. Granddaughters reported that turning points related to death or serious illness and participation in shared activities were the most significant ones in their relationships with maternal grandmothers.     

Gastrointestinal nematode infections of first-grazing season calves in Western Europe: general patterns and the effect of chemoprophylaxis

Research on the prevention of gastrointestinal nematode infections of cattle has mainly concentrated on comparing a specific chemoprophylactic treatment system to an untreated control group on a particular farm. Here, the results from analysis of 85 studies involving over 2000 first grazing season (FGS) calves put onto pasture for at least 4 months from late spring/early summer over a 26-year period in 13 countries in Western Europe are presented. Both control and chemoprophylactic treated FGS calf groups were considered. All chemoprophylactic systems (slow- and pulse-release boli, strategic treatments) were given early in the grazing season. Two general infection levels emerged--'sub-clinical' (32 studies) and 'clinical' (53 studies). The 'sub-clinical' infections were characterised by no clinical symptoms of parasitic gastroenteritis (PGE) being observed in the control groups. Mean faecal egg counts in the 'clinical' control groups were significantly higher than those for 'sub-clinical' control groups for almost the entire season with overall peaks of 275 and 100 EPG respectively. Maximum pasture larval counts were also significantly higher in the 'clinical' control groups with 44% of 'clinical' pastures > 10,000 L3 kg(-1) dry herbage by the end of the FGS, compared to only 15% of 'sub-clinical' pastures. There was a significant positive relationship between log transformed worm burdens from tracers put onto pastures for 2 weeks and the corresponding pasture larval count. No evidence of density dependence in tracer worm burden was observed. Weight gains in the 'clinical' control groups (375 g/day) were significantly lower than those of the 'sub-clinical' control groups (530 g/day). No symptoms of PGE were observed in any of the chemoprophylactic treated groups, but in those studies with an outbreak of PGE in the control group, the treated groups had significantly higher faecal egg and pasture larval counts than treated groups in 'sub-clinical' studies. The overall weight gain in chemoprophylactic treated calves in 'clinical' studies (600 g/day) was significantly lower than the chemoprophylactic treated calves in 'sub-clinical' studies (690 g/day), and was not significantly different from the weight gain of control calves in 'sub-clinical' studies. These results indicate that on heavily infected pastures, chemoprophylaxis will prevent PGE, but calves will still suffer production losses.     

The determination at housing of exposure to gastrointestinal nematode infections in first-grazing season calves

Various parameter estimates were assessed at housing in calves that had been exposed to gastrointestinal nematodes during a first grazing season. The analysis involved 41 groups of first grazing season (FGS) calves on 15 different farms in Belgium and comprised groups that had received chemoprophylactic treatment and untreated controls. Serum pepsinogen levels gave the clearest division between chemoprophylactic-treated calf groups (all were <2.6 U tyr), and untreated calf groups in which sub-clinical (range: 2.0-4.1 U tyr) and clinical infections (range 3.7-6.3 U tyr) occurred. There was also a tight relationship between individual pepsinogen values and adult Ostertagia burdens obtained at slaughter. In chemoprophylactic-treated groups there was a significant negative relationship between mean serum pepsinogen levels at housing and the proportion of the grazing season covered by different chemoprophylactic systems. Although only limited data on crude adult Ostertagia antigen ELISA were available, a good relationship between optical densities and estimated exposure was also found. The parasitological parameters, faecal egg counts and pasture Ostertagia larval counts at housing, and weight gain per day, gave less clear divisions among the three categories (chemoprophylaxis, sub-clinical and clinical). Distinguishing how much exposure a calf group has experienced during a first grazing season could help in designing more appropriate control measures for the FGS calves in the next year, assuring good protection and at the same time allowing sufficient exposure for the development of acquired immunity to Ostertagia, and for this serum pepsinogen is recommended.     

The effect of weather in modifying the pattern of pasture larval contamination with Ostertagia circumcincta

Serum complement activity, immunoglobulin levels and the circulating auto-antibodies were studied in the course of laser treatment of 20 cases of crural ulcer. After temporary changes a normalization of the humoral immune response was observed in the healing cases, while in the stagnating ones opposite trend was manifest. In none of the groups were detected circulating auto-antibodies against the investigated antigens.     

Prevention of gastrointestinal and lungworm infections in alpine calves: use of doramectin pour-on in before and after the alpine grazing season

The effect of doramectin pour-on (Dectomax 0.5% pour-on, Pfizer) against gastrointestinal nematodes (GIN) and lungworms was investigated in calves grazed on alpine pastures in Switzerland. Doramectin pour-on (0.5 mg/kg body weight) was administered topically to calves (n = 57, Group D) before and after the alpine grazing season (mid-June to end of September) when the calves were kept on altitudes between 1800 and 2600 m together with 20 untreated calves (Group K). Calves of both groups were grazed together during the alpine season and were subsequently moved to prealpine and home pastures where they were kept until stabling (end of November). Faecal examinations, performed 4 to 5 weeks after anthelmintic treatment of Group D calves showed a marked reduction of the trichostrongyle egg output, which was also low in the untreated calves. Low numbers of Dictyocaulus-larvae were excreted by the calves at turnout to the alpine pastures. At the end of September the mean excretion of Dictyocaulus-larvae had increased markedly in both groups. After treatment of Group D calves the larval output remained negative until stabling. In contrast, the larval excretion of the untreated calves (Group K) reached highest levels at the end of October and 4 calves exhibited clinical signs of dictyocaulosis. The results indicate that the strategic use of doramectin pour-on in June and in late September provided good protection against severe infections with D. viviparus. The infection level with GIN confirmed that these parasites are of minor relevance under the extensive grazing conditions on high alpine pastures.     

The effect of cimetidine on antipyrine metabolism in calves

The decline in the function of the growth hormone-releasing hormone, growth hormone, insulin-like growth factor (GHRH-GH-IGF) axis has been termed the somatopause. Many of the catabolic sequelae seen in normal aging has been attributed to this decrease in circulating GH and IGF-I. In order to provide hormone replacement therapy for the somatopause, elderly subjects have been treated with GH, IGF-I, or both hormones together. Whereas numerous beneficial effects on body composition, strength, and quality of life have been reported in some studies, other studies have reported only marginal functional improvements. Moreover, it is clear that both hormones can cause significant morbidity.     

Parasite spectrum and seasonal epidemiology of gastrointestinal nematodes of small ruminants in The Gambia

One hundred and four post mortem examinations of randomly selected sheep (52) and goats (52) were carried out weekly from March 1990 to February 1991. Gastrointestinal parasites were identified and counted. A large spectrum of 16 helminth species was found in 101 (97%) infected animals. The nematodes infecting small ruminants were, in order of predominance: Trichostrongylus colubriformis (96% of all animals), Oesophagostomum columbianum (82%), Haemonchus contortus (67%), Strongyloides papillosus (55%), Gaigeria pachyscelis (38%), Cooperia spp. (49%) and Trichuris ovis (12%). Forty-five (43%) necropsies revealed an infection with Moniezia benedeni, Avitellina centripunctata or Stilesia globulosa. Infections with Schistosoma bovis and Paramphistomum spp. were rarely seen. Goats carried significantly lower worm burdens than sheep and were less often infected by tapeworms. Nematode worm burdens followed a similar seasonal pattern in both host species. While Trichostrongylus colubriformis was also recovered in high numbers in the mid dry season, other species such as H. contortus, Strongyloides papillosus and Oesophagostomum columbianum reached distinct peaks in the rainy season (July-October). Different survival strategies for the prolonged dry season were observed. Haemonchus contortus outlived the unfavourable climatic conditions as inhibited larvae in the abomasal mucosa, while the other nematode species survived as adults with a reduced fecundity. Egg production per adult worm specimen was found to depend heavily on the season and egg counts in the dry season (November-June) did not correspond to the size of worm burdens. Unexpectedly high worm burdens were recovered from adult and old animals. Investigations of young animals indicated that no reinfection can occur during the dry season. The findings are discussed with regard to their relevance for strategic control of gastrointestinal nematodes in small ruminants.     

The effect of the first and second stages of tempering on microcracking in martensite of an Fe-1.22 C alloy

The effect of tempering on microcracking in the plate martensite of an Fe-1.22 C alloy was investigated by isothermal heat treatments in the temperature range between 180 and 225°C. The second stage of tempering, followed by X-ray measurement of retained austenite, was confirmed to depend upon the diffusion of C in austenite, and the transformation product was found to consist of very closely spaced cementite lamellae in ferrite. Microcracking, despite the volume expansion that accompanies the transformation of the retained austenite, decreased only slightly with time during the second stage. The major decrease in microcracking occurred during the first stage, a result attributed to the plastic deformation that accompanies the dimensional changes caused by the reduction of the lattice tetragonality of the high carbon martensite in the first stage. Metallographic observations of surface relief and etching effects associated with martensite plates provided evidence of the first-stage plastic flow. The authors were formerly Research Assistant and Professor, respectively at Lehigh University, Bethlehem, PA.     

The tomato Mi-1 gene confers resistance to both root-knot nematodes and potato aphids

Mi-1, a Lycopersicon peruvianum gene conferring resistance to the agricultural pests, root-knot nematodes, and introgressed into tomato, has been cloned using a selective restriction fragment amplification based strategy. Complementation analysis of a susceptible tomato line with a 100 kb cosmid array yielded a single cosmid clone capable of conferring resistance both to the root-knot nematode Meloidogyne incognita and to an unrelated pathogen, the potato aphid Macrosiphum euphorbiae. This resistance was stable. The Mi-1 gene encodes a protein sharing structural features with the nucleotide-binding site leucine-rich repeat-containing type of plant resistance genes.     

Role of embB in natural and acquired resistance to ethambutol in mycobacteria

The mycobacterial embCAB operon encodes arabinosyl transferases, putative targets of the antimycobacterial agent ethambutol (EMB). Mutations in embB lead to resistance to EMB in Mycobacterium tuberculosis. The basis for natural, intrinsic resistance to EMB in nontuberculous mycobacteria (NTM) is not known; neither is the practical implication of resistance to EMB in the absence of embB mutations in M. tuberculosis well understood. The conserved embB resistance-determining region (ERDR) of a collection of 13 strains of NTM and 12 EMB-resistant strains of M. tuberculosis was investigated. Genotypes were correlated with drug susceptibility phenotypes. High-level natural resistance to EMB (MIC, . or =64 microg/ml) was associated with a variant amino acid motif in the ERDR of M. abscessus, M. chelonae, and M. leprae. Transfer of the M. abscessus emb allele to M. smegmatis resulted in a 500-fold increase in the MICs. In M. tuberculosis, embB mutations were associated with MICs of > or =20 microg/ml while resistance not associated with an ERDR mutation generally resulted in MICs of < or =10 microg/ml. These data further support the notion that the emb region determines intrinsic and acquired resistance to EMB and might help in the reassessment of the current recommendations for the screening and treatment of infections with EMB-resistant M. tuberculosis and NTM.     

Effect of selenium and lodine supplementation on growth rate and on thyroid and somatotropic function in dairy calves at pasture

The effects of Se and I supplementation on growth rate and on thyroid and somatotropic function were examined for heifer calves from two herds fed pasture. Supplementation of calves with intraruminal Se pellets increased the basal plasma concentration of 3,5,3'-triiodothyronine and reduced the basal plasma concentration of thyroxine for both herds. For one herd, supplementation with Se increased the triiodothyronine response to challenge with thyrotropin-releasing hormone, increased BW gain, and tended to increase the plasma concentration of IGF-I. The plasma concentration of growth hormone was unaffected by Se supplementation. Supplementation with I increased the response of thyroid hormones to thyrotropin-releasing hormone but did not increase BW gain. Interaction between Se and I treatment within the herds was not apparent for any outcome variable. These data suggest that the effects of Se deficiency in grazing calves may be mediated by alterations in thyroid hormone metabolism but apparently are not mediated through modulation of the peripheral concentration of growth hormone.     

Effect of three sustained-release devices on parasitic bronchitis in first year calves

The effect of three intraruminal sustained-release devices (SRD) against Dictyocaulus viviparus infection was tested in five groups of six calves. Group 1 served as untreated controls, and groups 2, 3 and 4 were dosed with a levamisole SRD, a fenbendazole SRD, and an ivermectin SRD, respectively. Group 5 was vaccinated against lungworm and received a levamisole SRD. The calves were turned out on May 28 and the devices given seven days later. All the calves received trickle infections with a total of 200 lungworm larvae between 9 and 34 days after turnout. They were housed on October 28, challenged with 5000 lungworm larvae and slaughtered three weeks later. No clinical signs of parasitic bronchitis were observed during the study. The treated groups gained significantly more weight (P < 0.05) than the controls, but did not differ among themselves. Larvae were first detected in the faeces of the control group between 25 and 32 days after the first infection, and had a group mean of 21 larvae per gram (lpg) after 60 to 80 days, after which the lpg gradually decreased. In group 2, larvae were detected near the end of the grazing season and never exceeded a group mean of 1.5 lpg. In group 3, a very low larval output was observed after housing (group mean 0.1 lpg). Groups 4 and 5 never became patent. The results of an ELISA followed the pattern of larval output; optical densities above the cut-off value were recorded in groups 1, 2 and 3. On the basis of worm recoveries after challenge, group 1 was immune. Group 4 had significantly more lungworms than group 2. There were no significant differences in worm numbers between groups 2, 3 and 5, but the worms in group 5 were retarded in growth (P < 0.05).     

The effect of vitamin E on cortisol and lactate levels and on the acid-base equilibrium in calves exposed to transportation stress

The objective of this study was to examine the effect of vitamin E administration on plasma levels of cortisol and lactate, and on acid base balance in transported calves. In the study, eight calves, aged approx. ten days, divided into two groups, were used. 20 mg of tocopherol-acetate per kg body weight were administered orally to each of the four experimental calves 24 hours before loading. The calves were transported by road for 3 hours. Blood samples collected before and after the transportation were examined for acid base balance, lactate, and plasma vitamin E and cortisol levels. The administration of vitamin E led to a decrease of cortisol levels in 24 hours (from 7.6 +/- 9.5 to 4.2 +/- 0.2 nmol/l) as well as to a significant increase (p < 0.05) of plasma vitamin E levels 26 h after administration (from 2.52 +/- 1.36 to 12.28 +/- 6.14 mumol/l). There was no difference between the groups in cortisol response due to transportation stress (Tab. III). The transportation caused typical stress changes in lactate levels and acid base balance (lactacidaemia and the tendency to acidosis, Tab. III, IV). There was approx. threefold increase in plasma lactate concentrations due to transportation (from 2.49 +/- 0.69 to 6.35 +/- 3.75 mmol/l). The results of the present study demonstrated metabolic changes which has been reported to be typical of mild physiological stress reaction. In the present study, vitamin E had no significant effect on plasma levels of cortisol, and lactate, and acid-base balance.     

The preventive effect of the fungus Duddingtonia flagrans on trichostrongyle infections of lambs on pasture

Four groups of 8 parasite-naive Dorset-crossbred lambs, 3-4 months old, were turned out on infected pasture on 2 May and allocated to 4 separate paddocks. From May to September, 2 groups received Duddingtonia flagrans (10(6) chlamydospores per kg body weight per lamb per day) mixed in 100 g of barley, while the other 2 groups received barley only. All groups remained set-stocked until slaughter for worm counts on 10 October. In late June, all lambs were treated with fenbendazole due to severe parasitic gastroenteritis in all groups. The faecal egg counts were comparable for the 2 treatments throughout the grazing period. Larval development of Ostertagia/Trichostrongylus spp. in faecal cultures was 1-28% in the fungi-fed groups compared with 60-80% in the untreated groups (P < 0.05). In September, pasture larval counts of Ostertagia/Trichostrongylus were 930 and 4400 L3 kg-1 on paddocks of fungi-fed and untreated groups, respectively. Corresponding figures for Nematodirus spp. were 7200 and 11600 L3 kg-1, respectively. At slaughter, the number of immature Ostertagia spp. was 62% lower in the fungi-fed groups compared with the untreated groups (P < 0.05). Four parasite-free lambs were introduced to each paddock during the period 3-23 October and slaughtered for worm counts after 3 weeks of housing. The total worm burden of tracers on paddocks previously grazed by fungi-fed lambs was reduced 86% (P < 0.05; geometric means) compared with control groups, while significant reductions were also seen in abomasal worm counts (68%; P < 0.05), N. spathiger (98%; P < 0.05) and for N. battus (97%; P < 0.01). It is concluded that dosing sheep with D. flagrans while grazing may limit the build up of pasture contamination in the late grazing season and subsequently limit the intake of larvae in sheep.     

Gender processing in first and second languages: The role of noun termination.

In 2 picture-naming and 2 grammaticality judgment experiments, the authors explored how the phonological form of a word, especially its termination, affects gender processing by monolinguals and unbalanced bilinguals speaking German. The results of the 2 experiments with native German speakers yielded no significant differences: The reaction times were statistically identical for items from gender typical, ambiguous, and gender atypical groups. The 2 experiments with English bilinguals who had learned German as a second language (L2), however, provided evidence that the L2 word's termination plays a role in L2 gender processing. Participants were fastest when producing gender-marked noun phrases containing a noun with a gender typical termination and slowest when the noun had a gender atypical termination. Analogous results were obtained in the grammaticality judgment experiment. These findings support the assumption that there is interaction between the levels of phonological encoding and grammatical encoding at least in bilingual processing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)