Annual follow-up of the gastrointestinal parasitosis of the tepezcuintle,Agouti paca (Rodentia: Agoutidae) in captivity in the Mexican tropic

Previous reports showed that the tepezcuintle (Agouti paca) is commonly infested by gastrointestinal parasites (GIP), mainly Eucoccidiida and helminths. However, there is no available information on the frequency of those parasites and their faecal egg excretions at different moments during the year. These information would provide a valuable baseline for the establishment of control strategies against GIP in tepezcuintles under captivity. The objectives of the present study were to determine the prevalence of GIP orders and genera that infest tepezcuintles under captivity and, to describe the dynamics of faecal egg and oocyst excretion in a year. Ten tepezcuintles were sampled (faeces) twice every month for twelve months. The faecal samples were processed by the flotation and McMaster techniques. Two orders of parasites were determined: Strongylida and Eucoccidiida. Two genera of nematodes were also determined: Strongyloides and Trichuris. The prevalence of Strongylida eggs, Eucoccidiida oocysts and Trichuris sp. eggs reached 10-20% of animals in certain months. The most important genus was Strongyloides, found in 60 to 100% of the animals year round. The average excretion of eggs in the group was 45 to 372 eggs per gram. Tepezcuintles kept under captivity in Yucatan are parasited with Strongyloides sp throughout the year, but only occasionally had oocysts of Eucoccidiida and eggs of Strongylida and Trichuris sp.     

Breeding management in goat farms of Lombardy,northern Italy: Risk factors connected to gastrointestinal parasites

This study is the first parasitological survey dealing with goats at a regional scale in northern Italy. In particular, we characterized goat farms in Lombardy and investigated the risk factors of parasite infections there. Within our study area, both the breeding system and the size of the flocks varied. In fact, large flocks are mainly located down the valleys of Alpine areas and in the Prealps at low altitudes, such animals are reared under intensive husbandry. Medium-sized flocks are mostly found in mountainous areas where goats are reared under extensive or semi-extensive systems. Autochthonous races, then, are important in some marginal areas where a farm economy is supported by the promotion of traditional goat products, e.g. typical cheese and meat derivatives. Significant factors associated with the presence of parasites are (i) breeding system, extensive for Moniezia benedeni, semi-extensive for Strongyloides; (ii) size of the farm, over 100 goats for Strongyloides; (iii) altitude, above 500 m a.s.l. and up to 1000 m a.s.l. for M. benedeni and Strongylida; (iv) pasture, Strongylida; (v) season, autumn for M. benedeni; (vi) separation of goats into groups, (Skrjabinema). Goats in first lactation were significantly more infected with Strongylida and Trichuris than multiparous ones (both p < 0.001). Eggs excretion of Strongyloides was higher in pregnant females (p < 0.001). Differences emerged also for Nematodirus and Strongylida when eggs excretion was related to pregnancy (p < 0.05 and p < 0.001, respectively), but epg values of these nematodes were significantly higher in not pregnant individuals. Heavier infection with S. was found in lactating goats rather than in dry goats (p < 0.001), while the latter ones were more infected with Trichuris and Strongyloides (p < 0.05 and p < 0.001, respectively). In conclusion, according to the results of our survey, as to extensive husbandry we highly recommend correct practices in pasture management associated with a targeted programme of anthelminthic treatments for Stronylida and Cestoda. As to the rearing of large flocks almost entirely indoor, we noted a higher presence of other parasites, i.e. Strongyloides, probably due to a high density of heads associated with a scarce sanitary management. Concerning, then, young goats in first lactation and lactating females our data confirmed that they both are more vulnerable to the infection with Strongylida, while pregnant females are more prone to the infection with Strongyloides spp. This can be partially due to the synchronization of the reproductive cycle, as performed in most farms, and to the occurrence of the period of pregnancy in winter, when the animals are stabled indoor.     

Prevalence of anthelmintic resistance in gastrointestinal nematodes of dairy goats under extensive management conditions in southwestern France

The occurrence of benzimidazole (BZ) and levamisole resistance was investigated in 18 randomly selected dairy goat herds located in southwestern France and characterized by extensive management. On each of the 18 farms, 45 adult goats were randomly allocated into three groups of 15 animals each: an untreated control group, a group that was orally administered fenbendazole (10 mg kg(-1) body weight) and a group that received orally a levamisole drench (12 mg kg(-1) body weight). Individual faecal egg counts and pooled larval cultures were done 10 days after anthelmintic treatment. Naive lambs were infected with larvae obtained from control and fenbendazole treated groups and were necropsied 35 days after infection for worm recovery. Faecal egg count reductions (FERC) were calculated for fenbendazole and levamisole and, when less than 95 per 100, were considered as indicative of anthelmintic resistance. An in vitro egg hatch test (EHT) was conducted with thiabendazole on eggs isolated from pooled faeces of fenbendazole treated goats in nine farms. Faecal egg count reductions indicated the occurrence of benzimidazole resistance in 15 out of 18 farms. Among these farms, nine had EHT values above 0.1 microg thiabendazole ml(-1) confirming the benzimidazole resistance status. Levamisole resistance was detected in two farms through FECR. Based on necropsy results, the prevalence of benzimidazole resistance was higher in Trichostrongylus colubriformis, medium in Haemonchus contortus and lower in Teladorsagia circumcincta. In nine farms the benzimidazole resistance was monospecific whereas multispecific resistance was found in the six remaining farms. A negative relationship was found between FECR for fenbendazole and the average number of anthelmintic treatments given per year on the farm. Despite extensive management including a low number of treatments, the prevalence of benzimidazole resistance was very high suggesting that the repeated and sometimes exclusive use of benzimidazole drugs, even at low frequency, is probably the main cause in developing nematode resistance in dairy goat herds. The importance of other factors such as under-dosing or buying animals already carrying resistant nematodes are discussed.     

Dairy goat grazing systems in Mediterranean regions: A comparative analysis in Spain, France and Italy

In order to maintain small ruminant grazing systems it is necessary to know precisely how they work and what actions can be taken to improve them. The objective of this paper was to characterize, classify, analyse and propose improvements for the dairy goat grazing systems in three countries from the western Mediterranean area: Spain, France and Italy. A multivariate analysis was conducted with 21 indicators obtained from the data collected from 45 farms. As a result of the multivariate analysis, 82.5% of variance was explained by two principal components. The first component included proportion of cultivated pasture area and cultivated pasture area per goat. The second included goats present and forage supply per goat. After conducting a cluster analysis based on these two principal components, farms were classified into four groups. Group 1 was made up of French and Italian farms, which had a smaller territorial base but a high cultivated pasture area per goat, contributing to greater self-sufficiency in feed. However the concentrate per goat was too high in relation to milk production, which was medium. The difference between milk income and feed cost is also medium. Group 2 was basically made up of Italian farms. The farms in this group had the most extensive management systems, with a low use of inputs. However, the milk production was low, meaning that the difference between milk income and feed cost was also low. Group 3 was mainly made up of Spanish farms. On these farms the concentrate supply was excessive and the forage supply was low. The milk production per goat was medium and the difference between milk income and feed cost was small. Group 4 was made up mainly of French farms. The farms of this group had a moderate supply of concentrate although the forage supply was very high. They had a high milk production, which lead to a large difference between milk income and feed cost per goat.The main weaknesses observed are related to feeding management, particularly grazing, and to the goat productivity. In the former case research on the nutritional utilization of rangelands and pastures and correct feed supplementation is to be encouraged. In the latter, the production capacity of the goats present in these systems should be improved, without forgetting the balance between hardiness and general productivity.     

Distribution of nematode parasites of the digestive system in sheep (Ovis aries) and goats (Capra hircus) of the Piedmontese and Valdostano Alpine arc

A survey, carried out on gastro-intestinal nematodes of sheep and goats of Piemonte and of Valle d'Aosta (87 sheep and 12 goats) has shown the presence of the following species in sheep, Bunostomum trigonocephalum, Chabertia ovina, Cooperia curticei, Haemonchus contortus, Marshallagia marshalli, Nematodirus abnormalis, Nematodirus filicollis, Nematodirus helvetianus, Nematodirus spathiger, Oesophagostomum venulosum, Ostertagia circumcincta, Ostertagia lyrata, Ostertagia trifurcata, Skrjabinema ovis, Trichostrongylus axei, Trichostronglus colubriformis, Trichostronglus vitrinus, Trichuris ovis and Trichuris skrjabini; in goats, Bunostomum trigonocephalum, Chabertia ovina, Haemonchus contortus, Nematodirus filicollis, Nematodirus helvetianus, Oesophagostomum venulosum, Ostertagia circumcincta, Ostertagia ostertagi, Ostertagia trifurcata, Trichostrongylus axei, Trichostrongylus colubriformis and Trichostrongylus vitrinus. The percentage of each species in the two host is given in the text table.     

Evidence for Transmission of Bluetongue Virus Serotype 26 through Direct Contact

The aim of this study was to assess the mechanisms of transmission of bluetongue virus serotype 26 (BTV-26) in goats. A previous study, which investigated the pathogenicity and infection kinetics of BTV-26 in goats, unexpectedly revealed that one control goat may have been infected through a direct contact transmission route. To investigate the transmission mechanisms of BTV-26 in more detail an experimental infection study was carried out in which three goats were infected with BTV-26, three goats were kept uninfected, but were housed in direct contact with the infected goats, and an additional four goats were kept in indirect contact separated from infected goats by metal gates. This barrier allowed the goats to have occasional face-to-face contact in the same airspace, but feeding, watering, sampling and environmental cleaning was carried out separately. The three experimentally infected goats did not show clinical signs of BTV, however high levels of viral RNA were detected and virus was isolated from their blood. At 21 dpi viral RNA was detected in, and virus was isolated from the blood of the three direct contact goats, which also seroconverted. The four indirect barrier contact goats remained uninfected throughout the duration of the experiment. In order to assess replication in a laboratory model species of Culicoides biting midge, more than 300 Culicoides sonorensis were fed a BTV-26 spiked blood meal and incubated for 7 days. The dissemination of BTV-26 in individual C. sonorensis was inferred from the quantity of virus RNA and indicated that none of the insects processed at day 7 possessed transmissible infections. This study shows that BTV-26 is easily transmitted through direct contact transmission between goats, and the strain does not seem to replicate in C. sonorensis midges using standard incubation conditions.     

Gastrointestinal parasitic infections in intensive dairy cattle breeding: Update on the epidemiology and associated risk factors in northern Italy

Parasitic infections such as Strongylida and Eimeria still represent a major health problem of dairy cattle impacting their health, welfare, and productivity. In view of the scarcity of data on risk factors contributing to the spread of parasitic infections in cattle breeding, an epidemiological study in intensive dairy farms in northern Italy was planned. 495 animals (lactating and dry cows, heifers, and calves) from 19 farms were enrolled in the study. Individual fecal samples were analyzed by a quantitative copromicroscopic analysis to detect the number of Strongylida eggs or Eimeria oocysts per gram of faeces (EPG/OPG). Data concerning management, sanitary and biosecurity measures were collected using a questionnaire; a management measures score (MMS) was also calculated. The possible influence of risk factors on Strongylida and Eimeria was thus assessed by statistical analysis using generalized linear mixed models (GLMMs).Eimeria spp. was the most frequently detected parasitic taxon (herd and individual prevalence: 89.5% and 46.2%, respectively), followed by Strongylida (herd and individual prevalence: 63.1% and 16.6%, respectively). The presence of Strongylida resulted associated to the productive category (p-value = 0.028), with heifers and dry cows at higher risk of infection than lactating cows and calves, and to the MMS (p-value = 0.007). Higher prevalence values were recorded in farms with intermediate or low MMS compared to those with optimal MMS. As regard Eimeria infection, a greater effect of MMS on OPG was recorded in calves when compared to those recorded in heifers (OR = 0.228, p-value = 0.003) and dry cows (OR = 0.241, p-value = 0.009).Gastrointestinal parasitic infections still remain an underestimated problem in intensive dairy cattle breeding. MMS may help in the choice of strategies aimed at minimizing the impact of parasites on animal health, thus improving the productivity of the entire herd.     

Influence of breed and husbandry on viscosity of Israeli goat milk yogurt

Goat’s milk yogurt prepared from milk of different goat breeds on different farm types resulted in different viscosity. Yogurt from milk of goat breeds browsing on pasture was richer in solids and resulted in significantly higher viscosity compared with that of cow milk yogurt and yogurt produced from milk of goats fed hay and concentrate indoors. Milk from goats browsing on pasture was diluted in total solids content close to that of milk from goats kept indoors and cows. Yogurt made from this diluted milk still resulted in higher viscosity. It appears that milk from goat breeds browsing on pastures contains certain factor(s) that causes an increase in the viscosity of yogurt produced from it.     

Impact of indoor feeding at late lactation stage on body reserves recovery and reproductive performances of Baladi dairy goats fed on pastoral system

Adaptive capacities of Baladi goats facing situations of food restrictions and re-feeding during lactation have been studied. Three diets were tested: mountain natural rangelands during early lactation, agricultural pastures during mid-lactation and indoor stall feeding during late lactation. Body weight (BW), body condition (BCS) and plasma metabolites (NEFA) as well as milk production (milk yield, milk fat and milk protein contents) were measured in the different feeding situations. Effect of late lactation re-feeding on reproduction was assessed through kids’ birth weight and weight gain from day 0 till day 60 of age. Results showed that on rangelands, goats’ body condition degraded, with initially fat goats loosing more weight and being subject to a greater reserves mobilization than lean ones. These expressed an adaptive behaviour through increasing their daily feed intake and by an intense body reserves replenishment following their transfer to the agricultural pastures and indoor feeding. In late lactation, even goats kept on agricultural pastures showed a similar reconstitution, showing the high priority of body reserves replenishment during late lactation whatever the feeding level. The milk rebounds observed showed a good reactivity from the Baladi goat in response to a feed improvement either on agricultural pasture or indoor. At the end of lactation the milk yield decreased in all feeding situations proving the priority given by the Baladi goats to the body reserves replenishment over the milk production in order to ensure the next cycle. However, even if there was no difference in kids’ birth weights, kids from stall-fed dams had higher weight gains between 0 and 60 days of age when compared to those from underfed ones.     

Avoidance distance test in goats: A comparison with its application in cows

The present study investigates the feasibility in goats of an avoidance distance (AD) behaviour test set-up for cattle, and compares the results in the two species to assess the suitability of the test for on-farm welfare evaluation in goat farms.The tests were performed on 324 lactating cows (170 in small farms and 154 in large farms) and 271 lactating goats (108 in small farms and 163 in large farms), housed in free stall farms (12 dairy cattle and 17 dairy goat farms) in the Province of Sondrio, Northern Italy, following a protocol validated for dairy cows in the Welfare Quality^® project.After the assessors were adequately trained, this test was relatively easy to perform and no major difficulties were faced in either species. Goats exhibited a higher level of confidence with humans, as showed by lower AD (goats: 68.60 ± 4.98 cm; cows: 71.36 ± 4.37 cm; p < 0.10) and higher frequency of contacts (AD = 0) (goats: 45.8%; cows: 31.2%; p < 0.001).Farm size significantly affected AD values (lower in small farms) and frequency of contacts (higher in small farms) in goats, but not in cows. This was probably due to the less marked management difference between large and small farms of cattle than those of goats.The AD test seems feasible in goats; however, the experimenter contacted nearly half of the goats. To improve the sensitivity, a further level – represented by the possibility of gently stroking the goat's head after the contact – may be included in the test in addition to contact.     

Characterization of semi-extensive goat production systems in southern Spain

This study attempts to describe the semi-extensive goat farming sector in Andalusia (south of Spain) and to establish characteristics. Eighty-nine goat farmers were surveyed in three areas of this region. The survey examined all aspects of the systems, from socio-economy to management. A multivariate analysis (multiple correspondence and cluster) was used to determine the different farm characteristics. Most of the goat farms studied are single-worker or family managed. The farmers lack training and are elderly, so that continuity of the activity is not assured, although newcomers are usually young. All the farms have some area in ownership, although the farms most specialized in dairy goat products are the smallest in both ownership and total area. The roads are generally in good condition, except on farms with little land, situated in areas of the sierra. Machine-milking installations, closely related to the presence of infrastructures and of goats with a dairy tendency, are generally lacking, (this aspect is improving day by day). Artificial nursing is less generalized than machine-milking. Farms specializing in milk production, whose main activity is dairy goat farming, have dairy specialized breed or crossbred (milk and meat) goats. Feeding depends largely on grazing, with little area being cultivated to produce feed for the goats. Little distinction is made for the production level. Olive or acorn tree branches (Quercus ilex spp.) are used as feedstuff, depending on the types of tree predominating in the area. Five farm types were established, the differences depending on 14 variables of socio-economic aspects, level of production, infrastructure and installations, and feeding. Generated information from this study entails an advance into knowledge of goat farming systems in the Mediterranean area (where little information is generated). The relevance of this study is important since Andalusia has 40% of goats in Spain that produce more than half of the total goat milk in the country, which points out the socio-economical importance for most depressed areas in the region. This work supposes previous steps for improving the semi-extensive goat farming sector. From a methodological point of view, the discussion on variable types and utility establishes farm type characteristics.     

Coprologic evidence of gastrointestinal helminths of forest baboons, Papio anubis, in Kibale National Park, Uganda

The gastrointestinal parasites of baboons have been well characterized from savannah and desert habitats, but little is known about their gastrointestinal parasites in forest habitats. From May to June 2004, we collected 41 fecal samples from free-ranging olive baboons (Papio anubis) within the forested Kibale National Park, Uganda. Samples were examined to determine the prevalence of gastrointestinal helminths in this forest dwelling population of olive baboons. The prevalence of nematodes identified from fecal flotation was Oesophagostomum sp. (85%), Trichostrongylus sp. (22%), Trichuris sp. (46%), Strongyloides sp. (44%), Ternidens sp. (5%), Abbreviata sp. (2%), and Molineus sp. (2%). Flotation techniques also recovered unidentified eggs, probably of hookworm origin (22%). No parasite eggs were recovered by sedimentation of eight samples. Coproculture techniques using 13 of the 41 samples recovered larvae from Oesophagostomum sp., Strongyloides sp., and Trichostrongylus sp. The high prevalence of nematodes recovered in this study seems to support previous theories of high nematode infections in forested habits.     

Social hierarchy in the domestic goat: effect on food habits and production

Outside the scientific world, the effect of social behaviour on production is little taken into account, but the importance of this relationship has been sufficiently proven in some animal species. Nevertheless, there are scarce works that emphasise the importance of behaviour in the production of the goat. The main objective of this paper is to determine if there is a stable hierarchy of dominance in a flock of goats fed in pasture, and if this hierarchy influences somehow the diet selected in the pasture and in its production of milk and meat. The study was carried out in a flock of goats in semi-extensive grazing management. The interactions observed in the pasture during the supplementary feeding and during the milking were written down. This allowed us to determine the dominance rank. The diet was determined in the pasture by the direct observation method. The production of milk was measured daily. The meat production consisted on the weight of the kids in their first day of life and after a month. Among the most prominent results, the following should be indicated: (a) Within the herd, a clearly established, quite stable and linear hierarchic order exists. (b) The most aggressive animals are those that occupy the highest positions within the social hierarchy. (c) Age, large size and horns seem to be the physical factors that most favor dominance. (d) When more forage becomes available, differences appear in the diet chosen by dominant and subordinate animals, that is, they become more selective. In the months of greater shortage, these differences in feeding disappear, and they become more generalist. (e) The production of animals is affected by dominance. However, contrary to what might otherwise be thought, it is the middle range of goats that are the most productive.     

Quantitative trait loci associated with parasitic infection in Scottish blackface sheep

This study aimed to identify quantitative trait loci associated with endoparasitic infection in Scottish Blackface sheep. Data were collected from 789 animals over a 3-year period. All of the animals were continually exposed to a mixed nematode infection by grazing. Faecal samples were collected in August, September and October each year at ca. 16, 20 and 24 weeks of age; Nematodirus spp. eggs were counted separately from the other species of nematodes. Blood samples were collected in October from which immunoglobulin A (IgA) activity was measured and DNA was extracted for genotyping. In total, 139 Microsatellite markers were genotyped across eight chromosomal regions (chromosomes 1, 2, 3, 5, 14, 18, 20 and 21) in the sires and progeny were genotyped for the markers that were polymorphic in their sire. Evidence was found for quantitative trait loci (QTL) on chromosomes 2, 3, 14 and 20. QTL associated with specific IgA activity were identified in chromosomes 3 and 20, in regions close to IFNG (chromosome 3) and the MHC (chromosome 20). QTL associated with Nematodirus FEC were identified on chromosomes 2, 3 and 14. Lastly, QTL associated with non-Nematodirus Strongyle FEC were identified on chromosomes 3 and 20. This study has shown that some aspects of host resistance to gastrointestinal parasites are under strong genetic control, therefore these QTL could be utilised in a marker-assisted selection scheme to increase host resistance to gastrointestinal parasites.     

Physiological and behavioral reactions elicited by simulated and real-life visual and acoustic helicopter stimuli in dairy goats

Background  

Anecdotal reports and a few scientific publications suggest that flyovers of helicopters at low altitude may elicit fear- or anxiety-related behavioral reactions in grazing feral and farm animals. We investigated the behavioral and physiological stress reactions of five individually housed dairy goats to different acoustic and visual stimuli from helicopters and to combinations of these stimuli under controlled environmental (indoor) conditions. The visual stimuli were helicopter animations projected on a large screen in front of the enclosures of the goats. Acoustic and visual stimuli of a tractor were also presented. On the final day of the study the goats were exposed to two flyovers (altitude 50 m and 75 m) of a Chinook helicopter while grazing in a pasture. Salivary cortisol, behavior, and heart rate of the goats were registered before, during and after stimulus presentations.     

Impacts of production conditions on goat milk vitamin,carotenoid contents and colour indices

The content, composition and variation of vitamin compounds in goat milk have been little studied. An experimental design was based on 28 commercial farms, selected considering the main feeding system (based on main forage and especially pasture access), goat breed (Alpine vs Saanen) and reproductive management (seasonal reproduction), in the main French goat milk production area. Each farm received two visits (spring and autumn) that included a survey on milk production conditions and bulk milk sampling. Milk vitamins (A, E, B₂, B₆, B₉, B₁₂) and carotenoid concentrations plus colour indices were evaluated. A stepwise approach determined the variables of milk production conditions that significantly altered milk indicators. The main forage in the diet was the major factor altering goat milk vitamin and carotenoid concentrations and colour indices. Bulk milk from goats eating fresh grass as forage was richer in α-tocopherol (+64%), pyridoxal (+35%) and total vitamin B₆ (+31%), and b* index (characterising milk yellowness in the CIELAB colour space) was also higher (+12%) than in milk from goats eating conserved forages. In milk from goats eating fresh grass, concentrations of pyridoxamine, lutein and total carotenoids were higher than in milk of goats fed corn silage (+24, +118 and +101%, respectively), and retinol and α-tocopherol concentrations were higher than in milk of goats fed partially dehydrated grass (+45 and +55%). Vitamin B₂ concentration was higher in milk of goats eating fresh grass than in milk of goats fed hay or corn silage as forage (+10%). However, bulk milk when goats had access to fresh grass was significantly poorer in vitamin B₁₂ than when fed corn silage (?46%) and in γ-tocopherol (?31%) than when fed conserved forage. Alpine goats produced milk with higher vitamin B₂ and folate concentrations than Saanen goats (+18 and +14%, respectively). Additionally, the milk colour index that discriminates milks based on their yellow pigment contents was 7% higher in milk from Alpine than Saanen herds, but milk from Saanen goats was richer in lutein (+46%). Goat milks were richer in vitamins B₂ and B₁₂ and folates, but poorer in vitamin B₆ in autumn than in spring (+12, +133, +15 and ?13%, respectively). This work highlights that goat milk vitamin and carotenoid concentrations and colour indices vary mainly according to the main forage of the diet and secondly according to the breed and season.     

Development and survival of infective larvae of Haemonchus contortus and Trichostrongylus colubriformis on pasture in a tropical environment

A trial to determine the seasonal pattern of egg hatching and larval survival on pasture was carried out in representative wet and dry zones of Fiji. Fourteen plots were established on parasite-free pasture at each of two sites. One plot at each site was contaminated every month with faeces from naturally infected goats containing a known proportion of Haemonchus contortus and Trichostrongylus colubriformis eggs. Pasture was sampled at regular intervals after contamination and infective larvae identified and counted. Larvae of both species developed throughout the year in the wet zone but development was more sporadic in the dry zone. Larval counts generally declined to below detectable levels within 9 weeks of contamination between September and March but longevity increased during the cooler weather from April to August. The comparatively short larval survival times noted in this experiment may present opportunities for manipulation of parasite population dynamics in the wet tropics.     

The Dynamics, Prevalence and Impact of Nematode Infections in Organically Raised Sheep in Sweden

A three-year survey (1997–99) was carried out on organically reared sheep flocks throughout Sweden. The aim was to determine the prevalence and intensity of nematode infections and to establish relationships between sheep management practices and parasite infections. Faecal samples from ewes and lambs were collected from 152 organic flocks around lambing-time and during the grazing-period for analysis. Results were compared with the different management practices that farmers use to prevent parasitism in their flocks. A high proportion of the flocks was infected with nematodes. The most prevalent species were Haemonchus contortus, Teladorsagia circumeincta, Trichostrongylus axei, T. colubriformis and Chabertia ovina and infections progressively increased during summer in lambs grazing on permanent pastures. Severity of parasitic infection in lambs was highly dependent on egg output from the ewes. H. contortus was found in 37% of the flocks, even at latitudes approximating the Polar Circle. Nematodirus battus was recorded for the first time in Sweden during the course of this study. Lambs turned out onto permanent pasture showed higher nematode faecal egg counts (epg) than lambs that had grazed on pastures, which had not carried sheep the previous year. This beneficial effect of lambs grazing non-infected pastures persisted if the ewes were treated with an anthelmintic before turn-out and if the lambs were kept on pastures of low infectivity after weaning. In lambs, the prevalence and the magnitude of their egg counts were higher during autumn in flocks where lambs were slaughtered after 8 months of age, compared with flocks where all lambs were slaughtered before this age. These results will be used in providing advice to farmers of ways to modify their flock management in order to minimise the use of anthelmintics, but at the same time efficiently produce prime lambs.     

由成年转基因山羊体细胞而来的克隆山羊

在已经获得的乳腺特异性表达人促红细胞生成素 (rhEPO)成年转基因山羊 (Caprahircus)的基础上 ,取其耳尖成纤维细胞和卵巢颗粒细胞 ,进行体外传代培养 ,然后将这种培养的转基因山羊的体细胞移入去核的处于第Ⅱ次减数分裂中期的卵母细胞中 ,并进行电融合 ,构建重构胚胎 ,重构胚胎在体内培养 6d ,再将发育至囊胚或桑椹胚的重构胚胎移入同步情期的寄母羊子宫内。结果 ,有 2只寄母羊妊娠并最终产下 2只成活的克隆山羊。她们分别来自同一成年母羊的耳尖成纤维细胞和卵巢颗粒细胞。克隆羊经PCR RFLP图谱分析显示 :以克隆羊组织DNA为模板的PCR产物与相应的提供体细胞的基因羊的PCR产物的酶切图谱完全一致 ;并且经PCR对外源hEPO基因检测表明 2只克隆山羊均携带hEPO外源基因。由此证明获得了转基因成年体细胞的克隆山羊     

The establishment and reversibility of species affinities in domestic sheep and goats

The establishment and reversibility of cross-species attachments were studied in sheep and goats taken from their mothers at birth and reared in same- or cross-species pairs until 12 months of age. Species affinities were determined at eight to nine months of age by time spent proximate to stimulus herds of sheep and goats housed in separate enclosures within a larger pasture. Sheep reared with goats spent significantly more time with the stimulus goats than did controls (sheep reared with sheep). Likewise, goats reared with sheep spent a significantly greater percentage of time with the stimulus sheep than did control goats. At approximately 13 months of age the sheep were segregated from the goats in separate pastures and were retested, as before, for species affinities after 34 to 90 days of exposure to conspecifics. Experimental subjects demonstrated a significant reversal of species preferences. However, the reversal was more complete for subjects housed for 57 to 90 days in same-species groups than for those tested after 34 to 56 days of exposure to conspecifics. It was concluded that species affinities of sheep and goats are basically learned and that relatively long-standing cross-species social attachments can be reversed by approximately 60 to 90 days of same-species cohabitation.