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1.
In autumn 2006, a study of the age-dynamics of Echinococcus granulosus cyst abundance was undertaken from an abattoir study of 1081 sheep slaughtered in Naryn Province in central Kyrgyzstan, an area endemic for echinococcosis. The results demonstrated approximately 64% of sheep were infected with the prevalence increasing markedly with age. The mean abundance was 3.8 cysts per sheep. From established models, an infection pressure of 1.33 cysts per year was estimated. In addition all cysts were recovered from infected sheep and the numbers of protoscoleces was evaluated in each cyst. A new model was developed that examined the variation in numbers of protoscoleces per infected sheep with age. This demonstrated that young sheep aged 1-2 years had very few protoscoleces, but there was a massive increase as the sheep aged. The best-fitting model assumed that the number of protoscoleces in a sheep was proportional to the volume of the cysts. In this model, the radius of the individual cyst increased linearly with the age of the cyst and hence the volume increased with the cube of the cyst age. This combined with the linear increase in numbers of cysts with age resulted in a massive accumulation of protoscoleces with the age of sheep. When the model was parameterised it demonstrated that 80% of protoscoleces were present in sheep aged 4 years and older and this represented just 28% sheep slaughtered. An average sheep at 6 or more years of age has an abundance of over 9700 protoscoleces, whilst in a young sheep of 1 year of age an average of just 16 protoscoleces could be found. The average for the sampled population across all ages was 1562 protoscoleces per sheep. The maximum number of protoscoleces in a single cyst was just 482 for sheep aged 1 year rising to 92,000 for sheep aged 6 years or older. The mean volume of cysts containing protoscoleces increased from approximately 0.7 ml at 1 year of age to 8.8 ml at 6 years of age. Cysts containing protoscoleces ranged from a diameter of 0.5-8 cm with a volume of fluid ranging from 0.2 to 50 ml. It is hypothesised that removal of old sheep through a culling programme could substantially improve the control of cystic echinococcosis.  相似文献   

2.
Age-related intramuscular pharmacokinetics of cefquinome in sheep   总被引:2,自引:0,他引:2  
The pharmacokinetic profile of cefquinome was studied in one, six-months and one year old sheep following a single intramuscular doses of 1 and 10 mg kg−1 b.wt. Cefquinome concentrations in serum were determined by microbiological assay technique using Micrococcus luteus (ATCC 9341) as test organism. Following intramuscular administration of cefquinome, the absorption half-lives (t0.5(ab)) were 1.540, 1.037 and 0.664 h at a dose of 1 mg kg−1 b.wt. and 1.844, 1.290 and 1.605 h at a dose of 10 mg kg−1 b.wt. in the three ages, respectively. After the two doses, the maximum serum concentrations (Cmax) of 0.732, 1.145, 1.205 and 3.525, 5.088, 4.576 μg ml−1 were attained after (tmax) of 3.812, 3.029, 2.174 and 3.785, 2.824, 3.095 h in the three ages, respectively. The elimination half-life (t0.5(el)) and MRT values of cefquinome were longer in one-month old sheep compared to six-months old and yearling sheep. The absorption and elimination processes were delayed in newborn sheep of one-month old in contrary to six-month and yearling animals. The in vitro serum protein-binding tendencies were 8.254%, 11.586% and 13.002%, for one, six-months and one year old sheep, respectively. Based on this study and economically, an optimal intramuscular dosage regimen of cefquinome would be 1 mg kg−1 once daily in one-month, six-months and one-year old sheep to achieve and maintain the therapeutic serum levels within safe limits.  相似文献   

3.
Large amount of seed cake is generated as by-product during biodiesel production from Jatropha seeds. Presence of toxic phorbol esters restricts its utilization as livestock feed. Safe disposal or meaningful utilization of this major by-product necessitates the degradation of these phorbol esters. The present study describes the complete degradation of phorbol esters by Pseudomonas aeruginosa PseA strain during solid state fermentation (SSF) of deoiled Jatropha curcas seed cake. Phorbol esters were completely degraded in nine days under the optimized SSF conditions viz. deoiled cake 5.0 g; moistened with 5.0 ml distilled water; inoculum 1.5 ml of overnight grown P. aeruginosa; incubation at temperature 30 °C, pH 7.0 and RH 65%.SSF of deoiled cake seems a potentially viable approach towards the complete degradation of the toxic phorbol esters.  相似文献   

4.
Scrapie is a fatal degenerative disease of the central nervous system of sheep and goats. Adenosine 3′,5′-cyclic monophosphate (c-AMP) plays a key role in many biological processes, membrane permeability, lipogenesis, metabolism, neuronal activity, muscular contraction, cellular differentiation, hormonal and enzymatic activities, proteins synthesis, etc. and in inflammation, immune processes, cellular growth regulation and carcinogenesis. In this work the c-AMP plasmatic levels in Scrapie infected sheep and goats were studied. The study was carried out on 31 sheep of Comisana breed and 35 autochthonous goats belonging to two farms from Sicily. The evaluation of c-AMP levels in blood samples, taken from the jugular vein, was carried out by radioimmunoassay (RIANEN” c-AMP 125 - Dupont NEN Diagnostic). The results obtained show significantly higher c-AMP levels in animals with Scrapie (40.88 ± 2.08 pmol/L in sheeps; 43.54 ± 1.62 pmol/L in goats) than healthy animals used as controls (26.45 ± 0.76 pmol/L in sheeps; 28.17 ± 1.58 pmol/L in goats). The increase in c-AMP plasmatic levels could be correlated to alterations of central nervous system functioning and variations of neurotransmitters (NA, Ach, GABA, etc.) responsible for behavioural and neurological changes in Scrapie infected sheep and goats.  相似文献   

5.
The α-tocopherol transfer protein (α-TTP) is a ~ 32 kDa cytosolic protein that plays an important role in the efficient circulation of plasma α-tocopherol in the body, a factor with great relevance in reproduction. The α-TTP gene has been studied in a number of tissues; however, its expression and function in some ovine tissues remain unclear. A previous study from our laboratory has demonstrated α-TTP expression in sheep liver. In the present study we determined whether α-TTP is expressed in non-liver tissues and investigated the effects of dietary vitamin E on the α-TTP mRNA levels. Thirty-five male Tan sheep with similar body weight were randomly allocated into five groups and supplemented 0, 20, 100, 200 and 2000 IU sheep− 1 day− 1 vitamin E, for four months, respectively. At the end of the study, the animals were slaughtered and tissue samples from the heart, spleen, lung, kidney, longissimus dorsi muscle and gluteus muscle were immediately collected. We found that the α-TTP gene is expressed in sheep tissues other than the liver. Moreover, dietary vitamin E levels had influenced the expression levels of α-TTP gene in these tissues in a tissue-specific way. The technique of immunohistochemistry was used to detect α-TTP in tissues of the heart, spleen, lung, and kidney and we found that α-TTP was mainly located in the cytoplasm while no α-TTP immunoreactivity was detected in the cytoplasm of longissimus dorsi and gluteus muscle samples. Importantly, our findings lay the foundation for additional experiments focusing on the absorption and metabolism of vitamin E in tissues other than the liver.  相似文献   

6.
Livestock production systems utilize composting as a method of disposal of livestock mortalities, but there is limited information on the rate and extent of carcass decomposition. Detection of specific DNA fragments by PCR offers a method for investigating the degradation of carcasses and other biological materials during composting. However, the purity of extracted DNA is critical for successful PCR analysis. We applied a method to purify DNA from compost samples and have tested the method by analyzing bovine and plant DNA targets after 0, 4, and 12 month of composting. The concentration of organic matter from composted material posed a particular challenge in obtaining pure DNA for molecular analysis. Initially extracted DNA from composted piles at day 147 was discoloured, and PCR inhibitors prevented amplification of target plant or bovine gene fragments. Bovine serum albumin improved detection by PCR (25–50 μl final volume) through the removal of inhibitors, but only when concentrations of humic acids in extracted DNA were 1.0 ng μl−1 or less. Optimal purification of DNA from compost was achieved by chromatography using Sepharose 4B columns. The described DNA purification protocol enabled molecular monitoring of otherwise cryptic bovine and plant target genes throughout the composting process. The assay could likely be used to obtain PCR-amplifiable DNA that could be used for the detection of microbial pathogens in compost.  相似文献   

7.
Impacts of individual personality on group distribution were investigated using sheep (Ovis aries) as a model. In an indoor exploration test, individuals who visited <4 (out of 6) objects in a novel environment were classified as ‘shy’ (n = 10), and those who visited 5 or 6 objects were classified as ‘bold’ (n = 10). Nine weeks later, using a series of groups (n = 40) of either 5 shy or 5 bold sheep, we measured distribution at pasture and responses to disturbance and the approach of a human handler. When grazing undisturbed, the mean nearest neighbour distance and spread (minimum convex hull area) of shy groups were less than those of bold groups, with shy individuals moving towards one another more often. Shy groups explored a smaller area than bold groups. When disturbed, shy sheep were more likely to stop grazing and move closer together. Shy sheep kept further away from the handler and moved faster when driven. The results demonstrate a link between personality and group distribution, suggesting that our ‘shy’ and ‘bold’ individuals may occupy different positions on the shy-bold continuum documented for other species. We discuss implications for diet composition and impacts on vegetation grazed by animals with different personalities.  相似文献   

8.
The present study aimed to assess the efficacy of reduced doses of cloprostenol for synchronizing estrus and ovulation in hair sheep. With the aim to evaluate the luteolytic activity of reduced cloprostenol doses, a first experiment was performed using a relatively large (group H: 126 μg; n = 8), medium (group M: 68.25 μg; n = 6) and small (group L: 38.5 μg; n = 6) cloprostenol dose. Luteolysis was assessed at Days 3 and 6 after injection (Day 0) by progesterone concentrations (P4) and transrectal ultrasonography (US). In Experiment 2, sheep were randomly assigned to the same three doses to evaluate a protocol for estrous synchronization using two injections administered 9 days apart. A third trial was performed with ewes treated (9 days apart) with the large dose (H = 126 μg; n = 12) and with a small dose adjusted for facilitating volume management (LA = 43.75 μg; n = 12). Presence of estrous cycling was determined in all the ewes by US and P4 assay, at Days −9, −6, −2, 0 (Day of second cloprostenol injection), 8 and 11. Bleeding and US were done every 4 h from 16 h of the beginning of the estrus during the third trial to assess the preovulatory LH surge and timing of ovulation. Additionally, blood samples were drawn at Days 0, 1, 2 and 3 to assess estradiol (Experiments 2 and 3) and P4 (Experiment 2) concentrations during the ovarian follicular phase. In all experiments, percentage of animals showing luteolysis, preovulatory follicular dynamics and function and percentage of ewes showing behavioral estrus in response to treatment was similar among groups. Timing of estrus for group H was earlier than group L (28.6 ± 1.8 h compared with 37.1 ± 2.4 h; P < 0.05). In the third trial, the preovulatory LH peak was higher in the LA group than group H, in terms of maximum mean concentration during the surge (27.7 ± 1.8 ng/mL compared with 21.3 ± 2.2 ng/mL; P < 0.05) and area under the curve (AUC; 183.4 ± 12.7 ng/mL compared with 127.7 ± 10.9 ng/mL; P < 0.01). However, timing of ovulation was similar for H and LA groups. Thereafter, ovulation rate and luteal function at Day 11 were similar. Current results demonstrate that reduced doses of cloprostenol may be applied in a practical manner for reproductive management of sheep, with the additional advantage of reducing treatment costs.  相似文献   

9.
10.
In general, copper is primarily an osmoregulatory toxicant to fish and Cu toxicity is thought to be related to the rate of sodium loss. Looking at a previous research it is striking that gibel carp, Carassius auratus gibelio, do not seem so susceptible to the first ionoregulatory shock phase of Cu exposure, but rather build up physiological disturbances slowly until mortality occurs. Since it was noted that gibel carp experience severe hypoxia under Cu exposure, we hypothesised that, besides the Na loss, the slow depletion of liver glycogen stores contributed equally to the collapse of physiological integrity. It is clear from our results that glycogen stores are being depleted in Cu exposed fish and that dead fish suffered more extensive glycogen losses compared to surviving fish, with liver glycogen levels of 125 ± 8 mg g1 in dead fish compared to 230 ± 13 mg g1 in surviving fish. However, changes in liver glycogen did not contribute significantly to mortality, while changes in whole body sodium and the rate of sodium loss did. Whole body Na levels dropped from 1111 ± 48 μg g1 dry weight in control fish to 850 ± 54 μg g1 in surviving fish and to 607 ± 24 μg g− 1 in fish that had died resulting in Na loss rates of 1.25 ± 0.22 μg g− 1 h− 1 and 3.39 ± 0.19 μg g− 1 h− 1 in surviving and dead fish respectively. Our results support the finding that the rate of Na loss largely determines Cu toxicity in fish, even in resistant species.  相似文献   

11.
To retrospectively assess the effect of cryotherapy in patients with metastatic breast cancer (MBC) but without local recurrence after resection of the primary lesion, we divided 120 MBC patients into cryotherapy (91 patients) and chemotherapy (29 patients) groups. In the cryotherapy group, 37 patients with tumor recurrence received multiple cryoablations, while 54 patients received only a single cryoablation. Moreover, 62 cryotherapy-group patients underwent cryoablation immediately after the detection of metastases (timely cryotherapy); 35 patients received simultaneous immunotherapy (cryo-immunotherapy), and 29 patients underwent cryoablation in our hospital 3 months after receiving chemotherapy in other centers (chemo-cryotherapy and delayed cryotherapy). Overall survival (OS) after the diagnosis of MBC was assessed after a 10-year follow-up. The median OS was higher in the cryotherapy group (55 months) than in the chemotherapy group (27 months; P < 0.0001). In the cryotherapy group, longer median OS was associated with multiple (76 months) rather than single cryoablations (48 months; P = 0.0005) and with timely (67 months) rather than delayed cryoablation (48 months; P = 0.0012). The median OS was higher after cryo-immunotherapy (83 months) than after chemo-cryotherapy (48 months) or cryotherapy alone (43 months; P < 0.0001 for both). In conclusion, timely and multiple cryoablations, especially when combined with immunotherapy, offer significant advantages over chemotherapy in extending the OS of MBC patients.  相似文献   

12.
Otoacoustic emissions (OAEs) were measured in male and female Suffolk sheep (Ovis aries). Some sheep had been administered androgens or estrogens during prenatal development, some were gonadectomized after birth, and some were allowed to develop normally. As previously reported for spotted hyenas, gonadectomy did not alter the OAEs for either sex; accordingly, the untreated/intact and the untreated/gonadectomized animals were pooled to form the control groups. The click-evoked otoacoustic emissions (CEOAEs) exhibited by the female control group (N = 12) were slightly stronger (effect size = 0.42) than those in the male control group (N = 15), which is the same direction of effect reported for humans and rhesus monkeys. Females administered testosterone prenatally (N = 16) had substantially weaker (masculinized) CEOAEs than control females (effect size = 1.15). Both of these outcomes are in accord with the idea that prenatal exposure to androgens weakens the cochlear mechanisms that underlie the production of OAEs. The CEOAEs of males administered testosterone prenatally (N = 5) were not different from those of control males, an outcome also seen in similarly treated rhesus monkeys. Males administered dihydrotestosterone (DHT) prenatally (N = 3) had slightly stronger (hypo-masculinized) CEOAEs than control males. No spontaneous otoacoustic emissions (SOAEs) were found in any ears, a common finding in non-human species. To our knowledge, this is the first ruminant species measured for OAEs.  相似文献   

13.
The tapeworm Moniezia expansa and naturally infected sheep were investigated with respect to their cadmium accumulation. Cadmium chloride (CdCl2, 0.2 g) was added to 10 ml of distilled water and administered orally to the sheep every day for a period of 1 week. The cadmium content of M. expansa was lower than that in the liver tissues of sheep, although this difference was not significant. The highest mean cadmium concentrations were found in the liver of sheep infected with M. expansa (24.5 ± 11.5 mg kg−1 dry weight). The mean cadmium concentration measured in M. expansa was 21.5 ± 19.2 mg kg−1 dry weight, which was 31 and 1.5 times higher than levels determined in the muscle and kidney of the host, respectively, but 0.9 times lower than levels determined in the liver of host. Sheeps with M. expansa infection always had higher cadmium concentrations in the tissues (with the exception of the blood) than their uninfected conspecifics.  相似文献   

14.
Cystic echinococcosis (CE) is caused by the larval stage of Echinococcus granulosus, which in this disease the metacestode develop in visceral organs especially liver and lungs. The disease is present worldwide and affects humans as well as herbivores including cattle, sheep, camels, horses and others. Benzimidazole carbamate derivatives, such as mebendazole and albendazole, are currently used for chemotherapeutic treatment of CE in inoperable patients and have to be applied in high doses for extended periods of time, and therefore adverse side effects are frequently observed. This study was designed to evaluate and compare the in vivo effects of 0.5 mg/kg, BID, albendazole sulfoxide (ricobendazole) and two different therapeutic regimens of 0.5 mg/kg BID and 2 mg/kg every 48 h of albendazole sulfoxide loaded solid lipid nanoparticles. Albendazole sulfoxide loaded solid lipid nanoparticles was prepared by solvent diffusion–evaporation method. Fifty Balb/c mice were infected by intraperitoneal injection of protoscoleces and 8 months post infection, the infected mice were treated for 15 days with the above mentioned regimens. They were then euthanized and the size and weight of the cysts as well as their ultrastructural changes were investigated. Although the cysts showed reduced size and weight in the treated animals but these reductions were not statistically significant. The cysts in the animals which received albendazole sulfoxide loaded SLN every 48 h showed more ultrastructural modification. However, these ultrastructural changes should be supported by further biochemical and molecular studies before introducing it as an efficient therapeutic regimen for treatment of human and animal hydatid disease.  相似文献   

15.
In this study, we investigated the impact of domestic and wild prey availability on snow leopard prey preference in the Kangchenjunga Conservation Area of eastern Nepal—a region where small domestic livestock are absent and small wild ungulate prey are present. We took a comprehensive approach that combined fecal genetic sampling, macro‐ and microscopic analyses of snow leopard diets, and direct observation of blue sheep and livestock in the KCA. Out of the collected 88 putative snow leopard scat samples from 140 transects (290 km) in 27 (4 × 4 km2) sampling grid cells, 73 (83%) were confirmed to be from snow leopard. The genetic analysis accounted for 19 individual snow leopards (10 males and 9 females), with a mean population size estimate of 24 (95% CI: 19–29) and an average density of 3.9 snow leopards/100 km2 within 609 km2. The total available prey biomass of blue sheep and yak was estimated at 355,236 kg (505 kg yak/km2 and 78 kg blue sheep/km2). From the available prey biomass, we estimated snow leopards consumed 7% annually, which comprised wild prey (49%), domestic livestock (45%), and 6% unidentified items. The estimated 47,736 kg blue sheep biomass gives a snow leopard‐to‐blue sheep ratio of 1:59 on a weight basis. The high preference of snow leopard to domestic livestock appears to be influenced by a much smaller available biomass of wild prey than in other regions of Nepal (e.g., 78 kg/km2 in the KCA compared with a range of 200–300 kg/km2 in other regions of Nepal). Along with livestock insurance scheme improvement, there needs to be a focus on improved livestock guarding, predator‐proof corrals as well as engaging and educating local people to be citizen scientists on the importance of snow leopard conservation, involving them in long‐term monitoring programs and promotion of ecotourism.  相似文献   

16.
Hydatidosis, or echincoccosis, is a serious medical and veterinary problem in many countries, particularly those with rural communities where there is a greater contact between dogs and domestic animals. Domestic livestock act as intermediate hosts which are the main reservoir for the disease in humans. It is therefore very important to estimate the prevalence of hydatid cysts in slaughtered animals since it can be transmitted to humans through dogs, which act as the final host for the disease. From this point of view, the present study was suggested to determine the prevalence of hydatidosis in Sawakny sheep slaughtered in Riyadh city, Saudi Arabia. During the course of the study 12,569 Sawakny sheep were inspected for hydatidosis infection. An overall prevalence of 1.06% was detected among the examined sheep, with the highest prevalence occurring in winter (1.38%) and lowest prevalence in summer (0.67%). Sheep aged 6–12 months had a higher rate of infection than older animals, and males were the predominant carriers of infection (97.7%) compared to females (2.3%). The liver was the most infected organ (79.1%), followed by the lungs (14.6%), while concurrent infections of both the liver and the lungs occurred in 6% of cases. The fertility and viability rates of hydatid cysts in the liver (70.1% and 85.1% respectively) were higher than that in any other organs. In conclusion, it is evident that fertile cysts in slaughtered sheep could have an important role in the continuation of hydatid cyst transmission to humans through dogs. Considerable effort should be devoted to controlling the transmission of cysts from abattoirs by the secure disposal of infected offal. In addition, plans are required for further epidemiological studies and control programs.  相似文献   

17.
After menopause, critically estrogen low levels result in modifications in vaginal wall. This cross-sectional study aims to determine whether there is a change in the number of vessels in the lamina propria of the vagina after menopause in parallel to the ER-alpha expression on the vaginal wall. Twelve women who underwent a genital surgery for genital prolapse up to grade II were selected. They were divided into two groups: a premenopausal group (PG) consisting of six women who were 18–40 years old with FSH levels =12 mIU/ml and regular cycles, and a menopausal group (MG) consisting of six women at least one year after menopause who were <65 years old with FSH levels =40 mIU/ml. Slides were stained for ER-alpha immunohistochemistry, and an endothelial cell marker CD3 was used to label vessels which were identified by using a system for morphometry. The number of vessels was significantly higher in the PG than in the MG both on the anterior wall (PG: 1.055 ± 145.8 vessels/mm2, MG: 346.6 ± 209.9 vessels/mm2, p < 0.0001) and on the posterior wall (PG: 1064 ± 303.3 vessels/mm2, MG: 348.6 ± 167.3 vessels/mm2, p = 0.0005). The ER-alpha score was significantly higher in the PG than the score for the MG on both the anterior and posterior walls (PG: 6.0 ± 0.52, MG: 2.5 ± 0.89, p = 0.007; PG: 5.8 ± 0.79, MG: 2.7 ± 0.95, p = 0.03, respectively). There was a positive correlation between the ER-alpha score and the vessel concentration on the anterior (r = 0.6656, p = 0.018) and posterior (r = 0.6738, p = 0.016) vaginal walls. Age was strongly negatively correlated with vessel concentration on the vaginal walls (respectively r = -0.9033, p < 0.0001, r = -0.7440, p = 0.0055). Therefore, postmenopausal women with genital prolapse have a smaller number of vessels on the vaginal wall compared to normoestrogenic controls with the same pathological condition. Hypoestrogenism and advancing age are factors that are associated to these changes.  相似文献   

18.
Calves can develop long-lasting social relationships with peers. We examined the strength of the relationships between calves according to the time they had been together. Twenty-four female dairy calves were assigned to six groups of four animals (Type-1 partners) at 0.5 month of age. At 3.5 months of age, they were mixed with other calves (Type-2 partners) to form groups of 14. Type-3 partners were calves added to the experimental groups after 5.25 months. The calves stayed together until 1.5 years of age. Social preferences between the three partner types were examined in a Y-maze, and the position and activity of animals in the barn and pasture were followed in three periods. Behavioural synchrony, distance between animals, proximity and nearest neighbour were analysed. The calves more frequently butted Type-3 than Type-1 partners in the Y-maze (P < 0.05). They spent more time in proximity to Type-1 partners, and these were more often the nearest neighbours than other partners (P < 0.001). Synchrony and distance between animals were greater at pasture than in the barn (P < 0.01). Calves seem to form preferential relationships before 3.5 months of age. Keeping cattle together from an early age seems beneficial for them.  相似文献   

19.
We studied wolfCanis lupus Linnaeus, 1758 — livestock conflict in central Greece by investigating patterns of 267 verified wolf attacks on livestock for 21 months. Wolves attacked adult goats 43% and cattle 218% more than expected, whereas sheep 41% less than expected from their availability. Wolves killed less than four sheep or goats in 79%, and one cow or calf in 74% of depredation events, respectively. We recorded higher attack rates during wolf post-weaning season. Wolf attacks on strayed, or kept inside non predator-proof enclosures, sheep and goats, were on average two to four times respectively more destructive than those when livestock was guarded by a shepherd. Sheepdog use reduced losses per attack. Optimal sheepdog number ranged from 3 to 9 animals depending on flock size. Losses per attack were positively related to the number of wolves involved. Total losses per farm were positively correlated with the size of livestock unit but percentage losses per capita increased with decreasing flock size. Management implications to mitigate livestock depredation are discussed.  相似文献   

20.
The plasticizer di(2-ethylhexyl)phthalate (DEHP), used for producing polyvinyl chloride (PVC), acts as an endocrine disruptor with toxic effects on reproductive and developmental processes. Exposure to DEHP in humans is mainly by environment and food. Thus, our aim was to determine plasma levels in livestock animals using the ewe (Ovis aries) as a model. In a first trial, 150 samples from ewes of different ages (2 to 7 yr) and reproductive status (pregnant and nonpregnant) were analyzed by high-performance liquid chromatography (HPLC). DEHP was detected in 34.7% of the samples, with a mean level of 0.45 ± 0.01 μg/mL (range, 0.05 to 2.81 μg/mL). The percentage of nonpregnant animals with DEHP traces was higher in animals older than 4 yr (n = 66, 37.9%) than in younger animals (n = 69, 17.4%; P < 0.05), although the mean levels in ewes with residues were similar (0.16 ± 0.01 vs. 0.16 ± 0.02 μg/mL). All the pregnant ewes (n = 15) showed presence of DEHP, with higher plasma levels than that in nonpregnant females (1.42 ± 0.18 vs. 0.16 ± 0.01 μg/mL; P < 0.0001). For confirming the effect of pregnancy on mobilization of DEHP from body fat, 101 ewes of the same age were sampled in a second trial at a different farm. The percentage of animals with DEHP traces was higher in pregnant ewes (n = 32, 71.9%; P < 0.005) than in nonpregnant ewes (n = 37, 35.1%) or in ewes that recently gave birth (n = 32, 21.9%), although mean levels were similar (0.42 ± 0.02, 0.33 ± 0.02, and 0.34 ± 0.05 μg/mL, respectively). In conclusion, current results indicate a high incidence of ewes reared in the field showing accumulation of phthalates; percentage of animals with presence of DEHP increases with age, due to an extended period of exposure, but mainly during pregnancy, due to the mobilization of body reserves.  相似文献   

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