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1.
Faecal samples (n?=?1947) from captive wild impala (Aepyceros melampus melampus) were examined over a period of 14 months to determine quantitative seasonal helminth egg excretion patterns and qualitative protozoan oocyst excretion patterns. Geometric mean monthly faecal egg counts (FECs) ranged from 20 to 575 and coprocultures revealed three parasite genera, namely Trichostrongylus, Haemonchus and Strongyloides. Larvae of the Trichostrongylus spp. were most predominant from faecal cultures. No trematode eggs or lungworms were detected and eggs of the cestode Monezia were only seen in two samples during the entire study period. The nematode FECs showed a marked seasonal variation, being higher during the rainy season, moderate during the cool dry season and low during the hot dry season. The rainy season had significantly higher FECs than the dry season (P?0.05), but were significantly higher in pelleted faeces in the rainy season than the dry season (P?相似文献   

2.
Elephant and impala as intermediate feeders, having a mixed diet of grass and browse, respond to seasonal fluctuations of forage quality by changing their diet composition. We tested the hypotheses that (1) the decrease in forage quality is accompanied by a change in diet from more monocots in the wet season to more dicots in the dry season and that that change is more pronounced and faster in impala than in elephant; (2) mopane (Colophospermum mopane), the most abundant dicot species, is the most important species in the elephant diet in mopane woodland, whereas impala feed relatively less on mopane due to the high condensed tannin concentration; and (3) impala on nutrient-rich soils have a diet consisting of more grass and change later to diet of more browse than impala on nutrient-poor soils. The phosphorus content and in vitro digestibility of monocots decreased and the NDF content increased significantly towards the end of the wet season, whereas in dicots no significant trend could be detected. We argue that this decreasing monocot quality caused elephant and impala to consume more dicots in the dry season. Elephant changed their diet gradually over a 16-week period from 70% to 25% monocots, whereas impala changed diets rapidly (2?C4?weeks) from 95% to 70% monocots. For both elephants and impala, there was a positive correlation between percentage of monocots and dicots in the diet and the in vitro digestibility of these forage items. Mopane was the most important dicot species in the elephant diet and its contribution to the diet increased significantly in the dry season, whereas impala selected other dicot species. On nutrient-rich gabbroic soils, impala ate significantly more monocots than impala from nutrient-poor granitic soils, which was related to the higher in vitro digestibility of the monocots on gabbroic soil. Digestibility of food items appears to be an important determinant of diet change from the wet to the dry season in impala and elephants.  相似文献   

3.
The study was done in Lake Mburo area, Uganda, consisting of Lake Mburo National Park and surrounding ranches. The study involved monitoring changes of output of helminth eggs per gram (e.p.g.) by impala for 12 months. Fresh faecal samples, 178 in total, were collected from the rangeland and subjected to floatation and culture tests. There was a peak faecal e.p.g. output from March to April and from October to November. This period coincided with time of high rainfall and calving peak of impala. There was no faecal e.p.g. observed during the dry spell from June to July.  相似文献   

4.
Faecal nitrogen (FN) – the combination of metabolic nitrogen and residual food nitrogen – has been used as a proxy for diet quality in wild and domestic ruminants for over half a century. However, a common misconception in some of these studies is that FN is a direct proxy for dietary N, in spite of experimental evidence that links FN to general diet digestibility. Additionally, gastrointestinal nematodes (GIN) can alter N metabolism and increase FN by various mechanisms. To clarify the role of dietary N, fibre and GIN as a factor in FN excretion, 10 naturally parasitised sheep were fed two different isocaloric diets (LPF: low-protein, low-fibre; HPF: high-protein, high-fibre). One month after these diets began, a single anthelmintic treatment was applied to remove GIN, after which the sheep were kept on the same diet for an additional 2 weeks. Throughout the experiment, individual faecal samples were obtained to estimate both FN and GIN intensity (using faecal egg counts, FEC). In addition, two blood samples were taken before and after deworming to measure serum total protein concentrations (TP) as a proxy for protein absorption. In spite of the difference in dietary protein, FN was higher on an LPF diet, supporting the overall digestibility concept. The influence of GIN on FN was later revealed by the anthelmintic treatment, which led to a decrease of FEC and FN in both dietary groups. Serum total protein showed a slight but non-significant increase in both groups after the anthelmintic treatment. Our study supports not only the concept that FN is a proxy for diet digestibility, and not directly for dietary N, but also that gastrointestinal nematodes limit its use as a proxy for diet quality in ruminants, especially under high parasite loads (e.g., 1000 faecal eggs per gram of faeces). Such limitations should be considered before using FN for wildlife nutrition monitoring. Some recommendations are given to avoid misinterpretations.  相似文献   

5.
A study was carried out to determine if the protozoal fauna of indigenous African wild ruminants was different from that found in their domestic counterparts and if the animal's diet influenced the number and types of protozoa. Samples of rumen contents were collected in 1997 and 2001 from various indigenous African wild ruminants in Kenya. All three ruminant feeding types were sampled: browsers or concentrate selectors (giraffe and Guenther's dik-dik); intermediate or adaptable mixed feeders (impala, Thomson's gazelle, Grant's gazelle and eland); grass or roughage eaters (hartebeest and wildebeest). Total concentration of ciliate protozoa and percentage generic distribution were determined. In general, protozoal concentrations were higher in concentrate selectors, followed by the intermediate or opportunistic mixed feeders and lowest in the grass and roughage eaters. Both Thomson's and Grant's gazelle were protozoa-free in the 2001 samples. Entodinium percentages were considerably higher in concentrate selectors and intermediate mixed feeders, compared to roughage eaters. Two genera of protozoa previously found in only a few African ruminants, Epiplastron and Opisthotrichum, were observed in several additional animal species and represent new host records. A difference was noted in the protozoal species composition of the indigenous wild ruminants from that previously observed in African domestic ruminants.  相似文献   

6.
Stable isotope analysis of tooth enamel was used to investigate the relative proportions of grass and browse in seasonal and overall diets of impala Aepyceros melampus at Akagera National Park, Rwanda. Bulk enamel samples suggest that on average, impala ate c. 86% C4 grass year‐round, far more than in most previously studied impala populations across Africa. Intra‐tooth samples show that seasonal changes in the proportion of C4 grass versus C3 browse are minimal (c. 10%), the diet being dominated by C4 grass year‐round in contrast to other impala populations that consume ≥50% browse during the dry season. Intra‐tooth oxygen isotope values track carbon isotope changes to a moderate degree, but are not patterned clearly enough to permit identification of wet versus dry seasons. As other studies have shown that impala select high‐protein diets, the foraging behaviour at Akagera is probably because of the availability of palatable grass for much of the year in the edaphic grasslands around the lacustrine environments of the eastern portions of Akagera National Park.  相似文献   

7.
resh beef liver, sugar, and five different types of faeces were evaluated as supportive diets for egg development in the blowfly Phormia regina . Females on a sugar diet were unable to develop follicles beyond stage 3, whereas liver proved to be the best diet for complete egg maturation. Some faecal diets were unable to support egg maturation when fed upon for a short period of time; however, longer periods of feeding produced complete egg maturation. The necessity to feed for longer periods of time in order to produce eggs on most of these diets was attributed to their low protein content. Males, in a shorter period of time than females, obtained enough protein from faeces to activate the neuroendocrine system involved in mating.  相似文献   

8.
9.

Veal calves aged 8 weeks were fed iso‐energetic amounts of milk replacers with either a low (7.1g of calcium/kg of air‐dry diet) or a high concentration of calcium (11.6g of calcium/kg of air‐dry diet) for a period of 10 weeks. The extra calcium was added in the form of calcium formiate. Final body weight of the two dietary groups was similar. Faeces were collected during the final week of the trial. The high calcium diet raised faecal dry matter output by 87% and faecal energy by 70%. The extra output of faecal dry matter was composed of 36% and 37% of crude fat and ash, respectively. The extra faecal energy output was for 75% in the form of crude fat. The high versus low calcium intake not only depressed apparent digestibility of total lipids but also that of crude protein, carbohydrates and ash. It is concluded that a high calcium intake by veal calves reduced energy availability without affecting body weight gain.  相似文献   

10.
J. B. Foster    M. J. Coe 《Journal of Zoology》1968,155(4):413-425
The large animals of Nairobi National Park have been censused intermittently once a month from mid-1960 until the end of 1966. Of the 23 species discussed, the density per kilometre has been determined accurately for the following: Grant's gazelle, Thomson's gazelle, water-buck, impala, wildebeest, hartebeest, eland, buffalo, warthog, giraffe, zebra and ostrich. From these figures the biomass has been calculated for each species each year. After a peak biomass of 12,775 kg/sq. km during the drought of 1960–61 the population declined to and remained fairly level at about 5690 kg/sq. km from 1962 to 1966. This figure includes about 1050 kg/sq. km of cattle and sheep. The large predators account for only about 1.4 % of the total biomass of wild animals while removing about 15.5% from this group annually.  相似文献   

11.
黑斑羚粪便中碳同位素揭示的食性变化   总被引:1,自引:0,他引:1  
利用稳定碳同位素数据(δ13C)分析了南非克鲁格国家公园混食性黑斑羚(Aepyceros melampus)时间和空间尺度上的食性变化,验证了两个假说,即有蹄类食性变化是由生境中木本植物与草本植物的相对配比导致;降雨控制有蹄类生态。结果表明:黑斑羚的食性涵盖了精食者-粗食者采食谱系,且食性中木本与草本比例在不同月间、季节、年度和区域间存在很大变化。栖息于开放性热带稀树草原和草原中的黑斑羚通常采食比生境中更高比例的草本,但在时间尺度上并不恒定。在克鲁格北部的一个区域(Punda Maria) ,黑斑羚采食的草本比克鲁格国家公园中其它任何区域都多。与其它生境相比,在河边的黑斑羚采食草本数量更少,尤其是在食性空间变化更为明显的旱季。因此,我们的数据不支持有蹄类食性组成变化是由生境中木本与草本比例不同造成的假说,食性与降雨量间也无明显的关系。我们的结果支持草本中蛋白含量增加引起黑斑羚采食比例的增加这一模型。粪便中氮含量在时间和空间上的变化很小,揭示在可利用食物中,无论木本还是草本,黑斑羚进行选择采食以保证最好的食物质量。基于这些结果,我们认为更具体的食物选择和可利用性最适采食理论能够更好地解释这种生态学变化。  相似文献   

12.
This study investigated associations between pre-treatment cytokine expression and infection patterns, before and after de-worming, in humans exposed to two gastrointestinal nematode species. Quantitative measures of Ascaris lumbricoides and Trichuris trichiura infection (based on faecal egg counts) were estimated immediately before and 8-9 months after treatment in a Cameroonian population. Whole blood cytokine responses to parasite-derived antigens were assayed immediately pre-treatment. An overall measure of the tendency towards species-specific infection (increasing with A. lumbricoides faecal egg counts and decreasing with T. trichiura faecal egg counts) was significantly positively related to IL-10 levels in older (14-57 year) hosts. There was a significant negative influence of IL-5 on reinfection probability in T. trichiura but not A. lumbricoides. This effect coincided with reduced reinfection success in T. trichiura compared to A. lumbricoides. T(H)2 cytokine expression by younger hosts (4-13 year) was negatively associated with contemporary A. lumbricoides faecal egg counts before treatment. Following treatment, the pre-treatment T(H)2 cytokine expression data for younger hosts (now reflecting responsiveness 8-9 months in the past) were negatively associated with T. trichiura faecal egg counts. Taken together, these observations suggest a successional interaction between T(H)2-driven immune responses and species infection over time. However, any differential effects of the measured immune responses on species-specific recruitment, maturation and mortality were superimposed upon (and outweighed by) the effects of other factors favouring coinfection.  相似文献   

13.
本研究探讨了通过收集器不同粪便收集时间和饲料中肉骨粉(MBM)含量对异育银鲫干物质、蛋白、能量、磷的表观消化率 (ADC) 影响.不同梯度(0, 20, 40, 60, 80 ,100%)的肉骨粉替代鱼粉(FM) 蛋白配制成六种等氮 (粗蛋白: 410 g/kg) 等能 (总能: 18 kJ/g) 的饲料,通过11周的饲养实验,实验开始后2周开始收集粪便,收集时间分别是:排粪后 1 min, 投喂后4h和16h. 结果表明,干物质、蛋白、能量、磷的消化率明显随粪便收集时间增加而升高(p<0.05),但在高肉骨粉替代饲料中差异不显著(p>0.05). 干物质、蛋白、能量、磷的消化率随饲料中肉骨粉含量的增加呈线性或近线性下降.因此,在消化率测定中应该尽快收集排出的粪便以保证消化率的真实性.消化率是影响肉骨粉利用一个因素.  相似文献   

14.
We studied the food quality of the aphid Rhopalosiphum padi to the pirate bug Orius majusculus using Ephestia eggs as high-quality comparison prey. Several performance parameters were tested on individuals that had been reared and maintained on each of the two single-prey diets or on a mixed diet. All fitness parameters were lower in individuals fed aphids only, indicating poor food quality of this prey. Compared with the pure Ephestia egg diet, the mixed diet enhanced teneral mass, while adult survival and female starvation tolerance were negatively affected and all other traits were unaffected. Body protein proportions were constant across diets, whereas lipid proportion was low in the aphid treatment. Preference for aphids was lower following a monotypic aphid diet than when reared on Ephestia eggs or a mixed diet. The results confirm that R. padi is low-quality food for O. majusculus as it is for other generalist predators, even though O. majusculus may contribute significantly to population suppression of the aphid.  相似文献   

15.
Weaner sheep that had been hand-fed on diets containing increasing concentrations of protein for a 9-week period (when uninfected, or infected with Haemonchus contortus) were studied during the next 69 weeks when put on to pasture as a single, unsupplemented flock. During the 9-week period, groups of 12 sheep (six infected, six uninfected) were offered one of five iso-energetic (9.0 MJ kg(-1)) diets containing 10, 13, 16, 19 or 22% crude protein. All sheep were treated with anthelmintic at the end of the 9 weeks and then put out to pasture for 69 weeks, where they were all subject to the same environmental variables including nematode larval challenge. During the grazing period, animals that had previously received the higher protein diets consistently had higher live-weight gain and wool production, higher antibody responses to both H. contortus and Trichostrongylus colubriformis antigenic challenge in vitro, and lower faecal nematode egg counts than did the lambs previously offered the lower protein diets. Faecal egg counts of the grazing sheep that had been artificially infected with H. contortus while being hand-fed were similar to those of the uninfected sheep and there was no interaction between previous infection and dietary protein concentration. We conclude that short periods of enhanced post-weaning nutrition can have long-term and perhaps life-long effects on production.  相似文献   

16.
The objective of this study was to evaluate the anthelmintic efficacy of Iris hookeriana Linn. rhizome against gastrointestinal nematodes of sheep. A worm motility inhibition assay was used for in vitro study and a faecal egg count reduction assay was used for an in vivo study. The in vitro study revealed anthelmintic effects of crude aqueous extracts and crude ethanolic extracts on live Trichuris ovis worms (P < or = 0.05) as evident from their paralysis and/or death at 8 h after exposure. The aqueous extracts of I. hookeriana resulted in a mean worm motility inhibition of 54.0%, while ethanolic extracts resulted in a mean worm motility inhibition of 84.6%. The mean mortality index of aqueous extracts was 0.55, while for ethanolic extracts it was 0.85. The lethal concentration 50 for aqueous extracts was 0.45 mg ml- 1 and for ethanolic extracts it was 0.15 mg ml- 1. The in vivo anthelmintic activity of aqueous and ethanolic extracts of I. hookeriana in sheep naturally infected with mixed species of gastrointestinal nematodes demonstrated a maximum (45.62%) egg count reduction in sheep treated with ethanolic extracts at 2 g kg- 1 body weight on day 10 after treatment, closely followed by ethanolic extracts at 1 g kg- 1 body weight on day 10 after treatment (43.54% egg count reduction). The aqueous extracts resulted in a maximum of 31.53% reduction in faecal egg counts on day 10 after treatment with 1 g kg- 1 body weight. Thus ethanolic extracts exhibited greater anthelmintic activity under both in vitro and in vivo conditions; this could be due to the presence of alcohol-soluble active ingredients in I. hookeriana. From the present study it can be suggested that I. hookeriana rhizome exhibited significant anthelmintic activity against gastrointestinal nematodes of sheep and has the potential to contribute to the control of gastrointestinal nematode parasites of small ruminants.  相似文献   

17.
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.  相似文献   

18.
Twenty-five weaned 35-day-old piglets were used in a 35-day growth experiment to evaluate the effect of inclusion of chicory and ribwort forage in a cereal-based diet on growth performance, feed intake, digestibility and shedding of faecal coliform bacteria. A total of seven experimental diets were formulated, a cereal-based basal diet (B), and six diets with inclusion of 40, 80 and 160 g/kg chicory (C40, C80 and C160) or ribwort (R40, R80 and R160). Piglets had ad libitum access to feed and water throughout the experiment. Three and five weeks post-weaning faeces samples for determination of digestibility were collected once a day for five subsequent days. Additional faeces samples for determination of coliform counts were collected at days 1, 16 and 35 post-weaning. Piglets fed diet R160 had the lowest average daily feed intake (DFI) and daily weight gain (DWG), and differed (P < 0.05) from piglets fed diets B, R40 and R80. There were no differences in DFI and DWG between the chicory diets and diet B. Inclusion of chicory or ribwort had a minor negative impact on the coefficient of total tract apparent digestibility (CTTAD) of dry matter, organic matter and crude protein, whereas inclusion of both chicory and ribwort resulted in higher CTTAD of non-starch polysaccharides and neutral detergent fibre (NDF). The CTTAD of arabinose were higher for diets C160 and R160 than for diet B (P < 0.05), and the CTTAD of uronic acid was higher for diets C40, C80, C160, R80 and R160 than for diet B (P < 0.05). Age affected the CTTAD for all parameters (P < 0.05) except for NDF, with higher values at 5 than at 3 weeks post-weaning. The coliform counts decreased with increasing age (P < 0.05), but was not affected by treatment. The results indicate that inclusion of up to 160 g/kg of chicory do not negatively affect performance, whereas high inclusion of ribwort have a negative impact on feed consumption and consequently on growth rate. Both herbs have a higher digestibility of fibre compared to cereal fibre. Chicory and ribwort are both promising as feedstuffs to weaned piglets, but the low palatability of ribwort limits the inclusion level.  相似文献   

19.
The prevalence and intensity of oocysts of coccidia, particularly Eimeria species, and eggs of gastrointestinal nematodes in kids (2–4 months), young goats (5–12 months) and adult goats (>1 year) were determined in five large herds managed extensively in five villages in the dry zone. Of the representative samples examined, oocysts were found in 88% of kids, 91% of young goats and 83% of adults. Seven species of Eimeria were identified in faecal samples by salt flotation. Eimeria ninakohlyakimovae (31%), E. alijevi (29%) and E. arloingi (21%) were the most common species in all age categories. Other species encountered were E. christenseni (7%), E. jolchijevi (6%), E. hirchi (3%) and E. aspheronica (1%). Gastrointestinal nematode eggs were found in 89% of the kids, 94% of the young goats and 84% of the adult goats. Identification of gastrointestinal nematodes revealed Haemonchus contortus (90%) followed by Oesophogostomum spp. (8.5%) and Trichostrongylus spp. (1%) in all three age categories examined. Both Eimeria and gastrointestinal nematodes were found in 77% of the kids, 86% of the young goats and 71% of adult goats. The mean oocyst counts per gram of faeces in kids, young goats and adult goats were 9728, 1946, and 2667, respectively. The oocyst counts were not different significantly between age groups (P>0.05). The mean egg counts per gram of faeces in kids, young goats and adult goats were 1217, 1641 and 1092, respectively. The egg counts in kids were significantly lower than that in young goats (P<0.05). The intensity of Eimeria and gastrointestinal nematode infections between herds were significantly different (P<0.01).  相似文献   

20.
A comparative study of larval cannibalism in three species of ladybird   总被引:5,自引:0,他引:5  
Abstract. 1. Cannibalism was studied under laboratory conditions in three species of Coccinellidae (Coleoptera): Cycloneda sanguinea , Olla v-nigrum , and Harmonia axyridis . Larval cannibalism varied among species, C. sanguinea  > H. axyridis  ≥  O. v-nigrum .
2. Larvae of all species cannibalised more in response to reduced food availability (14 h starvation daily) than in response to reduced food quality (dry Ephestia eggs).
3. Larvae of H. axyridis cannibalised siblings at lower rates than non-siblings, but larvae of C. sanguinea and O. v-nigrum did not. Rates of cannibalism increased significantly with increasing size disparity among larvae of all three species.
4. Cannibalism in C. sanguinea and H. axyridis , but not in O. v-nigrum , increased with larval density, suggesting that not all attacks on conspecifics are driven by hunger.
5. Costs, not benefits, were the predominant effects of exclusively and partially cannibalistic diets. A diet of conspecific eggs yielded survival equivalent to the Ephestia egg diet for H. axyridis and O. v-nigrum , but developmental time was extended and adults were smaller. Larvae of C. sanguinea had superior survival and faster development on conspecific eggs than on the Ephestia egg diet. Only H. axyridis larvae survived as well on diets comprised exclusively or partially of conspecific larvae as on Ephestia eggs, although they developed more slowly.  相似文献   

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