The economic effects of trypanosomiasis in sheep and goats at a range research station in Kenya

Summary A study on the economic effects of naturally acquired trypanosomiasis in sheep and goats over a period of 35 weeks under range conditions in the Kiboko area of Kenya indicated that the financial loss from reduced weight gain and death amounted to 36·2 and 62·9 Kenya shillings per head for goats and sheep respectively. This was derived from the weight loss through death together with the reduced weight gain of the survivors compared with treated animals. The study also compared the efficacy of 3 drug regimes in goats and suggests that although quinapyramine (prophylactic) B.vet.C. provided the longest protective period, the weight increase of the stock under isometamidium chloride treatment was higher. The benefits of the drugs used are discussed.

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Los Efectos Economicos De La Tripanosomiasis En Ovejas Y Cabras En Kenya

Resumen Se llevó a cabo un estudio económico, sobre los efectos de la tripanosomiasis adquirida en forma natural, en ovejas y cabras en el área de Kiboko en Kenya. El estudio tuvo una duración de 35 semanas bajo condiciones de campo. Los resultados indicaron, que la pérdida monetaria debida a bajos aumentos de peso y muertes, tuvo un monto de 36.2 chelines (moneda de Kenya) por cabeza para cabras y ovejas respectivamente. Como parte del estudio, se comparó la eficacia de tres regímenes quimioprofilácticos y quimioterapéuticos en cabras. La quinapiramina (profiláctica) B vet C proporcionó el período más largo de protección, pero el incremento de peso de los animales bajo tratamiento con cloruro de isometamidio fue mayor. Se discuten los beneficios de las drogas usadas.

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Les Effets Economiques Des Trypanosomoses Chez Les Moutons Et Les Chevres Au Kenya

Résumé Une étude sur les incidences économiques des trypanosomoses naturellement acquises par des chèvres et des moutons entretenus sur des pâturages naturels pendant 35 semaines, dans le région de Kiboko au Kenya montrent que les pertes financières par perte de poids et mortalité atteignent respectivement 36,2 et 62,9 shillings kenyans par tête. L'étude a également porté sur l'efficacité relative de trois traitements médicamenteux chez les chèvres; il en résulte que bien que la quinapyramine (prophylactique) B et C donne une protection de plus longue durée l'augmentation de poids chez les animaux traités au chlorure d'isometamidium a été plus élevée.Les bénéfices résultent de l'utilisation de ces corps sont discutés.

     

Financial Implications of Rearing Sheep and Goats under Natural Trypanosomosis Challenge at Galana Ranch,Kenya

A study to compare the profitability of rearing sheep and goats under natural trypanosomosis challenge was carried out on Galana ranch in south-eastern Kenya between July 1996 and October 1997. Seventy-nine male weaner sheep and 79 male weaner goats were monitored monthly for weight changes and fortnightly for trypanosomosis. The animals of each species were divided into two groups. Group 1 was an untreated control, while group 2 was treated with isometamidium chloride (Samorin) at 0.5 mg/kg body weight every 3 months. In both groups, trypanosome infections were detected by microscopy and treated with diminazene aceturate (Veriben), at 3.5 mg/kg body weight, when the packed cell volume reached 17% or below. The profitability of each drug regime was expressed as the marginal revenue over the cost of trypanosomosis (MOT). There were greater losses occasioned by trypanosomosis in sheep than in goats. Animals of both species on chemoprophylaxis gave higher MOT values than those that received chemotherapy on diagnosis. However, the MOT values for the chemoprophylactic regime were higher for sheep than for goats, suggesting that the greater weight gain by sheep more then compensated for the higher cost of maintaining them under high trypanosomosis challenge. Thus, a Galana rancher would be better off keeping sheep rather than goats, other things being equal. The marginal revenue per dose of Samorin was lower than that of Veriben for both species, suggesting that strategic use of Samorin timed to precede the peak incidence of trypanosomosis might be a better option to raise the overall profitability in sheep and goats.     

湿热应激对藏绵羊和山羊生长性能、抗氧化能力以及免疫功能的影响

本试验旨在研究藏绵羊和山羊在相同营养及湿热应激条件下血清激素、抗氧化和免疫指标的变化规律,考察湿热应激对藏绵羊和山羊生长性能、抗氧化能力以及免疫功能影响的差异。选取年龄和体重[(45.83±3.54)kg]相近的藏绵羊与山羊(波尔山羊×本地黄羊)各6只,试验共进行135 d,其中预试期15 d,正试期120 d。每日测定温湿度指数(THI),每月测定藏绵羊和山羊的血清相关指标。结果表明:1)5—7月份,羊舍THI随月份的增加显著升高(P0.05),6—8月份羊舍THI均大于72,因此将6—8月份定为湿热应激期。2)7、8月份藏绵羊和山羊直肠温度和呼吸频率均显著高于5月份(P0.05),且湿热应激期内藏绵羊直肠温度和呼吸频率均显著高于山羊(P0.05)。3)正试期内,湿热应激使得藏绵羊和山羊的干物质采食量最大降幅分别为10.70%和10.44%,平均日增重(ADG)最大降幅分别为50.00%和47.82%。4)羊舍THI由71.17(5月份)升高到76.82(7月份),藏绵羊和山羊血清皮质醇和胰岛素浓度显著升高(P0.05),血清葡萄糖和三碘甲状腺原氨酸浓度显著降低(P0.05)。湿热应激下,藏绵羊血清中生长激素和甲状腺素浓度的最大降幅均大于山羊。5)除藏绵羊7月份和山羊8月份血清总抗氧化能力,藏绵羊和山羊7、8月份的血清超氧化物歧化酶、谷胱甘肽过氧化物酶活性和总抗氧化能力均显著低于5月份(P0.05)外,血清丙二醛浓度均显著高于5月份(P0.05)。湿热应激下,山羊血清超氧化物歧化酶活性、总抗氧化能力和丙二醛浓度变化幅度均大于藏绵羊。6)与5月份相比,藏绵羊和山羊8月份的血清免疫球蛋白A、免疫球蛋白M、免疫球蛋白G和白细胞介素-2浓度显著降低(P0.05),而血清肿瘤坏死因子-α浓度则显著升高(P0.05)。湿热应激下,藏绵羊血清免疫球蛋白、白细胞介素-2和肿瘤坏死因子-α浓度的变化幅度均大于山羊。综上所述,湿热应激状态下藏绵羊和山羊的呼吸频率和直肠温度升高,抗氧化能力和免疫功能降低,从而导致生长性能降低。藏绵羊生长性能和免疫功能受湿热应激影响较大,而山羊抗氧化能力受湿热应激影响较大。     

Growth and Mortality in Sheep and Goats under High Tsetse Challenge in Kenya

Trypanosomosis is a major impediment to livestock production and economic development in those areas of Africa where it is endemic. Although small ruminants appear to perform better than cattle in various agro-ecological zones, the importance of trypanosomosis has not been extensively investigated in these livestock. This study was designed to investigate the prevalence of trypanosomosis in sheep and goats in an endemic area and to evaluate the performance of different breeds under high tsetse challenge and the potential role of chemoprophylaxis in the control of the disease. The results showed that tsetse flies feed readily on small ruminants, and that these animals are susceptible to trypanosomosis. The Small East African goats acquired fewer infections than the Black Head Persian and Dorper sheep used in the study. In both sheep and goats, chemoprophylaxis with isometamidium chloride (Samorin, Rhone Merieux, Annecy, France) was protective, resulting in fewer infections and higher body weight gain. Trypanosomosis caused anaemia in both sheep and goats, and animals whose PCV fell below 15% rarely recovered, even with trypanocidal drug treatment. The peak transmission period was between 1 and 3 months after the peak tsetse fly density, which raises the possibility of effective strategic prophylaxis.     

冷季藏羊补饲试验效果观察

藏羊是青海地区特有的牲畜品种,生活在高海拔气候严寒,生长条件恶劣的环境下。但由于青藏高原冬季枯草期漫长,在枯草期内牧草供给缺乏,造成藏羊的体重损失严重,甚至会影响藏羊的正常生长发育,引发藏羊死亡。为进一步验证冬季藏羊补饲的效果,于2018年10月15日至2019年5月30日,从青海省达日县的一个藏羊养殖场选择50头2岁的母羊作为试验对象,按照随机原则将其划分为试验组和对照组,每组25头,试验组羊群在进行传统放牧养殖的基础上每天补充青干草0.4 kg,混合精饲料0.1 kg,对照组藏羊按照常规放牧方式进行管理,并在试验前、试验中期和试验末期各进行称重,测量增重和增重率,研究结果表明,在寒冷季节放牧养殖模式下,通过对羊群进行适量的饲料补充能增加机体的营养供给,试验组羊群在试验中期、试验末期的平均增重量分别为2.78、3.64 kg,增重率分别为13.11%、16.32%,而对照组的平均增重量和增重率呈现负相关,由此得出冬季寒冷季节补充适量的饲料有利于藏羊安全越冬,并维持身体膘情。     

Epidemiology of parasitic gastrointestinal nematode infections of ruminants on smallholder farms in central Kenya

In order to establish the infection pattern with gastrointestinal nematodes in ruminants in the central Kenya highlands, a study was carried out in 58 smallholder farms. The study involved monthly faecal examinations from sheep, goats and cattle and pasture sampling from eight communal grazing areas. Each month, six Dorper worm-free tracer lambs were introduced and four locally grazed cross-bred sheep were purchased for parasite recovery. The mean faecal egg counts (FEC) for cattle were low throughout the study period, whereas those for sheep and goats showed a seasonal pattern with high levels of infection occurring during the two main rainy seasons, especially in March, April and October. There were significant differences in egg counts over time and among farms. Haemonchus contortus was the most prevalent nematode in the tracer lambs whereas the previously exposed locally grazed sheep had significantly lower numbers of H contortus but significantly higher numbers of Trichostrongylus species The highest levels of infection in the tracer lambs occurred in November 1995 and January, May and June 1996. Based on this study, it is now possible to explore the possibility of using strategic treatments for the control of parasitic gastroenteritis in this area of Kenya.     

The point prevalence of gastro-intestinal parasites in calves, sheep and goats in Magadi division, south-western Kenya

Helminths cause great economic loss in livestock in Africa, and can be categorized as either direct or indirect losses. Arid and semi-arid lands (ASAL) in Kenya comprise 71% of total land area and harbour the largest population of cattle, sheep and goats. However, little information on the distribution and impact of gastro-intestinal (GIT) parasitism in these animals is available. This survey was conducted to establish the prevalence of GIT parasites infecting calves, sheep and goats and their relative importance in Magadi division, which is semi-arid. Faecal samples were obtained directly from the rectum of 109 calves, 133 goats and 20 sheep and submitted to the laboratory for faecal worm egg counts, and coccidial oocysts examination using a modified McMaster method. The significance of differences in mean egg count per gram (epg) between animal species and herds (farms) were assessed using analysis of variance. The overall prevalence of nematodes in the calves, sheep and goats was 69.2%, 80% and 82%, respectively. About 10% of sheep and goats had epgs higher than 1 000, the remainder having light to moderate infections. The overall prevalence of coccidial oocysts in calves, sheep and goats was 30%, 44% and 45%, respectively. Poor productivity in ASAL areas, where nutrition is often poor, is likely to be pronounced in the presence of parasite infections. These findings indicate that viable internal parasite control should be implemented in the study area in order to increase the productivity of the livestock there.     

Haemonchus contortus and Trichostrongylus colubriformis in pen-trials with Javanese thin tail sheep and Kacang cross Etawah goats

Weight gain costs due to infection were higher in sheep than goats, 28 and 17.5%, respectively, for Trichostrongylus colubriformis and 48.7 and 32.2%, respectively, for Haemonchus contortus. The extent of bodyweight cost attributed to anorexia in sheep infected with H. contortus was higher (13.5 g/day) than in sheep infected with T. colubriformis (2.3 g/day). On the other hand, bodyweight cost due to the other pathogenic effects in sheep infected with T. colubriformis were higher (35.6 g/day) compared to sheep infected with H. contortus (10.9 g/day). A strong relationship between faecal egg count and worm count (r=0.79, P=0.006) was shown only in sheep infected with T. colubriformis. About half of the infected sheep and goats had low or zero faecal egg counts throughout the study. In about 40% the egg count rose initially but became low by weeks 10-16, whereas in about 10% counts increased progressively throughout the period of observation and these animals also had the highest numbers of worms at slaughter. Packed cell volume was reduced in sheep and goats infected with H. contortus but serum protein and haemoglobin levels were unaffected. Sheep infected with T. colubriformis had a higher level of eosinophilia after 8 weeks (18.4%) than sheep infected with H. contortus (11.4%), whereas this pattern was reversed in goats and levels were also lower (4.1 and 8.9%, respectively). There was no apparent relationship between eosinophilia and resistance to infection with H. contortus or T. colubriformis.     

No loss of production due to larval challenge in sheep given continuous anthelmintic treatment via a controlled release capsule

This study aimed to quantify production loss due to larval challenge in sheep administered a controlled release albendazole capsule (CRC) and thus determine the suitability of CRC treated sheep as a proxy for worm-free sheep in grazing experiments. The experiment used an incomplete 2 × 3 latin square design with 81 Merino wethers. Sheep were either infected (INF) with mixed oral infection of albendazole-susceptible Haemonchus contortus, Trichostrongylus colubriformis, and Teladorsagia circumcincta (initial bolus then thrice weekly maintenance) or remained uninfected (UINF). Worm control treatments were with a CRC (CRCT), threshold treatment with a short-acting anthelmintic when worm egg count (WEC) exceeded 1500 epg (TT) or untreated (UT). The experiment was conducted in two 63-day periods (separated by a 14 day washout period) with infection treatments swapped between periods. A subset of animals was killed at the end of each period for worm counts and tissue sampling. Faecal worm egg count in UINF-UT reached 10,204 and 6078 epg at day 63 in periods 1 and 2, respectively, and remained 0 throughout in the CRT treatments. There was no difference in live weight gain or wool growth of INF-CRCT sheep (67 and 70 g/d) relative to UINF-CRCT (67 and 76 g/d). Live weight gain was significantly lower in INF-UT (27 g/d) and INF-TT (55 g/d) than UINF-UT (88 g/d) or UINF-TT (81 g/d) treatments. During the first infection period, greasy fleece weight growth was significantly lower in INF-UT (6.33 g/d) and INF-TT (6.37 g/d) than UINF-UT (7.80 g/d) or UINF-TT (7.32 g/d) treatments. The effects of infection on production persisted in INF-UT, but not INF-TT sheep for several weeks after termination of infection. Eosinophil counts were elevated in all infected groups and the antibody response to T. colubriformis was greater in INF-CRCT and INF-TT groups compared to uninfected sheep. Together, these results indicate that larval challenge in sheep with a CRC is mildly immunogenic but is not associated with production loss. The results also showed that the CRC itself reduced live weight gain and that anthelmintic treatment at a WEC threshold of 1500 epg reduces production loss during infections and prevents persistence of adverse effects following infection.     

Effects of supplemental feed with or without ionophores on lambs and Angora kid goats on rangeland

Effects of supplemental feed and of ionophore concentration in supplemental feed on gastrointestinal rate parameters, forage intake and weight gain were measured in individually supplemented grazing lambs and Angora kid goats. The 12 dietary treatments included negative control (NC; grazed forage only), positive control (PC; grazing plus 13.6 g supplement DM/kg.75), and PC plus monensin or lasalocid, each at 33, 66, 99, 132 or 165 mg/kg in the supplement. Gastrointestinal fill, retention time, turnover rate and fecal output were estimated by applying a single-compartment model to the fecal excretion of a single dose of ytterbium. Forage digestibility was estimated from forage and fecal concentrations of indigestible fiber. Supplemental feed increased digestibility of forage and total intake in sheep but had no effect on forage intake. In goats, supplemental feed did not increase digestibility of forage but decreased forage intake. Supplemental feed increased weight gain in both species. Increasing the monensin concentration in supplemental feed reduced supplement intake greatly in sheep and slightly in goats. Lasalocid did not affect intake of supplement by either sheep or goats. Overall, ionophores had minimal effects on the response criteria. Because feed intake and digestibility were not affected, any increase in gain or efficiency in lambs or kid goats on rangeland from consumption of ionophores must be a result of their therapeutic value or of improved physiological efficiency.     

A recent outbreak of rinderpest in East Africa

Rinderpest was brought under control in Kenya in 1976 but in April 1986 an outbreak of the disease occurred in cattle in Western Kenya, five kilometres from the Kenya-Uganda border. This was the first confirmed field outbreak of the disease in Kenya after a lull of over 10 years. Clinical disease was confined to unvaccinated zebu calves aged six to eight months from which rinderpest virus was isolated. High titres of antibodies to rinderpest virus were demonstrated in sera collected from sheep and goats that were grazing together with the affected cattle herds; there was, however, no evidence of clinical disease in these small ruminants and wildlife species in the affected area. The disease outbreak was rapidly stamped out by quarantine and vaccination.     

舍饲羊从育成阶段到成年阶段饲养管理

公羊和母羊从断奶到第1次配种前的阶段被称为育成羊,通常是指3~18月龄的幼龄羊,该阶段的羊群具有生长发育迅速,增重速度较快的特点,对饲养管理的要求相对较高,如果没有做好妥善的管理工作,羊群的增重放缓,生长发育不良,不利于提高经济效益,且易造成各种传染性疾病的发生。养殖管理人员应充分认识育成阶段生长发育不良会对羊群的繁殖造成的利影响,提高重视程度,构建完善的养殖管理方案,采取针对性措施将其解决,更好地促进育成羊的健康生长。该文主要论述舍饲养从育成阶段到成年阶段的饲养管理方案。     

低蛋白质日粮对育肥绵羊生长性能、胴体性状及肌肉脂肪酸组成的影响

本研究旨在研究降低全混合日粮蛋白质水平对育肥期绵羊生长性能、胴体性状及肌肉脂肪酸组成的影响.试验将32只平均体重为(38.14±0.45)kg的育肥期绵羊随机分为2组,每组8个重复,每个重复2头.两组绵羊在为期10周的试验期中分别饲喂蛋白质水平为13.5％和8.5％的全混合日粮.结果:将全混合日粮蛋白质水平从13.5％...     

Improved feed intake and body weight change in sheep treated with dexamethasone at entry into pens or feedlots

Treatment with the synthetic glucocorticoid dexamethasone sodium phosphate increased the feed intake of sheep within 24 h. A single treatment with the longer-acting compound dexamethasone trimethylacetate had a slower effect, but resulted in improved feed intake and enhanced body weight gain over a period of 7 to 14 days. Treatment was effective in sheep housed individually and in sheep penned in groups. The improvement in body weight gain disappeared 15 to 20 days after a single treatment, but in most studies treated sheep had less variability in weight change than untreated sheep at this time. A statistically significant increase in body weight gain was observed in 8 of 11 trials; in the other 3 trials, it appeared that the feed intake of the untreated sheep was already maximal. Wethers treated with dexamethasone trimethylacetate on arrival at an assembly point for live export arrived in the Middle East 23 days later with a lower mean weight loss, partly because fewer sheep lost a significant amount of weight.     

Seasonal variation of Oestrus ovis-specific antibodies in sheep and goats mixed flocks in Greece

The aim of this survey was to investigate the year-round epidemiological patterns of Oestrus ovis ELISA sero-prevalence in sheep and goats kept together under the same husbandry system in an endemic area of Greece. Twenty-five adult female sheep and 25 adult female goats, coming from a large mixed flock, were randomly selected, eartaged and monthly blood sampled during 1 year period (November 1998-October 1999). Serological prevalence in sheep was 100% all around the year. Mean intensities of specific O. ovis antibodies follow a seasonal evolution with higher mean titers between March and July than in winter. In contrast, the serological prevalences in goats were low specially in winter months (from October to January). No significant difference were noticed in goats antibody levels during the year period. The possible reasons of this difference of O. ovis sero-prevalence between sheep and goats are discussed.     

饮水温度和豆浆对育肥藏北母绵羊和藏北母山羊效果的影响

[目的]研究自由饮用18～20℃温水和每日饮用豆浆对补饲育肥藏北母绵羊（S）和藏北母山羊（G）的效果。[方法]试验用羊为淘汰的2～3岁藏北母绵羊和藏北母山羊。选择350只年龄接近、体重相近的藏北母绵羊,随机分为7组,每组50只。在试验期内,对照自由放牧组母绵羊50只,每日按照农牧民放牧习惯自由放牧,晚上不予补饲;绵羊6个试验组每日按照农牧民放牧习惯白天自由放牧,晚上收牧后给予一定补饲,补饲的精料颗粒料添加量为280 g/d,燕麦青干草为自由采食。经过预试验7 d,正式试验期49 d。试验前后,对每只试验羊称重。藏北山羊分组试验同藏北绵羊。试验结束后,随机在试验处理组和对照组中各选取母羊11只屠宰,随即测定试验羊的屠宰率。[结果]在相同饮水条件下,随10%豆浆饮用量的增加,体重和屠宰率差异显著（P<0.05）;在10%豆浆饮用量相同的试验组,饮水由冰水换为温水,体重和屠宰率差异极显著（P<0.01）。在不计人工投入和电费的条件下,育肥藏北母绵羊各组效益差异极显著（P<0.01）。 S4、S5和S6共3个试验组有经济效益,且随着饮水温度和豆浆量的增加,经济效益也越高（P<0.01）,S6试验组每只羊可带来高达105.95元的经济效益;育肥藏北母山羊各组效益差异亦显著（P<0.01）,且只有G6试验组每只羊可带来21.35元的经济效益。[结论]藏北母绵羊和藏北母山羊体重和屠宰率仍有较大的提升空间。选择合适的饲养模式对藏北母绵羊和藏北母山羊进行短期育肥,能够带来可观的经济效益。该试验研究为今后在饲草料相对缺乏的藏北牧区短期育肥绵羊和山羊提供了技术和数据参考。     

A study of cystic echinococcosis in slaughter animals in three selected areas of northern Turkana, Kenya.

In an attempt to establish the prevalence of cystic echinococcosis, a study was conducted in slaughter animals in three divisions of northern Turkana, Kenya. A total of 5752 goats, 588 sheep, 381 cattle and 70 camels were examined at slaughter. Echinococcus granulosus metacestodes were found in 19.4% of the cattle, 3.6% of sheep, 4.5% of goats and 61.4% of camels. The prevalence of cystic echinococcosis in cattle, sheep and goats was higher in Lokichogio than in either Kakuma or Central divisions. On the other hand, the prevalence of the disease in camels was higher in Central (84.6%) than either Lokichogio (70.6%) or Kakuma (50%). The differences in prevalence rates in different study areas are attributed to differences in environmental conditions, livestock stocking intensity and cross-border migration of livestock.     

Clorsulon pharmacokinetics in sheep and goats following oral and intravenous administration

Clorsulon was measured in plasma and urine of sheep and goats after administration of a single intravenous (i.v.) and after a single oral dose of 7 mg/kg. A three-compartment model with elimination occurring from the central compartment was determined to best describe the i.v. data, whereas a one-compartment model with a single exponential absorption phase best described the oral plasma data. The bioavailability of orally administered clorsulon was approximately 55% in goats and 60% in sheep. Peak plasma concentrations occurred at 14 h and 15 h after oral administration in goats and sheep, respectively. Absorption from the gastro-intestinal tract effectively prolonged the elimination of clorsulon by increasing the elimination half-life from 17 to 28 h in sheep and from 12 to 23 h in goats for the i.v. and oral routes, respectively. In both goats and sheep, approximately 50% of the i.v. dose was recovered in urine as parent drug at 48 h after administration, whereas 41% and 30% of the dose was recovered after oral administration for goats and sheep, respectively. The elimination rate constant (kel) in goats was nearly twice as large as the value determined in sheep, and the urea under the i.v. plasma curve in goats was only 63% of the value in sheep indicating that goats are more effective in their capacity to eliminate clorsulon than are sheep. These differences in drug disposition between sheep and goats may account for the reduced efficacy of clorsulon reported in goats.