seasonality

Seasonal variation of strongylosis in working donkeys of Ethiopia: a cross-sectional and longitudinal studies

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Publication details
Publication date: 
24 May 2017
Page numbers: 
1-7
DOI number: 
10.1007/s00436-017-5485-z
Abstract

Helminths are one of the major health problems of working donkeys, often with heavy worm burden and contributing to their early demise and/or reduction in their work output. Cross-sectional and longitudinal studies were conducted to investigate the current infection prevalence and level of strongyles infection donkeys would acquire through different seasons in the mid-lowland agro-ecological zones of Ethiopia. For this purpose, faecal samples from 206 (cross-sectional study) and 102 (longitudinal study) randomly selected donkeys were directly collected from the rectum and analysed. For the longitudinal study, the 102 donkeys dewormed at the end of main rainy season, beginning of October, were monitored for the level of strongyle infection they would acquire during subsequent dry and short rainy seasons. The cross-sectional study of 206 donkey has revealed an overall infection prevalence of 89.3% (95% confidence interval (CI) = 84.4, 92.9). Donkeys in the lowland zone showed a significantly higher strongyle infection prevalence (P = 0.0126) and mean eggs per gramme of faces (EPG) (P = 0.001; 2775 EPG) compared to donkeys in the midland zone (980.8 EPG). Age, sex and body condition did not have any significant effect on either the infection prevalence or level of infection (P > 0.05). The longitudinal study has shown a significantly lower strongyle infection prevalence (P = 0.003) and level of infection donkeys acquired (P = 0.001) in the subsequent dry and short rainy seasons compared to the main rainy season following October deworming. However, these values were not significantly different between the two agro-ecological zones (P > 0.05). This study clearly showed that parasitic infections are primarily acquired during the main rainy season when pasture/herbage coverage is relatively better, and the environment is conducive for parasites survival and development. On the other hand, the finding of majority of donkeys shedding low or no eggs during the dry and short rainy seasons showed that October deworming was effective, and donkeys acquire low or no parasitic infection during the subsequent dry and short rainy seasons. Therefore, the practice of anthelmintic treatment of donkeys at the end of short rain in May may not be necessary, and October deworming once a year is sufficient.

Online references

Seasonal infestation of donkeys by lice: phenology, risk-factors and management

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Lauren Ellse, Faith A. Burden, Richard Wall. April 2014. Seasonal infestation of donkeys by lice: phenology, risk-factors and management. Veterinary Parasitology.

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Publication details
Publication date: 
19 April 2014
DOI number: 
10.1016/j.vetpar.2014.04.012
Abstract

A longitudinal study was undertaken over a 21 month period to examine the seasonal abundance of lice infesting donkeys, the risk factors which predispose donkeys to infestation and the effectiveness of louse management. All the lice seen were Bovicola (Werneckiella) ocellatus. A strong seasonal pattern, which was correlated with mean monthly temperature, was observed with higher prevalence and intensity in the cooler, winter months (October-March). Overall infestation in these animals was over-dispersed, suggesting that some individuals are strongly predisposed to infestation. Donkey age and mean hair length were characteristics which affected louse prevalence: older and younger donkeys and donkeys with longer hair harboured the highest numbers of lice. However, the practice of coat-clipping, to reduce the infestation, resulted in a lower louse prevalence only in the summer, suggesting that clipping is not an effective form of louse control in cooler months. Higher louse burdens were associated with larger areas of visible excoriation and hair damage, suggesting that B. ocellatus does adversely impact animal welfare. However, the ability of animal carers to estimate louse presence or absence accurately on an individual donkey was not sufficiently high to allow targeted selective treatment of heavily infested animals to be employed effectively. As animals are housed in closed herds these findings suggest that clipping in the summer and treating all animals with insecticide in late autumn, prior to turn-in may be an effective louse management strategy.

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Seasonal variation of digestible energy requirements of mature donkeys in the UK

Citation

Stephanie J. Wood, David Smith, Catherine J. Muir, Derek Cuddeford. October 2006. Seasonal variation of digestible energy requirements of mature donkeys in the UK. Presented at 5th International Colloquium on Working Equines. (30 October - 2 November 2006). Addis Ababa, Ethiopia.

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Presentation details
Date presented: 
Monday 30 October 2006
Abstract

At present there are no published feeding guidelines specific to donkeys. Current recommendations are to feed 0.75 of horse energy needs on a body weight basis. However, it has been shown that donkeys have a greater digestive efficiency than horses and ponies and thus, feeding them as though they were small horses results in excess energy intake and, as a consequence they become obese. The formation of feeding guidelines begins with the estimation of the energy requirement for maintenance, as this is the value upon which nutrient requirements are related to. The aim of the study was to determine the maintenance digestible energy requirements of mature donkeys during each UK season. Twenty mature donkeys (10 male, 10 female) were selected for use in the study. The donkeys were fed a diet of hay and barley straw in quantities that were adjusted to maintain body weight. An equilibration period of minimum 16 days was followed by a five day total faecal collection; this was carried out for each season. Food and faecal samples were analysed for dry matter (DM), organic matter (OM), digestible energy (DE), crude protein (CP), neutral-detergent fibre (NDF) and acid-detergent fibre (ADF); nutrient and energy intakes were calculated. There was a significant seasonal effect on all intakes except NDF and ADF. DM and DE intakes showed significant increases in winter compared to summer, rising by 42 and 35%, respectively. Digestible crude protein (DCP) intakes increased during winter and spring but were significantly lower in autumn compared to all other seasons. A strong seasonal effect was exerted on all in vivo digestibilities although there was no effect of sex. OM, NDF and ADF intakes were affected by sex with male animals having higher intakes compared to female animals. Comparison of these results with NRC (1989) horse requirements showed a considerably reduced requirement by donkeys for energy and protein and thus it was concluded that feeding tables specific to horses are not suitable for calculating donkey requirements.

Proceedings
Publisher: 
The Donkey Sanctuary
Publication date: 
30 October 2006

A survey of seasonal patterns in strongyle faecal worm egg counts of working equids of the Central Midlands and Lowlands, Ethiopia

Citation

Mulugeta Getachew, Feseha Gebreab, Andrew F. Trawford, Stuart W. Reid. December 2008. A survey of seasonal patterns in strongyle faecal worm egg counts of working equids of the Central Midlands and Lowlands, Ethiopia. Tropical Animal Health and Production. 40:8. 637-642.

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Publication details
Publication date: 
1 December 2008
Volume: 
40
Issue: 
8
Page numbers: 
637-642
DOI number: 
10.1007/s11250-008-9142-5
Abstract

A study was conducted for two consecutive years (1998-1999) to determine the seasonal patterns of strongyle infection in working donkeys of Ethiopia. For the purpose 2385 donkeys from midland and lowland areas were examined for the presence of parasitic ova. A hundred percent prevalence of strongyle infection with similar seasonal pattern of strongyle faecal worm egg output was obtained in all study areas. However, seasonal variations in the number of strongyle faecal worm egg output were observed in all areas. The highest mean faecal worm egg outputs were recorded during the main rainy season (June to October) in both years in all areas. Although an increase in the mean strongyle faecal egg output was obtained in the short rainy season (March-April) followed by a drop in the short dry season (May), there was no statistically significant difference between the short rainy season and long dry season (Nov-Feb) (P > 0.05). A statistically significant difference however, was obtained between the main rainy season and short rainy season, and between the main rainy season and dry season (P < 0.05). Based on the results obtained it is suggested that the most economical and effective control of strongyles can be achieved by strategic deworming programme during the hot dry pre-main rainy season (May), when the herbage coverage is scarce and helminthologically 'sterile', and the arrested development of the parasites is suppose to be terminating. This could insure the greatest proportion of the existing worm population to be exposed to anthelmintic and also reduces pasture contamination and further infection in the subsequent wet season.

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