خيارات البحث
النتائج 1011 - 1020 من 2,008
Normal haematological values of Galla goats in Kenya
1989
Wesonga, H.O. | Nandokha, E.
Haematological values of healthy Galla goats have been determined. These values have been found to differ from those reported by other authors in different breeds of goats from various countries. Those values found to be of highly significant difference (P
اظهر المزيد [+] اقل [-]The effect of essential oils of tagetes minuta and tithonia diversifolia on on-host behaviour of the brown ear tick rhipicephalus appendiculatus
2018
Wanzala, W. | Hassanali, A. | Mukabana, W.R. | Takken, W.
On-host behaviour of Rhipicephalus appendiculatus was studied in the field in Bungoma County in Kenya to evaluate the putative repellent effects of essential oils of Tagetes minuta and Tithonia diversifolia at its predilection feeding site. Oils of both plants caused a disruption of orientation, movement and attachment behaviour of ticks. More ticks dropped off in the treatments with the two essential oils than with the control. Treating the ear pinna with the essential oil of T. minuta caused the highest percentage of ticks to drop off the host body. No tick reached the ear pinna treated with the essential oil of T. minuta and up to 30% of ticks (from the forehead release site) reached the ear base. When the ear pinna was treated with the essential oil of T. diversifolia, one tick reached the ear pinna and up to 40% of ticks (from the dewlap release site) reached the ear base. The results show that T. minuta repels ticks more strongly than T. diversifolia. However, both essential oils offer possibilities for exploitation of potentially effective and environmentally acceptable tools for on-host tick control.
اظهر المزيد [+] اقل [-]The effect of essential oils of tagetes minuta and tithonia diversifolia on on-host behaviour of the brown ear tick rhipicephalus appendiculatus
2018
Wanzala, W. | Hassanali, A. | Mukabana, W.R. | Takken, W.
On-host behaviour of Rhipicephalus appendiculatus was studied in the field in Bungoma County in Kenya to evaluate the putative repellent effects of essential oils of Tagetes minuta and Tithonia diversifolia at its predilection feeding site. Oils of both plants caused a disruption of orientation, movement and attachment behaviour of ticks. More ticks dropped off in the treatments with the two essential oils than with the control. Treating the ear pinna with the essential oil of T. minuta caused the highest percentage of ticks to drop off the host body. No tick reached the ear pinna treated with the essential oil of T. minuta and up to 30% of ticks (from the forehead release site) reached the ear base. When the ear pinna was treated with the essential oil of T. diversifolia, one tick reached the ear pinna and up to 40% of ticks (from the dewlap release site) reached the ear base. The results show that T. minuta repels ticks more strongly than T. diversifolia. However, both essential oils offer possibilities for exploitation of potentially effective and environmentally acceptable tools for on-host tick control.
اظهر المزيد [+] اقل [-]Livestock intensification and use of natural resources in smallholder mixed farming systems
2013
Samdup, T. | Udo, H.M.J. | Viets, T.C. | Zijpp, van der, A.J.
Bhutan aims to intensify livestock production not only to improve livelihoods of farming households and to meet the increasing demands of livestock products, but also to sustainably use natural resources. This paper assesses the impact and trends of livestock intensification on the use of Common Property Resources (CPR), and how this affects the cattle numbers that can be maintained and the nitrogen (N) and phosphorus (P) flows at the farm. Data on household, cropping and livestock activities were collected through interviewing 183 households in extensive, semi-intensive, intensive, and intensive peri-urban areas in the years 2000 and 2004. In the extensive and semi-intensive areas, CPR was the most important source of Total Digestible Nutrients (TDN) for cattle. In the intensive areas with a majority of crossbred cattle, the farmers relied less on CPR than in the other two areas, but still about one quarter of the TDN requirements were met by grazing CPR. Grazing in the CPR provided the highest proportion of NP inputs at farm level; without grazing on CPR all four areas would have had highly negative soil nutrient balances. Intensification of livestock production through crossbreeding has not resulted in major reductions in cattle numbers per farm, but it is contributing to reduced use of CPR by farmers. Intensification partly replaces farm nutrient flows from CPR with nutrient inputs through increased use of concentrates, conserved fodder, and fertilizers. More awareness of nutrient management is required among farmers coupled with more research on nutrient assessments.
اظهر المزيد [+] اقل [-]Livestock intensification and use of natural resources in smallholder mixed farming systems
2013
Samdup, T. | Udo, H.M.J. | Viets, T.C. | van der Zijpp, A.J.
Bhutan aims to intensify livestock production not only to improve livelihoods of farming households and to meet the increasing demands of livestock products, but also to sustainably use natural resources. This paper assesses the impact and trends of livestock intensification on the use of Common Property Resources (CPR), and how this affects the cattle numbers that can be maintained and the nitrogen (N) and phosphorus (P) flows at the farm. Data on household, cropping and livestock activities were collected through interviewing 183 households in extensive, semi-intensive, intensive, and intensive peri-urban areas in the years 2000 and 2004. In the extensive and semi-intensive areas, CPR was the most important source of Total Digestible Nutrients (TDN) for cattle. In the intensive areas with a majority of crossbred cattle, the farmers relied less on CPR than in the other two areas, but still about one quarter of the TDN requirements were met by grazing CPR. Grazing in the CPR provided the highest proportion of NP inputs at farm level; without grazing on CPR all four areas would have had highly negative soil nutrient balances. Intensification of livestock production through crossbreeding has not resulted in major reductions in cattle numbers per farm, but it is contributing to reduced use of CPR by farmers. Intensification partly replaces farm nutrient flows from CPR with nutrient inputs through increased use of concentrates, conserved fodder, and fertilizers. More awareness of nutrient management is required among farmers coupled with more research on nutrient assessments.
اظهر المزيد [+] اقل [-]Optimisation of breeding schemes for litter size, lambing interval, body weight and parasite resistance for sheep in Kenya
2011
Verbeek, E. | Kanis, E. | Bett, R.C. | Kosgey, I.S.
The current study optimised breeding schemes for litter size (LS), lambing interval (LI), body weight (BW) and gastrointestinal parasite resistance for sheep in Kenya. Selection for the breeding goal traits was performed in a conventional way using information on phenotypes only. For gastrointestinal parasite resistance, information on genetic makers was used, with faecal egg count (FEC) as an indicator trait. Selection for parasite resistance was partly based on field measurements and the possibilities for marker-assisted selection (MAS) were explored. Several selection schemes were defined based on whether a classical selection only was used (Latin number 1), a quantitative trait loci (QTL) for FEC was assumed to be available (2), that the correlation between FEC and BW was assumed to be positive (unfavourable-Roman I) or negative (favourable- II) and finally how FEC was included in the index (i.e., no inclusion (A), with FEC (B) or with FEC QTL (C-F)). The schemes with overlapping generations were evaluated using the computer program SelAction. Rams, ewes and total selection responses in US dollars ($) per animal, and rams' and ewes' accuracies for each scheme with a favourable or unfavourable correlation were estimated. The differences in total selection responses between schemes that did not include FEC in the selection index resulted in a response of $0.16 in scheme 1AI and $0.20 in scheme 1AII. In schemes 1BI and 1BII, FEC was included in the index. The responses in scheme 1BI and 1BII were $0.165 and $0.217, respectively. The increase in response in schemes II compared with schemes I was due to a favourable correlation between BW and FEC. The different FEC index traits had a different effect on economic response. It should be noted that increased emphasis on selection for FEC will reduce the relative responses to the breeding goal traits BW, LS and LI. Consequently, the goal of selection for FEC should be to maintain acceptable levels of gastro-intestinal parasite resistance as well as sufficient improvement of LS and BW.
اظهر المزيد [+] اقل [-]Influence of male or female headship on the keeping and care of small ruminants: the case of the transitional zone of Ghana
2011
Duku, S. | Price, L.L. | van der Zijpp, A.J. | Tobi, H.
The study was undertaken in the Ejura-Sekyedumasi District of Ghana to investigate how household headship characteristics and labour availability relate with the household’s decision to keep and spend time on small ruminants. Key informants were interviewed prior to a census of all the 407 households in two villages, to collect demographic, crop, and livestock data, which was used in bivariate and logistic regression analyses. A subsequent time use study involved a stratified sample of 24 households, and the t- test was used to compare households. In general, female-headed households (FHH) were of lower socio-economic status, and had fewer adult household members and less livestock, compared to male-headed households (MHH). The final logistic regression model had a 77.1% success rate in predicting households keeping small ruminants, with socio-economic status and sex of the household head, presence of poultry and the number of active adults as significant predictors. Characteristics of FHH that kept small ruminants were not significantly different from their male counterparts, but the former spent less time feeding their animals. The odds of keeping small ruminants were ultimately 2.1 times higher for male-headed households. The low socio-economic status of most FHH with less labour availability is a disincentive for small ruminant rearing
اظهر المزيد [+] اقل [-]Role of traditional enclosures on the diversity of herbaceous vegetation in a semi-arid rangeland, southern Ethiopia
2010
Angassa, A. | Oba, G. | Treydte, A.C. | Weladji, R.B.
Grazing management and seasonality strongly influence the recovery potential of herbaceous vegetation in semi-arid rangelands of southern Ethiopia after history of heavy grazing. We investigated effects of management (enclosures versus grazed landscapes), age of enclosures and seasonality related to rainfall (i.e., independent variables) on herbaceous biomass, grass basal cover, herbaceous species abundance, species richness and diversity in a savanna rangeland of southern Ethiopia. We further assessed the relationship between the herbaceous biomass and species richness. Management significantly affected most of the herbaceous response variables (i.e., comparing enclosures and open grazed). Herbaceous biomass, grass basal cover, herbaceous species richness and diversity were greater in enclosures than in grazed areas. Rainfall was also influential on herbaceous biomass, grass basal cover, abundance of herbaceous species, herbaceous species richness and diversity. Herbaceous biomass, abundance and diversity did not however vary with the age of enclosures, while herbaceous species richness appeared to decrease as the age of enclosures advanced. Grass basal cover initially decreased and later on increased with the age of enclosures, so that the older enclosures disclosed improvement of grass basal cover.
اظهر المزيد [+] اقل [-]Livestock-rangeland management practices and community perceptions towards rangeland degradation in South Omo zone of Southern Ethiopia
2010
Admasu, T. | Abule, E. | Tessema, Z.K.
Rangeland dynamics in South Omo Zone of Southern Ethiopia: Assessment of rangeland condition in relation to altitude and Grazing types
2010
Terefe, A. | Ebro, A. | Tessema, Z.K.