Genital Disorders,Linear and Testicular Characteristics in Menz Rams     

Hibret A  Toé F  Mukasa-Mugerwa E  Kassa T  Markos T 《Tropical animal health and production》2001,33(3):219-227

Clinical examination, bodily condition score (BCS), heart girth (HG), body length (BL), wither height (WH), and scrotal circumference (SC) were assessed on 486 mature Ethiopian Menz rams, on small farms, in local markets, and at the main abattoir in Addis Ababa from December 1994 to April 1995. Almost 27% of the rams were found to be unfit for breeding. Poor general condition, mainly in the form of respiratory disorders, was seen in 1.2% of the rams. Balanoposthitis, epididymitis and orchitis were the most common pathological conditions, affecting the external reproductive organs in 14.6%, 4.5% and 4.1% of the rams, respectively. Testicular calcification, cysts and testicular haemorrhagic lesions were detected in 4, 6 and 8, respectively, of the 60 rams examined at necropsy. The BCS, HG, BL and WH averaged 2.1±0.5, 67.7±5.0 cm, 60.1±4.5 cm and 60.1±4.3 cm, respectively. The mean SC was 25.5±3.9 cm and did not vary significantly with age (p>0.05). Among the linear body measurements, the highest correlation was between BL and WH (r = 0.66). SC was found to be most closely correlated to HG (r = 0.46). More investigations into the relationship between the present findings and actual fertility, and on their practical application in the selection of rams for breeding is recommended.  相似文献   

Reproductive Performance of Crossbred Dairy Cows in Different Production Systems in the Central Highlands of Ethiopia     

Shiferaw Y  Tenhagen BA  Bekana M  Kassa T 《Tropical animal health and production》2003,35(6):551-561

The study was conducted to examine the fertility status of crossbred dairy cows in mixed crop-livestock production (MCLP), market-oriented specialized dairy production (MSDP) and urban dairy production (UDP) systems, including the Holetta Agricultural Research Center (HARC). Data on general farm management variables and reproductive histories were collected from study farms by questionnaire and from individual cow records. Age at first service and age at first calving were 29.58 months (n = 424) and 40.6 months (n = 348), respectively. Cows managed under UDP were younger at first service and at first calving (p<0.05). The mean intervals from calving to first service and to conception were 141.98 days (n = 284) and 185.02 days (n = 219), respectively. The mean calving interval for cows was 551.82 days (n = 258). Cows in MCLP had longer intervals from calving to first service and to conception and longer calving intervals than those managed under MSDP, UDP and HARC. First service conception rate (43.42%), number of services per conception (1.75) and pregnancy rate (79.29%) did not differ significantly between production systems. Reproductive performance was best in UDP followed by HARC and MSDP. The difference between MCLP and the rest points to particular difficulties in that system. To improve reproductive performance and economic benefit, there should be conservative stocking rate, sensible year-round feeding, a herd health plan, and sustainable extension service.  相似文献   

Molecular characterization of Newcastle disease viruses isolated from rural chicken in northwest Ethiopia reveals the circulation of three distinct genotypes in the country     

Tsegaw Fentie  Alireza Heidari  Roberta Aiello  Tesfu Kassa  Ilaria Capua  Giovanni Cattoli  Mesfin Sahle 《Tropical animal health and production》2014,46(2):299-304

Newcastle disease (ND) is a highly contagious disease that affects many species of birds and causes significant economic losses to the poultry industry worldwide. Fifteen Newcastle disease virus (NDV) isolates obtained from rural chickens in northwest Ethiopia in 2011 and 2012 were characterized genotypically. The main functional region of the F gene was amplified and sequenced (260 nucleotides). Among the Ethiopian NDV isolates, 2 isolates had the virulent motif ¹¹²R-R-Q-K-R-F¹¹⁷ at the cleavage site of the fusion protein while 13 isolates contained the lentogenic motif ¹¹²G-G/R-Q-G-R-L¹¹⁷. Phylogenetic analysis based on the variable region of the F gene indicated that the two isolates exhibiting the virulent motif belonged to lineage 5 (genotype VII) subgenotype d and the remaining 13 isolates were grouped into lineage 2 (genotype II). The nucleotide sequences of lineage 5 isolates were genetically related to the Sudanese NDV isolates, suggesting potential epidemiological link of ND outbreaks between neighbouring countries. The lentogenic strains shared similarities with La Sota vaccine strain and probably originated from the vaccine strain either through direct exposure of birds to the live vaccine or to infectious La Sota-like strains circulating in rural poultry. This study provides genetic evidence on the existence of different NDV genotypes circulating in the rural poultry in Ethiopia. The virulent NDV continues to be a problem in poultry sector in Ethiopia, and their continuous circulation in rural and commercial poultry calls for improved surveillance and intensified vaccination and other control measures.  相似文献   

Effect of source germplasm and season on the in vivo haploid induction rate in tropical maize     

Aida Z. Kebede  Baldev S. Dhillon  Wolfgang Schipprack  Jose L. Araus  Marianne Bänziger  Kassa Semagn  Gregorio Alvarado  Albrecht E. Melchinger 《Euphytica》2011,180(2):219-226

For in vivo production of doubled haploid (DH) lines in maize, the rate of haploid induction is of crucial importance. Maternal haploid induction depends primarily on the inducer used as a pollinator. However, the source germplasm used as a maternal parent and the environmental conditions for induction may also influence haploid induction and these aspects have not been examined in tropical maize so far. The objectives of our study were to (i) monitor the variation for haploid induction rate (HIR) among diverse source germplasm in tropical maize, (ii) determine the relative importance of general (GCA) and specific (SCA) combining abilities for HIR, and (iii) investigate the influence of summer and winter seasons and genotype × season interactions on this trait. Ten inbreds were mated in a half diallel design. The resulting 45 F₁ single crosses were pollinated with the haploid inducer hybrid RWS × UH400 during the summer 2008 and winter 2009 seasons in a lowland tropical environment in Mexico. HIR of the single crosses averaged over seasons ranged from 2.90 to 9.66% with an overall mean of 6.74%. Mean HIR was significantly (P < 0.01) higher during the winter (7.37%) than summer season (6.11%). Significant (P < 0.01) variation was observed due to GCA effects of parental inbreds of single crosses but not for SCA, GCA × season and SCA × season interactions. Our study underpins that a higher HIR in tropical maize can be obtained by selecting appropriate source germplasm and undertaking pollination under favorable environmental conditions.  相似文献   

The effect of mastitis on milk progesterone concentration in dairy cows     

T Kassa  K A Ahlin  K Larsson  H Kindahl 《Nordisk veterinaermedicin》1986,38(6):352-359

A within cow comparison was made between milk progesterone levels in healthy and mastitic quarters. Material was collected from cows with mastitis induced by bacterial inoculation, or by inoculation with bacterial endotoxin. Furthermore material from cows with spontaneous subclinical mastitis was used. Milk progesterone levels were lowered due to mastitis. However, the decrease was not large enough to cause misinterpretation of where in the oestrous cycle (luteal phase or non-luteal phase) the samples were taken.  相似文献   

Reproductive Disorders of Crossbred Dairy Cows in the Central Highlands of Ethiopia and Their Effect on Reproductive Performance     

Shiferaw Y  Tenhagen BA  Bekana M  Kassa T 《Tropical animal health and production》2005,37(5):427-441

The study was conducted to estimate the proportion of reproductive disorders and to determine factors affecting reproductive performance of crossbred dairy cows under four different production systems in the central highlands of Ethiopia. The principal postpartum reproductive disorders were retained fetal membranes (14.7%) and uterine infection (15.5%). Anoestrus was the major postpartum reproductive problem in the mixed crop–livestock production system (38.6%) and was significantly associated with this production system. Apart from anoestrus, the occurrence of reproductive disorders was not significantly associated with a production system. Most of the reproductive disorders occurred as a complex rather than as a single abnormality. Two or more abnormal conditions were seen in 11.4% of the cases. Each reproductive trait measured was affected adversely by reproductive disorders. Cows with reproductive disorders in each production system, lactation group and suckling and non-suckling group had longer intervals from calving to first service and to conception (p < 0.001) and required more services per conception (p < 0.001). Pregnancy rate and conception to first service were 84.7% and 51.7%, respectively, for cows without reproductive health problems; and 64.2% and 15.1%, respectively, for cows with reproductive disorders (p < 0.001). Overall, intervals from calving to first service were shorter (p < 0.05) than in younger cows. Intervals from calving to first service and to conception were longer in suckling than in non-suckling cows (p > 0.05). Cows with a good body condition score (>3.5) at calving had shorter calving to first service and conception intervals than cows in poor condition (p < 0.001). The results showed that reproductive abnormalities, coupled with poor body condition, are important factors that contributed to reproductive inefficiency. An appropriate reproductive health management, a reliable artificial insemination service and supplementary feeding could be the management options to reduce or alleviate some of the problems.  相似文献   

Reduced Milk Production in Udder Quarters with Subclinical Mastitis and Associated Economic Losses in Crossbred Dairy Cows in Ethiopia   总被引：2，自引：1，他引：1  

Mungube EO  Tenhagen BA  Regassa F  Kyule MN  Shiferaw Y  Kassa T  Baumann MP 《Tropical animal health and production》2005,37(6):503-512

The objective of the study was to estimate the losses associated with subclinical mastitis (SCM) in crossbred dairy cows in the Central Highlands of Ethiopia. A split udder investigation was performed with 30 cows to determine production losses associated with SCM. Each quarter of the study cows was examined using the California Mastitis Test (CMT) and quarter milk production was measured over a period of 8 days. Production losses were determined for different CMT scores by comparing production of quarters with CMT score 0 to quarters with CMT scores trace, 1, 2 and 3, respectively. Using data from a recently published study, economic losses were determined for different farm sizes and production subsystems by multiplying the prevalence of the respective CMT scores with the production losses associated with these CMT scores. Mean quarter milk production was 0.82 + 0.40 kg per milking in the split udder trial. Milk production was reduced by 1.2%, 6.3%, and 33% in quarters with CMT scores 1+, 2+, and 3+, respectively. Using data from the published study, a quarter with SCM lost an average of 17.2% of its milk production. Production losses associated with SCM were estimated at 5.6% for the Addis Ababa Milk Shed. Stratified losses were highest (9.3%) in urban dairy farms (UDF) and small-scale farms (6.3%). The estimates of the financial losses ranged from US$29.1 in dairy herds in secondary towns (DHIST) to US$66.6 in UDF. A total loss of US$38 was estimated for each cow per lactation. Reducing mastitis in UDF (highest prevalence) to the level of DHIST (lowest prevalence) could reduce the loss by US$35. As this does not include costs associated with treatment or culling of diseased cows, this figure probably underestimates the possible benefits of control measures.  相似文献   

GBP5 promotes NLRP3 inflammasome assembly and immunity in mammals     

Shenoy AR  Wellington DA  Kumar P  Kassa H  Booth CJ  Cresswell P  MacMicking JD 《Science (New York, N.Y.)》2012,336(6080):481-485

Inflammasomes are sensory complexes that alert the immune system to the presence of infection or tissue damage. These complexes assemble NLR (nucleotide binding and oligomerization, leucine-rich repeat) or ALR (absent in melanoma 2-like receptor) proteins to activate caspase-1 cleavage and interleukin (IL)-1β/IL-18 secretion. Here, we identified a non-NLR/ALR human protein that stimulates inflammasome assembly: guanylate binding protein 5 (GBP5). GBP5 promoted selective NLRP3 inflammasome responses to pathogenic bacteria and soluble but not crystalline inflammasome priming agents. Generation of Gbp5(-/-) mice revealed pronounced caspase-1 and IL-1β/IL-18 cleavage defects in vitro and impaired host defense and Nlrp3-dependent inflammatory responses in vivo. Thus, GBP5 serves as a unique rheostat for NLRP3 inflammasome activation and extends our understanding of the inflammasome complex beyond its core machinery.  相似文献   

Expansion of Eucalypt Farm Forestry and Its Determinants in Arsi Negelle District, South Central Ethiopia     

Dereje Jenbere  Mulugeta Lemenih  Habtemariam Kassa 《Small-Scale Forestry》2012,11(3):389-405

Declining natural forests and growing demands for wood products are encouraging the rapid expansion of eucalypt farm forestry in Ethiopia, and Arsi Negelle district represents areas with recent plantation expansion in the Rift Valley area of Ethiopia. This study assessed trends in eucalypt planting over the last five decades, identified the determinants, and examined perceptions of local stakeholders towards this expansion in the district. Quantitative data were gathered through a household survey and farm level inventory. About 90% of the respondents had planted eucalypts, and 52% of them were engaged in planting since the late 1990s. About 11% converted cropland to eucalypt woodlots, which is also a growing trend in the area. Proximity to Arsi-Forest Enterprise (P?<?0.01) and area of land holding (P?<?0.01) positively and significantly affected both decision to plant and land area allocated to eucalypts plantings. Active labour in the family negatively and significantly (P?<?0.05) affected planting decisions, while education level of the household head positively and significantly (P?<?0.05) affected land area allocated to eucalypts plantings. Despite strong policy discouragement and perceived adverse ecological effects by the farmers themselves, 96% of them and 90% of the district experts support the expansion. Eucalyptus has become the most desired and planted tree genus, and economics not ecology appears to drive its expansion. Unless better alternative sources of cash income and substitutes for energy and construction materials are found, its expansion is likely to continue even at the expense of cropland. It is concluded that research is needed to fine-tune current eucalypt farm forestry practices to reduce the associated ecological externalities, rather than grossly banning eucalypt planting by smallholders.  相似文献   

Efficacy of RM110, a novel trypanocide,in the treatment ofTrypanosoma evansi infections in camels     

D. Zelleke  B. Kassa  S. Abebe 《Tropical animal health and production》1989,21(4):223-226

Camels artificially infected with a field stock of Trypanosoma evansi isolated from a camel near Gewane, Ethiopia were cured by treatment with RM110, administered by subcutaneous injection at 0.3 or 0.6 mg/kg body weight. Local reactions were mild and transient. Further evaluation of RM110 is indicated, in particular the determination of minimum curative doses for this and other T. evansi stocks in camels.  相似文献