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Newcastle disease (ND) is perceived to be the major constraint in village chickens of Ethiopia causing huge economic loss. Village chickens are mobile and pass through markets, and live chicken markets are a highly productive source of ND virus replication, maintenance, and spread. However, in northwest of Ethiopia, there is a dearth of information on the role of live chicken markets in the maintenance and spread of ND in the village chickens. Therefore, a total of 480 apparently healthy chickens in the 4 live chicken markets were sampled with the aim to detect and estimate ND virus infection. Tracheal and cloacal swabs were collected from each bird and processed for virus isolation in 9- to 11-day-old embryonated chicken eggs, and hemagglutination inhibition (HI) assay was performed on all sera samples. The overall infection rate of ND virus was reported to be 39.2% (95% CI: 34.8–43.5). Of all chickens, 34.6% (95% CI: 30.3–38.9) had mean HI titer ≥4 log2, which was considered as protective. The mean hemagglutination titer for the ND virus was reported to be 6.0 log2, and mean antibody titer was reported to be 6.2 log2, with no statistically significant variation among the markets (P > 0.05). Newcastle disease occurrence was detected in all seasons of the year in the live bird markets, with the highest prevalence (55.8%) during the prerainy dry season (April and May), showing evidence for climatic and socioeconomic aspects as a risk factor in the occurrence of ND in indigenous chicken. In vivo virulence tests, mean death time of the embryo, and the intracerebral pathogenicity index revealed the presence of all pathotypes of ND virus strains: velogenic, mesogenic, and lentogenic. Apparently, healthy appearing birds were reported to be reservoirs of velogenic ND virus strains that could initiate endemicity of ND cycles in the village setting. Hence, it is strongly recommended to implement appropriate prevention and control measures to mitigate the economic loss caused by the disease.

This study was conducted from May 08 to June 08, 2017 in Gidami District, Kellem Wollega Zone, Oromia Regional State, Ethiopia. The objective of the study was to assess the occurrence of trypanocidal drug resistance in naturally infected cattle in identified hot spots villages of Gidami district. An initial cross-sectional prevalence study was conducted in seven villages from November 2015 to June 2016. Based on the outcome of the cross-sectional study, Kellem and Gry Sonka villages with highest trypanosome prevalence (28% and 30.85%) respectively were selected. An abbreviated 28-day field prototocol study was used to estimate resistance to 1 mg/kg bw isometamidium chloride (ISM) and 7.0 mg/kg bw diminanzene aceturate (DA). In this study, 100 purposively selected trypanosome positive cattle were ear-tagged and allocated into two treatment groups: a group I were treated with 2% solution of 1 mg/kg bw ISM and a group II were treated with 7% solution of 7 mg/kg bw DA. The treatment day was considered as day 0 and the treated cattle were monitored for trypanosomes and packed cell volume (PCV) levels on days 14 (for DA and ISM) and 28 (for ISM) post treatment. A treatment failure rate of 25% of the cattle in the ISM treated group on days 14 and 28 were indicative of resistance, whereas in the DA treated group the response was assessed only on day 14 post-treatment. The results of the study confirmed the presence of drug resistance to the maximum recommended doses of ISM and DA in Giray Sonka and Kellem villages of Gidami district. Out of 50 trypanosome positive cattle treated with ISM, 68% had persistent infections on day 28 post-treatment. Similarly, of the 50 trypanosome positive cattle treated with 7 mg/kg bw DA, 36% had persistent trypanosomes on day 14 post treatment. Of all ISM and DA treatment failures T. congolense accounted for (70.59%; 66.67%), T. vivax (23.53%; 27.78%) and T. brucei (5.88%; 5.55%) respectively. Drug resistance has indeed been a considerable threat in all villages of Gidami district, but the situation is magnified in Giray Sonka and Kellem villages. Thus, an integrated control approach of trypanosomosis should be conducted to ensure sustainable animal health and production in the area. In addition beside tsetse control, rational use of trypanocidal drugs and control of co-infections to exploit self-cure against resistant trypanosome populations are recommended. Furthermore, extensive data on trypanocidal drug sensitivity tests using advanced molecular techniques considered as elucidative.

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 dollars 29.1 in dairy herds in secondary towns (DHIST) to US dollars 66.6 in UDF. A total loss of US dollars 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 dollars 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.

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

An investigation was carried out into the behavioural and physical signs of oestrus in 70 Fogera cows and heifers between December 1993 and May 1994 at Metekel Cattle Breeding and Improvement Ranch, Ethiopia. Retrospective information generated from records made between 1991 and 1994 was evaluated for some aspects of the reproductive indices. The mean±SD duration of oestrus (n = 136) was 10.6±4.5 h (range 2.2–21). Most oestruses (63.2%) started during the day (06:00–18:00). The incidence of oestrus was significantly affected by months (χ2 = 21.86; p

The aim of this study was to evaluate testicular cytological profiles of apparently healthy dromedary bulls during rutting and non-rutting periods. Pairs of testes from 26 (18 non-rutting and 8 rutting seasons) dromedary bulls 6-12 years old that were slaughtered at Akaki, Addis Ababa abattoir were sampled. A 21 gauge needle attached to 20mL syringe was used to collect Testicular Fine Needle Aspiration (TFNA) samples and five aspiration smears were prepared from each testis. A total of 312 slides (260 Testicular fine Needle Aspiration and 52 imprints) were examined. The mod ified May-Grunwald Giemsa (mMGG) technique and a light microscope were used to assess cellularity, morphology and quantification of the testicular. Sertoli and spermatogenic cells were identified and counted. The spermatic index (SI), Sertoli cell index (SEI) and the relationship between SI and SEI indexes (SSEI) were used to assess the ratio between mature spermatozoa and nursing cells. There were differences (P0.05) between the rutting and non-rutting seasons among the spermatogenic and Sertoli cells. There were no differences between groups for primary spermatocyte numbers, early spermatid numbers and SSEI. There was no differences (P0.05) between TFNA and imprint smear slides of the testicular cells except for Sertoli cell count and SEI. Filarial worm larvae were present on the TFNA smear slides of four animals. Imprint and TFNA smear slides had comparable cytological profiles in dromedary bulls and significant differences were observed between rutting and non-rutting periods.

An experimental study was conducted to evaluate the effect of vaccines produced in Ethiopia from vaccine strains used worldwide on the transmission characteristics of velogenic Newcastle disease virus field strain after different vaccination schemes. Chickens were vaccinated with Hitchner B1, La Sota or I-2 via the intraocular and intranasal routes. Vaccine and challenge viruses induced high antibody levels, both in inoculated and contact birds. Prime-boost vaccination protected birds against morbidity and mortality and significantly reduced the incidence of viral shedding from chickens compared with single vaccinated and unvaccinated birds. Protection from disease and mortality was correlated with the presence of positive antibody titres (4 log2) at day of challenge. Most of the unvaccinated and in-contact birds excreted the virus and showed a high level of antibody titres, indicating the high infectivity of the challenge virus. The detection of the challenge virus in most of vaccinated birds demonstrated that the tested vaccination protocols cannot fully protect birds from viral infection, replication and shedding, and vaccinated-infected birds can act as a source of infection for susceptible flocks. The high mortality observed in unvaccinated birds and their contacts confirmed the virulence of the challenge virus and indicated that this field virus strain can easily spread in an unvaccinated poultry population and cause major outbreaks. Progressive vaccinations supported by biosecurity measures should therefore be implemented to control the disease and introduction of the virus to the poultry farms.

The objective of this study was to examine the quality of successive dominant follicles (DFs) after induced heat stress. Non-lactating dairy cows expressing estrus at normal intervals were allocated randomly to heat stress (HS; n=8) and control (C; n=8) groups. Cows received GnRH (100 microg, i.m.) on Day 0, a progesterone CIDR-B device on Day 4 and prostaglandin (PGF(2alpha); 25mg, i.m.) on Day 7 upon removal of the CIDR device. The DF and follicles5mm were aspirated on Day 8, and GnRH (100 microg) injected following aspiration, to initiate a new follicular wave. In this manner, a DF was aspirated every 8 days (one "follicular cycle") for 10 cycles. After the first follicular cycle, HS cows were placed in environmental chambers for 7 days during the second follicular cycle (8h per day at 43.3 degrees C set point and 16h per day at 24 degrees C for 4 days, and 8h per day at 43.3 degrees C set point and 16h per day at 32.2 degrees C set point for 3 days; relative humidity, 40%) and thereafter maintained outdoors with control cows at a mean ambient temperature (18.5 degrees C; range 12.7-26 degrees C). Rectal temperature increased (P0.001) in HS as compared with C cows (39.28+/-0.01 degrees C versus 38.78+/-0.01 degrees C). Concentrations of estradiol (E(2); 1662+/-189 versus 1493+/-188ng/ml) and progesterone (P(4); 44.7+/-5 versus 54.1+/-5.1ng/ml) in follicular fluid (FF) of DF did not differ between C and HS treatments, respectively. Total FF protein concentration was greater (P0.05) in HS (99.7+/-2.3mg/ml) than in C (92.7+/-2.3mg/ml). Heat shock protein 90 (Hsp 90) in FF was not altered by heat stress. IGF-II ligand blots were conducted with FF samples (n=79) from four HS and four C cows. There was a predominance of IGFBP-3 in 76 of 79 FF samples, indicating healthy follicular status, and only three FF samples had the lower molecular weight IGFBP-2 indicative of a poor quality follicle. Plasma P(4) and E(2) concentrations did not differ between C and HS groups. The number of class 1 and 3 follicles increased during and just after heat stress, but the number of class 2 follicles did not differ between C and HS cows. Heat stress appeared to induce a decrease in follicular dominance, but GnRH-induced follicular cycles resulted in development of healthy preovulatory follicles in both groups.

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.

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 (112)R-R-Q-K-R-F(117) at the cleavage site of the fusion protein while 13 isolates contained the lentogenic motif (112)G-G/R-Q-G-R-L(117). 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.

SummaryThis study was conducted in the central highlands of Ethiopia during 1990–92 to examine the effects of diet and partial suckling on lactation and reproductive performance of Boran (Bos indicus) cows. Primiparous Boran cows were allocated to dietary supplementation or no supplementation with either milking or partial suckling based on body weight at calving. All cows received grass hay ad libitum and the supplemented groups were provided with additional concentrate feed which supplied 222 g/kg DM crude protein and 10 MJ/kg DM energy. Calves were weaned at 8 weeks of age. Mean (±S.E.) dam calving and calf birth weights were 314±11·4 and 25±0·6 kg. Body weights at first postpartum oestrus and at conception were not affected by suckling. Supplemented cows however, were heavier at first oestrus (P = 0·06) and at conception (P < 0·01) than non-supplemented cows. Lactation length was longer (P < 0·01) and mean daily milk yield higher (P < 0·001) in suckled than in milked cows. Diet, however, did not influence either lactation length or daily milk yield. In suckled cows, mean daily milk yield declined sharply after weaning (week 9) and was lower by 38 and 43% of week 8 production in the supplemented and non-supplemented groups, respectively. The overall mean lactation yield was 212·4±64·6 litres; with a significant (P < 0·05) diet × suckling interaction effect. Concentrations of milk fat, total protein and total solids were not affected by either diet or suckling treatment. The postpartum anoestrus interval was longer (P < 0·01) in non-supplemented than in supplemented cows, but did not differ between suckled and milked cows. The percentage of cows cycling by 150 days postpartum was higher (P < 0·05) in supplemented than in nonsupplemented and in milked than in suckled (P > 0·05) cows. By this interval, a higher (P < 0·05) percentage of supplemented-milked (90%) cows cycled than in the other three treatment groups (48·5%). Pregnancy from the first insemination ranged from 45·5 to 63·6% in the four treatment groups. It was concluded that although partial suckling extended the postpartum anoestrus interval, lactation length and milk yield were improved. The negative effects of partial suckling on postpartum reproduction could be overcome with the appropriate dietary supplementation. The economic tradeoff between dietary supplementation, milk yield and reproduction has to be determined in partially suckled cows.

Ten Boran and 12 Boran × Friesian bulls with a mean (± standard error of the mean) age and body weight of 20.2 ± 0.5 months and 225.5 ± 2.5 kg were used over a 1 year period to determine the effect of plane of nutrition and season on body and testicular growth and on semen traits. Within genotype, bulls were allocated to either a high (HP) or a low (LP) plane of nutrition. Data on body weight, serotal circumference (SC) and semen characteristics were collected every 2 weeks. Body weight and SC increased (P

A retrospective study was carried out to evaluate the reproductive performance of Holstein-Friesian cattle in Alage Dairy Farm in the Rift Valley of Ethiopia using data recorded from July 1983 to June 2005. Data of cows with complete information were considered, and a total of 1,104 records for calving to conception (Cal-Con), calving interval (CI), and number of services per conception (NSC), and 721 records for age at first service (AFS) and at first calving (AFC) were analyzed. The overall means (± S.E.) of AFS, AFC, Cal-Con and CI, and NSC were 991.4 ± 24.3, 1,265 ± 24.3, 285.8 ± 18.9, 561.3 ± 18.9 days and 1.69 ± 0.1, respectively. Parity significantly influenced NSC, Cal-Con, and CI. Season and year showed a significant effect on all the parameters, indicating the role of the environment and more specifically the influence of nutritional conditions at least for the long AFS and AFC, management practices, and climate on reproductive performance of the study herd. A more focused study to discern the elements of the reproductive constraints have been recommended.

This study, with the objective of assessing the effect of risk factors on dairy cow mastitis in the central highlands of Ethiopia, was undertaken between February and September 2001 in the urban and peri-urban areas of Addis Ababa, Ethiopia. A prevalence study and questionnaire survey were carried out simultaneously. Clinical examination of lactating udders and California mastitis test (CMT) determined clinical and subclinical mastitis, respectively. Risk factors for subclinical and clinical mastitis were identified from data on animals and farm management by chi-square analysis and subsequent logistic regression. Cows aged at least 8 years, with poor body condition, with at least 8 parities and in at least the eighth month of lactation had a significantly higher risk for subclinical mastitis (p

Gonadal and extragonadal sperm reserves were determined in testicular and epididymal tissues obtained from Boran (n=10) and Boran x Friesian (n=12) bulls fed either a high or low plane nutrition diet for a 1-year period. The bulls were 32 months of age at castration. Mean (+/-SEM) daily body weight gains over a 1-year period were 776+/-34 and 264+/-34 g/day (P0.001) for bulls on high and low nutrition, and their respective body weights at castration were 458+/-17 and 276+/-17 kg (P0.01). Mean body weights did not differ between Boran and Boran x Friesian bulls. Mean scrotal circumference measurements were 32.1+/-0.6 and 28.8+/-0.6 cm for the high and low planes of nutrition (P0.01) and 31.8+/-0.7 and 29.2+/-0.6 cm for the Boran and the Boran x Friesian bulls (P0.05). Paired testes and epididymal weights averaged 432+/-22 and 313+/-22 g (P0.01) and 46.3+/-2.0 and 32.5+/-2.0 g (P0.001) for bulls on the high and low planes of nutrition, respectively. Boran x Friesian bulls had significantly heavier (P0.05) testes, but epididymal weithts did not differ between breeds. Although daily sperm production per gram was not influenced by either plane of nutrition or breed, daily sperm production differed between high (5.3 x 10(9)) and low nutrition (2.9 x 10(9)) bulls (P0.001) and between Boran (4.6 x 10(9)) and Boran x Friesian (3.5 x 10(9)) bulls (P0.01). Extragonadal sperm reserves were significantly higher in high than in low nutrition bulls (13.1 x 10(9) vs 6.9 x 10(9); P0.001) and in Boran than Boran x Friesian bulls (12.9 x 10(9) vs 7.1 x 10(9); P0.01). The cauda epididymis contributed 50 to 54% to the total epididymal sperm reserves. It was concluded that the plane of nutrition influenced growth rates and testes and epididymal weights, and it improved gonadal and extragonadal sperm reserves in young Boran and Boran x Friesian bulls.