Assessment of impacts of tsetse and trypanosomosis control measures on cattle herd composition and performance in southern region, Ethiopia.

This study was conducted to assess the impact of tsetse and trypanosomosis control measures on cattle herd size and composition, herd dynamics, and milk yield in Wolaita and Gamogofa Zones, southern Ethiopia. The study showed that the average number of cattle herd size in tsetse challenged areas was significantly higher than those in tsetse-controlled areas. The number of non-pregnant dry cows, bulls and oxen were significantly higher in tsetse challenged areas than the other two study areas. The rate of cattle addition to and disposal from the herd were significantly higher in tsetse challenged areas. Cows in Southern Tsetse Eradication Project (STEP) and community tsetse controlled areas were able to give 26-27 %, 25-29 % and 17-21 % more daily milk yield at the beginning, middle and end of lactation, respectively, than those in tsetse-challenged areas. In addition, cows in STEP and community tsetse controlled areas had lactation length longer by 1.20 to 1.35 months; age at first calving was shorter by 5.30 to 5.10 months; and calving interval was shorter by 4.20 to 3.20 months than cows in tsetse-challenged area, respectively. Hence, tsetse and trypanosomosis control both by the community and project would play key role in the improvement of cattle productivity.

Impact of tsetse and trypanosomiasis control on cattle herd composition and calf growth and mortality at Arbaminch District (Southern Rift Valley, Ethiopia).

The effect of tsetse/trypanosomiasis control on cattle herd composition and growth and mortality of calves in tsetse controlled (by Southern Tsetse Eradication Project (STEP)) and uncontrolled blocks in southern Ethiopia was assessed. Structured questionnaire was used to interview 182 households to estimate cattle herd composition and calf mortality. Calves were bled to examine the presence of trypanosomes by the buffy coat technique. Forty NGU traps were deployed and fly catches determined. A case-control study was performed on 40 calves for 6 months to estimate calve growth parameters. Accordingly, the mean cattle herd size was lower in tsetse-controlled block than in the uncontrolled block, whereas the relative number of calves in a herd tend to be higher in the tsetse-controlled block (P = 0.06). While there was no report of cattle mortality in tsetse-controlled block, 16.48 % of the respondents have lost calves in tsetse-uncontrolled block in 1 year time. The prevalence of trypanosome positive calves was 2.95 % for uncontrolled block but no positive case in tsetse-controlled block. The apparent densities of flies/trap/day in tsetse-uncontrolled block were 30-fold higher than in tsetse-controlled block (P < 0.01). The case-control study revealed that the mean body weight gain of calves in tsetse-controlled block (40.23 ± 0.7 kg) was significantly higher than that of the uncontrolled block (34.74 ± 0.68 kg). The above findings strongly suggest that the intervention by the STEP project has significantly reduced tsetse population and trypanosomiasis consequently contributing to improved calf growth and survival.

Sero-prevalence of bovine brucellosis and its risk factors in Jimma zone of Oromia Region, South-western Ethiopia.

A cross sectional sero-prevalence study was conducted on 1,595 cattle in Jimma zone, Ethiopia to investigate the status of bovine brucellosis and identify potential risk factors. Sera samples were analyzed using Rose Bengal Plate Test (RBPT) and Complement Fixation Test (CFT). The overall individual and herd level sero-prevalences were 3.1% (n = 1,595) and 15.0% (n = 227), respectively. The sero-prevalence of bovine brucellosis at individual animal level was significantly higher in non-pregnant (11.18%) than pregnant (2.77%) and lactating (22.35%) than non-lactating animals (2.46%). Moreover, significantly higher sero-prevalence was observed in herds of larger sizes. Individual animal sero-prevalence was also positively associated with the occurrence of abortion (26.98 and 1.54% in those with and without previous history of abortion, respectively). Generally, the sero-prevalence of bovine brucellosis found in Jimma area was not high and the sero-prevalence was closely associated with some of the risk factors considered at individual animal and herd level.

Milk yield and reproductive performance of dairy cattle under smallholder management system in North-eastern Amhara Region, Ethiopia.

This study was conducted in South Wollo Zone of Amhara Regional State, Ethiopia, to assess the milk yield and reproductive performance of indigenous and crossbred cattle under smallholder management conditions. Questionnaire survey was used to collect retrospective data on the performance of dairy cattle in 186 households. Thirty two postpartum cows (16 indigenous and 16 crossbred) were selected purposively and monitored for five months and milk samples were collected twice per week from each cow to determine postpartum ovarian activity using ELISA techniques. Daily milk yields at all stages of lactation were significantly (P < 0.01) higher in crossbred than indigenous cows. Crossbred cows had significantly (P < 0.01) longer lactation length and shorter age at first calving, while calving interval was significantly shorter in cows that gave previous calves during the wet season than the dry season. Only six cows (18.8%) showed heat signs on an average of 136 days postpartum of which one was a crossbred and five were indigenous. While, 11 cows (34.3%) resumed ovarian activity until 150(th) day postpartum among which three were crossbred and eight were indigenous.

Epidemiological Survey of Peste des Petits Ruminants in Ethiopia: Cattle as Potential Sentinel for Surveillance.

Peste des petits ruminants (PPR) is a highly contagious viral disease of small ruminants; it emerged in countries previously free of the disease following the eradication of rinderpest. PPR is classified by international organizations as the next priority animal disease for global eradication campaign. Assessment of the local situations is the first step in the eradication efforts. The objective of this study was to investigate and compare the seroprevalence of PPR in cattle, sheep, and goats under two livestock production systems in Ethiopia: North Shewa zone of Amhara region represents a highland sedentary life style characterized by mixed livestock-crop production system; Zone Three of Afar region represents a lowland nomadic life style characterized by pastoral livestock production system. N-competitive ELISA PPR test was performed on sera from 2,993 animals ≥6 months old sampled at watering and grazing points. Multivariable logistic regression models comparing the seropositivity between the two production systems were built by classifying doubtful results as positive, negative, or excluding them from the data. The odds ratio (OR) comparing overall PPR seroprevalence in the sedentary North Shewa Zone compared to the nomadic Zone Three ranged from 19 to 27 (P < 0.001), depending on how doubtful results were classified, which contrasts with what has been reported in the literature. This is not likely to be related solely to vaccination, since seroprevalences in cattle and small ruminants were similarly high or low in the respective zones (0-4% for Zone Three and 20-40% for North Shewa Zone), and cattle were not likely to be vaccinated. The OR of seropositivity for goats compared to cattle ranged from 1.9 [95% confidence interval (CI): 1.3-2.7; P < 0.001] to 2.2 (95% CI: 1.5-3.1; P < 0.001) when doubtful results were excluded or classified as negative, respectively. When doubtful results were classified as positive, association between seropositivity and animal species was not significant (P > 0.05). Our results suggest to further investigate cattle as sentinel animals for PPR surveillance.

Effect of Brucella infection on reproduction conditions of female breeding cattle and its public health significance in Western tigray, northern ethiopia.

The most common clinical manifestations of brucellosis in livestock are associated with reproduction. This paper reports the result of a cross-sectional study conducted between October, 2007 and April, 2008 in Western Tigray, North Ethiopia, with the objectives of assessing the effect of Brucella infection on reproduction conditions of female breeding bovine and to explore the presence of Brucella seroreactors in vulnerable humans. A total of 1,354 and 246 sera were collected from female cattle and humans, respectively. The sera were screened using Rose Bengal plate test (RBPT), and positive samples were confirmed by complement fixation test (CFT). Reproductive conditions for female cattle and risk to human brucellosis seropositivity were tested by using logistic regression analysis. The result indicated that the overall prevalence in female cattle was 6.1%. The study showed 1.2% prevalence among human risk groups, all of which were herdsmen. Logistic regression identified parity status, calving interval, abortion history, and abortion period were significantly associated with seropositivity. The association was not significant with reproductive status and parity number. Proper hygienic practices and team work between veterinary and health personnel should improve the efforts to combat disease transmission.