Dairy cattle lameness prevalence, causes and risk factors in selected farms of southern Ethiopia

A cross-sectional study was conducted from October 2018 to December 2019 to estimate the prevalence of lameness in dairy cows, to assess the causes and associated risk factors in southern Ethiopia. A total of 2009 dairy cows were visually and clinically examined, and the overall prevalence of lameness was found to be 14. 1% (95% CI=12.7-15.7). The prevalence of lameness was significantly (P< 0.05) higher in Arsi Negelle, Yirgalem, and Wolaita Sodo than in Wondo Genet and Hawassa. The prevalence of lameness was also associated with the stages of pregnancy and parity (P < 0.05). Generally, the prevalence of lameness in dairy cows was increasing with the increase in parity and stage of pregnancy. The main abnormalities observed in this study were hooves overgrowth (6%), lesions between hooves (4%), lesions on legs (2.2%), trauma (0.6%), arthritis (0.5%), and a sole ulcer (0.3%). Most of these abnormalities were mainly due to faulty management. Hence, based on this finding it is recommended that hoof management and trimming are very essential components of lameness control. Furthermore, early detection and treatment of lame cows; training of the owners on hoof management; and improvement of the housing are helpful to keep lameness at a lower level.

Influence of breed on the quality of in vivo produced embryos from Boran and Holstein Friesian cross dairy breed in Ethiopia

The variation of the dairy breed can determine the success of bovine embryo transfer by influencing the quantity and quality of in vivo embryo production. In this experiment, output and quality of in vivo produced embryos using semen of progeny tested Holstein Friesian (HF) sire in Boran and HF*Boran F1 cross cows, and semen from purebred Boran sire in HF*Boran F1 cross and Boran cows were evaluated. Boran (n=18) and HF*Boran cross (n=18) breed donor dams were superovulated using a previously optimized follicular stimulating hormone (FSH) (Pluset®) dose regimen: 650 IU for HF*Boran cross and 250 IU for Boran breeds. Each cow was flushed on Day-7 post insemination and embryos were evaluated for their developmental stages and quality. Superovulatory response rates were 88.9% and 83.3%, respectively, for Boran and HF*Boran with no significant (P>0.05) breed differences. Total recovery rates were relatively lower (56.5%) in Boran compared to in HF*Boran (67.4%). The mean (±SE) embryo flush outputs were 6.5±0.8 for Boran and 6.9±0.7 forHF*Boran with no significant breed difference. Recovery of a transferrable embryo was significantly higher (68.0%; P<0.05) in HF*Boran dam inseminated with HF sire semen. Boran cows yielded a significantly higher (P<0.05) proportion of unfertilized ovum (57.6 %) irrespective of the sire breeds. Comparatively, a higher number of degenerated embryos were produced by HF*Boran cows. This study demonstrated that the presence of breed-related differences in both the quality and quantity of in vivo produced Bovine embryos.

Anthelminthic effects of extracts of indigenous browses from mid rift valley of Ethiopia

This study was conducted to evaluate the potential anthelminthic properties of extracts of leaves of indigenous browses (Acacia seyal, Acacia senegal, Acacia tortilis, Millettia ferruginea, and Vernonia amygadalina) based on three in vitro assays. Acetone extracts of browses at different concentrations (75 to 1200 μg/ml, for egg and larvae and 100mg/ml for an adult) were tested on three developmental stages of Haemonchus contortus (eggs, infective larvae, and adult worms) using egg hatch assay (EHA), larval migration inhibition assay (LMIA) and adult worm motility inhibition assay (AMIA). Significant effects were obtained with all five browses but differences were observed depending on the parasitic stages. The effects of five browse extracts on egg hatching were concentration-dependent, the highest (P<0.05) egg hatch inhibition rate was observed at 1200 μg/ml concentration for all browses. All extracts had a higher effect (P<0.01) than that of the negative control, phosphate buffer saline (PBS). In contrast, no concentration-response relationship was found for infective larvae and adult worms, although more potent effects were observed with the highest concentrations. The LMI rate (70%) induced by Vernonia amygadalina extract, at a concentration of 300 μg/ml, was the highest (P<0.05) of all other browses, even at higher concentrations. The highest LMI rate (62%) induced by Acacia senegal extract at higher concentration, was lower than that of LMI rate (70%) induced by Vernonia amygadalina, at 300 μg/ml concentration. Vernonia amygadalina was found to be highly and rapidly effective against adult worms inducing the highest mortality rate (90%) as soon as 4 hrs after incubation. Overall, the in vitro results suggest that these five browses do possess anti-parasitic properties and Vernonia amygadalina showed the most effective anti-parasitic property. These effects remain to be confirmed through in vivo study.

Morphometrical study of the reproductive tract in Boran (Bos indicus) heifers in Ethiopia

Boran breed is the most suitable type of cattle breed for arid and semi-arid regions of Ethiopia due to their adaptive characteristics. Understanding their reproductive anatomy is important for successful reproductive management and has many implications for the application of assisted reproductive technology, and interpretation of physiological changes at different stages of their reproductive cycle. In this study, data of the anatomical structures of the reproductive organs of 20 Boran heifers were measured and characterized at different stages of reproduction. The mean (±SE) length (L) of the vagina, cervix, and body of uterus were 13.17±2.98 cm, 7.19±1.28 cm, and 6.70±1.08cm, respectively. The mean (±SE) length of the right uterine horn and oviduct was 18.47 ±2.54 and 18.17 ±1.27cm, respectively and that of the left were 18.05±2.73 and 17.45±1.80 cm, respectively. The mean ±SE weight (W) of right and left ovaries were 2.44±1.51 gm and 2.44±1.51 gm, respectively. The mean ±SE Length x Width x Thickness of the right ovary was 2.10±0.59 x 1.75±0.35 x 0.83±0.36 and that of the left was 1.97±0.41 x 1.58±0.29 x 0.67±0.33 cm. The mean (±SE) weight of the whole reproductive organ (without the vulva) was 301.35±66.34gm. The ovarian size was influenced by the presence of the corpus luteum(CL) usually larger with its presence.

Bovine trypanosomosis and its vectors: prevalence and control operations in Kellem Wollega, Western Ethiopia

A cross-sectional study was conducted to estimate the prevalence of bovine trypanosomosis and to assess farmers’ perception of the disease and its control operations. From October to April 2012, a total of 586 cattle were sampled for the prevalence study. Buffy coat procedure and haematocrit value determination were performed. To capture the fly that was involved in the transmission dynamics, one hundred monopyramidal traps were deployed for 72 hours. A semi-structured questionnaire was conducted to study farmers’ perceptions of the diseases and their control operations. Trypanosomal infections were diagnosed in only 8.7 % (51) of animals. The overall prevalence of trypanosome infection in cattle was significantly varied between study districts (33.1% Dale Sadi and 66.9% Dale Wabera). Most infections were due to Trypanosoma congolense (81.8%) followed by T. vivax (15.6%) and mixed infections (2.6%). The association of hematological value changes and trypanosome infections was profound. The overall Packed Cell Volume (PCV) values of sampled cattle were 25.8%. A significant (P< 0.05) variation in PCV values was recorded in infected (20.8%) and non-infected (26.5%) cattle. In the study period, a total of 2055 flies were captured and of which 92% belong to the genus Glossina followed by Stomoxys and Tabanids. Four types of tsetse species (G. pallidpes, G. m. morsitans, G. tachinoides, and G. f. fuscipes) were identified. The questionnaire survey revealed that trypanosomosis is the most important problem for agricultural activity and animal production in the study areas. Farmers are well aware of the problem, means of transmission, and the different control methods. Integrating tsetse control program with other trypanosomosis control options is recommended.

Enzymatic and fecundity evaluation of Fasciola hepatica exposed to different doses of γ- irradiation in Ethiopian sheep

The upshot of γ-irradiated Fasciola hepatica infection on the activity of plasma glutamate dehydrogenase (GLDH) and γ-glutamyl transpeptidase (GGT) was evaluated in 36 sheep infected with a single dose of 30, 60, 120, and 240 grays and those kept as negative and positive control over 17 weeks. During this period, serum and faecal samples, as well as body weight gains, were taken at weekly intervals. Furthermore, the effects of the irradiation dose (500) for oral vaccination and on the recovery of adult flukes were assessed following primary infection. Eggs were first detected in the faeces of infected sheep on week 8 post-infection. The parasite viability was severely affected by doses of γ-irradiation of 120 Gy or 240 Gy. In the aforementioned doses, relatively low numbers of mature flukes of about 60 (17.1%) and 38 (10.8%) were recovered than the control group, respectively. The sensitized lambs also showed less hepatic damage compared with the controls as indicated by lower levels of the serum enzyme glutamate dehydrogenase and γ- glutamyl transferase significant body weight loss was observed between weeks 6 and 8 post-infection followed by a steady increase of the mean weight of infected animals across time. In conclusion, vaccination of sheep with γ irradiated metacercariae of F. hepatica appeared to affect the number and development of the fluke population resulting in reduced hepatic damage during migration, reduced fecundity after patency, as measured by worm and egg counts, levels of serum glutamate dehydrogenase and γ- glutamyl transferase.

Estrus characteristics, ovarian response to synchronization hormones, and fertility of crossbred dairy heifers managed under a semi-intensive system

This study aimed to characterize estrus sign/s which best predict the time of ovulation and determine ovarian responses to different synchronization protocols and conception rates to fixed-time artificial insemination in Boran*Holstein crossbred heifers. In the first part of the study, twenty-seven heifers were observed for estrus signs (from induced and natural) and the relationship of various estrus signs with ovulation time was evaluated by using ultrasonography. In the second part, 91 Boran*Holstein crossbred heifers were randomly grouped into three groups. Group one heifers (n=28) received 100μg gonadotropin-releasing hormone (GnRH) on day zero (D0), 500μg prostaglandin F2α (PGF2α) on day 7 and 100μg of GnRH on day 9. Group 2 heifers (n=32) were treated as group one but additionally received progesterone as controlled internal drug release (CIDR). Group three heifers (n=31) were treated as those in group 2 but without injection with GnRH on day 0. In all the 3 groups’ insemination was made at 19h of the second GnRH. The results showed that irrespective of estrus source type (induced or natural), score for standing to be mounted, mounting other heifers, and non-receptive mount by other heifers showed a strong positive correlation with ovulation time (r=0.67, P<0.05). Standing estrus duration, and time elapsed from standing estrus to ovulation were shorter (P<0.05) in induced estrus. The conception rate was 39.3% in synchronized ovulation in the absence of CIDR. The conception rate in timed insemination was 56.3% when ovulation was synchronized by combining CIDR, PGF2α, and GnRH. In conclusion injection of GnRH on day zero together with treatment with CIDR improved ovulation rate, the number of new corpus luteum, and conception rate. Heifers that ovulated within the first 24h after timed insemination had a higher (P<0.05) conception rate than heifers ovulated after 24h of timed insemination. Cycling heifers at day zero had a greater (P<0.05) conception rate than non-cycling.

Quality of injectable oxytetracycline circulating in legal markets of Addis Ababa, Ethiopia using physiochemical and sterility analysis

This study was conducted to evaluate the quality of different brands of injectable oxytetracycline solutions circulating in the legal markets of Addis Ababa with respect to physicochemical characteristics and sterility. Nine brands of oxytetracycline with thirteen different batches were randomly purchased from veterinary drug stores in the city. The physical assessment was performed by using a checklist that was prepared based on the World Health Organization guidelines. The qualitative and quantitative analysis of active pharmaceutical ingredients (API) was performed by High-Performance Liquid Chromatography. The sterility test was assessed by using the direct inoculation method. All samples passed the identity, the assay, and the sterility tests. However, there were statistically significant differences (P<0.05) among brands in the quantity of API. The highest percentage of the API was recorded in brand G (112.12%± 1.86) while the lowest was seen in brand H (92.61%± 1.5). This study revealed that all brands passed both physicochemical and sterility tests except for the differences in the API level among brands. Strict regulation, monitoring, and wider-scale surveillance are required to assure sustainable control of substandard, unsterile, and falsified pharmaceutical products in the country.

Comparative evaluation of the immune responses of seven chicken ecotypes to vaccination against Newcastle disease

Newcastle disease (ND) is a highly contagious viral disease of poultry with high mortality. The local velogenic viral pool of the ND strains influences its severity and occurrence. ND vaccination is the most feasible approach to control the disease. However, some ND-vaccinated groups within chicken populations are susceptible to velogenic ND infection developing outbreaks with marked pathological lesions and shedding of the virus. Vaccine strain-related factors as well as inadequate vaccine application and delivery methods during vaccination might explain the suboptimum ND vaccine efficacy. In this study, however, we propose that host factors may contribute to the suboptimal vaccine efficacy in vaccinated chickens. We, therefore, compared the immune response of five Ethiopian chicken ecotypes to ND immunization in the presence of two reference breeds (Fayoumi and Bovans). All chickens received initial immunization at age of 21 days with HB1 ND vaccine followed by two-times LaSota booster immunization at age 50 and 120 days. Subsequently, serum was collected fortnightly post-vaccination at age 35, 65, and 135 days for immune response analysis using the hemagglutination inhibition (HI) test. HIantibody was significantly higher at days 135 > 65 > 35 in each ecotype following the third, second, and first vaccination, respectively. The different chicken ecotypes had significant differences in HI antibody response to the ND vaccination. Accordingly, the HI titer was significantly higher in Jarso > Cheffe > Fayoumi > Arsi > Bovans > Tepi > Horro suggesting antibody titer and ND vaccine efficacy of the ND vaccine depends on host factors. Moreover, some chicken groups within each ecotype had low HI titer. Chicken ecotypes with weak immune responses may not completely clear the virus from their body; thus, they can serve as a reservoir host by maintaining the ND virus. We conclude that herd immunity level and blanket vaccination program based on the results of a single host genetic group can be misleading during developing and recommending a new vaccine. Hence, understanding the host determinant factors in the immune response during vaccination can lead to improved efficacy and protection against ND in chicken populations.

Fore-Stomach Foreign Bodies: prevalence, associated risk factors and types affecting cattle slaughtered at Gondar ELFORA abattoir, northwest Ethiopia

In Ethiopia, recurrent drought and feed shortage coupling with high level of environmental pollution predispose the animals to foreign body ingestion. A cross-sectional study with systematic random sampling approach was employed from November 2018 to April, 2019 with the objectives of estimating the prevalence; identify associated risk factors and to categorize the types of foreign body in cattle slaughtered at Gondar ELFORA Abattoir. Ante-mortem and postmortem examinations were used to collect the data. From the total of 384 animals examined, the overall prevalence of foreign body was 83(21.61%). Adult and old animals were 4.33 (95% CI=0.98, 19.00, p=0.052) and 4.54 (95% CI=1.03, 19.96, p=0.045) times more likely to have a chance of getting foreign body than young animals by keeping another factors constant, respectively. However, the difference is not statistically significant for adult cattle. Moreover, poor and medium body conditioned animals were 2.19 (95% CI=1.04, 4.56, p=0.037) and 1.51 (95% CI=0.72, 3.13, p=0.273) times more likely to acquire foreign bodies than good body conditioned animals by keeping another factors constant. In the positive cases (N=83), 41(49.40%), 34(40.96%), 8(9.64%) and 0(0%) of the foreign bodies were found in the rumen, reticulum, both rumen and reticulum, and omasum, respectively. Majority of foreign bodies identified (79.51%) were non-metallic in nature, including clothes, plastics, rope, sand and stone. Designing and implementation of appropriate solid waste disposal and management practices are strongly recommended to reduce the risk of ingestion of indigestible foreign bodies. Keyword: Abattoir; Cattle; Foreign body; Fore stomach; Prevalence