獣医科学と技術

In this present study, experimental infestations of the definitive hosts of cattle Sarcocystis were realized to identify the species existing in our regions. For that purpose, 200 g of a mixture of oesophagi and diaphragms infested by cysts of Sarcocystis were administered to 7 dogs, 2 cats and 2 Magot monkeys. Only dogs excreted oocystes and sporocystes of Sarcocystis cruzii, although cysts with thick wall were present in broyats.

This study was conducted to evaluate the effects on external eostrus signs and hormonal profile of pigs reared with feed formulated by subtitling soya bean meal (SBM) with blood meal (BM). Blood, used to formulate the experimental diets was collected from apparently healthy cattle at slaughter, boiled and sun dried. Thereafter, the BM was used to formulate four grower pig diets: A, B, C and D, containing 50.0, 75.0, 100.0 and 0.0% (control) SBM as replacement for BM. Following feed formulation, 16 Landrace×Large White crossbred weanling pigs were selected and used for the study. They were aged 6.0 to 6.5 weeks, with average body weight of 12.24 kg. The pigs were randomly allotted to the 4 treatment groups, each of which was further divided into two; with 2 pigs as replicate. Individual animal was maintained on experimental diet that was equivalent to 5.0% of its average body
weight as ration from beginning to the end of study. At their 6.5 months of age, the gilts were observed two times daily for symptoms of eostrus. Following the manifestation of eostrus signs, scoring for the vulva changes was carried out and values obtained were compared between treatment groups at first, second and third eostrus cycles, respectively. Similarly on their forth eostrus cycle, the gilts were bled every 30 min for 6 hours and sera obtained was used to determine their hormonal profile. Hormone assay was done by ELISA technique. Results showed no dietary treatment affected most of the parameters investigated within the study period. Thus, age at puberty, duration of standing reflex, intensity of reddening, and swelling of the vulva and eostrus cycle length showed no significant
(P>0.05) variation, when compared to the control. The study showed that while the duration of standing reflex increased, intensity and duration of reddening and swelling of vulva rather decreased with eostrus cycle number. The hormonal assay showed that estradiol-17β levels of groups A, B and C were significantly (P<0.05) higher than the control group D animals. BM inclusion had no significant effect on Luteinizing and Follicle Stimulating Hormonal profile of the gilts, but their pulsatile release at the 3rd and 6th hours was evident. It is concluded that inclusion of BM in formulating pig diets under tropical humid conditions is safe. It does not interfere with some key reproductive parameters in gilts, such as their age at puberty, manifestation of eostrus signs and reproductive hormonal profile.

A cross sectional study was conducted from October 2010 to March 2011, on apparently healthy slaughtered cattle in Haramaya University Slaughter House to determine prevalence of Escherichia coli, with special emphasis on Escherichia coli O157:H7, and its antimicrobial susceptibility pattern. Carcass swab samples were collected and pre-enriched in buffered peptone water and plated on MacConkey agar plate. Presumptive colonies were confirmed by biochemical tests. Further identification of Escherichia coli O157:H7 was done by plating the isolatedm bacteria on Sorbitol MacConkey agar; and then colorless colonies were subjected to Escherichia coli O157:H7 Latex agglutination test. From a total of 113 samples collected, Escherichia coli was isolated from 35 (30.97%) and out of these, 3 (2.65%) were found to be Escherichia coli O157:H7. The difference in prevalence was not statistically significant (P>0.05) between local and cross breeds (χ2=0.11, df =4), among age group of animals (χ2=2.56, df=1) and origin of animals (χ2=2.56, df=2). The isolated bacteria were subjected to antimicrobial susceptibility testing and the majority were found to be susceptible to Chloramphenicol (30 μg), Kanamycin (30 μg), Spectinomycin (SH, 100 μg). The presence of E. coli O157:H7 in raw meats reaching to consumers indicated possible risks of infection to people through the consumption of raw (undercooked) meat and cross contamination of other food products. Therefore, control measures at all stages of food chain was recommended.

Identification of emaciated animals is a straight-forward. Occasionally, the cause of the emaciated condition is not natural, and neglect is suspected. In this report, several cases of starvation due to neglect are described and the diagnosis of neglect due to starvation will be discussed.

A cross sectional study was carried out to determine prevalence of bee lice, and to find out associated risk factors in Holeta and its surroundings, West-Shoa zone of Oromia region. Of 385 bee colonies examined, overall prevalence of 42% lice infestation was observed. The highest prevalence (70.8%) of bee lice was observed in Gemechis, followed by Holeta (50%), while the lowest prevalence (17.1%) was observed in Jaldu. Prevalence of lice observed in bees kept in apiary management system (50.4%) had statistically significant difference (P<0.05) to those bees kept in backyard (37.9%). Higher prevalence of bee lice observed in medium altitude areas (50.4%), was not statistically significant (P>0.05) to that of highland areas (40.4%). In conclusion, different level of prevalence of bee lice was observed among the different study sites, between medium land and high altitude areas, between apiary and backyard management system, and between types of hives. Therefore, bee keepers should be informed
regarding factors affecting occurrence of bee lice, including altitude, management system, and type of hives to control bee lice in their hives. Further study on the distribution and magnitude, and financial impact of bee lice was suggested.

Staphylococcus aureus is a major infectious organism causing mastitis. Certain fatty acids have been shown to inhibit the growth of pathogens including Staphylococcus aureus. An in vitro experiment was conducted to determine the effects of prostaglandin F2α (PGF2α) on growth of S. aureus. Flasks containing tryptic soy broth (TSB) were inoculated with S. aureus Novel, and subsequently treated with PGF2α (dinoprost tromethamine) at concentrations of 0, 0.3, 0.6, 1.2, and 2.4 mg/ml. Cultures were incubated at 37°C for 24 h and sampled every 3 h. The entire experiment was conducted three times in duplicates. Bacterial growth was assessed by counting colony forming units (CFU) in triplicates. Data were analyzed by repeated measures analysis of variance and reduced and full dummy variable regression models to determine the effect of PGF2α concentrations on growth patterns of S. aureus
over time. There was an effect of treatment and treatment by time interaction (P<0.05) on mean log CFU, indicating that bacterial growth over 24 h was different across treatments. At time of inoculation (0 h), mean log CFU values were not different among treatments; however at 24 h, mean log CFU for each PGF2α treatment was different from control and decreased (P<0.05) with increasing concentrations of PGF2α. The predicted growth curve for each treatment was different (P<0.05) when compared with the control, and the rate of bacterial growth was less for 1.2 mg/ml PGF2α when compared with the control and 0.6 mg/ml. The bacterial growth was completely inhibited during the 24 h period in 2.4 mg/ml PGF2α treatment. Furthermore, a non-linear regression model was employed to estimate the dose response at the 24 h, and revealed that 1.2 mg/ml was the minimum inhibitory dose. These results provide evidence, for the first time, that PGF2α, in the form of dinoprost tromethamine, has bacteriostatic and bactericidal effects on S. aureus in vitro.

Thermal stress is a major cause of production losses in the dairy and beef industries. Dairy animals are more heat sensitive as average milk yield has increased. During thermal stress physiological and biochemical changes occurs in the animal body which directly or indirectly affect the production. This review clearly describes about biochemical and physiological changes occur during thermal stress in bovines.

The present report describes the accidental detection of an ectopic columnar epithelium with interspersed gobblet-cells and a light smooth muscle layer in an ileocaecal lymph node, from an adult Aberdeen Angus crossbreed cow, which was infected with Mycobacterium bovis. The morphological features reminded intestinal epithelium, and an intestinal choristoma was diagnosed.