Research Note: Responses of broiler chickens to in ovo feeding with clove and cinnamon extract under hot-humid environments.

An experiment was carried out to evaluate the responses of broiler chickens to in ovo injection of aqueous extracts of clove and cinnamon under a hot-humid environment. The study involved the use of seven hundred hatching eggs from broilers (Ross 308) which were incubated with the use of standard protocol (37.8°C). The incubating eggs (100 each) were randomly selected and assigned to 7 treatments on day 17.5 of incubation, viz.: un-injected eggs (UE), eggs injected with 0.5 mL distilled water (DW), 2 mg clove (CL2), 4 mg clove (CL4), 2 mg cinnamon (CN2), 4 mg cinnamon (CN4), and 3 mg ascorbic acid (AA).Data on physiological parameters, hatchability, chick quality, and anatomical characteristics of the chicks were collected and analyzed using one-way analysis of variance. The results obtained revealed that the hatchability of eggs of AA and CN2 was higher compared to DW and UE. However, the hatchability of DW and UE was higher than those of CN4. The total chick quality scores of the control were similar to the other groups. Chick weights at hatch were similar in CL2, CN2, and AA but heavier than CN4, CL4, UE, and DW. The chick-to-egg ratio in AA was comparable to CL2 and CN2 but higher than UE, DW, CN4, and CL4. Total scores for chick quality of AA birds were similar to those of UE, CL2, and CL4 birds but higher than DW, CN2, and CN4 birds.

Genetic parameter estimates for milkability traits and their relationship with somatic cell score in South African Holstein cattle.

Milkability is an important functional trait, which is directly related to milking costs and udder health. There are no milkability traits incorporated in the South African dairy cattle breeding objectives and genetic parameter estimates for these traits are not available in this population. The main objective of the study was, therefore, to estimate the genetic parameters for milkability traits and its correlation with somatic cell scores in South African Holstein cattle. Data consisted of production and milkability records of 2719 Holstein cows, from ten herds, collected from 2016 to 2018. Genetic parameters were estimated by a multi-trait animal model using the restricted maximum likelihood (REML) procedure. Means for milking time (MT), average milk flow (AMF), maximum milk flow (MMF), and somatic cell score (SCS) were 5.20 min, 1.91 kg/min, 2.99 kg/min, and 2.06, respectively. The heritability estimates were low to moderate from 0.19 ± 0.07, 0.24 ± 0.06, 0.36 ± 0.11, and 0.41 ± 0.12, respectively, for SCS, AMF, MT, and MMF. The genetic correlations were significant (P < 0.05) among the three milkability traits ranged from - 0.31 ± 0.05 between AMF and MT to 0.85 ± 0.02 between AMF and MMF. Positive genetic correlations were observed between AMF and MMF, while the correlations for MT with the remaining milkability traits were negative. Genetic correlations of SCS with AMF, MMF, and MT were - 0.13 ± 0.04, 0.13 ± 0.04, and - 0.25 ± 0.12, respectively. The mean estimated breeding value (EBV) was estimated using cattle birth dates, and there was an increase in AMF of 0.0001 kg/min EBV per year on cattle born during the period 2002 to 2014. Maximum milk flow also showed an increasing genetic trend of 0.0003 kg/min per year over the same period. On the other hand, the genetic trend for MT was undesirable, as it increased by 0.0003 kg/min per year. The moderate to high heritability estimates for milkability traits showed that selection for improvement was possible in South African Holstein cattle. High genetic correlation between AMF and MMF implied that these two may be regarded as the same trait. Milking time can contribute towards improving the accuracy of estimating EBVs for SCS in a multi-trait analysis, and vice versa, due to the moderate correlation between the two traits. The marginal genetic trend in milkability traits may be an interrelated response to selection of other traits already under selection in the population such as SCS. Results of the current study provided a basis for including milkability traits of South African Holstein cattle in the breeding objectives.

Temporal and spatial distribution of cattle anthrax outbreaks in Zimbabwe between 1967 and 2006.

This retrospective study aimed to assess the spatial and temporal distribution of anthrax and to identify risk areas in Zimbabwe. The data were extracted from the monthly and annual reports of the Division of Livestock Production and Veterinary Services for the period 1967 to 2006. The data were analyzed in relation to temporal and spatial factors. The hot-dry season was found to be significantly (X (2)=847.8, P<0.001) associated with the occurrence of anthrax in cattle, and the disease was found to be approximately three times more likely to occur during this season compared to other seasons. Anthrax outbreaks demonstrated a gradual temporal increase from an annual mean of three outbreaks for the 5-year period (1967-1971) to 42 for the 5-year period (2002-2006). Similarly, the data demonstrated a spatial increase in the number of districts affected by anthrax between 1967 and 2006, with 12 districts affected for the 10-year period (1967-1976) that expanded to 42 districts for the 10-year period (1997-2006). The majority of outbreaks (83.7%) were recorded in rural areas, and 11 districts were found to be at a higher risk than others. There is need to develop differential vaccination strategy, other control strategies and preventive recommendations to reduce anthrax in high-risk districts. In the medium- to low-risk districts, maintenance of effective surveillance systems and improvement of awareness is very important to detect and contain outbreaks early.

Risk factors for Brucella spp. infection in smallholder household herds.

Risk factors for Brucella infection, the association and impact of Brucella seropositivity on abortions were investigated in cattle (n=1291) reared in smallholder household herds (n=203) from six geographical areas of Zimbabwe between September 2004 and 2005. Data on management, abortion and herd structure were collected. Sera were tested for Brucella antibodies using the Rose Bengal test and a competitive enzyme-linked immunosorbent assay. Data were analysed by generalized estimating equation and logistic regression models. Brucella antibodies were estimated at 5·5% and 22·9% for individual cattle and herds, respectively. Abortions were reported in 3·2% of cows and 22·0% herds. The age of cows and Brucella seropositivity predicted abortion. For herds, Brucella seropositivity, geographical area, purchase of cattle and large herd size were independently associated with increased odds of abortion. Exposure to Brucella had a significant impact on abortion. These results highlight the important risk factors for Brucella spp. infection in smallholder herds. Thus, brucellosis control programmes which take these factors into consideration will be beneficial.

Herd-level factors for Brucella seropositivity in cattle reared in smallholder dairy farms of Zimbabwe.

A cross-sectional study was conducted to investigate factors for Brucella seropositivity in smallholder dairy cattle herds from Gokwe, Marirangwe, Mushagashe, Nharira, Rusitu and Wedza areas located in different agro-ecological regions of Zimbabwe between September 2004 and November 2005. Sera were collected from cattle aged > or = 2 years from 203 herds. Data on herd-level and management variables were collected using a structured questionnaire. Sera were screened for anti-Brucella antibodies using the Rose Bengal test (RBT) and confirmed by competitive ELISA (c-ELISA). A herd was classified as Brucella seropositive if at least one animal tested seropositive on both tests. The herd-level factors for Brucella seropositivity were tested using multivariable logistic model with herd infection status as dependent variable while the levels of exposure in individual animals within-herds were analysed by negative binomial regression using the number of positive animals as the outcome. Of the 203 herds tested, 52 (25; 95% CI: 18.1, 31.9%) tested seropositive for brucellosis. Using the logistic regression model we identified area, with both Rusitu (OR=0.26; 95% CI: 0.07, 1.03) and Wedza (OR=0.07; 95% CI: 0.01, 0.49) having lower Brucella seropositivity compared to Gokwe. Keeping mixed cattle breeds (OR=8.33; 95% CI: 2.70, 25.72) compared to single breed herds, was associated with increased herd seropositivity. The farmer's knowledge of brucellosis was associated with lower odds (OR=0.17; 95% CI: 0.05, 0.55) of farms testing seropositive. The odds of Brucella seropositivity were progressively higher with increasing stocking density and herd size. Using the negative binomial regression model we identified area, keeping mixed breed herds, stocking density and herd size as independently associated with increased counts of seropositive cattle in a herd.

Combination therapy using intratumoral bacillus Calmette-Guerin (BCG) and vincristine in dogs with transmissible venereal tumours: therapeutic efficacy and histological changes.

Therapeutic efficacy and histological changes after bacillus Calmette-Guerin (BCG), vincristine and BCG/vincristine combination therapy of canine transmissible venereal tumours (CTVT) were studied. Twenty dogs with naturally occurring CTVT in the progression stage were divided into 4 groups and treated with intratumoral BCG, vincristine, BCG/vincristine combination therapy or intratumoral buffered saline (control group). Tumour sizes were determined weekly and tumour response to therapy was assessed. Tumour biopsies were taken weekly to evaluate histological changes. Complete tumour regression was observed in all the dogs treated with BCG, vincristine and BCG/vincristine combination therapy. BCG/vincristine combination therapy had a statistically significantly shorter regression time than BCG or vincristine therapy. No tumour regression was observed in the control group. Intratumoral BCG treatment resulted in the appearance of macrophages and increased numbers of tumour infiltrating lymphocytes (TILs) followed by tumour cell apoptosis and necrosis. Treatment with vincristine resulted in increased tumour cell apoptosis, reduction in the mitotic index and a decrease in the number of TILs. Tumours from dogs on BCG/vincristine combination were characterised by reduction in the mitotic index, and appearance of numerous TILs and macrophages followed by marked tumour cell apoptosis and necrosis. This study indicates that combined BCG and vincristine therapy is more effective than vincristine in treating CTVT, suggesting that the clinical course of this disease may be altered by immunochemotherapy.

Canine transmissible venereal tumour: assessment of mast cell numbers as indicators of the growth phase.

Mast cells are immune cells that are involved mainly in type 1 hypersensitivity reactions, and they have been implicated in tumour angiogenesis. In this study we assessed the presence of mast cell numbers and microvessel density during the progression and regression stages of natural spontaneous canine transmissible venereal tumours (CTVT). Mast cells were demonstrated by histochemical staining with toluidine blue, alcian blue and safranin O. Microvessel counts were demonstrated by immunohistochemical labelling with an antibody against the endothelial cell marker factor VIII. Mitotic cells, apoptotic cells and tumour infiltrating lymphocytes were counted from haematoxylin-eosin-stained sections. Tumour fibrosis was evaluated on Masson's trichome-stained sections. The results showed that progressing tumours had significantly higher mast cell counts and microvessel counts at the invasive edges of the tumours than did regressing tumours. In both the progressing and regressing tumours, microvessel counts were significantly positively correlated with mast cell counts. Regressing tumours had significantly higher mast cell counts of the whole tumour than progressing tumours. The results also showed that progressing tumours had significantly higher mitotic rate than regressing tumours, and fibrosis and apoptosis were significantly higher in regressing tumours than progressing tumours. There were no significant differences between the biochemical and haematological values of dogs with progressing and regressing tumours. These results suggests that mast cells play a role in CTVT progression probably by promoting vascularization at the invasion front during the progression phase, and that mast cell count could be used as one of the histological factors to indicate growth stage of CTVT.

Canine cutaneous neoplasms: prevalence and influence of age, sex and site on the presence and potential malignancy of cutaneous neoplasms in dogs from Zimbabwe.

Histopathological examination was performed on cutaneous biopsies from 900 dogs with skin lesions from Zimbabwe, collected from 1996 to 2000. Clinical data were collected from medical records. Sixty per cent (540/900) of the cases were tumours and 40% (360/900) were non-neoplastic inflammatory or degenerative diseases. Thirty different histological types of tumour were diagnosed. The prevalence of epithelial, mesenchymal, lymphohistiocytic and melanocytic tumours was 39.4%, 44.4%, 7.4% and 8.7%, respectively. The 10 most common tumours, comprising 73.7% of all cutaneous neoplasms, were mast cell tumours, squamous cell carcinomas, perianal gland adenomas, lymphomas, benign melanomas, haemangiosarcomas, sebaceous gland adenomas, fibrosarcomas, lipomas and malignant melanomas. The prevalence of various neoplasms, age of affected dogs and sites of occurrence were similar to surveys in other countries, except that in Zimbabwe there was a greater prevalence of lymphomas and of tumours associated with increased exposure to ultraviolet light (squamous cell carcinomas, haemangiosarcomas and melanomas). For all classes of tumours the sex of the dog did not have any significant influence on the likelihood of developing a tumour. For a dog diagnosed with a tumour located on the trunk, the tumour was significantly more likely to be an epithelial tumour than a non-epithelial tumour The occurrence of melanocytic tumours on the trunk was significantly lower than at other sites. Lymphohistiocytic tumours were 10 times more likely to occur at multiple locations as opposed to single locations.

Effect of host age in the distribution of adult Trichinella zimbabwensis in the small intestines of golden hamsters (Mesocricetus auratus) and Balb C mice.

Golden hamsters (Mesocricetus auratus) and Balb C mice were experimentally infected with Trichinella zimbabwensis to determine the effect of host age in the distribution of adult stages in the small intestines. The hamsters and mice were divided into two groups of young and old animals. Hamsters aged 90 days were designated as young and those aged 360 days were designated as old while mice of 30 days of age were designated as young and those aged 90 days as old. To recover the adult parasites of T. zimbabwensis, the small intestines of each animal were separated and divided into four equal parts and each part was slit open longitudinally. The contents were incubated in 0.85% saline for 4 h at 37 degrees C before the adult worms were recovered from the saline. They were fixed in 70% alcohol and counted under a dissecting microscope. In both young and old hamsters and mice, T. zimbabwensis adult worm counts were significantly higher (P < 0.05) in the second segment of the intestines thus invariably reflecting a significantly high count (P < 0.05) in the first (anterior) half of the small intestines. From this study it was demonstrated that host-age had no effect on the distribution of T. zimbabwensis adult worms in the different segments of the small intestines of golden hamsters and Balb C mice.

Non-traumatic paraplegia [correction of paraplegis] in a Zimbabwean population--a retrospective survey.

OBJECTIVES: To ascertain the aetiology of non-traumatic paraplegia in a Zimbabwean population and to compare findings with other studies from Africa. DESIGN: Retrospective survey over a six year period. SETTING: National Rehabilitation Centre, Ruwa, Zimbabwe. SUBJECTS: 159 patients referred to the National Rehabilitation Centre with non-traumatic paraplegia. RESULTS: The commonest causes of non-traumatic paraplegia were neoplasms (28% of cases) of which a third were metastatic, followed by tuberculosis (TB) (27%). Transverse myelopathy of unknown aetiology was diagnosed in 11% of cases and 6% had Guillain Barré syndrome. Miscellaneous conditions included: degenerative bone and joint conditions, degenerative cord disorders and infections. In 7% of cases no diagnosis was reached. On admission all patients were confined to wheelchairs. On discharge 49% had regained some degree of mobility. A year after discharge 48% were known to be alive and 18% had died. The fate of 34% was not known. CONCLUSIONS: The aetiology of non-traumatic paraplegia in a Zimbabwean population is similar to that reported from other African countries, with tumours and tuberculosis accounting for over half the cases. Survival appears to be related not only to the primary condition but also to the severity of the disability.

Problems, struggles and some success with spinal cord injury in Zimbabwe.

Spinal cord injury is a common occurrence in Zimbabwe and carries with it a high morbidity and mortality. In the past almost all patients discharged from hospital were dead within a year. Reasons for this high mortality are presented. The establishment of the National Rehabilitation Centre has had a profound impact on the survival of these individuals as well as on improving their quality of life. The results of a retrospective survey on the mortality and life situation of individuals with spinal cord injuries sustained through trauma are presented. However major unresolved problems are inadequate housing, lack of financial support, practically no prospect of employment and depression compounded by boredom.