Characterization of indigenous chicken production systems in Kenya

Indigenous chicken (IC) and their production systems were characterized to understand how the whole system operates for purposes of identifying threats and opportunities for holistic improvement. A survey involving 594 households was conducted in six counties with the highest population of IC in Kenya using structured questionnaires. Data on IC farmers’ management practices were collected and analysed and inbreeding levels calculated based on the effective population size. Indigenous chicken were ranked highest as a source of livestock income by households in medium- to high-potential agricultural areas, but trailed goats in arid and semi-arid areas. The production system practised was mainly low-input and small-scale free range, with mean flock size of 22.40 chickens per household. The mean effective population size was 16.02, translating to high levels of inbreeding (3.12%). Provision for food and cash income were the main reasons for raising IC, whilst high mortality due to diseases, poor nutrition, housing and marketing channels were the major constraints faced by farmers. Management strategies targeting improved healthcare, nutrition and housing require urgent mitigation measures, whilst rural access road network needs to be developed for ease of market accessibility. Sustainable genetic improvement programmes that account for farmers’ multiple objectives, market requirements and the production circumstances should be developed for a full realization of IC productivity.     

Breeding objectives for indigenous chicken: Model development and application to different production systems

A bio-economic model was developed to evaluate the utilisation of indigenous chickens (IC) under different production systems accounting for the risk attitude of the farmers. The model classified the production systems into three categories based on the level of management: free-range system (FRS), where chickens were left to scavenge for feed resources with no supplementation and healthcare; intensive system (IS), where the chickens were permanently confined and supplied with rationed feed and healthcare; and semi-intensive system (SIS), a hybrid of FRS and IS, where the chickens were partially confined, supplemented with rationed feeds, provided with healthcare and allowed to scavenge within the homestead or in runs. The model allows prediction of the live weights and feed intake at different stages in the life cycle of the IC and can compute the profitability of each production system using both traditional and risk-rated profit models. The input parameters used in the model represent a typical IC production system in developing countries but are flexible and therefore can be modified to suit specific situations and simulate profitability and costs of other poultry species production systems. The model has the capability to derive the economic values as changes in the genetic merit of the biological parameter results in marginal changes in profitability and costs of the production systems. The results suggested that utilisation of IC in their current genetic merit and production environment is more profitable under FRS and SIS but not economically viable under IS.     

Nonsuppurative encephalitis in a dog

A 4-year-old male German Hunting Terrier presented with tremor, dyspnea, trismus, spasms of the musculature of the larynx and pharynx, and hypothermia and subsequently died despite intensive clinical care. Prior clinical signs included vomitus and diarrhea. Microscopic examination of the brain revealed a multifocal nonsuppurative brain stem encephalitis; a few intralesional neurons contained intranuclear inclusions. By immunohistochemistry, Aujeszky disease virus (Suid herpesvirus 1) antigen was detected in neurons in the brain and in ganglion cells of the trigeminal ganglia. Viral culture of brain tissue confirmed the presence of Aujeszky disease virus. Histopathologic findings in the brain with the identification of Aujeszky disease virus by immunohistochemistry and polymerase chain reaction are consistent with Aujeszky disease virus-induced encephalitis. Sequencing revealed a 100% homology of the isolated Aujeszky disease virus with Aujeszky disease virus isolates of wild boar from Eastern Germany.     

Effect of a rumen-protected conjugated linoleic acid mixture on hepatic lipid metabolism in heifers

This study was performed to assess the effects of rumen-protected conjugated linoleic acid (CLA) on hepatic lipid metabolism in heifers. In particular, it was of interest whether feeding CLA causes development of fatty liver as observed recently in mice. Thirty-six growing heifers with an initial body weight of 185 kg were allotted to three treatment groups and fed daily 250 g of different rumen-protected fats for 16 weeks: The control group received 250 g of a CLA-free control fat, the CLA100 group received 100 g of a CLA fat containing 2.4% of cis-9, trans-11 CLA and 2.1% of trans-10, cis-12 CLA and 150 g control fat and the CLA250 group received 250 g of the CLA fat. CLA supplementation had no effect on animal performance parameters, liver weight and hepatic triglyceride concentration. Moreover, mRNA expression of hepatic genes involved in lipogenesis, β-oxidation and fatty acid transport was not influenced by dietary CLA. The fatty acid composition of hepatic total lipids, with particular consideration of ratios of fatty acids indicative of Δ9-, Δ6- and Δ5-desaturation, was also less influenced by dietary CLA. In conclusion, the study shows that dietary rumen-protected CLA has less effect on hepatic lipid metabolism in young heifers and does not induce the development of a fatty liver such as in mice.     

Complete atrioventricular block secondary to cardiac lymphoma in a dog

Third degree atrioventricular (AV) block was observed in a patient with a roughly spherical mass measuring approximately 1 × 1 × 1 cm, visible in the basilar portion of the interventricular septum on 2-dimensional transthoracic echocardiographic examination. The patient had a brief history of lethargy and episodic collapse, and the owner elected to euthanize the dog after the mass lesion was discovered. Necropsy revealed multiple masses within the interventricular septum, ventricular free walls and atrial myocardium. The final diagnosis was large cell (T-cell) lymphosarcoma.     

Diagnostic value of the neutrophil myeloperoxidase index in horses with systemic inflammation

The myeloperoxidase index (MPXI) was investigated as a diagnostic indicator of systemic inflammation in a retrospective study using data from 859 hospitalised horses. A reference interval of 8.5-10.4 for the MPXI was established. In horses with systemic inflammatory response syndrome (SIRS), the MPXI was significantly lower than in healthy horses, those with localised inflammation and those with sepsis. The MPXI in horses with sepsis was also significantly lower than in healthy animals and those with localised inflammation. Horses in the SIRS group with leucopenia, white blood cell (WBC) count within the reference interval (WRI) or leucocytosis had significantly lower MPXIs than healthy horses, those with localised inflammation and those with sepsis in the same WBC count subgroups. In horses with sepsis and WBC count WRI, the MPXI was significantly lower than in healthy horses or those with localised inflammation. MPXI is a useful complementary tool to identify horses with systemic inflammation, especially if they have WBC counts WRI.     

Assessing long term effects of compost fertilization on soil fertility and nitrogen mineralization rate

Background

Fertilization with organic waste compost can close the nutrient cycles between urban and rural environments. However, its effect on yield and soil fertility must be investigated.

Aim

This study investigated the long-term effect of compost on soil nutrient and potentially toxic elements (PTEs) concentration, nutrient budgets, and nitrogen (N) mineralization and efficiency.

Methods

After 21 years of annual compost application (100/400 kg N ha^–1 year^–1 [100BC/400BC]) alone and combined with mineral fertilization, soil was analyzed for pH, organic carbon (SOC), nutrient (total N and P, N_min, extractable CAL-P, CAL-K, and Mg), and PTE (Cu, Ni, Zn) concentrations. Yields were recorded and nutrient/PTE budgets and apparent net mineralization (ANM, only 2019) were calculated.

Results

N efficiency was the highest in maize and for mineral fertilization. Compost application led to lower N efficiencies, but increased ANM, SOC, pH, and soil N, and surpluses of N, P, and all PTEs. Higher PTE concentrations were only found in 400BC for Cu. Nutrient budgets correlated with soil nutrient concentration. A surplus of 16.1 kg P ha^–1 year^–1 and 19.5 kg K ha^–1 year^–1 resulted in 1 mg kg^–1 increase in CAL-P and CAL-K over 21 years.

Conclusion

Compost application supplies nutrients to crops with a minor risk of soil-accumulation of PTEs. However, the nutrient stoichiometry provided by compost does not match crop offtakes causing imbalances. Synchronization of compost N mineralization and plant N demand does not match and limits the yield effect. In winter wheat only 65–70% of N mineralization occurred during the growth period.     

Choice of shrinkage parameter and prediction of genomic breeding values in elite maize breeding populations

Genomic selection (GS) is a promising alternative to marker‐assisted selection particularly for quantitative traits. In this study, we examined the prediction accuracy of genomic breeding values by using ridge regression best linear unbiased prediction in combination with fivefold cross‐validation based on empirical data of a commercial maize breeding programme. The empirical data is composed of 930 testcross progenies derived from 11 segregating families evaluated at six environments for grain yield and grain moisture. Accuracy to predict genomic breeding values was affected by the choice of the shrinkage parameter λ², by unbalanced family size, by size of the training population and to a lower extent by the number of markers. Accuracy of genomic breeding values was high suggesting that the selection gain can be improved implementing GS in elite maize breeding programmes.     

COMPUTED TOMOGRAPHIC FEATURES OF BASIHYOID ECTOPIC THYROID CARCINOMA IN DOGS

Eight dogs with a firm, nonpainful swelling in the ventral laryngeal region and with a final diagnosis of ectopic thyroid carcinoma were investigated by Computed Tomography (CT) at six different institutions. Computed Tomography findings were reviewed, focusing on lesion volume, shape, margins, relationship with surrounding structures and adjacent vessels, attenuation characteristics, and presence of metastases. Ectopic thyroid carcinomas were seen as oval‐to‐bilobed masses centered on the basihyoid bone with associated bone lysis, highly vascularized capsules with central poorly contrast enhancing areas. In all cases there was laryngeal wall infiltration, in two dogs invasion of the laryngeal lumen and in one case invasion of the ventral muscular and subcutaneous plane. Metastases were found in retropharyngeal lymph nodes (three cases) and in the lung (two cases). Ectopic thyroid carcinoma should be considered in the differential diagnosis when a mass in the basihyoid region is present. Described CT features may be typical for ectopic thyroid neoplasia and could be used to help decide the therapeutic plan.