Host response to successive challenges with lentogenic and velogenic Newcastle disease virus in local chickens of Ghana.

Newcastle disease (ND) is a highly contagious viral disease that constantly threatens poultry production. The velogenic (highly virulent) form of ND inflicts the most damage and can lead to 100% mortality in unvaccinated village chicken flocks. This study sought to characterize responses of local chickens in Ghana after challenging them with lentogenic and velogenic Newcastle disease virus (NDV) strains. At 4 wk of age, chicks were challenged with lentogenic NDV. Traits measured were pre- and post-lentogenic infection growth rates (GR), viral load at 2 and 6 d post-lentogenic infection (DPI), viral clearance rate and antibody levels at 10 DPI. Subsequently, the chickens were naturally exposed to velogenic NDV (vNDV) after anti-NDV antibody titers had waned to levels ≤1:1,700. Body weights and blood samples were again collected for analysis. Finally, chickens were euthanized and lesion scores (LS) across tissues were recorded. Post-velogenic exposure GR; antibody levels at 21 and 34 days post-velogenic exposure (DPE); LS for trachea, proventriculus, intestines, and cecal tonsils; and average LS across tissues were measured. Variance components and heritabilities were estimated for all traits using univariate animal models. Mean pre- and post-lentogenic NDV infection GRs were 6.26 g/day and 7.93 g/day, respectively, but mean post-velogenic NDV exposure GR was -1.96 g/day. Mean lesion scores ranged from 0.52 (trachea) to 1.33 (intestine), with males having significantly higher (P < 0.05) lesion scores compared to females. Heritability estimates for the lentogenic NDV trial traits ranged from moderate (0.23) to high (0.55) whereas those for the vNDV natural exposure trial were very low (≤ 0.08). Therefore, in contrast to the vNDV exposure trial, differences in the traits measured in the lentogenic challenge were more affected by genetics and thus selection for these traits may be more feasible compared to those following vNDV exposure. Our results can form the basis for identifying local chickens with improved resilience in the face of NDV infection for selective breeding to improve productivity.

Knowledge, attitude, and practices on usage, disposal, and effect of plastic bags on sheep and goats.

The objective of this study was to evaluate knowledge, attitudes, and practices of people in the Nairobi and Kajiado Counties, Kenya, on the usage, disposal, and effect of plastic waste on sheep and goats (shoats). A semi-structured questionnaire was used to collect data from 384 respondents in four communities in the two counties. Most of the people irrespective of their age, occupation, and educational status used plastic bags of some type on a daily basis. A high proportion of the respondents (37.0%, 142) used plastic bags because of the low cost. Approximately, 79.1% (304) disposed used plastic bags in open dumps. A total of 147 (38.3%) households kept shoats. Out of these, 38.1% (56) purchased feed and also allowed their animals to roam. Most of them (45.3%, 174) thought that lack of feed for the animals was the main reason why shoats roam and scavenge at refuse dump sites and road sides. A large proportion of the respondents (44.5%, 143) mentioned death of animals as the ultimate consequence of ingestion of waste plastic bags. Though, the respondents were aware that indiscriminate disposal of used plastic bags could result in death of the animals from which they derive their livelihoods, they nevertheless continued with the practice. There is a need for a paradigm shift in the way and manner plastic bags are used and disposed.

Gross and histopathologic findings in sheep with plastic bags in the rumen.

The objective of this study was to evaluate the gross and histo-pathological lesions caused by plastic bags in the rumen of sheep. Sixteen (16) castrated, one-year old Dorper sheep were used for the study. The animals were divided into 4 groups each consisting of 4 sheep. Three of the groups had 129 g, 258 g and 387 g of plastic bags, respectively, introduced into the rumen through rumenotomy, while the fourth group, without implants served as control. All the animals were observed daily for 6 weeks following implantation. All animals were euthanized on day 42 and subjected to gross and histopathological examination. Gross changes observed at post mortem included; atrophy of the muscle and body fat, atrophy and fibrosis of the spleen, liver, kidneys and hydropericardium. Gross lesions in the rumen included stunting, atrophy, thinning and loss of ruminal papillae, erosion, ulcerations and nodular formation on the ruminal mucosa. Histopathological examination revealed atrophy, ulceration, erosion and disruptions of the stratified epithelial layer of the papillae. Other changes included parakeratosis, hyperkeratosis, prominent rete pegs, oedema and severe hydropic degeneration of different parts of the mucosal layer. There was increased mononuclear cell infiltration, increase in the number of lymphatic vessels and lymphangiectasis in the submucosa and oedema in the muscularis and serosal layers. The pathological changes observed contributed to clinical signs and may interfere with the absorption of nutrients resulting in poor condition of the animal, and loss of production and productivity.

Full genome sequence of a peste des petits ruminants virus (PPRV) from Ghana.

The full genome of a peste des petits ruminants virus (PPRV) isolated from a sheep lung sample collected in Ghana, Western Africa, in 2010, has been sequenced. Phylogenetic analysis demonstrated that the virus clustered within the lineage II clade while comparison of its full genome with those of other PPRV strains revealed the highest identity (96.6 %) at a nucleotide level with the PPRV strain Nigeria/76/1. This is the first full genome sequence generated for a PPRV lineage II isolated since 1976.