Complement fixing antibodies against arboviruses in horses at Lagos, Nigeria

Sixty-two sera horse collected from two stables at Lagos, Nigeria, were tested for complement fixing antibody to 8 arbovirus antigens; Chikungunya, Igbo-Ora, Yellow fever, Wesselsbron, West Nile, Potiskum, Uganda S and Rift Valley fever. Ten per cent of the horse sera examined contained CF antibody to one or more of the test antigens and indicated considerable arbovirus activity in the two stables. Reactions with flavivirus antigens were most common and the highest antibody titres were obtained with Wesselsbron and Yellow fever viruses. Eleven per cent of the sera tested reacted with alphavirus antigens while 10 per cent were positive for Rift Valley fever virus CF antibodies.     

Ratios of Nutrients in Lowland Rice Grown on Two Iron Toxic Soils in Nigeria

ABSTRACT

Iron (Fe) toxicity is a widespread nutritional soil constraint affecting rice production in the wetland soils of West Africa. Critical levels of total iron in plant causing toxicity is difficult to determine as different rice cultivars respond to excessive Fe^{2 +} in various ways in what is called “bronzing” or “yellowing” symptoms (VBS). An investigation was conducted to evaluate the relationship between plant growth and nutrient ratios at four iron levels (1000, 3000, 4000 μ g L^?1) and control. This involved two rice cultivars (‘ITA 212’ and ‘Suakoko 8’), and two soil types (Aeric Fluvaquent and Aeric Tropaquept). The experimental design was a 2 × 2 × 4 factorial in a completely randomized fashion with four replications. The results showed that nutrient ratios [phosphorus (P)/Fe, potassium (K)/Fe, calcium (Ca)/Fe, magnesium (Mg)/Fe, and manganese (Mn)/Fe), Fe content, and Fe uptake vary widely with the iron levels as well as with the age of the cultivars. The iron toxicity scores expressed as VBS increased with increasing Fe^{2 +} in the soils, resulting in simultaneous reduction of the following variables: plant height, tiller numbers/pot, relationships grain yield (GY) and dry matter yield (DMY). There were no significant difference between nutrient ratios, Fe contents, Fe uptake, the GY and DMY of both rice cultivars on both soil types. Multiple stepwise regression analysis showed that Fe uptake and Fe contents contributed 42% and 17% respectively to the variation in the grain yield of ‘ITA 212’ on Aeric Tropaquept. On both soil types and cultivars, Fe uptake and Fe content contributed between 26 and 68% to the variation in the DMY, while the nutrient ratios (P/Fe, K/Fe, Ca/Fe, and Mn/Fe) contributed between 3% and 13% DMY. Thus, it could be concluded that iron toxicity in rice is more a function of a single nutrient (Fe) rather than nutrient ratios.     

Dairy cow preference for a soft track surface

Abstract

Extract

As dairy herds get larger cows have to walk further, and foot care becomes more important. Lameness from bruising of the soles of the feet is a particular hazard (Tranter and Morris 1991 Tranter, W P and Morris, RS. 1991. A case study of lameness in three dairy herds. New Zealand Veterinary Journal, 39: 88–96. [Taylor &; Francis Online], [Web of Science ®] , [Google Scholar], especially on hard tracks with loose angular stones or grit (Clackson and Ward 1991 Clackson, DA and Ward, WR. 1991. Farm tracks, stockman's herding and lameness in dairy cattle. Veterinary Record, 129: 511–512.  [Google Scholar]. One way of reducing this problem might be to provide an overlay of woodchips on top of the normal hard track. This would provide a softer grit-free surface, which could be more comfortable for the cows.     

Swine Influenza in Sub‐Saharan Africa – Current Knowledge and Emerging Insights

Pigs have been associated with several episodes of influenza outbreaks in the past and are considered to play a significant role in the ecology of influenza virus. The recent 2009 pandemic influenza A/H1N1 virus originated from swine and not only did it cause widespread infection in humans, but was also transmitted back to swine in Asia, Europe and America. What may be the prevailing situation in Africa, particularly in sub‐Saharan Africa, with respect to the circulation of classical swine or pandemic influenza? The ecology of influenza viruses, as well as the epidemiology of human or animal influenza, is poorly understood in the region. In particular, little is known about swine influenza in Africa despite the relevance of this production in the continent and the widespread pig husbandry operations in urban and rural areas. In this review, the gap in the knowledge of classical and pandemic swine influenza is attributed to negligence of disease surveillance, as well as to the economic and public health impact that the disease may cause in sub‐Saharan Africa. However, emerging serological and virological evidence of swine influenza virus in some countries in the region underscores the importance of integrated surveillance to better understand the circulation and epidemiology of swine influenza, a disease of global economic and public health importance.     

Blood pressure and electrocardiographic effects of acepromazine in anaesthetized horses

Acepromazine, a phenothiazine tranquilizer, causes hypotension in standing horses ( Parry et al. 1982 ). However, a retrospective study ( Taylor & Young 1993 ) showed that acepromazine pre‐anesthetic medication did not affect arterial blood pressure (MAP) in anaesthetized horses. This study examined the effects of acepromazine on MAP during romifidine–ketamine–halothane anaesthesia in horses anaesthetized for various surgical procedures. Forty‐four horses were allocated by block randomization to groups A and B. Group A received acepromazine 0.05 mg kg^?1 IM 30 minutes before induction of anaesthesia, group B did not. All horses received romifidine 0.1 mg kg^?1 IV 5 minutes before anaesthesia was induced with diazepam 0.05 mg kg^?1 and 2.2 mg kg^?1 ketamine IV. The horses' trachea were intubated and horses breathed 50% oxygen and 50% nitrous oxide plus halothane (concentration adjusted as required clinically) from a circle breathing system. Nitrous oxide was discontinued after 10 minutes and analgesics, flunixin 1.1 mg kg^?1 and either morphine 0.1 mg kg^?1 or butorphanol 0.05 mg kg^?1 (matched for horses undergoing the same procedure) administered IV. The facial or dorsal metatarsal artery was catheterized for direct measurement of MAP (every 10 min) and withdrawal of blood for gas analysis (every 30 min). The electrocardiogram (ECG) was monitored continuously with a 10 seconds printout obtained every 10 minutes. Intermittent positive pressure ventilation (IPPV) was instigated if PaCO₂ exceeded 9.3 kPa (70 mm Hg). Dobutamine was infused (1.0–5.0 kg^?1minute^?1) if MAP < 58 mm Hg and was continued until MAP > 70 mm Hg. Mean age, weight and duration of anaesthesia were compared between the groups using a t‐test for independent samples. Gender distribution and numbers of horses requiring IPPV or dobutamine were compared between groups using a chi‐squared test (with Yates correction). To compare MAP over time, the area under the curve (MAPAUC) was calculated and compared between groups using a t‐test. Horses receiving dobutamine were excluded from MAPAUC and MAP comparisons. The ECG printouts were examined for arrhythmias. There were no significant differences between groups (p > 0.05). Group A contained three stallions, 10 geldings and nine mares, aged 6.3 years (range 0.75–18). Group B comprised eight stallions, 11 geldings and three mares aged 7.3(1–16) years. Duration of anaesthesia was group A 97 (50–140) minutes, group B 99 (50–160) minutes. Eight horses in group A and three in group B required IPPV. Nine horses in group A and four in group B received dobutamine. Mean arterial pressure ranged from 60 to 128 mm Hg in group A and 58–96 mm Hg in group B. Mean MAPAUC was 5941 mm Hg minute^?1 in group A, in B 6000 mm Hg minute^?1. Atrial pre‐mature complexes were recorded from one horse in group B. No other arrhythmias were detected. Although MAP was lower in the acepromazine group, this appeared unlikely to cause a clinical problem. The incidence of arrhythmias was too low to determine the influence of acepromazine in this study.     

Swim-up fry production in the African Catfish Clarias gariepinus (Burchell) broodstocks fed with differently heated soybean-based diets

Four hundred and eighty matured yearlings of Clarias gariepinus (Burchell) (female=182±10 g; males=208±5 g) distributed into groups of 30 specimens (sex ratio 1:1) were fed differently heated soybean‐based diets. Seven approximately iso‐nitrogenous (31% crude protein) and iso‐caloric (13.97 kJ g^?1) diets were prepared from either raw soybean (SAMSOY 2, TGX 636–02D) or soybean seeds autoclaved for 5, 10, 15, 20, 25 and 30 min. The untreated and the variously heat‐treated soybean meals were mixed with other ingredients to prepare diets designated as DSoy0, DSoy5, DSoy10, DSoy15, and DSoy20, DSoy25 and DSoy30 according to the treatment time of the soybean portion of the diets, and were fed to the fish broodstocks for 84 days. The fishmeal‐based diet (DFM) served as the reference diet. The duration of heating soybean component of the experimental diet significantly (P<0.05) affected the growth performance and the number of eggs produced by the broodstocks, the percentage number of eggs fertilized and hatched as well as the survival of the progenies. The progenies of the brood fish fed diets DFM and DSoy25 with a yolk sac size of 2.78±0.6 and 2.42±0.5 mm, respectively, had significantly (P<0.05) larger yolk sacs, which were also absorbed at a significantly faster rate of 0.61±0.02 and 0.51±0.03 mm day^?1, respectively, than progenies of broodstocks fed other experimental diets. Swim‐up fry survival rates were also better in hatchlings from broodstocks fed DFM (89.5%), DSoy25 (83.8%) and Dsoy 20 (80.5%) diets than progenies from other experimental diets. This study showed that soybean meal portion processed at 116°C and 1.2 kg cm^?2 pressure for 25 min in the diet, which ensures normal reproductive function and production of healthy progenies in C. gariepinus, could serve as a substitute for fishmeal in the broodstock diets.     

Detection and isolation of 2009 pandemic influenza A/H1N1 virus in commercial piggery,Lagos Nigeria

WHO declared pandemic of A/H1N1influenza in 2009 following global spread of the newly emerged strain of the virus from swine. Presently there is a dearth of data on the ecology of pandemic influenza H1N1 required for planning of intervention measures in sub Saharan Africa. Herein we report isolation of 2009 pandemic influenza A/H1N1 in an intensive mega piggery farms operation in South West Nigeria.     

Yellow fever haemagglutination-inhibiting, neutralising and IgM antibodies in vaccinated and unvaccinated residents of Ibadan, Nigeria

A survey for yellow fever virus haemagglutination inhibiting (HI) and neutralising (N) and IgM antibodies was carried out in unvaccinated people in Ibadan and in those immunised with the yellow fever 17-D vaccine. A total of 207 people were tested for HI antibody to yellow fever and two other flaviviruses namely: Wesselsbron and Uganda S. viruses. Prevalence of HI antibody to each flavivirus antigen was as follows: Yellow fever 26%, Wesselsbron 18% and Uganda S 33%. Of the 207 people, 37 (18%) had yellow fever N antibody. There was a higher prevalence of N antibody to yellow fever virus in adults than children. Twenty-one people vaccinated with 17-D yellow fever vaccine donated post-vaccination sera; 10 (48%) had no prevaccination HI antibody, 7 (33%) had HI antibody to one flavivirus and 4 (19%) to two or more flaviviruses. Ninety percent of seronegative people and all those with prevaccination flavivirus antibodies developed HI or N antibody, following vaccination. A total of 58 unvaccinated people were tested for yellow fever IgM antibody by an enzyme linked immunosorbent assay, 2 (3%) were positive; suggesting that active yellow fever transmission was in progress at the time of survey.     

Management of Two Potentially Iron Toxic Benchmark Wetlands Using Integrated Approach for Rice Production in Nigeria

To manage iron toxic rainfed lowlands on a sustainable basis for rice production, a trial was conducted using an integrated approach (i.e. tolerant genotype and fertilizer nutrients). This trials involved two rice cultivars ITA 212 and Suakoko 8 in two cropping seasons (1994 and 1995) and on two potentially iron toxic soil types with excessively high active Fe contents of between 4.43 % and 5.15 %, respectively, located in two agro‐ecological zones in Nigeria. The effects of fertilizer nutrients (N, P, K, Zn, N+P, N+K, N+Zn, N+P+K, N+P+K+Zn and control) were evaluated on the grain yield (GY) and nutrient uptake (leaf analyses) of the rice plants using stepwise multiple regression analysis (SMRA). Results showed that these soils are acidic and had sub‐optimal macronutrient and micronutrient contents coupled with excessively high active Fe (Fe_H) of between 4.43 % and 5.15 %. Fertilizer nutrients N+K, N+P+K and N+P+K+Zn consistently appeared to result in higher GY compared to others on both soil types. Plant analysis of both rice cultivars showed no apparent deficiencies in elemental composition with regard to macronutrients and micronutrients. Results of SMRA showed that tissue K, Zn and Mg contents were significantly related (P < 0.01) to the GY of the two rice cultivars.