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L-carnitine (B-hydroxy-Y-N-trimethyl aminobutyrate) is a water-soluble product, found in animals, plants and microorganisms. Its synthesis takes place from two important amino acids, lysine and methionine. Essentially, L-carnitine has an intermediary role in metabolism. It promotes energy metabolism for cell and regulates co-enzyme A concentration in cystosol and mitochondria, which are important in glucose and lipid metabolism. L-carnitine was first isolated from the chicken embryo in a significant amount, but is absent in the egg. Under normal physiological conditions, the endogenously synthesised levels are sufficient for normal growth and functions. Its requirements are increased in stressful conditions and during metabolic and physiological higher demands, such as growth and laying periods. L-carnitine increases energy production, fat metabolism and improves immune status in birds, which is energy demanding. In this review, several aspects of the beneficial effects of dietary supplementation of L-carnitine on poultry health and production are briefly summarised.
Mycotoxins are secondary fungal metabolites of structurally diverse groups occurring worldwide as contaminants of cereals such as wheat, corn, maize, peanut, and barley, which comprise the main ingredients of poultry diets. Milk thistle (Silybum marianum) has wide range of beneficial properties, including data showing its positive effects in protecting the liver of birds exposed to aflatoxins. Trials have shown that in broilers affected by aflatoxicosis, which adversely affected feed intake, weight gain, feed efficiency, serum biochemistry and immune status, supplementation of diets with silymarin reduced the detrimental effects, thereby improving the productivity and health. Although promising results have been reported, established doses and further research on the standardisation of this herb will increase its uses as alternative to synthetic drugs. The following review discusses several important aspects of the beneficial properties of milk thistle on poultry growth performance in experimentally induced aflatoxicosis.
The present study was conducted to appraise the ontogenic radio-sensitivity of a serious tropical pest, Spodoptera litura (Fabr.). The molecular responses pertaining to the phenoloxidase (PO) pathway and an anti-oxidant defense mechanism were evaluated in order to understand its implication in pest control at pre-harvest and post-harvest intervals. Irradiation exhibited an inverse relationship with age with respect to impact on developmental and transcriptional responses. Transcript abundance of PO cascade enzymes, prophenoloxidase (slppo-2), its activating enzyme (slppae-1) and free-radical scavenging enzymes, superoxide dismutase (slsod) and catalase (slcat) was evaluated upon gamma irradiation alone and the dual-stress of radiation plus microbial challenge. The slppo-2, slppae-1, slsod and slcat transcripts were significantly up-regulated in F1 L6 larvae (6th-instar) resulting from 100 Gy sub-sterilized male adults and unirradiated female moths. The extent of upregulation was relatively higher in comparison with L6 survivors (6th-instar larvae) developed from irradiated neonates (L1) treated with 100 Gy. Upon Photorhabdus challenge, the transcripts were down-regulated in irradiated L1 suggesting increased larval susceptibility to bacterial infections. Radioresistance increased with the age of the insect, and molecular responses (transcript abundance) of insect defense mechanism were less influenced when older age (F1 progeny) were irradiated. These findings will help to optimize the gamma dose to be employed in inherited sterility technique for (pre-harvest) pest suppression and (post-harvest) phytosanitation and quarantine, and suggest compatible integration of biorational tactics including nuclear technology.
Fusarium wilt caused by Fusarium oxysporum, Schlecht. emend. Snyd. & Hans. f. sp. ciceri is prevalent in most chickpea-growing countries and is a major devastating disease. Host plant resistance is the most practical method of disease management. Indigenous chickpea germplasm reveals a heterogeneous genetic make-up and the response of resistance to wilt is an unexplored potential source for disease resistance. There are 70 indigenous germplasm lines selected on the basis of their agronomic performance and diverse areas of collections in the country. Of these, four accessions had a highly resistant score of 1 and six had a score of 3 using a 1–9 rating scale, indicating their level of resistance to Fusarium wilt (race 4). Other germplasm accessions of chickpea were found to be moderately resistant to highly susceptible disease reaction. Likewise, the same set of germplasm was also screened for Meloidogyne incognita (race 1) using pot culture under controlled condition. Only one accession was found to be resistant to this pest. These resistant gene sources can be utilised effectively for race-specific chickpea wilt and root-knot resistance breeding programmes.
Poultry researchers and nutritionists are looking for viable alternative feed additives since conventional supplements have been criticised for their potential negative impact on the food chain. Among the currently available poultry feed additives, natural herbs and plants have been widely advocated due to their reported widespread beneficial effects. Garlic (Allium sativum) is one such potential feed supplement which has recently been reported as having a wide range of beneficial effects on the production performance and physiological biochemistry of broilers and laying hens. Notable beneficial effects have been seen on growth, feed efficiency, egg production and quality, as well as stimulation of immune system and lowering blood cholesterol levels in poultry birds. The results reported vary from author to author probably due to variations in the dose of the product fed, the duration of feeding and processing techniques employed.
Two reviews are available in published literature relating to the effects of ascorbic acid on poultry performance. The first review was written by Pardue and Thaxton in 1986 who reviewed the role of ascorbic acid in alleviating the negative effect of heat stress in poultry birds. The second review was presented by Whitehead and Keller in 2003, who detailed the general effects of ascorbic acid in poultry birds, not taking into consideration ‘heat stress’. The first review is deficient in the literature published after 1986, while the second review does not describe the effect of ascorbic acid in heat stressed birds. The present review describes the past and present knowledge of ascorbic acid in alleviating heat stress in poultry birds with new aspects. Heat stress is associated with compromised performance and productivity through a decline in feed intake, nutrient utilisation, growth rate, egg production and quality, feed efficiency and immunity. Heat stress is also characterised by a reduced antioxidant status in birds, resulting in increased oxidative stress. Moreover, male fertility is decreased when birds are exposed to heat stress. Supplementation of 250 mg of ascorbic acid per kg of feed has been found to be optimum to improve feed intake, body weight gain, feed efficiency, egg production and quality, nutrient digestibility, immune response and antioxidant status in poultry birds. This work compiles past and present information about the role of ascorbic acid in heat-stressed poultry.
In the last decade, there has been growing interest in the use of natural herbs and medicinal plants as feed additives in poultry diets to maximise their potential output. Ginger is one such potential rhizome with a wide range of medicinal effects. In broilers and layers, this plant has been used in different forms, doses and durations. In this review, documented effects of ginger in poultry feed on feed intake and feed conversion ratio, growth and weight gain, carcass yield, egg production and quality, antioxidants and blood biochemistry, with their possible mechanisms of action, are discussed.
There is growing interest in developing natural alternatives to antibiotic growth promoters in order to maintain both birds’ performance and health. In the last decade, Turmeric has been extensively used in poultry diets. Turmeric is a natural herb of the ginger family, Zingiberaceae. Wide range medicinal properties of this plant have been advocated. In poultry feed, Turmeric has been extensively used in different concentrations, dosages and durations. In this review, the beneficial effects of this plant on growth, weight gain, feed conversion ratio, ameliorative effect on liver health, immunomodulatory and antioxidative effects are reviewed.
Modern commercial broilers appear to have compromised immunocompetence, higher mortality and lower resistance to stressors. To overcome these, dietary manipulation seems to be the easiest approach, and this has been supported by research investigations conducted over the last few decades. The goal of enhancing the immune system of broilers is laudable for both economic and welfare reasons. Vitamin E (VE) is now well accepted as nature's most effective lipid-soluble, chain-breaking antioxidant. This antioxidant vitamin has been shown to improve both cell-mediated and humoral immunity in broiler chicks. However, the effect of this vitamin depends upon dose, age and genetics of the broiler chicks. Several mechanisms have been postulated for the beneficial effects of this vitamin. In this review, several aspects of the immunomodulatory effects of VE are reviewed.
Recent studies have suggested that avian semen contains a high proportion of polyunsaturated fatty acids (PUFAs) which are characterised by an increased susceptibility to lipid peroxidation. Free radicals are produced as a consequence of lipid peroxidation and these can impact on the fertility of male birds. The seminal plasma has been equipped with a defence mechanism called antioxidant capacity which protects semen integrity against the negative impact of ROS (reactive oxygen species). From the available literature, it can be surmised that lipid peroxidation is one of the major causes of low fertility in male birds which can be remedied with supplementation of exogenous vitamin E. Vitamin E provides biological stability to spermatozoal plasma membranes by inhibiting the generation of reactive oxygen species (ROS). Recent studies have suggested a role of vitamin E in improving semen quality and subsequent better fertility. In this review the current knowledge of physiology of ROS and antioxidative role of vitamin E to treat avian male fertility is discussed.
We determined the prevalence of microsporidia Enterocytozoon (Ent.) bieneusi and Encephalitozoon (E.) intestinalis infection in patients with chronic diarrhoea and hepatocellular carcinoma (HCC). A total of 330 stool samples were examined from 171 (52%) patients with chronic diarrhoea, 18 (5%) with HCC while 141 (43%) were controls. Stool microscopy, polymerase chain reaction (PCR) with species-specific primers for Ent. bieneusi and E. intestinalis and sequencing were carried out. Microsporidia were found by trichrome staining in 11/330 (3%) and E. intestinalis by PCR in 13/330 (4%) while Ent. bieneusi was not detected. PCR for E. intestinalis was positive in 8/171 (5%) stool samples from patients with chronic diarrhoea, 2/141 (1·4%) samples from healthy controls and in 3/18 (17%) samples from patients with HCC. In the chronic diarrhoea group, E. intestinalis was positive in 4/171 (2·3%) (P=0·69) stool samples compared to 2/18 (11%) (P=0·06) in the HCC group and 2/141 (1·4%) from healthy controls. E. intestinalis infection was significantly associated with chronic diarrhoea and HCC in these patients who were negative for HIV. Stool examination with trichrome or species-specific PCR for microsporidia may help establish the cause of chronic diarrhoea.
Moulting is a complex process, induced by diet manipulation, which results in renewal of reproductive system and subsequent better production. Conventionally, moulting has been practised by utilising feed withdrawal in many developing countries, however, this has been associated with many drawbacks. Alternative types of moulting practices have been studied, however, these are not practised widely due to a range of undesirable effects. As a consequence of the beneficial effects on laying hens, better post-moult performance and a less criticised method according to poultry welfare advocates, Zn-induced moulting has been considered superior to forced-moulting. Different aspects of Zn-induced moulting related to physiology and production, with special reference to immunohistochemistry of pituitary gland as affected by Zn-induce moulting are included in this review.
Heat stress is associated with compromised performance and productivity in poultry due to declines in feed intake, nutrient utilisation, growth rate, egg production and quality, feed efficiency and immunity. Additionally, heat stress is characterised by reduced antioxidant status in birds, resulting in increased oxidative stress. Heat stress is also linked with increased economic losses due to mortality of birds. Vitamin E is a major chain-breaking antioxidant in biological systems. An optimum response with supplementation of vitamin E in feed has been found to improve feed intake, body weight gain, feed efficiency, egg production and quality, nutrient digestibility, immune response and antioxidant status in poultry birds. This work compiles past and present information about the role of vitamin E in heat-stressed poultry.
We analysed the data from the control group in a typhoid vaccine trial in Karachi to assess the differences in individual-, household- and cluster-level characteristics for developing typhoid fever. The annual incidence of typhoid in children aged 2–16 years in the control arm of the vaccine trial was 151/100 000 population. After adjustment, the risk of typhoid was lower with increasing age [risk ratio (RR) 0·89, 95% confidence interval (CI) 0·83–0·95], was higher with an increase in population density (RR 1·13, 95% CI 1·05–1·21) and was lower in the households using a safe drinking-water source (RR 0·63, 95% CI 0·41–0·99). Typhoid fever affects younger children living in areas of high population density and lack of access to safe water in Pakistan. A combination of environmental and biological interventions is required to prevent the continued epidemiological and economic impact of typhoid fever in high-risk areas of Pakistan.
We determined the prevalence of Entamoeba (E.) histolytica, E. dispar and E. moshkovskii in patients with chronic diarrhoea associated with abdominal pain or discomfort mimicking irritable bowel syndrome. Stool samples were collected from 161 patients with chronic diarrhoea and from 157 healthy controls. Stool microscopy with modified trichrome stain, culture and polymerase chain reaction (PCR) for Entamoeba spp. differentiation was performed. Microscopy demonstrated Entamoeba cysts in 44% (57/129) of patients with diarrhoea compared to 29% (44/151) of controls (P=0·009). In patients with diarrhoea, PCR for E. histolytica was positive in 9% (11/129) (P=0·008), E. dispar in 19% (24/129) (P=0·117) and E. moshkovskii in 19% (24/129) (P<0·001). E. histolytica and E. moshkovskii were significantly associated with diarrhoea while E. dispar was found equally in both groups.
This paper provides an estimation of the point prevalence of fascioliasis and its economic impact in terms of increased milk yield after chemotherapy of a bovine population from the district of Toba Tek Singh, Punjab, Pakistan. A total of 2400 cattle and buffaloes were examined quantitatively using the McMaster egg-counting technique. Infected cattle and buffaloes (50 of each) were randomly selected and each divided into two groups of 25 animals. Groups A (buffaloes) and C (cattle) were treated with oxyclozanide (orally, 16.6 mg kg− 1 body weight). Groups B and D served as negative controls for buffaloes and cattle, respectively. Pre- and post-treatment milk yield was recorded to determine if there were any changes in milk yield after treatment. Of 2400 faecal samples analysed, 654 (27.25%) were positive for Fasciola spp. with a mean number of eggs per gram (EPG) of 503.2. The point prevalence and worm burden of fascioliasis was significantly higher (OR = 2.13; P < 0.05) in buffaloes (34.58%; 415/1200; mean EPG maximum likelihood = 521.4) as compared to that of cattle (19.92%; 239/1200; mean EPG maximum likelihood = 415.8). Among the parasite species, F. gigantica (19.88%; 477/2400) was predominant (OR = 3.12; P < 0.05) as compared to F. hepatica (7.38%; 177/2400). An average daily increase of 0.67 and 0.87 litres of milk, with 0.41% and 0.37% more fat per animal, was observed in oxyclozanide-treated buffaloes and cattle, respectively. The economic value of reduced production of infected animals was estimated as US$0.33 and 0.32 per animal per day for cattle and buffaloes, respectively.
An infrared heat reflecting multilayer thin film filter comprising alternate layers of ZrO2 and SiO2 has been modeled and prepared on a BK7 glass substrate using RF-magnetron sputtering. Initially, the individual films of the used materials have been characterized by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) for structural and surface quality prior to the deposition of multilayer structure. Spectral analysis showed that the filter has an average transmission of greater than 90% in 450 to 700 nm range and less than 2% in 700-1100 nm band fulfilling the design requirements. The XRD study of multilayer structure showed few peaks of ZrO2 along with a solitary peak for SiO2 indicating some crystallinity for ZrO2 layers in the structure. Hardness analysis showed that the initial phase of the indentation is predominantly ductile with gradual transition in behaviour from ductile to brittle with increased penetration. Interface analysis of multilayered structure was carried out by Rutherford back scattering using Tandem 5 MeV ion accelerator, showed that interfaces formed in the multilayer structure are sharp and no substantial evidence of interlayer diffusion or mixing at the interfaces.
This paper attempts to review changes in the lives of hearing-impaired patients within the developing world, brought about by globalisation and development. The paper also explores limitations to improved care and addresses the collective moral responsibility of developed nations.
Analysis of literature.
Within developing nations, large populations have emerged with a similar pattern of problems, access to information and aspirations as those living in developed nations. However, marked differences in income have persisted. These trends have resulted in a relative increase in the proportion of the hearing-impaired population in need of cochlear implantation, while at the same time restricting their access to such treatment.
The emergence of global markets and media and a shared sense of destiny amongst the people of this planet should translate into a concerted, worldwide effort to assist the deaf in developing countries. Much more can be done within existing resources and frameworks to improve the quality of these peoples' lives.