Wheat product effective against mycoplasma

A group of researchers in Hungary has tested the efficacy of fermented wheat germ extract (FWGE) in chickens challenged with mycoplasma gallisepticum (MG). They found that fermented wheat germ extract was as effective against MG as the well known anti mycoplasma drug, tiamulin. Fermented wheat germ extract is a standardised extract of wheat fermented by the yeast, Saccharomyces cerevisiae (Immunovet-HBM, Biomedicin Co. Ltd, Hungary).

The study used 90 three week old chickens (initially free of MG and M. synoviae) and exposed them to aerosol infection of MG. For 9 days, one group (30 birds) received a diet containing fermented wheat germ extract (3.0g/kg feed), a second group with tiamulin (200mg active ingredient/kg feed), and a third group was untreated. The fourth group was exposed to PBS aerosol as a negative control. On day 9, all chickens were slaughtered and examined for the presence of gross and histological lesions, the presence of the challenge strain in the organs and specific antibodies in the serum.

In the groups treated with fermented wheat germ extract and with tiamulin, the chickens remained clinically healthy and there were no significant differences between the two treatments in term of bodyweight gain or feed conversion. The number of birds with gross lesions (15 and 11, respectively) and lesion scores (25 and 25, respectively) of the fermented wheat germ extract and tiamulin treated groups were significantly lower than in the infected untreated group (25 birds, lesion score of 190). No mycoplasma was reisolated from other organs in the fermented wheat germ extract treated birds, and the number of mycoplasma isolations from the respiratory tract samples was less frequent (10) than from the infected untreated group (64), in which 35 samples from other internal organs were also positive. Twenty percent of the birds treated with fermented wheat germ extract showed serological response with a 5% reaction score, whereas in the infected, untreated group, 83% of birds were reactors, with a 63% reaction score.

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Test on a new anti-aflatoxin agent

Silymarin, the standardised extract of Silybum marianum, is used as a liver protector in man, and is a potent anti-hepatotoxic agent. This study, carried out by a group of Italian scientist, focused on assessing the effect of a silymarin-phospholipid complex (silymarin phytosome; Sil) on the toxic effect of aflatoxin B1 in a small group of broiler chickens.

Over the whole growth cycle, bodyweight gain and feed intake were lower in aflatoxin-treated birds than the controls (P<0.05). However, bodyweight gain an feed intake were higher in the aflatoxin+Sil group than the positive control receiving aflatoxin alone (P<0.05), and not different from the control birds. No treatment differences were noted on liver weight.

The researchers concluded that Sil can provide protection against the negative effects of aflatoxin B1 on the performance of broiler chicks.

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Poultry campylobacter source found in lungs

The source of campylobacter on poultry farms and in processing plants is probably the birds lungs, according to the latest research.

The bacteria can contaminate live chickens during production or transport, or catcasses during scalding. In either case, campylobacter moves to contaminate respiratory air sacs and could then contaminate the abdominal cavity.

Microbiologist studied campylobacter before and after chicken carcasses were scalded to remove the feathers, an intergal step in poultry processing.

In a commercial processing plant, researchers collected ten carcasses on each of three days, before and after scalding. They rinsed the whole carcasses and respiratory tracts and took samples for campylobacter, E. coli and other bacteria.

The resulst showed the same type of campylobacter were in the carcass and respiratory tract samples. The number and type of campylobacter in the respiratory tracts remained the same before and after scalding.

This suggests the respiratory tract is an important source of campylobacter contamination in the interior of the carcass before sculding. The airborne bacteria could be inhaled by the live birds during production or transport, meaning significant levels of the bacteria were already in their respiratory tracts before processing.

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Understanding campylobacter in turkeys

Scientist in ARS’s are helping to make meals worry-free for people who enjoy turkey. The unit part continues to break new ground in protecting consumers against harmful food-borne bacteria like campylobacter.

A breaktrough is on the horizon, through research by molecular microbiologist using competitive exclusion.

Competitive exclusion is a benficial intestinal bacterium’s protective effect that limits colonisation by some bacterial pathogens. This method has been applied toward protecting chickens from colonisation by salmonella. Now were focused on excluding campylobacter from turkeys.

The team is using a DNA fingerprint method called ARISA (automatic ribosomal intergenic spacer analysis) to detect changes in intestinal microbial communities.

This team’s methods are part of an overall strategy to asses intestinal microbial flora dynamics troughout turkey production. They are using an emerging technology known as molecular mircobial ecology, which involves identifying and tracking microbess associated with gut colonisation by food-borne pathogens.

rall strategy to asses intestinal microbial flora dynamics troughout turkey production. They are using an emerging technology known as molecular mircobial ecology, which involves identifying and tracking microbess associated with gut colonisation by food-borne pathogens.

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In-shell vaccine for chick disease

Scientist in the UK are developing a new way to vaccinate chicks against infectious bronchitis virus (IBV) while they are still in their egg.

A pre-hatching prototype vaccine virus which provides immunity to IBV has been developed by scientist at the Institute for Animal Health and vaccine company, intervet UK. It can be delivered to chicks still in the egg (in-ovo) using robotic ‘vaccinator’.

The researchers, funded by the Biotechnology and Biological Science Research Council, Department of the Environment, Food and Rural Affairs and Intervet UK, used a reverse genetic system to produce new vaccine strains. Existing strains, which are usually delivered by less efficient spray or drinking water dosage, van prevent chicks hatching if delivered in the egg.

The scientist have extracted a so-called ‘spike protein’ from a pathogenic virus strain which triggers an immune response, and incorporates it into a harmless non-pathogenic strain. This hybrid virus was able to induce immunity when inoculated before hatching. When hatched chicks were exposed to the virulent M41 strain, we observed protection rates of up to 100%. We currently trying to modify the vaccine further, in collaboration with intervet, to make it suitable for commercial use.

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Cool water washing slows egg pathogens

Using cold water instead of warm during a second wash of eggs can help cooling, which reduces the risk of pathogen growth both inside and outside the shell.

Researchers with the US Department of Agriculture together with those from Auburn University studied the frequency of salmonella, campylobacter, listeria and other pathogens in eggs commercially washed in cool water. Their findings were reported .

The researchers tested three water temperature schemes in dual washing commercial systems:

• -          The first used water at 120^oF (48.9^oC) for both washes or the eggs
• -          The second used water at 120^oF (48.9^oC) for the first wash and 75^oF (23.9^oC) for the second
• -          The third used water at 75^oF (23.9^oC) for both washes.

Using warm water for the first wash and cooler water in second wash was most effective in terms of reducing egg temperature and microbial levels. While salmonella, campylobacter and listeria were all detected in shell emulsion and wash-water samples from the cool-water washing treatments, none was detected in the eggs contents throughout the storage period of 8 weeks.

Current USDA quality standards require processors to use wash water of at least 90^oF (32.2^oC)

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Test to distinguish between battery and free range eggs without visiting the farm

Scientists have developed a method of determining whether eggs labelled as ‘free range’ or ‘barn’ have, in fact, been laid under battery conditions. The procedure, published in Journal of the science of food and agriculture, means eggs can be tested without the need to visit farms.

The give-away is the dust that the eggs pick up from the surface on which they are laid. Because the eggs are wet when freshly laid, the dust attaches to the shell surfaces. The pattern this creates varies accoring to whether the eggs where laid on cage floors, barn nest boxes or outside. These distinctive patterns can easily be distiguished under ultraviolet light because the dust fluorestes.

The authors found that the prevalence of white double parallel lines with 2.0-2.5 cm spacing was a distinguishing feature for eggs laid on wire floors in cages. They concluded that if five or more eggs in a sample of 90 eggs have double fluorescent lines, there is a greater than 999 in 1000 probability that the batch contains some cage-laid eggs.

The method is effective in distinguishing between free range eggs and those laid on a wire floor cage. It does not damage the eggs and can be applied at any stage in the egg marketing chain.

Washing egg can remove or obscure the double lines, so the authors recommend that in countries where egg washing is common, it is best to perform the test before wasing. Distinguishing features in eggshell fluorescence can be used to identify when eggs have been washed, and they can also be used in preliminary screening tests for sun exposure, which in some countries is a cause of runniness of the egg white.

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Enriching chicken with vitamin E

A group of sicentist working in Barcelona, Spain, have found that the vitamin E level in chicken meta can boosted by feeding higher levels of a-tocopheryl acetate to the birds. Furthermore, the content was maintained, even after 7 months of storage at minus 20^oC. The meat could supply about 25% of the recommended dietary allowance.

A factorial design was used for the experiment: three different dietary fat sources (beef tallow, fresh and oxidised sunflower oils and linseed oil), a-tocopheryl acetate (0 or 225mg/kg feed), and ascorbic acid (0 or 110mg/kg/feed).

Raw meat fatty acid composition was affected by dietary fat sources and tocopheryl acetate supplementation. After cooking, it was only affected by dietary fat source. Birds fed linseed oil yielded meat rich in n-3 fatty acids, especially linolenic acid, and the meat would provide about 20% of the recommennded intake for this fatty acid. Birds fed fresh or oxidised sunflower oil produced meat rich in n-6 fatty acids, while those fed beed tallow had meat rich in saturated and monounsaturated fatty acids.

The a-tocopherol content of raw and cooked dark chicken meat was only affected by tocopherol supplement.

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Why is the avian flu virus so dangerous for humans

Scientist have established a theory why the H5N1 strain of avian influenza (AI) virus is so dangerous for himans. The disease so far has been fatal in more than half of the people who have contracted it since 2003.

The explanation lies in the patient’s viral load and the subsequent inflammatory response, say researcher from the Oxford University Clinical Research Unit in an article published in Nature Medicine.

Dr Menno de Jong and colleagues assessed 27 people at the Hospital for Tropical Diseases in Ho Chi Minh City, Vietnam. Eighteen of the patients were infected with H5N1; the other nine had contracted common human influenza viruses.

The investigators learned that those who had H5N1 were carrying substantially higher viral concentrations in their blood and throat than their counterparts who had sub-types of human flu. The H5N1 infected patients who died had much higher viral load than those who survived. The team concluded that the higher the level H5N1, the greater the likehood of death. The severity of lung damage and the increased risk of dying probably were associated with high levels of cytokines, low levels of lymphocytes and the resulting intense inflammatory response in H5N1 patients, the scientists suggested.

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Egg turning angle and prequency impact on embryo position

In a co-operative project between the universities of Ankara, Turkey and North Carolina State, USA, it was concluded that the incidence of malpositioned embryos was increased by a reduced turning angle. However, the effects was ameliorated by increasing the frequency of turning. The work was reported by Drs Elibol and Brake.

Two experiments, each comprising two trials, were carried out to determine if a turning angle of less than 45^o from vertical could be succesful in terms of the number pf malpositioned embryos, i.e. with the head at the narrow end of the egg.

Hatcing egg from commercial broiler breeders flocks aged 55-61 weeks were turned at angles of 35^o, 40^o, or 45^o degrees every hour for 18 days in experiment 1. Turning angle had no effect on fertile hatchability but the incidence of mapositioned embryos was higher in the eggs turned at 35^o degrees than with the other treatments.

In experiment 2, egg were subjected to turning angles of 35^o and a turning frequency of every 60 or 15 minutes, or 45^o every 60 minutes. This time, turning angle and frequency had no effect on fertile hatchability or embryonic mortality. However, the incidence of malpositioned embryos was higher in the group turned with a 35^o angle hourly than with the other treatments.

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Foot pad dermatitis could be eliminated trough breeding

Interesting work by a group of Danish researchers hints that it may in future be possible to select against the susceptibility of broiler to foot pad dermatitis (FPD) without adversely affecting performance.

Scientist at the Danish Institute of Agricultural Science in Tjele found that, at 0.31, the heritability for susceptibility to foot pad dermatitis pad lesions was quite high compared to the heritability for body weight. The hertability of hock burn (HB) susceptibility, however, was only 0.08 and so a solution to this condition trhough selection is unlikely.

A total of more than 2000 birds from 2 strains (fast-growing and slow-growing) were allocated to groups in two time-separated replicates. The development of foot pad dermatitis and hock burn were recorded weekly from day 8 to slaughter on a sample of the live animals. The feet and hocks of all birds were investigated at slaughter (4 or 6 weeks form the fast-growing strain and 8 or 10 weeks for the slow-growing strain).

No foot pad dermatitis lesions and very few low-grade hock burn were found in slow-growing birds. In the fast-growing strain, the first signs oh both lesions were seen in week 2, and the incidence of both type of lesions increased therafter. Bodyweight did not affect foot pad dermatitis but more hock burn was found at higher bodyweight.

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Salmonella infection affected by moulting

Using a tissue culture procedure, scientist at the USDA in Athens, Georgia, USA, have concluded that moulting may affect the invasion of tissues by Salmonella enteris (SE) in laying hens.

They conducted three identical trials in which 80-week-old, active laying hens were divided into two groups of 6 birds each. The moulted group was subjected to a 14-day period of feed withdrawal, and the fully-fed group was offered a standard layer ration. After feed treatment, the crop, ileum, caecum and ovary were collected and subjected to a series of treatment to prepare them for incubation with salmonella enteritis. This was followed by the removal ob bacteria that had not penetrated the tissues, and the counting of salmonella enteritis that remained in the tissues.

Salmonella enteritis invasion of the ovaries was reduced in tissues from moulted hens in trials 1 and 2 compared with full-fed control (>1.2 log reduction) but not in trial 3. Salmonella invasion oh the caeca of moulted hens was numerically increased in trials 1 and 2 and significantly increased in trial 3 compared to the controls (>0.8 log increase). No significant differences in salmonella enteritis invasion were detected for crops and ileum.

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