Wednesday, December 21, 2011

Ascites (Water Belly) in Broiler Chickens during Winter Season

Ascites (or water belly) is a condition of fast growing broiler chickens in which the excess amount of ascitic fluid accumulated in the abdominal cavity. It has become major concern to the poultry industry around the world. This condition is extremely common in high altitude & more particularly during winter / cooler season.

Ascites is associated with inadequate supply of oxygen, poor ventilation and respiratory disease complex aetiology. Morbidity is usually 1-5%, mortality 1-2% but can be up-to 30% at high altitude.

During winter season broilers are fed high energy diets to meet their nutritional demands. Since fast growing broilers have high basal metabolic rate (BMR), to metabolize high energy diet, their body needs of oxygen multipliers. There is high demand of blood through heart & lungs for proper body function due to high BMR & high energy diet.

This physiological demand increase pulmonary arterial pressure (hypertension). Bird lungs have very little ability to expand and the blood capillaries in the lungs are not able to handle increased blood flow or blood pressure. The result is an increased pressure in the liver with leakage of blood fluids, without the red blood cells, into the body cavity forming ascites or water belly.

Following may be the cause of ascites (water belly):

Today´s broilers grow much faster, eating less feed. The growth of the heart and lungs has not increased in size proportional to the increase in body weight and breast meat yield. The rapid growth of the bird means more oxygen demand, requiring more work out of the heart and lungs.
Anything that limits oxygen uptake from the lungs is going to cause the heart to work harder. Diseases of the lungs and poor ventilation may be involved. Major cause of Oxygen deficiency :
a) Presence of ammonia in the poultry house. Birds are unable to get adequate oxygen as they inhale air full of ammonia so blood is deprived of oxygen supply.

b) The dust particle in the air of poultry shed are inhaled by the birds and while exhaling they settle in various part of air sacs, specially thoracic air sac where air stays for longer period which leads difficulty for birds to breath hence deficiency of oxygen in the blood.

c) Presence of high carbon dioxide level in the shed either due to overcrowding, poor ventilation, blocking fresh & cold air during winter with curtains or due to lack of proper exhaust fans results deficiency of oxygen in the blood of bird.

Excess levels of sodium in the water or salt in feed leads to increased blood pressure in the lungs. Many feed millers still use fish meal high levels of sodium. Levels of sodium over 400 ppm could cause problems in broilers.
High altitudes have long been known to cause heart failure and ascites.
Chilling is a common cause in small flocks. It causes an increased blood flow through the lungs.
Signs of ascites:

High rate of panting is often observed in ascitic birds even the absence of apparent heat stress.
Gurgling sound often accompany as they often just sit with panting.
Birds which are ascitic may show sign of Cyanosis (a blue discolouration of skin) especially around comb & wattles.
Ascitic birds tire out easy and often die on their bellies.
Most death begins at about 3 weeks of age.
If their belly is opened, a cup or more of fluid or jellied material will pour out.
Lungs of ascitic bird may often appear pale or greyish. Lungs are extremely congested & oedematous.
Liver enlargement is often seen.
Thickening of right side myocardium & dilation of the ventricle are very common.
Microscopic finding - increased cartilage nodules in lung.
Sometimes birds die from the effects of too much blood and fluid in their lungs before there is any significant amount of fluid in the body cavity.
Identification:

To differentiate from broiler "Sudden Death Syndrome" and "Bacterial Endocarditis", a cardiac specimen (Troponon T) can be measured in blood.

How to minimize ascites (water belly)?

Keep air quality fresh by moving air regularly and efficiently. In the colder months, it is better to add heat and keep the air moving than to shut down vents or reduce airflow in an effort to conserve heat.
Treat litter by "Liiteron" to reduce ammonia production. Litter treatment is important to reduce incidence of water belly.
Restricting feed, feeding a mash diet, or using a less energy and protein diet.
Checking sodium level of water, if sodium level is high then consider using an alternate source of water that is better quality for the first 3 - 4 weeks.
Replace fish meals with other readymade source like amino acid arginine, if it is being used as Sodium level more than 400 ppm could be problem for broiler.
Careful attention to brooding temperature is also critical for minimizing water belly.
Prevent respiratory disease conditions.
Select breeds which are not genetically susceptible to this condition.
The objective should be to minimize progression leading from pulmonary hypertension to terminal ascitis or water belly condition for availing better profit during winter season. Best Management Practice is only answer to reduce problem of Ascites (Water belly) and insure better ROI.

Author : Ganesh Kumar Dahal (Guybro)

Sunday, September 4, 2011

Poultry Production Without Antimicrobials

A healthy intestine is vital for good health and production in poultry, according to Dr Richard Bailey, poultry health scientist with Aviagen.
Speaking on the importance of the intestinal microbiota for chicken health at the joint session of the British Society of Animal Production and the UK Branch of the World's Poultry Science Association earlier this year, Dr Bailey said that one of the key aims of producing animals for the food chain is to obtain good growth rates and performance through feed conversion efficiency while maintaining optimal animal health. To achieve this, a healthy gut is essential, he said.
Optimal intestinal health is heavily reliant upon the acquisition and maintenance of a balanced intestinal microbiota, which has become one of the key topics in the European poultry industry.Microorganisms reside in all known habitats, therefore, animals have had to evolve in a world full of bacteria, viruses, fungi and protozoa. Part of the evolutionary process has resulted in symbiotic relationships between an animal and its microbial residents.
The intestinal microbiota of an animal is a complex population of microbes dominated by a large bacterial community. The composition of this community is highly dynamic with spatial shifts in population along each region of the intestinal tract in relation to the change in conditions of each section.With total bacterial cells numbers outnumbering the host's own cell number by a ratio of 10 to one, it is not surprising that the intestinal microbiota plays a vital part in the health and well-being of all animals, Dr Bailey said.
Many mechanisms have been identified by which the microbiota promotes host health. It has been found that the intestinal microbiota aids digestion, protects against pathogens, produces nutrients and plays a role in the development and maturation of the immune system.With the advent of culture-independent DNA technologies, our knowledge of the composition of the intestinal microbiota has improved greatly, explained Dr Bailey. Using these techniques, it has been suggested that the intestinal microbiota of the chicken comprises around 640 species of bacteria from 150 different genera. The increased application of molecular methods has revealed that culture-based methods had vastly underestimated the complex community of bacteria within an animal's microbiota.
It has been demonstrated that the composition of the intestinal microbiota is affected by factors such as sex, age, dietary intake and health status of the host. The exact relationship between the host and its resident microbiota is still an active area of research and it is becoming ever more apparent that the intestinal microbiota is highly influential in terms of host health and immunity. Culture-independent techniques combined with '-omics' technologies have allowed microbiologists to learn more about the relationship between the host and its resident microbiota.
There is a delicate balance between the host, intestinal microbiota, the intestinal environment and diet, continued Dr Bailey. If there is an imbalance in the relationship, the composition of the intestinal microbiota may alter. The shift in microbial populations can have a negative effect on the host, leading to poor growth and impaired performance. This is seen in cases of dysbacteriosis.
Dysbacteriosis is a digestive condition of poultry and has been broadly described as an overgrowth of the intestinal microbiota – especially members of the Bacteriodetes, Clostridium spp. and E. coli – which can lead to non-specific enteritis. Onset is usually between 20 and 30 days of age and it is thought to be triggered by changes in diet, poor management and overcrowding. The condition rarely causes clinical signs but it can adversely affect bird performance.
Typically, dysbacteriosis is treated using antimicrobial therapy. However, with increasing pressure on veterinarians and poultry producers in many countries to reduce antibiotic use, there is a need to find alternatives to promote good intestinal health and prevent intestinal upsets.The management of intestinal health without antimicrobials is a wide area of research. The use of a probiotic supplement is a popular approach, said Dr Bailey. Probiotics have been found to boost enteric health by inhibiting the growth and/or attachment of less favourable bacteria in the intestinal tract or by modulating the composition of the intestinal microbiota towards a more favourable community.
Intestinal bacteria derive most of their energy from the host's diet so poultry feed composition has a major influence on bacterial populations and it is possible to modulate the microbiota by altering the diet and including specific components, such as essential oils, oligosaccharides (in the form of prebiotics), enzymes and specific carbohydrate sources.
Deciding on the best approach is not easy as results from intervention studies can vary. The key to the maintenance of intestinal health is to understand how the intestinal microbiota changes at key points in the bird's life and how to prepare the bird for these changes.
The combination of practical field experience from poultry producers and veterinarians with laboratory research into the relationships between the host and its microbiota is likely to reveal further ways by which enteric health can be improved in future.
Summing up, Dr Bailey said that intestinal health is vital for good overall health and performance in poultry, as in other animals. Disruption of the resident bacteria can have detrimental effects, leading to digestive upsets and a loss in performance. However, he said, there is a mounting body of evidence indicating that the intestinal microbiota can be successfully modulated by the use of probiotics, when the appropriate product is administered correctly and at the appropriate time.
Research into alternatives to antimicrobials remains an important area of study. A number of research groups from across the globe have demonstrated in laboratory trials that there is a place for products such as probiotics in helping to control gut pathogens, thus reducing the need for antimicrobials. They also have potential to help establish a healthy gut microbial population early in the chick's life and potentially prevent intestinal imbalances as the result of common stressful events, such as feed change, vaccination or thinning, added Dr Bailey.
Source :www.thepoultrysite.com/articles/2144/poultry-production-without-antimicrobial

Thursday, September 1, 2011

AI study: “Culling more effective than vaccinating”

In economic and epidemiological terms, the practice of culling on farms within a radius of 1 to 3 km of infected farms is the best method of combating Highly Pathogenic Avian Influenza (HPAI) according to a recent study.
Vaccinating chickens within a radius of 3 km of an infected farm may at first appear to be cheaper, but it is less effective because the epidemic spreads further and lasts longer. This was one of the findings of a study performed by LEI together with the Central Veterinary Institute (CVI), both part of Wageningen UR, the Netherlands.
Matters researched included the consequences of preventative culling and of vaccination programmes within a radius of 1, 3 and 10 km of a farm infected with Highly Pathogenic Avian Influenza, also known as bird flu. The results of this research are described in the report ‘Control of Highly Pathogenic Avian Influenza’. This report demonstrates that an epidemic is shorter in duration when preventative culling takes place, but that this results in culling taking place on more farms than in the case of vaccinations. Emergency vaccinations are less effective in shortening the duration of the epidemic, although they do reduce the number of infected farms. The EU strategy of only implementing culling on infected farms is not effective enough in helping to control an outbreak in a densely-populated poultry-rearing area.
In the report, the researchers describe the various strategies available to the government in the event of an outbreak of HPAI. The report was commissioned by the Ministry of Economic Affairs, Agriculture & Innovation to provide a basis for decisions made in the event of a new HPAI epidemic. In this regard, account must be taken of the fact that large-scale preventative culling is increasingly less acceptable to society, according to the researchers. Society tends to call for alternative control measures such as vaccination.
Source :http://www.worldpoultry.net/news/ai-study-“culling-more-effective-than-vaccinating”-9292.htm

Thursday, June 23, 2011

Poultry Disease Prevention Checklist

Poultry Disease Prevention Checklist

A useful checklist for poultry producers to rate their disease prevention practices and preparedness from Dr Casey W. Ritz of the Department of Poultry Science at the University of Georgia.

Disease prevention is much less stressful and costly than disease control and recovery. Biosecurity measures are a critical component of disease prevention. Use this list to rate your disease prevention practices and preparedness. Check the box for all questions to which you can answer ‘yes’. A score of 80 or better is outstanding, 70 to 79 excellent, 60 to 69 good, 50 to 59 just fair, and 49 or less indicates a definite need for improvement.

A. Score 5 points for each ‘yes’ answer.

My farm is isolated from other poultry facilities.
My poultry houses are set back at least 200 feet from public roads.
Access deterrents are in place such as warning signs at entrances, perimeter fencing or gated driveways.
My buildings are secured with locks.
My employees do not own poultry.
No other avian species are kept on my property.
I have a pest management programme to control mice, rats and other pests.
B. Score 4 points for each ‘yes’ answer.

My birds are observed every day for abnormal symptoms and overall flock health.
I routinely analyse my poultry production, feed consumption, and mortality records for signs of problems.
Dead birds are picked up daily from the houses for appropriate disposal.
My farm has secure dead bird disposal, with no access to birds or animals.
Vehicles or people cannot enter my farm or poultry houses without my permission or knowledge.
Visitors must park vehicles in a designated area and sign a logbook.
Score 3 points for each ‘yes’ answer.

My poultry housing is animal- and wild bird-proof.
All tools and equipment are cleaned and disinfected before coming on my farm.
Production houses are thoroughly cleaned and disinfected between flocks.
Production house entryways are routinely cleaned and disinfected.
Disinfectant footbaths are at each entryway of every facility and are routinely cleaned and recharged.
Debris and vegetation are cleaned up and kept clear of the production facilities.
Feed spills are cleaned up quickly when they occur.
For necessary visitors, I provide clean coveralls and boots.
My employees do not travel to other poultry premises not under my control.
Score 2 points for each ‘yes’ answer.

All utility and service vehicles entering my farm are properly sanitised before entry and the drivers do not enter the poultry houses.
Farm employees work only in assigned areas; they do not go to other areas of the farm.
Dead birds are not carried from house to house.
Poultry waste from other farms is never spread on the fields adjacent to my farm.
I have instructed my employees and service personnel about poultry disease and on-farm prevention measures.
Score 1 point for each ‘yes’ answer.

Household pets are kept away from the poultry buildings.
I have implemented a fly control programme for my farm.
I follow all company-implemented disease prevention measures on my farm.
I regularly attend educational programmes to keep abreast of new developments in disease control.
----------- Total (Perfect score = 100)

June 2011

Wednesday, June 22, 2011

Prolapse, how to anticipate?

Prolapse during production is usually related to poor skeleton development during rearing, even if body weight during production is at target. In future, try to achieve upper limit of target weight from 4 to 8 weeks of age. The following tips may help to reduce losses in this flock.
1. Do not exceed 16 hours light duration (better 15 hours). Also reduce light intensity (maximum 40 lux in open house, 20-30 lux in environment control house).
2. Adjust ME in feed to lower limit of recommendations.
3. Supplement Vitamin C @ 1 g/l drinking water in morning hours.

Steps 1 and 2 may slightly decrease egg produciton and egg size BUT you have to opt mortality or reduced production. Adopt these measures until 28 weeks of age. Thereafter resume normal practices.
Source : Dr.Anjum

Six Top Tips we must know on water supply of poultry farm

Six Top Tips we must know on water supply of poultry farm
Profitability in poultry production can only be optimized when everything goes right, and that includes keeping the birds healthy.

Hygienic Water supply system is one of the most important key factors for good health and growth of poultry. It is important for water to remain hygienic all the way until it reaches the birds, and so water & drinker lines hygiene must be a focus of attention for the farm. Water lines should be thoroughly cleaned and sanitized at regular intervals.

1. Adjust drinkers to correct height

2. Fix leaks

3. Look out for air locks

4. Install a filter to prevent sediment build-up

5. Prevent bio-film by flushing

~ immediately after any intervention of medication

~ one minute for every 30 meters of pipe length

~ at least once a week

~ more than once a day during warm weather

~ use high pressure (1.5-3.0 bars)

6. Use high quality acidifier in water for desired pH level

Water source get contaminated with various organic and inorganic substances resulting in high pH thus chances of growing pathogens including salmonella sp., E. coli and fungi is high. Contamination of drinking water in poultry is formidable.

Generally it is recommended that optimum pH of drinking water of poultry should be around 4.5 to 5.5 and B value of feed should be low to maintain normal gastric pH of birds.

Since gastric pH is higher in chicks than in growers and adult birds, an utmost care should be taken during brooding period of chicks for:

-» Reducing chick mortality

-» Controlling E. coli, Salmonella and fungi

-» Improving FCR and weight gain

-» Reducing ammonia in litter

-» Reducing moisture in litter

To take care of the routine problems of poultry farm, we add sanitizers, acidifiers, medications, nutritional supplements & vaccines etc without understanding chemical interaction into the water which itself comes carrying its own baggage of organic & inorganic material.

We will have to keep in mind that while some chemical interaction could be synergistic, actually helping one another to work better but in the mean time making wrong solution may create problem by reducing effectiveness of the additives and some time leading to hazardous effect to birds & environment.

Following are some action & interactions which we must understand while preparing drinking water to poultry:

☞ Hydrogen peroxide (H₂O₂) and Chlorine (Cl) are not compatible so should not be used at the same time. Both are oxidizer and they will turn on each other.

☞ Copper sulfate is not compatible with Chlorine (Cl) however Copper sulfate which is an antimicrobial & antifungal agent actually enhances the effectiveness of H₂O₂ so they can be run at the same time with separate medicators.

☞ Organic iodine (Not the inorganic) is very compatible with Chlorine. This combination can help to prevent a full-blown respiratory infection if it is used early enough to treat sniffing, a loose croupy cough.

☞ Iodine, like Chlorine, works better at a lower pH.

☞ Chlorine is not compatible with any compound that act as reducing agent which would include most minerals water additives.

For example, products that contain copper, sulfur or iron will tie up the Chlorine and make it unavailable to work effectively as a sanitizer.

☞ Antibiotic like Chlortetracycline & tetracycline works best in low pH range. If you have alkaline water, adding good acidifier liquid actually enhances absorption of these products. But product like Penicillin & Sulpha drugs works better in pH above 7 so turning off the water acidifier during medication with penicillin & sulpha group is recommended.

☞ Vaccines are typically protein so at any time vaccines are used in water, the water pH should be above 4.

☞ All sanitizers lose efficacy at colder water temperatures. Chlorine, chlorine dioxide & peroxide/ozone are all temperature sensitive so colder water will slow down their reaction time.

☞ Peroxide is strong oxidant and contact with personnel is extremely dangerous. Peroxide deteriorates gradually even when stored correctly.

☞ There would be slime blooms in water system after the use of antibiotics. The antibiotic disrupts the microbial population in waterline system just as it does in the GI tract, allowing microbes such as yeast & mould to grow undisturbed.

So, thorough cleaning of water pipeline system to remove the slime using 3% hydrogen peroxide solution with high pressure flushing water routinely is recommended as & when required.

Regular use of best quality acidifier in fresh drinking water of poultry farm will solve routine problems but it should have following traits:

Ability to reduce pH of drinking water as well as GI tract content.
Should reduce B-value of ingredients for improvement of digestion & assimilation.
Must suppress bacteria that are "pH sensitive" like E.coli, Salmonella, Campylobacter, C. perfringens, Listeria etc.
Must work in fore gut as well as in hind gut
Should be stable in all pH ranges.
Make sure that you are using perfect hygienic water for your birds and not a complicated solution.
Published on: 06/21/2011
Rating:
Author : Ganesh Kumar Dahal

Tuesday, June 14, 2011

Managing Fertility: Good Breeding Shows

Advice on how to promote enhanced fertility in the flock from Maciej Kolanczyk of Pas Reform.


The percentage of fertile eggs is one of the most important parameters influencing the economic performance of a breeder flock. An embryo can, of course, only develop from a fertile egg.
Fertilisation takes place – and thus can only be influenced on – the breeder farm. When we consider fertility, we usually think of the males. Yet in reality, the percentage of fertile eggs is a synthetic expression describing the condition and activity of the males, the condition of the females – and the propensity of both sexes to behave as nature intended. Sexual behaviour is closely allied to the contentment and welfare of the flock. Or put another way, fertility can be seen as a reliable measurement of the flock’s overall well-being.
A flock performing well in respect to fertility is in which both cockerels and hens are healthy and well developed. Both groups (sexes) should be uniform, with similar levels of maturity and well matched in size, good feathers and healthy, strong legs. These tend to be the characteristics of flocks in a low-stress environment, with sufficient space to promote natural behaviour and an optimum diet.
With these conditions, the inevitable changes related to the advancing age of the birds will be synchroninised. In this sense, fertility is a trait that can be regarded as a dynamic process, rather than as a single characteristic. From the economic point of view, the deciding factor is the level of fertility that can be delivered in the late production period, after 45 weeks. This is also a time when the most differences between the flocks can be observed.
Advice
To promote enhanced fertility in the flock:
Give special attention to development and uniformity in rearing: a good start in the first week, harmonic, steady growth, maintaining body weight standards from the beginning of the chick’s life and especially at 11 weeks are essential.

Synchronise the maturity of males and females. Many potential problems arise from differences in development between the sexes. Males tend to mature earlier and may behave too aggressively for successful breeding.

Observe behaviour in the poultry house in the afternoons – and be prepared to respond quickly. A good flock should remain active and well mixed at this time.

Restrict water consumption at any age and take care of litter as a key factor in determining the house environment. Dry, loose litter helps the birds to remain clean and well feathered with healthy legs. Maintain feed to water ratio as 1:1.7 to 1.9 in rearing and 1:1.8to 2.2 in the production period. Always ensure that the house is dry and warm.

Avoid stress by limiting factors like diseases, drastic changes of housing conditions, feed composition or quantity, temperature and other basic parameters. Stick to routines.

Stimulate mating by sprinkling grain on the litter in the afternoons. Let the males play the role of landlords, so they have the chance to show their leading position in the flock.

Never keep too many males in the flock. Quantity cannot replace quality.

It is better to keep fewer good cockerels than many of varying quality.

If possible, replace old cockerels with new, mature males after 45 weeks of age. Alternatively, introduce ’intra-spiking’, i.e. exchange males between different houses. This creates a new social order that encourages increased activity and renewed fights for social position. Replace or exchange at least 40 per cent of the males in a house.
June 2011
Source :http://www.thepoultrysite.com/articles/2026/managing-fertility-good-breeding-shows

Sunday, June 5, 2011

Diagnosis of infectious bursal disease by immunoperoxidase technique*

Faculty of Veterinary Medicine, University of Ondokuz Mayıs, Samsun, Turkey; 2Faculty of Veterinary Medicine, University of Ankara, Ankara, Turkey; 3Faculty of Veterinary Medicine, University of Kirikkale, Kirikkale, Turkey; 4Faculty of Veterinary Medicine, University of Kafkas, Kars, Turkey
Summary: The diagnosis of infectious bursal disease of naturally infected 21-day-old chickens was investigated with im-munoperoxidase method. Viral antigens were observed in the macrophages and lymphocytes of the bursa of Fabricius. It was ob-served that the method was sensitive and specific and it could be used in the diagnosis of this disease.
Key words: Immunohistochemistry, infectious bursal disease, polyclonal antibody,

Infectious bursal disease (IBD) virus is the causa-tive agent of a highly contagious disease of young chick-ens. The disease is widespread in chickens and has a great economic importance for both broiler and pullet growers (4,6,7). IBD is normally diagnosed in veterinary laboratory by the isolation of causative virus in eggs and/or cell cultures and demonstration of bursal lesions. However, these procedures can be relatively time con-suming and some strains either can not adapt themselves or not show characteristic changes on embryos. There-fore, diagnosis of the disease might be difficult and dem-onstration of viral antigen by immunoperoxidase (IP) method useful for differential diagnosis and confirmation of histopathological changes (2,3,5). Present study describes detection of IBD virus in the bursa of Fabricius (bF) within naturally infected 21 days old chickens by the indirect IP method using polyclonal antibodies. Twenty one days old 30 chickens showing clinical signs of IBD virus infection were collected from com-mercial flocks. All chickens were euthanasied by cervical dislocation and systemically necropsied. Tissue speci-mens were collected from bF, spleen, liver, cecal tonsil, kidney, lung, heart and brain, than fixed in buffered for-malin and processed for paraffin embedding. Two sec-tions were cut from each block, one for IP method and the other for hematoxyline and eosin staining. The con-trol group was sampled at the same intervals and in-cluded 30 specific pathogen free chickens.
For the IP method, formalin fixed paraffin embedded tissue sections from field cases and SPF chickens were deparaffinized and hydrated. Hydrated samples were reacted with 3% hydrogen peroxide in methanol for 30 minutes at room temperature to quench endogenous peroxidase activity and blocked with normal goat serum for 30 minutes. Serum was blotted and slides were incubated with polyclonal chicken anti serum to IBD virus (1/100) for 30 minutes in a humidified chamber. The slides were incubated with peroxidase labelled rabbit anti-chicken IgG (1/1000 sigma) for 30 minutes and reacted for 5 minutes in DAB, counterstained with hematoxyline. Macroscopically, no significant gross lesions were observed in organs except bF. The basic finding was a slight increase in the weight of bF (bF mean weight was 3,1 gr and 2,8 gr, in naturally infected chickens and control group, respectively). Microscopically, the main pathological alterations were degenerative and multifocal necrotic changes in the lymphocytes belonging to the medullar zone of bF. In the interstitial tissue, acute in-flammation characterised by heterophil accumulation and edema was observed. Cystic cavities were found in the medulla of some follicles. In control chickens, no mac-roscopic and microscopic lesions were seen bF or the other organs.
Immunohistochemically, IBD virus antigens were detected in lymphoid cells in the cortex and medulla of lymphoid follicles of the bF (Figure 1). Strong stain intensity and great numbers of positive cells were ob-served. In addition of these findings, antigens were found mainly in macrophages within all follicles and the inter-stitium. No antigen was observed in the other organs and the control chickens.
In the experimental studies, IBD virus antigens have been detected in macrophages within follicles, the interstitium and the lymphoid cells of bF (1,6,8). This antigen localisation was confirmed by our study. IBD virus antigens have also been observed in lymphocytes of spleen, thymus and cecal tonsil (8). However, in the present study, antigens could not been observed in these organs of naturally infected chickens. This may be due to the field cases of IBD virus have a high virulence and/or acute infections.
It has been recorded that the indirect IP method with polyclonal antibodies were used for detecting viral antigens in the bursae of chickens experimentally in-fected with IBD virus (6). These method findings were confirmed by the present study in naturally infected chickens. The protocol used in this work was verified high sensitivity of the IP test. It can be performed very rapidly, a large number of specimens can be processed quickly. Moreover, subclinical infection of IBD may be diagnosed by this technique.
References

1. Cruz-Coy JS, Giambrone JJ, Hoerr FJ (1993): İmmu-nohistochemical detection of infectious bursal disease vi-rus in formalin-fixed, paraffin-embedded chicken tissues using monoclonal antibody. Avian Dis, 37, 577-581.

2. Eterradosi A, Picault J, Drouin P (1992): Pathogenicity and preliminary antigenic characterisation of six infec-tious bursal disease virus strains isolated in France from acute outbreaks. J Vet Med, 39, 683-691.

3. Fernandes A, Martin M, Sierra M (1989): Immunohis-tological identification of both infectious bursal and Marek virus antigens in the bursa of Fabricius. Dtsch Tierarzl Wschr, 96, 157-160.

4. Haziroglu R, Maeda M, Nakamura K, Haritani M, Narita M (1988): Diagnosis of infectious bursal disease (IBD) by immunofluoresence. Ankara Univ Vet Fak Derg, 25, 289-298.

5. Jonson L, Engstrom B (1986): Immunocytochemical detection of infectious bursal disease and infectious bron-chitis viral antigens in fixed, paraffin embedded chicken tissues. Avian Pathol, 15, 385-393.

6. Kovacevic SA, Gagic M, Lazic S, Kovacevic M (1999): Immunohistochemical detection of infectious bursal dis-ease virus antigen in the bursa of fabricius of experimen-tally infected chickens. Acta Vet. (Beograd), 49, 13-20.

7. Lukert PD, Saif YM (1997): Infectious bursal disease. 721-738. In: BW Calnek, H J Barnes, CW Beard, McDou-gald L R, Saif M Y (Eds.): Disease of Poultry. Iowa State University Press, Ames, Iowa.

8. Tanimura N, Tsukamoto K, Nakamura, K, Narita M, Maeda M (1995): Association between pathogenicity of infectious bursal disease virus and viral antigen distribu-tion detected by immunohistochemistry. Avian Dis, 39, 9-20.
Geliş tarihi: 31.10.2003 / Kabul tarihi: 16.02.2004
Yazışma Adresi:
Doç.Dr.Tolga Güvenç
Ondokuzmayıs Üniversitesi,
Veteriner Fakültesi, Patoloji Anabilim Dalı,
Kurupelit Kampüsü, Samsun.

Saturday, March 5, 2011

Sexing of day-old chicks

Sexing of day-old chicks

Sexing day-old chicks can be accomplished by one of two methods: 1) vent sexing or 2) feather sexing. Each method has difficulties that make it unsuitable for use by the small flock owner. Vent sexing relys on the visual identification of sex based on appearance of sexual organs. Feather sexing is based on differences in feather characteristics at hatch time. A brief explanation of each method is as follows.

Vent sexing of chicks at hatching has complications that make it more difficult than sex determination of most other animals. The reason is that the sexual organs of birds are located within the body and are not easily distinguishable. The copulatory organ of chickens can be identified as male or female by shape, but there are over fifteen different different shapes to consider. Therefore, few people have experience with determining the sex of birds because of the difficult nature of the process. Most of these highly trained individuals are employed by large commercial hatcheries. The training to be a chick sexer is so difficult and lengthy that the average poultry owner finds it unjustifiable.

Feather sexing is based on feather characteristics that differ between male and female chicks. The method is very easy to learn by the poultryman, but the feather appearances are determined by specially selected genetic traits that must be present in the chick strain. Most strains (breeds) of chickens do not have these feather sexing characteristics and feathering of both sexes appear identical.

The most convenient method of sexing chickens by the small flock owner is to care for the birds until they begin showing the natural secondary characteristics of their sex. In males, the combs and wattles will become larger than those on females and the head will become more angular and masculine looking. The female will remain smaller than the male and is more refined or feminine looking. In some varieties the feathers of each sex will develop a characteristic color pattern that identifies it. These varieties of birds are similar to the feather-sex strains of chickens discussed above. Sexing based on secondary sex characteristics can usually be performed after chicks attain 4 to 6 weeks of age.

Source : http://msucares.com/poultry/management/poultry_sexing.html

Sexing of day-old chicks

Sexing of day-old chicks

Sexing day-old chicks can be accomplished by one of two methods: 1) vent sexing or 2) feather sexing. Each method has difficulties that make it unsuitable for use by the small flock owner. Vent sexing relys on the visual identification of sex based on appearance of sexual organs. Feather sexing is based on differences in feather characteristics at hatch time. A brief explanation of each method is as follows.

Vent sexing of chicks at hatching has complications that make it more difficult than sex determination of most other animals. The reason is that the sexual organs of birds are located within the body and are not easily distinguishable. The copulatory organ of chickens can be identified as male or female by shape, but there are over fifteen different different shapes to consider. Therefore, few people have experience with determining the sex of birds because of the difficult nature of the process. Most of these highly trained individuals are employed by large commercial hatcheries. The training to be a chick sexer is so difficult and lengthy that the average poultry owner finds it unjustifiable.

Feather sexing is based on feather characteristics that differ between male and female chicks. The method is very easy to learn by the poultryman, but the feather appearances are determined by specially selected genetic traits that must be present in the chick strain. Most strains (breeds) of chickens do not have these feather sexing characteristics and feathering of both sexes appear identical.

The most convenient method of sexing chickens by the small flock owner is to care for the birds until they begin showing the natural secondary characteristics of their sex. In males, the combs and wattles will become larger than those on females and the head will become more angular and masculine looking. The female will remain smaller than the male and is more refined or feminine looking. In some varieties the feathers of each sex will develop a characteristic color pattern that identifies it. These varieties of birds are similar to the feather-sex strains of chickens discussed above. Sexing based on secondary sex characteristics can usually be performed after chicks attain 4 to 6 weeks of age.

Source : http://msucares.com/poultry/management/poultry_sexing.html

Thursday, February 24, 2011

Nutrient Requirement of Poultry

Poultry diets must be formulated to provide all of the bird's nutrient requirements if optimum growth and production is to be achieved. There are six classes of nutrients:
Carbohydrates - the major source of energy for poultry. Most of the carbohydrate in poultry diets is provided by cereal grains.
Fats - provide energy and essential fatty acids that are required for some body rocesses.Proteins - required for the synthesis of body tissue (particularly muscle), physiological molecules (such as enzymes and hormones), feathers and for egg production. Proteins also provide a small amount of energy.Vitamins - organic chemicals (chemicals containing carbon) which help control body processes and are required in small amounts for normal health and growth.Minerals - inorganic chemicals (chemicals not containing carbon) which help control body processes and are required for normal health and growth.
Water.
Factors affecting the nutrient requirement of poultry
The nutrient requirements of poultry are affected by a large number of factors, including:
Genetics (the species, breed or strain of bird) - Different species, breeds or strains of bird have different average body sizes, growth rates and production levels and will also absorb and utilise nutrients from feed with different levels of efficiency, leading to different nutrient requirements. As the genetics of commercial poultry is constantly changing, so are their nutrient requirements. Consequently, breeders of commercial poultry provide information on the specific nutrient requirements for the birds they sell.
Age - Nutrient requirements are related to both body weight and the stage of maturity.
Sex - Prior to sexual maturity the sexes have only small differences in their nutrient requirements and males and females can usually be fed the same compromise diet to achieve acceptable growth rates. Differences in nutrient requirements are larger following the onset of sexual maturity and significantly different diet formulations are then required for each sex.
Reproductive state - The level of egg production in hens and sexual activity in males will affect nutrient requirements.
Ambient temperature - Poultry have increased energy requirements to maintain normal body temperature in cold ambient temperatures and the opposite in hot ambient temperatures. The process of digestion of food produces body heat and the amount of heat produced will vary according to the nutrient composition of the diet. This is called the heat increment of the diet. In cold temperatures it may be desirable to formulate a diet with a higher heat increment and the opposite in hot temperatures.
Housing system - The type of housing system will influence the level of activity of the birds and therefore their energy requirements.
Health status - Birds experiencing a disease challenge may benefit from an increase in the intake of some nutrients, most commonly vitamins.
Production aims - Optimal nutrient composition of the diet will vary according to production aims, such as optimising weight gain or carcass composition, egg numbers or egg size. Poultry that are raised for breeding purposes may need to have their energy intake restricted to ensure that they do not become obese.

This interesting article is published courtesy of and with full permission from the Poultry Cooperative Research Centre (CRC), Australia.