31 January 2016
Philemon Buruzi
There is heightened interest in raising indigenous chickens in the country at the moment. As the indigenous birds are fast gaining commercial recognition and widespread consumer appreciation, there has been an upsurge in the number of players joining this very promising poultry value chain. The major players in question are the breeders of the indigenous birds, fertilized eggs producers, hatchery operators and the farmers who raise and fatten the birds for the market. The sector is fast getting so organized that today one can procure any quantity of day old indigenous chicks with little effort, a feat which was not attainable in the five years ago. Nevertheless, as the sector strives to take root challenges are arising and hounding the farmers, particularly the new entrants. In the past few weeks, I have been inundated by farmers’ emails and calls regarding the issue of disease resistance of the indigenous birds. The major concern raised is to the effect that the farmers are observing a significant departure from the norm in terms of the birds’ ability to deal with diseases as well as general vitality. Traditionally our indigenous birds are famed for their hardiness, adaptability, high disease resistance and low maintenance. However, these highly sought-after characteristics seem to be waning away as the intensification of the indigenous birds gathers momentum. This article shall tackle some of the major reasons for the above-mentioned shift from the norm and attempt to proffer some practical solutions to these challenges.
Chick Quality
One of the possible causes of death being experienced could be poor quality of chicks. If one is not producing they own chicks as is the case with most new players in the indigenous poultry sector in Zimbabwe there is need to make judiciously checking the quality of the chicks which they procure in order to avoid problems along the way. There is raft of problems that emanate from the hatcheries which can easily be passed onto the farmer if they are not vigilant enough during procurement. Sadly, most of the farmers I have interacted with lately confessed that they are not able to differentiate chicks that are likely to die before the expiry of 14 days and those that will survive to maturity. Lack of technical skills is always costly because they are numerous hatchery flaws that one should astutely avoid. These are chicks with improperly healed navels as well as those with buttons. The belly characteristics should also be such that there is least likelihood of the chick to succumb to a disease called omphalitis. Commercial hatcheries normally have quality control protocols which select against defective chicks, but now the scenario we have in the indigenous poultry sector is that a good number of the day old chicks are coming from small-scale hatcheries and individuals who in most cases do not put so much emphasis on chick quality issues. It therefore remains the farmers’ responsibility to demand quality before they part with their money and walk away with a box full of problems.
Vertically Transmitted Diseases
In the attempt to avoid unwarranted deaths, it remains important for the farmers to carefully consider their sources of chicks. Chicks should be procured from sources that are famed for the provision of good birds. This helps in the evasion of inheriting some vertically transmitted diseases. By this I am alluding to those diseases that are passed from the parent hens through the egg to the chicks. Quick examples that come to mind are such daunting bacterial disease as salmonellosis and mycoplasmosis as well as viral diseases like avian encephalomyelitis, egg drop syndrome and leukosis just to mention but a few. As such all hatching eggs should be procured from disease free flocks to avoid this challenge. Whilst this may prove very difficult a feat to accomplish particularly ascertaining the disease statuses of the parent flock before procurement. Currently it really is a difficult exercise to execute as the sector is still in fledgling phase hence the observed increase in disease incidences. However, there are some producers I know who have perfected their art of keeping these indigenous birds. Such should be one’s target when searching for disease-free birds as well as hatching eggs.
Maternal Immunity
The disease immunity exhibited by the chicks of the indigenous chickens is largely as a result of the presence of antibodies inherited from the parents. The mother hen packages an array of antibodies in the yolk of the egg for use by the resultant chick during the first few weeks of life. This is the period during which the chick will be developing the capacity to produce its own antibodies so it relies on the passive immunity passed on from the parents. What must be appreciated is the fact that antibodies are varied and they are specific to the antigens they respond to. In addition to that, the birds produces antibodies specific to a certain pathogen after mild exposure to that particular disease. This therefore means that the array of antibodies packaged by the hen into the egg for later use by the chick is never uniform as it can only possess antibodies that represent the disease challenges that it has been exposed to. So, the chick is geared to thwart off any disease challenges that are common in its mother’s environment. The problem arises in our situation where the chick will be called upon to thrive in another environmentdifferent from its mother’s. Our scenario is such that the breeding hens are in Chiweshe for instance and the eggs are purchased by a hatchery operator in Harare who later sells the chicks to a farmer in Marondera. In such a case the expected disease resistance in the first week or so will not be attained owing to the fact that the chick will be presented with diseases different from the ones experienced by its mother hen in Chiweshe. In essence the chick will not be able defend itself since it might not have all the antibodies required in the new area. To get around this challenge and ensure survival of chicks, vaccination support should be availed to any bird imported from another area. In addition to that biosecurity should be especially during the early days in order to avoid exposing the chicks to diseases that they are not able to manage.
Husbandry Methods
The observed reduction in the ability to deal with disease challenges could in part be stemming from the husbandry practices preferred on the birds by the farmer. Whilst it remains true that our indigenous birds are disease tolerant and hardy when compared to broilers and the like, it does not follow that they can make do with mismanagement and gross ill-treatment as most of us would like to believe. These birds require good conditions too in order for them to thrive. For instance, if one chooses to raise chicks from day old without the mother hen, they have to find a way of keeping them warm artificially. I have attended to situations where the element of providing warmth is summarily ignored on the basis that the indigenous birds are “stronger” than broilers. That is not correct given that naturally they would get a warm covering from their mother.
In addition to that, as the commercialization of the bird gathers momentum, there is a growing tendency to grow the birds under conditions that somewhat resemble intensive production systems. The conditions in question refer to housing and space allowance per bird. The attempt to confine indigenous chickens in cages or fowl runs where they are crowded all day infringes they freedom and right to expression of their natural behavior. Whilst this may not worry most of us as we chase the dollar, it has untoward effects on the health of the birds. The stress which the birds experience as they endure the conditions of the cage or pen is responsible for most of the deleterious impacts on health that most farmers are grappling with. Stress stimulates the release of a cocktail of ‘stress hormones’ which are known to have immune- suppression effects thus exposing your birds to infections.
Free-ranging birds tend to be healthier than their caged counterparts owing to the fact that as they wander around the yard they get in contact with a lot of environmental pathogens. They are able to develop antibodies for all the local pathogens thus building the disease resistance for which indigenous birds are famed. In addition to that, they tend to get access to nutrients from diverse sources which in some cases have a role to play in disease resistance. It is without doubt that free-ranging birds also benefit from the ample exercise which they get as they move around. It also remains an advantage on the part of the birds especially the young ones; to be exposed to sunshine as it confers them with vitamin D. Therefore, the farmer should be careful to keep his/her husbandry practices as close to ideal as possible in order to benefit fully from the disease resistance, hardiness and productivity of the indigenous birds. Should there be a significant deviation in terms of how one manages the birds then they should also take the correct steps in terms of vaccinations, biosecurity as well as stress management in order to eschew losses.
Nutrition
A well fed bird performs better in the face of a disease challenge than its malnourished counterpart. The issue of nutrition is one of the key drivers of the observed reduction in disease resistance especially when it comes to confined indigenous chickens. This is so because a good number of the poultry keepers especially those that joined the rush recently are so confident that the indigenous chickens can make do with very little of their input to the extent that they do not make any deliberate effort to secure good nutrition for their birds. There is this general belief that indigenous birds just require small grains only as feed. I have seen people queue up to procure hordes of sorghum after which they feel they have done justice to the nutritional needs of their birds, how unfortunate that is. Indigenous chickens require a balanced diet just like any living body for them to function optimally, produce as well as deal with any disease challenges. Whilst sorghum and other small grains are good as supplements to those birds that are free ranging, they should not be taken to constitute a sole diet for those birds in confinement because the birds cannot derive all their nutrient needs from a single type of grain.
When birds are free ranging they have better chances of access to a whole array of nutrients because they eat greens from which the bulk of vitamins and minerals are obtained. Not only that they access lots of proteins when they consume such things as worms, termites and insects. The grains that most of us are so fanatical about are largely carbohydrates. So, if one decides to raise the birds in confinement, efforts should be directed towards availing a balanced meal to the birds if they are to thrive well. They need good supplies of vitamin A, vitamin E and micronutrients especially selenium in order to build capacity to fight off infections. It is against this background that I suggest that farmers reconsider the way they are feeding their birds and try to mimic the dietary provisions available to the birds when kept under natural systems if they hope to enjoy the usual disease resistance and productivity of the indigenous chickens.
It is therefore imperative that farmers pay due attention to the production fundamentals highlighted in the discussion above in order to get optimum performance from their indigenous birds. The ability to keep the birds healthy is key to the success or failure of any poultry venture and road –runners are no exception.
For all questions and comments: email philemonburuzi@gmail.com. Responses will be provided within the shortest possible time.
18 June 2014
By Philemon Buruzi
The cost of raising a broiler is rising steadily as a consequence of the prices of inputs which have been on the upward trend in the last few years. In times like these most producers would have considered the easy way out, which is to adjust the selling price of their commodities in order to cushion themselves. Unfortunately for Zimbabwe’s poultry producers, the situation cannot be dealt with that easily because the steady rise in production costs has come at a time when there is this much talked about deflation coupled by a burgeoning number of local poultry producers. This has seen unprecedented increase in competition for customers whose buying power has been waning with each passing day as a result of the economic challenges bedevilling the country at the moment. This scenario has left scores of small scale producers asking whether anyone can rear poultry profitably under these circumstances. My response has always been “yes you can, if and only if you increase your production efficiency.”
Loosely defined- production efficiency in this case alludes to resource utilisation in such a manner that one realises optimal output having put in the least of resources. This is achieved through making sure that management techniques gun for high feed conversion ratios, improved survivability and achievement of market weights in a short time.
In broiler production the 1st seven days are very crucial in that this is the period when there is a marked development of the skeleton, muscles as well as vital organs such as the respiratory organs and the gastro-intestinal tract. This is the period when the chick must develop a good appetite and establish its feeding habits. This has overall bearing on the performance of the broiler later on, for instance, a well developed gastro-intestinal system will be instrumental in achieving better feed conversion ratios. In the same vein, a chick which fails to achieve good systems development early enough will have immunological impairments such that when the yolk sac wanes the chick will struggle with fighting off infections. This often hampers overall growth, feed conversion, flock uniformity and ultimately survivability. Given that in livestock production weight is used to measure growth performance; in broiler production the seven-day weight is considered a very good indicator of how well a chick has started off. It is also used to predict how well the bird will fare in its later life in terms of parameters such as feed conversion efficiency, survivability and target market weights.
A chick weighs around 40g at day old and with good husbandry can grow increasing its weight about 4.25 times to reach a target seven –day weight of 180g. The reason why husbandry practices have to be up to scratch is because for the chick to achieve the target weight it uses 80% of its energy for growth and the remainder for maintenance. If this order is derailed by either inappropriate temperature regimes, irregular supply of nutrients or water, the target is missed. This often leads to the proliferation of small underweight birds in the flock and an unnecessary peak in overall mortality.
For one to reach the much revered seven-day weight of 180g they have to pay attention to a number of factors as enshrined below:
Feed: Chicks should be able to find feed and water as soon as possible following their placement in the brooder house. This is essential in that when a chick is hatched it survives on the residual yolk from where it draws antibodies and nutrients. The chick experiences very minimal growth as long as the yolk has not been fully absorbed. The complete absorption of the yolk sac is stimulated by the entrance of feed in the gut of the young chicks and rapid growth processes are initiated. Hence provision of feed as early as possible after placement gives the chicks a good head start.
Crop fill: If a chick fails to take in enough feed to fill its crop by end of three days, one is sure to have small birds that fail to recover for their entire life. One should therefore check crop filling after 24 hours and above 85% of the birds should have filled their crops. Pay attention to feed intake again at day four, because as yolk sac absorption is finalised, digestive upsets may cause a dip in feed intake. Feed should be easily accessible, that is, feeding space should be ample and distance travelled to access feed should be very minimal.
Diet characteristics: The diets that one feeds to the chicks should be formulated in such a way as to provide highly digestible materials given the fact that the chicks system is not yet developed. More so, the feed presentation (i.e. mash or crumbs) should be appropriate as to facilitate high intakes to support the expected rapid growth.
Disease Control: Management should ensure that chick placement is done under strict sanitary conditions and bio-security protocols are judiciously observed. This is important in hedging the chicks from infection because any infectious challenge that occurs at this stage will cause a growth check. Also given that the immune status of the chicks is still fragile, any disease challenge can actually result in unnecessary mortalities.
Brooding Environment: Brooding houses should be able to provide temperatures, humidity and ventilation that encourages feed intake. Taking for instance, if the temperatures are too low, the chicks will move away from feeder pans choosing to huddle near source of heating in the house. During that time their energy is then used for heat generation in their bodies at the expense of growth. On the contrary if the temperature is too high chicks also stop feeding in an attempt to lower the body temperatures.
In conclusion let me draw your attention to the fact that research has revealed that the final weight of the bird is increased by between 80-90g when the 7-day weight increases from 160 to 180g. In addition to that, 7 day weight above 180g led to an improvement in feed conversion by 10 points which translates to a 5% reduction in feed requirements. Of importance is the fact that higher 7 day weights showed marked reduction in overall mortality which means that a good number of birds will make it to slaughter age. Hence by pushing to achieve the target 7-day weight one realises that they harvest more broilers of higher weight using far less feed. So in this case you will have a competitive advantage when entering the market.
For all questions and comments: email philemonburuzi@gmail.com. Responses will be provided within the shortest possible time.
3 June 2014
Philemon Buruzi
As the egg production sector in Zimbabwe continues to grow we have a considerable number of new players coming on board. Over 70% of the small scale egg producers we have today depend on hens raised by others which they procure at point of lay. Whilst this avenue is preferred by a lot of farmers owing to the fact that it takes away the hustle of raising the birds from day old and also saves time. It is indeed a good experience to place layers today and start picking eggs in the f few days that follow and hit the market. It is however important to draw the attention of producers to the fact that this method also harbour some demerits which are ruinous to business especially for those attempting the egg production venture for the first time. It needs be known that the productivity exhibited by the hens as from beginning of lay till the end is founded strongly in the rearing phase of the birds. Given the fact that one has not been part and parcel of the rearing process, that farmer is not wary of the foundation that has been laid so far up to point of lay and it is possible to be saddled with problems emanating from poor pullet rearing management. In as much as it is impractical for every farmer to raise their own pullets, this article serve to equip the farmer with the cardinal physical aspects to look out for in a bid to get an insight of the quality of birds as well as their potential to produce before purchasing. Do not be hoodwinked by enticing marketing statements, just pay attention to the characteristics discussed hereafter.
Body weight
Upon settling to purchase some point of lay pullets from your chosen source, make sure that you know the strain or breed of bird that you are buying. This is important because the recommended weights at which you stimulate the birds into production varies according to breed or strain. For instance Lohmann Brown Classic layers attain reproductive maturity at 1.6 -1.7kg whilst the Hy-line Brown layer’s target weight at commencement of production is 1.4-1.6 kg live-weight. Armed with that information a farmer should check if the point of lay birds on offer have reached the recommended body weights, if not avoid such hens because research as well as experience has shown that forcing underweight birds into production does not yield good results. The fact that the birds will have reached maturity age yet underweight is indicative of poor husbandry practices experienced during the rearing phase that subjected the birds to serious growth retardation. Underweight birds could also result from birds that were poorly introduced to feed during the first few weeks of their lives resulting in a flock characterised by poor appetites. Such hens cannot perform to expectations during the laying period as they will be unable to eat enough to sustain high levels of production. It is more profitable to delay the onset of lay whilst you feed the birds on a nutrient rich diet until they have attained the target weights because if they are rushed into production they will produce very few , small eggs and persistence after the peak production period will be low.
Flock uniformity
The uniformity of the flock is as important as the attainment of target body weights. This is so because egg production is best when a batch performs optimally, not individual birds. The expectation is to have all the birds housed dropping an egg each per day for a uniform and constant daily pick. It is therefore imperative for a farmer to ensure that as they buy point of lay birds 85% of the birds are within 10% of the average weight of the flock. This follows the fact that poor pullet body weight uniformity complicates proper feeding plans especially the laying period as birds of different weights require different quantities and at times even different formulations of feeds. If there is wide variance in terms of weight, one will be confronted by a situation whereby the pullets come into lay at different times as a result of the fact that underweight birds tend to commence laying late and also produce very small eggs.
In addition to the scenario portrayed above, lack of uniformity allows you to have an insight into how the pullets were raised. A flock characterised by birds that suffered from enteric diseases such as coccidiosis, Infectious Bursal Disease, bacterial enteritis and runting and stunting syndrome are likely to exhibit apparent lack of uniformity due to these growth checking diseases. Moreso greater variation in weights is observable in flocks that were raised under overcrowded conditions whereby competition is rife at the drinkers and waters or rather the birds were given inadequate poor quality feeds. Undue water restrictions which in turn suppress feed intake also cause lack of uniformity as does exposure to stressful conditions. Avoid such birds; they will deal you no good.
Breast Muscle Development
The examination of the extent of breast muscle development is another easy way of determining whether you are buying quality pullets or not. A good pullet at the aged 18 weeks should have a well developed breast muscle and this serves as an indicator of a well groomed pullet with good future productivity prospects. The essence of the good muscle build –up is that whilst it is a direct contributor to target weights alluded to above, muscles have the responsibility of storing glycogen. Glycogen forms the rapidly available source of energy for egg production especially at commencement of laying and during peak production. As such a pullet that comes into egg production without insufficient muscles will not harbour sufficient energy to power the high levels of egg production as is expected of the modern layer. Vigorously select against birds with poor breast muscle.
Skeletal frame
This is just but one factor that can easily be used by any farmer to select good layers at point of lay without partaking in any cumbersome measurements. From just the look of the skeletal frame size, one can choose a productive hen. Generally the larger the skeleton, the better the production from that bird. This is so owing to the fact that, a larger skeleton presents a better skeletal mineral reserve which enhances lifetime productivity. There is huge skeletal mining and loss of structural bones during the early production phase mainly due to the hen’s inability to derive all its requirements from dietary intake. The minerals taken from the bones are channelled towards egg-shell formation which is an essential part of the egg formation process. The frame size is so important to productivity that it is advisable to purchase a lean but large framed pullet than an obese but small framed bird even if they are of the same weight, because the small framed bird despite its huge muscle and fat reserves will not be able to sustain high productivity and maintain good shell quality as does the large framed hen
Vaccinations
There are a number of diseases which every pullet should have been vaccinated against buy the time it reaches 18 weeks of age. Some of the major diseases to watch out for in layers are Mareck’ s disease, New Castle Disease, Infectious Bronchitis, Infectious Bursal Disease Egg drop syndrome and fowl pox. These diseases have been identified as the most important in as far as egg production is concerned. They however vary widely in their impacts on the egg production enterprise, from those that can cause wide spread mortalities, some cause sudden cessation of egg production and other cause the surfacing of inexplicable phenomena like soft shelled eggs, flat sided eggs or worse still shell-less eggs. It is therefore expected that someone selling off point of lay birds should have vaccinated against these disease. Nevertheless what we have observed is that a good number of point of lay growers cheat when it comes to vaccination against the aforementioned diseases in a bid to minimise costs. They are quick to point out that their stock was vaccinated against the whole array of diseases when in actual fact the opposite is true. It is therefore advisable to request for evidence that can serve as verification that indeed all the pertinent vaccinations were undertaken or simply stick to reputable sources of layers.
In order to steer clear of problems, it is advisable to procure the point of lay birds from reputable and trusted producers whose quality control is beyond question. I however am cognisant of our situation here in Zimbabwe whereby one might fail to acquire the pullets from the reputable sources due to one reason or another. In such cases one can surely scout for an alternative suppliers, but to hedge in your investment please do check out for parameters discussed earlier.
For all questions and comments: email philemonburuzi@gmail.com. Responses will be provided within the shortest possible time.
Philemon Buruzi
There is always a time in the life of a broiler farmer when they come across a batch of birds that fails to perform to expectations. Most of the times when such a case comes up, the blame is put squarely on the shoulders of the hatchery which produced the chicks. It is quite often that you hear somebody mention that such and such a company sold me ‘rejects’ after the birds have failed to grow up to the expected size. Some might want to attribute the poor performance to poorly formulated feeds or lack of requisite husbandry experience on the part of the farmer but I can testify that I have encountered this scenario in circumstances whereby the farmer is an experienced broiler producer who has been in the industry for years. A case whereby chicks are procured from the best hatchery in the country whose quality control system is beyond question and the same goes for the feed used – top quality. The batch in question is accorded the same treatment as all the other batches that preceded it and the birds do not die significantly or show apparent signs of ill-health but the growth rate fails to meet the grade. Realising that this could be some kind of disease most farmers visit the drug stores and they are advised to purchase vitamin stress packs, antibiotics and at times anti-coccidial drugs all to no avail. What then could be the cause of all that?
The scenario described above is that of a disease called Runting-Stunting Syndrome also known as the malabsorption syndrome. This is a disease that strikes the birds whilst they are still young such that the runting and stunting start to manifest as early as the first week. Runting and Stunting Syndrome is caused by what is widely believed to be a group of viruses whereby reoviruses and enteroviruses are major players. The viruses attack the gastrointestinal tract of the affected birds which results in failure to adequately digest as well as absorb the feed ingested. It is important to note that after viruses have damaged the intestinal walls, bacteria and other microorganisms take advantage and attack the damaged tissue exacerbating the already compromised health of the bird.
Signs and Symptoms
Owing to the fact that the intestines of the affected birds are damaged by the enteroviruses, there is usually a case of diarrhoea during the initial phases of the disease. There is a general show of vent pasting and faecal stripes at back-end of the affected young chicks. This has often been mistaken for coccidiosis by many broiler farmers leading them to purchase hordes and hordes of irrelevant drugs. The failure by the broiler to fully digest and absorb the ingested feed results in undigested feed being visibly present in the faecal matter which always points to another prominent sign of Runting and Stunting Syndrome –that is the birds consume their own faecal matter.
Given that the feed eaten is passing through the gastro-intestinal tract virtually untouched, the feed conversion rate plummets by up to 20 percent and as a result the growth rate is heavily compromised , hence a good number of the broilers show extreme growth retardation. There is an obvious sign of poor growth whereby the body size and weight does not tally with the expected for the birds age as illustrated in the picture below:
These birds are of the same age
Stunting which is a dominant feature at the initial stages of the disease is temporary and tends to fizzle away as the bird ages but the runting is permanent and remains in force up to the point of slaughter. The development of feathers is also hampered and in some cases abnormal feathers develop as shown below:
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A closer look at the affected birds reveal an excessive withdrawal of pigmentation from beak and shanks of the legs, a feature which earned the disease the name “pale disease syndrome”. Furthermore the affected birds tend to develop distended and pendulous abdomens owing to a voracious appetite against a backdrop of digestive malfunctions. The said digestive malfunction are responsible for the excessive flushing that accompanies this disease and often leads to cases of wet litter and excessive litter caking. As flushing persist other vital dietary elements especially vitamins are lost and this leads to arousal of what become known as secondary symptoms such as encephalomalacia, a result of vitamin E deficiency.
Treatment and Control
Runting and Stunting Syndrome is caused by viruses and just like all other viral diseases there is no cure for it. It therefore means that the only way to deal with this disease is to prevent its occurrence. Unfortunately owing to the fact that the virus that is responsible for causing the disease has not been isolated, there is no vaccine for the disease yet. Hence it is recommended that high levels of hygiene in the poultry house and its surroundings be maintained at all times in order to reduce the levels of the field viruses. It is also important to observe all bio-security measures in order to curb the introduction of the viruses from outside the farm boundaries as well as from outside into the poultry house. When all this has been done it remains fundamental to ensure that predisposing factors such as improper temperature regulation, ventilation, inadequate or improper feed as well as general stress are avoided especially during the brooding period. Never allow build up in the poultry house as this allows the field viruses to accumulate and one day infect and affect your chicks right on the day of placement.
For all questions and comments: philemonburuzi@gmail.com. Responses will be provided within the shortest possible time.
http://www.agriuniverse.co.zw
Philemon Buruzi
The profitability of any broiler enterprise is hinged on the number , quality and weight of the birds that make it to slaughter stage. A good number of small scale poultry farmers in Zimbabwe are not very particular about the quality of the meat produced or the weight as it is usual that one sells off live birds at a fixed price regardless of the parameters mentioned above. This article focuses on what most of us think matter the most, that is the numbers that make it to slaughter or to the market. Whilst it is desirable for any to have 100% survivability , it remains normal to incur some mortalities in the broiler business. Suppliers of day old chicks and poultry production experts state that for these modern genetics a mortality of 5% is acceptable as normal and does little impact to your bottom line and anything above that should be cause for concern. That withstanding it is commonplace for one to experience a batch of chicks that just die in large numbers often without very good explanation. When this occurs within the first 14 days of chick placement, it is generally known as early chick mortality and the various causes of early chick mortality are explored hereafter.
Hatchery Problems
The hatcheries have an obligation to deliver good quality chicks. Generally a good quality chick is one that is alert, active, well hydrated, free of diseases and deformities. There are chicks that succumb within the first two weeks of their lives owing to errors committed at the hatcheries. At day old a farmer can detect a problem chick by checking to see if the legs are dehydrated. Also take note of the colour of the colour of the legs and hocks. If the hocks and legs exhibit a reddish pigmentation accompanied by swelling, that chick will surely succumb before depletion time. Obvious candidates for early mortality are detected by inspecting the underside of the day old chicks. If you notice black dots on the belly just about the navel and or a large yolk sac, that alone spells trouble. An inappropriately absorbed yolk and unhealed navel often leads to a fatal disease called omphalitis, which is a result of the invasion of the navel and yolk sac by bacteria. This condition is responsible for some of the mortalities that occur within 7 days of chick placement. These problems are the direct responsibility of the hatcheries’ quality control department to screen out chicks with the above-mentioned anomalies. However time and again one such chicks find their way onto the market either by way of human error or otherwise.
Diseases
It is important to note the role played by infections in early chick mortality. Owing to the fact that the chicks are still young and lack the requisite capacity to fight off infection, mortalities due to infection can be quite rife within the first 10 days. This normally accompanies a breakdown in bio-security. There are several diseases associated with early mortality but the most common ones are pullorum, salmonelloses, colibacillosis. These diseases are discussed briefly below:
Pullorum diseaseis an acute systemic disease in of young birds. The distinguishing sign of pullorum disease is a white diarrhoea, ruffled feathers, breathing difficulties, chirping and high death rate. The morbidity and the mortality are particularly high between the 7th - 10th day after placement. The affected chickens appear somnolent, depressed and their growth is retarded. The feathers around the vent in many chickens is stained with diarrhoeic faeces or pasted with dry faeces.
Colibacillosis is a respiratory disease common in young birds, as it capitalises on immune-suppressed birds. Morbidity can vary and mortality ranges between 5-20%. The major signs of colibacillosis are respiratory afflictions, coughing, sneezing and snick. The disease also causes reduced appetite and resultant poor growth rates.
Salmonelloses is a group of acute rapidly spreading diseases caused by various sub-types of salmonella bacteria. It affects birds of any age even up to 90% of the flock but resultant mortality is low. Major signs of salmonelloses infection are diarrhoea, vent pasting, loss of appetite , ruffled feathers , crowding close to heat sources ,sitting with drooping wings and closed eyes.
Nutrition
It is important to ensure that the feed taken by the chicks is balanced enough to provide all the nutrients required by the birds in order to achieve the expected growth rates. In addition to that feeds should be of good quality that is free from disease causing organisms, moulds and other adulterants because feed can act as a portal via which toxins enters the birds.
Vitamin deficiencies: Vitamins are essential and they are derived from the diet taken in by the birds. In older broilers dietary shortage of these vitamin is not detrimental because they tend to have stored vitamins in the liver. Day old chicks tend to depend on the vitamins passed on from parents through the egg and this lasts only for 7 days. If diet is deficient in vitamins then problems start to manifest. General signs of fat soluble vitamins(i.e A,D.E & K) in chicks are growth retardation, anorexia, weakness, incoordination, emaciation and ruffled feathers ; whilst lack of water soluble vitamins( B- complexes and C) is shown by of weight, poor feathering, poor growth, dermatitis, perosis, nervous signs and anaemia. Vitamin deficiencies are not always fatal except in severe cases. The significance of vitamin deficiency is that it predisposes the birds to infections as it compromises immunity build up. Further the lack of vitamins interferes with the metabolic processes which can result in gross malfunctioning of vital such organ as the brains. Such cases often lead to mortalities.
It is prudent to mention at this stage that it is not only deficiencies that can be fatal, the opposite is also true. An excess of one or more nutrients above the optimum level can prove to be very fatal. A good example is salt poisoning. If salt is taken excessively via feed or water intake it results in early chick mortality which are often difficult to explain.
Farmers should ensure that they use fresh feed as mouldy feeds expose the young birds to mycotoxins. These are poisons that found in mouldy feeds and grain as fungal metabolic by-products. Mycotoxins are highly fatal and when present in very good concentrations can cause sudden high mortalities upward of 80%.
Poor husbandry Practices
Many farmers are always found wanting when it comes to general management of the birds , the poultry house and adherence to bio-security protocols.
Brooder temperature: Whilst it is common knowledge to all that day old chicks require brooding where a source of heat is provided, the common problem encountered most of the time is getting the temperature right. When brooding temperature are above optimum (i.e between 30 0C – 32 0C during the first week), the chicks become heat stressed and after prolonged exposure to such conditions, they die of dehydration and vent blockage. On the other hand when temperatures slump lower than desired the chicks are hit by pneumonia and mortalities do occur by chilling. When cold the young birds tend to stop feeding, huddle together and in most cases more chicks die of smothering than from the low temperatures. To do away with this problem farmers should ensure that recommended temperatures are achieved, stabilised and maintained. This temperature should be measured at chick level.
Ventilation: Adequate ventilation is a key factor to broiler survival especially in the first 2 weeks. Good ventilation allows for equitable distribution of heat around the house as well as maintain good air quality. Poor ventilation leads to accumulation of noxious gases such as ammonia, carbon monoxide and carbon dioxide. Ammonia gas is very toxic and it kills chicks in large quantities once it surpasses 100ppm (parts per million). Whilst it is impossible to run an ammonia free poultry house, it is recommended to keep the concentration ammonia below 10 ppm. The following signs point to an uncomfortable level of ammonia gas in the house: irritation of mucous membranes and eyes, reduced feed intake, retarded growth rate, haemorrhages and death. Carbon monoxide tend to accrue when one uses fossil fuels as source of heating in the poultry house for it normally comes from incomplete combustion of fuels. Carbon monoxide is quite toxic to chicks at concentrations between 2000-3600 ppm whilst carbon dioxide causes serious respiratory challenges, suffocation and death when its concentration in the air goes beyond 30% by volume.
Humidity: Away from poisonous gases that can bedevil the air, it is important to note that the ventilation mechanism should take care of the humidity levels of the air in the poultry house. High relative humidity can compromise litter quality and create a conducive environment for the proliferation of pathogens. It can also delay the healing and drying up of navels in day old chicks paving way for the entry of bacteria resulting in omphalitis and death.
Floor space: This is one parameter often taken for granted by smallholder farmers unbeknown to them that it has the potential to decimate one’s project. In crowded pens chick mortalities are rife due to physical stampede as well as dehydration and starvation resulting from inadequate feeder and watering space. When chicks are crowded the litter is constantly damp which creates an enabling environment for diseases to thrive and in such cases ensuing mortalities are inexplicable.
Bio-security: As you seen earlier in this article, early chick mortality can be caused by infections and most of these are bacterial. The occurrence of a bacterial infection is testimony to prevalence of unsanitary conditions in your environment. This is resultant of failure to observe bio-security protocols and proper sanitation measures. All this comes about as a result of poor management on the part of the farmer.
Conclusion
Farmers can minimise early chick mortalities by ensuring that they procure their day old chicks from reputable suppliers whose standards are certified in order to avoid inheriting problems that were cultured at the hatchery. The same could be said of the feed which without doubt should be purchased from reputable stockfeed compounders famed for churning out quality feed as a way of avoiding deficiencies as well as toxicity. Having acquired quality supplies, it then remains the farmer’ s duty to make sure that his management practices ensure a conducive environment for the chicks to thrive and does very little to allow disease a chance to creep in. This and a little more will surely see one managing to push a batch up to slaughter stage having lost only 5% of the birds or less.
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