Broiler Signals African Edition (English edition)

The book Broiler Signals African edition follows the bird on a broiler farm in Africa. As day-old chicks they have to be of excellent quality and this book provides you the tools to assess day-old chicks.

After the initial week, the broilers have to start growing fast and efficiently, which asks for a good intestinal health. Once they grow older and larger heat stress might become a problem in warm climates. Leg quality often becomes a problem as the birds get heavier and litter deteriorates towards the end of production. Bringing the birds to the market may include processing broilers in a cold chain requiring a lot of attention to hygiene.

Broiler Signals African edition is a practical guide that shows you how to pick up the signals given by your animals at an early stage, how to interpret them and what action to take.

ISBN 978-90-8740-364-5

What can you smell or do your eyes sting?

A predominant smell of ammonia indicates hot litter.

Feel whether the chick has eaten good feed and enough feed. www.roodbont.com

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AFRICAN EDITION

BROILER SIGNALS A PRACTICAL GUIDE TO BROILER FOCUSED MANAGEMENT

AFRICAN EDITION

Broiler Signals is part of the successful Poultry Signals© series.

Poultry Signals© presents practical knowledge of animal oriented poultry farming in an easy, accessible format.

1. What do I see?

2. Why is this happening?

3. What should I do?

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AFRICAN EDITION

Steps aimed at improving management:

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Observe the birds’ behaviour: how do they react to you?

A practical guide to broiler focused management

A practical guide to broiler focused management

Listen to their breathing. You’ll hear if there are any problems.

Broilers are fast growing animals that need constant care. Your birds continuously send out signals: about their health and whether they feel happy and comfortable. If you are able to recognise these signals in practice, you can use them to improve your management. For the African poultry farmer this means being alert in the broiler house, observing and listening to the birds.

Make sure you have a good start! Everything in place and the farm free of poultry diseases. Also make sure you have procedures to keep it that way! Choose the breed that best fits your circumstances. And do you have sufficient feed of good quality available? Water is the cheapest of all nutrients, but the most important one. Often, water seems a bit neglected. If well managed it supports your production, if not managed well it is a source of problems (bad feed conversion, heat stress, diseases).

SIGNALS

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broiler production is a sprint. There’s no time for mistakes.’

BROILER

In theory we all know more or less what to do. But not every poultry farmer puts this theoretical knowledge into practice. So Broiler Signals doesn’t just devote space to the latest insights, but also focuses on how to turn knowledge into effective action.

By consciously examining signals and analysing them you can optimise your operational management step by step.

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‘If keeping laying hens is like running a marathon,

I m p ro v in g y o u r re s u lt s a n d a n im a l welfa re

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If you only look out for technical aspects (daily growth, feed and water consumption, etc.), you may miss other import-ant signals from the broilers and their living environment. Always use all your senses.

BROILER SIGNALS

Us e al l y ou r senses

9 789087 403645

By consistently asking yourself these questions and structurally correcting the management of your birds, your results will improve significantly.

Because healthy, stress free broilers will benefit your bottom line.

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AFRICAN EDITION

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BROILER SIGNALS

A PRACTICAL GUIDE TO BROILER FOCUSED MANAGEMENT

Contents

2. Before you start Planning Types of broilers What the figures tell you Main parameters to record Key performance indicators (kpi) Uniformity Using recorded data Biosecurity for profit Biosecurity outside the farm Biosecurity on the farm Man is biggest hazard!

Vermin Biosecurity in practice

14 14 15 17 18 19 20 20 21 22 23 24 25 26

3. The broiler’s environment Outdoor climate determines housing Temperature + moisture = heat Comfortable climate Broiler housing Provide sufficient ventilation Floors and litter Litter management Litter quality Light Light intensity

28 29 30 31 32 33 35 36 37 38 39

4. Water and feed Water Drinking height Water/feed ratio assessment Water quality assessment Ensuring water quality Vulnerable: young chicks Particles in drinking water (biofilm) Cold water in hot areas Feed Nutrients

40 41 42 43 44 45 46 47 48 49 51

5. Day-old chicks Quality of day-old chicks Navel and cloaca Belly Feathering Legs Beak Vertical transmission Vaccination Injections in the hatchery Eye/nos drop vaccination Vaccination on-farm

58 59 60 61 62 63 64 65 66 67 68 69

8. Breathing and heat stress 96 Anatomy 97 Indoor climate 98 Heat stress 99 Climate management in high temperatures 100 Effective temperature (wind chill factor) 101 Above 30°C: danger zone 102 Breathing is silent problems aren’t!

103 9. Leg quality Remove lame birds Lameness and its causes Enterococcal infection Footpads Skin scratches Improve litter quality Litter as a source of heat Wet manure due to excess urine

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6 8 11 12

53 54 56

6. The first week 70 Bird density 71 Before the chicks arrive 72 Transport risks: hygiene and stress 73 Placing the day-old chicks 74 ‘Cold-blooded’ chicks 75 Brooding rings 76 Eating well 79 Drinking well 80 Yolk inflammation or navel infection 81 Weak chicks 82 Identifying causes of death 83 Use antibiotics in a responsible way 84 A good start is half the success 85

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1. Picking up the signals Using the signals Senses Anatomy

Feed ingredients Feed formulation Non-essential nutrients

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4 4

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Introduction Spotlight on the broiler

7. Optimal growth and development Points to watch out for: behaviour Points to watch out for: physical traits Gut health and development Gastrointestinal problems Signals from droppings Orange matter Wet manure Coccidiosis Risks at feed transitions

86 87 88 89 90 91 92 93 94 95

104 105 106 107 108 109 110 112 113

10. Final phase and slaughter 114 Increase in mortality rate 115 Sold live or chilled?

116 Catching broilers 117 Cleanout of the empty broiler house 118 Downtime time reduces infections 119 The slaughtering process 120 Killing and bleeding 121 Scalding 122 Plucking 123 Evisceration 123 Bruises, wounds and inflammations 125 Further processing 126 Chilling 127 11. Broiler health Healthy birds Specific diseases Viral diseases Bacterial diseases Nutrient deficiencies

128 129 130 130 133 134

Index

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Spotlight on the broiler

Train yourself to look and see Poultry Signals is a concept where we don’t start with the theory how things should be, but how things are in practice and relate this to the theoretical background each poultry farmer should have. Proper care of your birds starts with critical observation. The signals you see have to be put in the proper context. Stop and think about the signals your birds are sending. The longer you spend on this, the more subtle signals you will see.

The three basic questions a broiler farmer must keep on asking themselves are: 1. LOOK: What am I observing?

2. THINK: Why is this happening?

3. ACT: What should I do?

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Broilers grow very rapidly in a short time.

That can’t be emphasised often enough. So when you take action, don’t think in days but in hours or even less. The slightest interruption can disrupt the delicate process. Result: growth stagnates, and birds get sick and die. As a poultry keeper, there’s little more you can do once something has gone wrong. So it’s all the more important to prevent problems, or at the very least react quickly to the signs. And if it’s already too late, make sure that by recognising and acknowledging the problem you avoid it next time around. Broilers tell you a great many things through the signals they send out, in their behaviour, their physical characteristics and their environment.

This is precisely what Broiler Signals is all about.

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Introduction

The first week

Many things are known about dayold chicks: parent animals, hatching egg quality, the hatching process and transport all affect the quality of the day-old chick. The task on the broiler farm is to give these animals the best possible care. Mistakes made when the chicks arrive and during the first week can’t be undone later on.

The basis has been laid and now the bird needs to start growing and developing its organs, skeleton and muscles properly if they are to keep pace with this rapid growth.

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Day-old chicks

1 day 4

7 days

14 days

Optimal growth and development The focus now shifts to the gastrointestinal system, the prerequisite for growth. Feed intake increases rapidly and the feed type is often changed at this stage, so there is a lot of pressure on the gastrointestinal tract, increasing the risk of gut problems. This is a vulnerable time for the chicks. Pay special attention to the droppings.

21 days B roile r Signa ls - Afric a n edi t i on

Not a textbook Broiler Signals isn’t a textbook full of tables of standards and guidelines. The main aim of this book is to train you to pick up signals from your birds. It also invites you to dip in and out of it and linger now and again to read a little deeper into the subject. Or you can just read a page or two now and then and put it aside again. You’ll discover something new every time.

LOOK-THINK-ACT

How the book is structured The book follows the cycle on a broiler farm. At every age a different theme that you’ll need to pay particular attention to or that may arise is highlighted.

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Which signal can you see here?

Leg quality

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The broilers need to be kept warm in the first few weeks of their lives.

But by now they are producing so much heat themselves that they have difficulty getting rid of it. They do this mainly via the airways, and it’s around this time that most respiratory problems occur.

The broiler house is getting fuller and fuller with broilers that are busy eating and drinking ... and excreting.

With such a thick blanket of birds, the litter doesn’t dry out so easily any more. Coupled with the fact that the broilers are getting heavier and rest a lot, this regularly leads to foot problems and breast and hock irritations.

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Breathing and heat stress

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This bird is passive and is therefore unhealthy. A healthy bird wants to eat all the time. So its feed intake should increase constantly with age. If it doesn’t, this may be an indication of gut problems.

Also check the quality of its droppings.

28 days Introd u c t i o n

35 days

Final phase and slaughter You’ll see another strong growth spurt in the last week. It’s too late to make any more adjustments now, although avoiding problems around this time makes all the difference between profit and loss. At slaughter even more signals become apparent that are literally under the skin. They won’t help you this time around but they can help you do things even better next time.

42 days 5

CHAPTER 1

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Picking up the signals

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Broilers grow fast and there is almost no time to fix mistakes. So you have to start by making sure you have everything in place to receive the young chicks and prevent things from going wrong later on.

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A good poultry farmer is able to pick up subtle signals and uses this in his management of the flock.

Use all your senses If you only look out for technical aspects (daily growth, feed and water consumption, etc.), you may miss other important signals from the broilers and their living environment. Always use all your senses.

Even before you enter the broiler house, you’ll hear whether the birds sound different. Don’t go inside straight away: look and listen without disturbing the flock first. Pay attention to the distribution of the birds. Use your eyes and ears to see and hear how active the birds are and whether they are reacting more, less or differently to your arrival than usual.

Also use your senses to observe the heat and cold or draught in the broiler house. Every irregularity needs to be attended to.

senses look

listen smell

feel taste

Use all your senses to recognise the signals.

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Once you entered the poultry house, start looking from a distance to their behaviour before moving around.

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Look from flock to chicken Start your inspection by observing the whole flock.

How are they spread out in the space? Are they avoiding certain places, maybe because the climate is different there (draught, cold, light)? Try to spot the differences between birds. Are they uniform? How do they differ? Is it in alertness, condition or in another way? Pick up birds that seem different and take a closer look. If you discover an irregularity, see whether it is an incidental case or a signal of a bigger underlying problem.

Also pick up some birds at random and assess them. Not all abnormalities are immediately obvious. Things you observe in detail can only be properly assessed in their context. So look from chicken to flock as well. Sometimes you will need to take a step back to be able to see things better.

Check the flock from outside the poultry house. This way you can observe the flock unnoticed without disturbing the birds.

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You’ll pick up a lot of signals during the daily routine of feeding, removing dead and abnormal birds and adding extra litter. But make sure you also do some inspections without doing other things at the same time. Then you will be more aware of the signals because you are giving observation your full attention. If you are doing other things at the same time you will disrupt the birds’ behaviour, causing relevant signals to be lost. The birds will also react less to your presence if you come into the house more often without doing anything specific. An inspection is a tour of the whole house. Make sure you pay attention to all the birds and all areas of the house. So look everywhere: front, back and middle. Stay calm and take your time!

Making a sound by hitting a bucket might also help to startle the birds and observe their reaction.

1. P ic k i n g u p t h e si g n a l s

Put a chair in the house and sit on it for a few minutes at regular intervals to observe the birds. Only then will you pick up on any irregular behaviour.

By hitting the corrugated iron wall at the beginning of your inspection, you can assess the chicks’ reaction and immediately select the ones that do not respond.

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LOOK-THINK-ACT

Using the signals Use what you see to improve your flock management. A genuine signal will be repeated. Think about what you are seeing and how it relates to the circumstances: does it happen often, at different times, to different birds, on other farms? Go and see for yourself or ask people.

Know when risks are likely to occur and keep one step ahead by eliminating them or being extra alert if you are expecting them.

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Vulnerable birds There will always be some vulnerable birds in a flock, such as poorly developed ones. They will be the first to suffer from disease, lack of water or other shortcomings. These are also the signal birds: the first ones to tell you that something is wrong; all the more reason to be aware of them.

Think about which birds and problems these are, in terms of your particular farm and how you can respond to them promptly.

Some birds will also pose a risk to others, e.g. as a source of infection.

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What should you do with this bird?

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This is a high risk bird. It is not able to get to feed and water and will die anyway. But other birds may peck at it or in a hot climate it will start decaying fast, leading to further problems. Take it out directly and cull it.

Signs humans can’t see

Aids such as an infrared camera show what the human eye can’t see. The roof of this house during a cold night has not been properly insulated: the ridge is about 10°C colder than the rest of the roof.

Result: it cools down and condensation forms, possibly dripping on the floor. Wet litter is a cause of many health problems.

If you see anything that draws your attention: take a closer look.

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B roile r Signa ls - Afric a n edi t i on

Farm blindness You can only recognise an irregularity if you know what is normal. You will learn what is normal by observing as often and as objectively as possible.

But be aware of the dangers of farm blindness.

Farm blindness is when you see the situation on your own farm as the norm. Limit farm blindness by talking to colleagues and advisors. Act on critical comments. Also go and look at other poultry keepers’ operations (but always comply with biosecurity rules).

LOOK-THINK-ACT

How to observe your birds in a structured way:

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1. Look at them both with and without doing other things.

The chicks are creeping up to the wall and pecking at it. This is often a sign of anxiety or stress. Broilers are flight animals and seek protection when there is an unexpected visit. If the birds are pecking calmly at the wall, this may be an indication of a problem with the feed.

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house. The same applies to processes such as feeding. Look at the front, middle and back of the feeding system that is being filled. What is happening there?

5. Look at different times and in different circumstances.

6. At regular intervals, stand still in the broiler house and also get down and move about at the level the birds live at.

7. Identify critical times, susceptible birds and danger zones and keep an extra eye on them.

What do these chicks tell you?

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chicken and then back to the flock.

3. Look for averages and extremes.

4. Look at the front, back and middle of the

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2. Look at the whole flock, the individual

Limit farm blindness by talking to colleagues and advisors.

1. P ic k i n g u p t h e si g n a l s

When you walk through the house, look at the birds that don’t run away quickly from under your feet. These are signal birds that can tell you things.

The birds that run away first are the stronger birds. The track you leave behind you will close again. Whether this happens fast, slowly or not at all is also a signal of the birds’ vitality.

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CHAPTER 2

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Before you start

Before you start raising broilers you have to make some important decisions and make sure you meet all requirements. Do you have an adequate poultry house? What is your choice of breed? The most

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important is, however, do you have a sufficient amount of feed to raise the broilers up to slaughter weight and is this of sufficient quality. And is your water supply of good quality and quantity?

Planning Planning is key. If you buy day-old chicks you already know how much feed you need, how much water you need, how much space you need and how you are going to market the final product. If one of these factors is not covered yet, don’t start!

Things to do before you start

It is not uncommon that a broiler farmer finds out he hasn’t got sufficient feed stuff to raise the broilers up to market weight. Often a cheap or inferior feed is than used to cover the gap, but the birds will just stop growing or develop all kind of problems.

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• • • •

Make a planning from day-old chick to market Decide which breed to use Have a proper farm recording in place Ensure that you have sufficient quality feed and water

B roile r Signa ls - Afric a n edi t i on

Types of broilers Broilers or layers, in many countries farmers make a choice for either of the specialisations.

The demands placed on such highly specialised varieties mean that they need highly specialised care. In sub-optimal conditions these brands may face problems. Such conditions may occur in open housing in warm climates. You will have to make a choice for the type and breed that fits you, the circumstances and of course the market best.

Standard Broiler

Eggs

Eggs and meat

Meat

2. B ef o re y o u st a r t

Ross 308.

Slaughter age 35-50 days.

The Hubbard strains are popular for slower growth.

Image courtesy of Aviagen

The SASSO Rainbow is multicolored and multi-purpose: can be raised for both eggs and meat.

Image courtesy of Hubbard

CobbSasso.

Minimum slaughter age 50-70 days.

Image courtesy of Aviagen

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Cobb 500.

500 Slaughter age 35-50 days.

Image courtesy of Cobb

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On both ends of the spectrum you find the specialised, high productive brands/breeds, but there is a whole range in between that might fit your production system better for an optimal final result. Various poultry breeding companies have solutions for all purposes.

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Robust varieties A disadvantage of fast-growing varieties is that they tend to be quite vulnerable. Under optimal conditions they show fast growth, but when conditions are not optimal they suffer (mortality, heat stress, inadequate feed, diseases). Especially the higher mortality of fast-growing varieties under suboptimal condition is a problem.

More robust breeds may grow a bit slower and require more feed before reaching marketable weight, but at least they stay alive and keep growing. The slower growth rate allows the body and organs to handle the growth better. The parent stock of robust varieties in general have a better egg laying performance than specific meat breeds.

Dual purpose

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Fast-growing varieties The most commonly used varieties globally (Ross and Cobb) are fast growers. These are bred for high proportion of breast meat, good appetite and efficient feed conversion, as well as a high growth rate. Living conditions must be optimal to express their genetic potential.

Standard Layer

Rowan Ranger.

Minimum slaughter age 63 days.

15

CHAPTER 5

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Day-old chicks

In general day-old chicks are bought by broiler farmers. The quality of the day-old chicks determines

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for a large part your final results. So make sure you have good starting material.

Chick A

Chick B

Before you start, you have to know the breed you are buying and the vaccinations they received (and their mothers). The weight of day-old chicks doesn’t tell you much about the quality. If the chicks have a large residual yolk in their body, they may weigh the same but are of lower quality. Chick length is a better indicator of the chick’s quality.

This should be 18 centimetres or more, depending on parent stock age (young parent stock * 18, older parents > 18).

Chick A, with a small residual yolk, has absorbed sufficient nutrients, is more vital, and would have had a stronger start (if it was still alive...). The smaller chick B has a large residual yolk. The chicks itself are also smaller. It has absorbed insufficient nutrients.

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B roile r Signa ls - Afric a n edi t i on

Quality of day-old chicks

LOOK-THINK-ACT

On arrival, pick up chicks from various trays for a proper assessment so you can adapt your management to the quality of the chicks. The schedule below can help you with this. Weigh 5% of the chicks for a good idea of the initial weight of the day-old chicks and pay attention to uniformity.

There are various abnormalities based on which chicks are rejected and separated from other chicks.

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Yellow = better?

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A fit and healthy day-old chick gets on its feet again within three seconds, even when you put it on its back.

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Some people think that yellow chicks are more vital than white ones. But this is often due to formalin in the hatcher baskets, which colours the down. In the past, chicks that didn’t receive disinfection were considered less healthy, so colour was associated with health.

Early hatched chicks are in contact with formalin for longer and will darker yellow, but might be weaker than the ones hatched later.

The legs should feel warmer when pressed against your cheek. The thermal image on the left shows warm legs. The legs in the image on the right are cold (they should appear lighter yellow than the hand).

Check points for day-old chicks Check

Right

Wrong

Reflex

Lay chick on its back. It should stand up within 3 seconds

Chick takes more than 3 seconds to stand up: chick is listless

Eyes

Clean, open and shiny

Closed, dull

Navel

Navel should be closed and clean

Bumpy: remnants of yolk; open navel; feathers smeared with albumen

Feet

Feet should be a normal colour and not swollen Feel warmer than your cheek

Red hocks, swollen hocks, malformations, deformed toes, cold

Beak

Beak clean with closed nostrils

Red spots; dirty nostrils; malformations

Yolk sac

Stomach soft and malleable

Stomach hard and skin taut

Down

Should be dry and shiny

Down wet and tacky

Uniformity

All chicks the same size

More than 20% of chicks are 20% heavier or lighter than average

Temperature

Should be 40°C 2-3 hours after arrival

Above 42°C: too high, below 38°C: too low

5. Day- o l d c h i c k s

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CHAPTER 8

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Breathing and heat stress

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Chickens can’t sweat. Instead they have to expel excess heat in the air they exhale. The way chickens breathe is therefore an important indicator of whether they are too hot. Chickens have a completely different respiratory system from mammals and are therefore susceptible to airway diseases. So you’ll

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need to watch out for any early signs of respiratory problems, especially as the birds grow older and bigger. And the density of birds (in kg/m2) gets higher.

Chicken lungs are small and do not expand. Unlike mammals, the lungs of birds end in air sacs. The air sacs – nine of them – are balloon-like features that are distributed throughout the body. Chickens breathe in and out via these air sacs. Like bellows, they draw in air and expel it again via the lungs.

Chickens do not breathe using the diaphragm as mammals do, as they don’t have one. So they can only breathe by moving the ribs and the breast bone. If they cannot do this, for instance if they are being held too tightly or bunch together in fright, they can quickly suffocate.

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Visible respiratory signals • • • •

dirty beak due to nasal discharge watery eyes or tear stripes panting with open beak red eye membrane

B roile r Signa ls - Afric a n edi t i on

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Anatomy

nostrils lungs

anterior air sacs parabronchi lungs bro nc hu s posterior air sacs

Inhaling The air sacs inflate as the body cavity expands and air is drawn from the beak into the posterior sacs. At the same time, the air that was in the lungs is drawn into the anterior sacs.

nasal cavity: consists of several interconnected chambers.

beak opening w

Exhaling

in dp ip e

windpipe:

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air sacs

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reinforced with cartil-age rings to prevent it from closing during breathing. Branches into two smaller tubes (bronchi).

The windpipe is more than just a hollow tube

NH3

tissue

cilia are not functioning properly, harmful pathogens can penetrate deep into the body because the air sacs are distributed throughout the body. This is different from mammals, in which these organisms don’t get further than the lungs.

formalin

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mucus layer

3. Immune cells in the lungs that kill harmful pathogens. If the

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The incoming air is freed from impurities in three ways: 1. The mucous lining traps impurities.

2. Cilia push impurities back up to the throat, but other substances such as particulates and bacteria can penetrate further into the respiratory system. cilia

The air in the posterior sacs is pushed into the lungs, where gas exchange takes place.

The air from the anterior sacs is also exhaled now. This creates a non-stop, one-way flow of air through the lungs.

anterior air sacs parabronchi lungs bro nc hu s posterior air sacs

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dust

Inhaled air is cleaned by cilia in the windpipe which work mucous and any adhered particles back up to the beak.

Contact with irritants such as formalin in the hatcher affects the cilia, stopping the mucous lining from moving and causing it to thicken.

Harmful particles remain enclosed in the stationary mucous lining.

These harmful particles infect the underlying tissue.

Signals of respiratory infections

Early infection, runny nose, half-closed eyes 8. B re a t h i n g a n d h e a t stres s

Advanced respiratory problem

Severe infection: nose and eyes are completely closed 97

Indoor climate

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heat up. More ammonia and fatty acids will form, and you’ll be able to smell the house from quite a distance. Even low concentrations of ammonia (10 ppm) can damage the cilia in the windpipe, causing excessive mucous production. Harmful organisms can now easily penetrate into the respiratory system. The result: lower slaughter weights and poor feed conversion.

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The dust in a broiler house comes from the feed, the skin and the feathers, but also from the litter and dry manure. Dust irritates the airways and can carry large numbers of pathogens such as E. coli, Salmonella or viruses like Gumboro. Stale, pungent or ‘heavy’ air in the broiler house is a sign of poor ventilation. The bottom layer of litter may be damp, even if the top layer is dry and loose. This often indicates a cold surface underneath. If ventilation is poor, moisture and unwanted gases (e.g.

CO2, NH3 and methane) are not being removed effectively. The higher the stocking density, the more you need to do to keep the litter in good condition: the birds cover the litter like a warm blanket and the ventilation doesn’t reach the litter.

If you don’t intervene, the litter will continue to

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Always go down to bird level to really assess the climate the bird experiences.

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If the nasal cavity gets infected the nostrils will fill with pus and swell up. The infection can spread, causing moisture to accumulate under the skin, sometimes so badly that the eyes are forced shut. These birds won’t be able to find food and drink. This is caused by bacterial infections, often secondary to a viral infection like TRT.

Before you can smell ammonia you can feel it in your eyes. If your eyes start burning or watering, this is the first sign of poor air quality.

You can’t see dust

Dust is bad for humans and animals alike. At first glance you may think it’s not that bad in this house (left), but if you take another picture using flash it becomes clear how much dust there really is (right).

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B roile r Signa ls - Afric a n edi t i on

Heat stress Panting: too hot, short of air, or forewarning of death?

When a broiler gets too hot, it will pant fast with its beak open.

You can tell by the rapid up-and-down movement of its throat. At the same time it will often raise its feathers and hold its wings out slightly from its body, allowing its skin maximum contact with the circulating air to dissipate more heat. If the density of birds in the house is too high and the birds are pressed up against each other, they will struggle to do this. If they can lie with their chests on the ground they can expel heat quite easily through the thinner plumage and thinner fat layer on the chest. But if the litter is too hot they won’t be able to expel heat through the floor.

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As the broilers get older their daily growth rate increases rapidly, as does their feed consumption.

Only 25% of the energy they take in is used for movement, growth, breathing and body temperature maintenance (41°C core temperature). The other 75% is lost in the form of heat. But chickens can’t sweat. Their main way of getting rid of this excess heat is by evaporating moisture during respiration. High relative humidity very soon causes chickens problems: their airways have to work much harder to evaporate moisture into the air.

During hot seasons use sodium bicarbonate (1 g/kg feed) and vitamin C (50 mg/kg feed) to reduce heat stress.

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A broiler’s environmental needs change during its life. At the beginning of the heat it needs has to be supplied. At the end of the production cycle the opposite is true: the house is full, the birds are bigger and they produce a lot of heat that they need to get rid of through ventilation.

Sufficient ventilation is also necessary to get rid of CO2, moisture and NH3, and for the supply of fresh air, which becomes more important he end of the cycle towards the cycle.

Heat stress and gut damage. Don’t feed broilers during the hottest part of the day. In order to get rid of the superfluous heat, more blood flows to the skin and less to the gut. If this lasts too long, gut damage can occur. Less feed in the gut means that less oxygen is needed for digestion and less heat is produced by the body.

8. B re a t h i n g a n d h e a t stres s

Getting G i used d to the h h heat. B Broilers il can ‘learn’ to tolerate higher temperatures. If the temperature increases very gradually, they can withstand temperatures of up to 38°C. In temperature fluctuations of more than 8°C per day, a broiler can’t adjust its body processes fast enough. The ability to adjust also depends on the genetic make-up of the chickens.

Vitamin C against stress. Vitamin C is needed to produce certain stress hormones. Broilers are not yet able to produce enough vitamin C themselves and even less when suffering from heat stress.

It is useful to add extra vitamin C to the drinking water in that case.

Bicarbonate (HCO3) also helps.

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CHAPTER 11

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Broiler health

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There are numerous poultry diseases and it is outside the scope of this book to mention them all.

However, the most important ones need mentioning. Some of them have received due attention on

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other places in this book.

Chickens that are not feeling well often sit in a hunched-up position. This can be a signal of coccidiosis.

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If birds are sick, you can isolate them from the flock. If the disease is contagious you prevent other birds to get infected and you can monitor the health development of the bird.

A clear difference between a healthy and unhealthy bird. Look at the stunted development of the comb, dirty feathering, pale eyes, wattles and comb! In this case there was a problem with calcium in the diet.

B roile r Signa ls - Afric a n edi t i on

Healthy birds A healthy bird is less prone to diseases, grows faster and more efficient and will give you a better price once sold. But do you know how to distinguish a healthy bird from an unhealthy one? nice and cheerful sound

Healthy broiler

clear eyes

red and clear comb and wattles

behaviour: alert, stands up when approached

clean nostrils straight neck concave back

pink and moist mucous membranes

no injuries to head, neck, back and tail

closed beak, normal breathing proudly upright posture

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filled crop full muscled breast straight keel bone

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pink, undamaged breast skin

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wings well positioned along her body straight, yellow legs, and not overly warm straight toes

clean, smooth and even plumage

smooth and flexible joints

firm droppings

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smooth footpads

Unhealthy broiler

screaming, squeaking, congested sound

eyes: mucous, semi-closed, frothy, swollen, white eye, dry, dull/pale in colour

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comb/wattles: pale, purple

swollen nasal cavity

behaviour: sits still in a corner, lethargic and slow convex back

bare and curved neck

pecking and scratching injuries

dirty, moist nostrils

drooping and hunched up posture

open beak, gasping tongue and mucous empty crop membranes pale, dull and dry damaged breast skin: ammonia burn, litter spots, breast blisters

soft, mushy abdomen (ascites) wings drooping along her body or standing out

skinny breast, little muscles wet, soggy litter

crooked keel bone thick joints

hot legs (fever) lame, crooked legs, pulled up foot pad lesions 11. B ro i l e r h e a l t h

plumage: dirty, fluffed out, faded, worn, no symmetry

sitting on hocks (hock dermatitis) 129

If you only look out for technical aspects (daily growth, feed and water consumption, etc.), you may miss other import-ant signals from the broilers and their living environment. Always use all your senses.

‘If keeping laying hens is like running a marathon, broiler production is a sprint. There’s no time for mistakes.’

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A practical guide to broiler focused management

AFRICAN EDITION

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Observe the birds’ behaviour: how do they react to you?

SIGNALS

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The book Broiler Signals African edition follows the bird on a broiler farm in Africa. As day-old chicks they have to be of excellent quality and this book provides you the tools to assess day-old chicks.

After the initial week, the broilers have to start growing fast and efficiently, which asks for a good intestinal health. Once they grow older and larger heat stress might become a problem in warm climates. Leg quality often becomes a problem as the birds get heavier and litter deteriorates towards the end of production. Bringing the birds to the market may include processing broilers in a cold chain requiring a lot of attention to hygiene.

Broiler Signals African edition is a practical guide that shows you how to pick up the signals given by your animals at an early stage, how to interpret them and what action to take.

ISBN 978-90-8740-364-5

What can you smell or do your eyes sting?

A predominant smell of ammonia indicates hot litter.

Feel whether the chick has eaten good feed and enough feed. www.roodbont.com

I m p ro v in g y o u r re s u lt s a n d a n im a l welfa re In theory we all know more or less what to do. But not every poultry farmer puts this theoretical knowledge into practice. So Broiler Signals doesn’t just devote space to the latest insights, but also focuses on how to turn knowledge into effective action.

By consciously examining signals and analysing them you can optimise your operational management step by step.

Steps aimed at improving management: 1. What do I see?

2. Why is this happening?

3. What should I do?

By consistently asking yourself these questions and structurally correcting the management of your birds, your results will improve significantly.

AFRICAN EDITION

BROILER SIGNALS A PRACTICAL GUIDE TO BROILER FOCUSED MANAGEMENT

AFRICAN EDITION

Broiler Signals is part of the successful Poultry Signals© series.

Poultry Signals© presents practical knowledge of animal oriented poultry farming in an easy, accessible format.

A practical guide to broiler focused management

Listen to their breathing. You’ll hear if there are any problems.

Broilers are fast growing animals that need constant care. Your birds continuously send out signals: about their health and whether they feel happy and comfortable. If you are able to recognise these signals in practice, you can use them to improve your management. For the African poultry farmer this means being alert in the broiler house, observing and listening to the birds.

Make sure you have a good start! Everything in place and the farm free of poultry diseases. Also make sure you have procedures to keep it that way! Choose the breed that best fits your circumstances. And do you have sufficient feed of good quality available? Water is the cheapest of all nutrients, but the most important one. Often, water seems a bit neglected. If well managed it supports your production, if not managed well it is a source of problems (bad feed conversion, heat stress, diseases).

BROILER

BROILER SIGNALS

Us e al l y ou r senses

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Because healthy, stress free broilers will benefit your bottom line.