James J. Warren Senior was born on October 10th, 1892, in Batavia, New York. The Warren family started breeding Rhode Island Reds (RIR) in 1923. James J Warren Jr. was born in 1929, graduating with an MSc in Poultry in 1951. In 1956, he took over research at the company and the following year assumed responsibility as General Manager.

One of the important phases of the development programme was the establishment of the Warren Research Farm, set up to test 100s of strains and genetic combinations searching for superior birds. The JJW “blueprint for breeding improvement” was to become a major factor in improving the breeds and crosses, and in developing new and promising combinations of both white and brown egg layers.

In 1958, Jim Warren started working with Mme Studler on the Studler Sex-Sal-Link (SSL). In 1964, it was introduced in to the UK as the Warren Studler Sex-Sal-Link (SSL). The original SSL was extremely efficient, but if it suffered severe stress it would not recover. A different male combination was used to produce the SSL EMP and gave it extreme stress resistance. That was the basis of the success of the SSL throughout the world.

The Warren is the result of extensive consultation, and focused research into the best solution for the rapidly expanding free range sector in the UK. Bred from proven Hendrix lines, it is set to become the champion of free range.

The Warren will be slightly larger framed with all the advantages of modern hybrid egg quality, productivity and performance. Resilient and well behaved, no matter what it encounters, the Warren is ready for the rigours of the range.

A full management guide pdf is available for download below.

Here is some useful information from our guides.

Lighting programmes and other management techniques for our laying hens

The lighting programme should be suitable for your production goals, production system, condition of the flock and time of housing. In general, the step down should be slow enough to allow good early body weight development for the hens. The timing and amount of the first step up in day length is critical, and it should be judged on a flock-by-flock basis, taking account of the flock’s health, body weight development, uniformity, age of movement to laying house, season, system of production and production goals.

The closer to 12 weeks, and the bigger the day length increase, the greater the effect on maturity. Egg size is influenced by the weight at first egg but can also be effectively controlled by nutrition.

Flocks of laying hens that are pushed in to lay too early will risk later production problems. We would recommend producers not to give a light increase before the following criteria are met:

• 1450g Body weight (UK Alternative/Free Range systems)
• 80% Uniformity.

Do not change the lights-off time once the flock is in lay. In practice, this means that we advise you to fix the lights-off time as soon as possible after housing, and to increase the day length by adding light in the morning.

Seasonal variation

Seasonal variation in a controlled environment house (lightproof) can cause seasonal fluctuations of day length to interfere with the hen laying performance. Therefore, for a windowless house, it is also necessary to adapt the standard lighting programme to the hatch season. Flocks hatched in the ‘off season’, with reduced day length, should be light stimulated earlier than birds reared in the increasing day length season. In houses where light control is not possible, the minimum day length should not be less than the natural day length, between 8 and 18 weeks of age.

Rearing chicks

Body weight development
Good early growth is critical, and by 5 weeks, chick body weight should be as high as possible, since frame and internal organ development take place in this period. The birds should be monitored for weekly growth from delivery, and any negative variation to standard should be looked in to.

In particular, the first few days of chick life are crucial to obtaining good development and later uniformity.

Brooding temperatures, provision of ample water, fresh feed, and good bio-security are all important for laying hens. If necessary, the stepping down of the day length should be slowed.

• 5 to 14 weeks – When the chick’s body weight is on or above the standard, try to obtain the same growth per week as the given standard. When their body weight on 5 weeks of age is lower than our standard, it is important to achieve standard body weight as quickly as possible.
• From 14 weeks onwards, try to achieve a body weight as high as possible.

Uniformity
Uniformity of pullet body weight (+/–10%) should be at least 75% at 10 weeks of age and at least 80% from 15 weeks onwards.

Feeding layer chicks
The best possible diets should be fed in the first few weeks of life – financial input here will be rewarded with better production later in life.

• Crumbs/pelleted feed can be useful in maximising early body weight for the hens. After 6 weeks, mash is the favourable feed presentation.
• Clean water should be available at all times to the hens and care should be taken, so there is provision for demand at peak times.

Thorough cleaning after flock depletion and continuous dosing/periodic cleansing, with a suitable product, to maintain water standard, are good practice to reduce bacterial challenge on the birds. After clean-out, any chemicals used to clean the water system must be thoroughly flushed through. Care should also be taken when vaccinating the hens, and no chemicals or residue should be present at this time.

The habit of cleaning up feed in the tracks or pans should be started in the latter half of the rear (by week 7). Ideally by week 7 in rear, the egg layer pullets are trained to ‘mealtimes’ with an eat-out period in the middle of their day. One third of the day’s feed intake should be distributed in the eat-out period and the balance during ‘mealtimes’.

Vaccination
This too is crucial to a successful flock. Consult with your veterinary surgeon as to what vaccinations will be necessary to protect your flock in rear and lay. Apply the vaccine with care to ensure that all birds receive a dose of active vaccine. Managers and staff should be given professional training. The use of proportioners and water buffers is advised.

Monitor the blood titre levels of important vaccines such as IB. If the priming levels are poor, birds should be re-vaccinated at least 14 days prior to receiving inactivated (injected) vaccines. It is a good idea to store sera taken 3 weeks after housing so base line titres can be obtained in case of a suspected challenge of field virus.

Transfer to the laying house
This is a stressful period for the birds due to handling and transport involved in movement from rearing to laying facilities, and the change from rearing to laying environment. This should be done 4 weeks (ideally) and certainly no later than 2 weeks before egg production starts. This will give the bird enough time to adapt to the situation in the new environment.

Preparation – rearing farm
Birds must always conform to the breed body weight.

Light intensity and rearing temperature should be adjusted, over a period of 2 to 4 weeks, and must be equal to the level in the laying house. 2 weeks prior to transfer the birds should not be handled, except for routine uniformity and body weight checks. Chicks must have every opportunity to grow, even during this critical period.

Insoluble grit (where appropriate) should have been provided for the flock, ideally during the entire rearing period, but at least 2 weeks prior to transfer.

Feed withdrawal before departure should not exceed 6 hours and should be adapted to transport duration and climatic conditions.

Preparation – laying farm
An appropriate terminal hygiene programme must be implemented to avoid disease transmission.

Maintenance and repairs to complete before arrival of stock:

• Flush the water system and provide fresh water the day before arrival of new stock.
• Where nipple lines are used, ensure the height is slightly above the back of the birds (for the first 7 days), then raised to ensure birds “comfortably stretch” to use the nipples. Bell drinkers should be filled to double the normal depth, and lowered to a height of 20 cm above floor level, for the first 2 or 3 days.

The house should be dried prior to the arrival of the new flock and preheated in cold season.

Transfer
An ideal time for transfer laying hens is during the early morning. If the birds are unloaded by the time their day started on the rearing farm, disturbance to their routine of drinking and eating is minimised.

Transport vehicles and equipment must be clean and disinfected.

The flock should be transferred within the same day according to local legislation.

The whole procedure should be fast with the loading of the birds, transport and unloading all conforming to local regulations. Additionally, every effort should be made before and after transfer to maintain water and feed intake according to the normal routine of the stock.

Precautions should be taken to minimise undue exposure to wind and rain/sun during transfer procedure.

Fibre for egg layers
Egg layers have a specific requirement for fibre. Deficiency in fibre can lead to feather pecking. Poor feathering observed in a flock without feathers visible on the floor could be a sign of a lack of fibre. A good supply of fibre improves feathering, decreases mortality, improves gut health and digestion. Fibre provided to layer hens must be insoluble and as much as possible of a coarse presentation. Fibre could be provided through the feed by oilseed meal (sunflower/rapeseed), alfalfa (or lucerne) and oats. Cereal by-products could provide a good amount of fibre in the feed, but their presentation is usually too fine to have ‘structure effect’ on the digestive tract. In alternative systems, fibre could be provided directly in the building. We advise the use of a coarse fibre such as straw, alfalfa (or lucerne), wood shavings, rice/oat husk, silage etc. These materials must be available in the building through round feeders or directly as a ball on the scratching area. Hens must have a free and ad libitum access to fibre sources. We advise not to spread fibre directly on the floor. To prevent floor eggs, fibre supply must be introduced after peak production when the birds are well trained to use the nest.

Preparation for the rearing farm
Layer chicks must always conform to the breed body weight. Light intensity and rearing temperature should be adjusted, over a period of 2 to 4 weeks, and must be equal to the level in the laying house. Two weeks prior to transfer, the birds should not be handled, except for routine uniformity, and body weight checks.

The chicks must have every opportunity to grow, especially during this critical period. Insoluble grit (where appropriate), should have been provided for the flock, ideally during the entire rearing period, but at least two weeks prior to transfer. Feed withdrawal before departure should not exceed 6 hours, and should be adapted to transport duration and climatic conditions.

Preparation for the laying farm
An appropriate terminal hygiene programme must be implemented to avoid disease transmission between hens.

Maintenance and repairs to complete before arrival of stock:

• Flush the water system and provide fresh water the day before arrival of new stock. Where nipple lines are used, ensure the height is slightly above the back of the birds (for the first 7 days), then raised to ensure birds “comfortably stretch” to use the nipples.
• Bell drinkers should be filled to double the normal depth, and lowered to a height of 20 cm above floor level, for the first 2 or 3 days. The house should be dried prior to the arrival of the new flock and preheated in cold season.

Transfer
An ideal time for transfer is during the early morning. If the birds are unloaded by the time their day started on the rearing farm, disturbance to their routine of drinking and eating is minimised. Transport vehicles and equipment must be clean and disinfected. The flock should be transferred within the same day, according to local legislation.

The whole procedure should be fast with the loading of the birds, transport and unloading, all conforming to local regulations. Additionally, every effort should be made before and after transfer, to maintain water and feed intake according to the normal routine of the stock.

Precautions should be taken to minimise undue exposure to wind, rain, or sun, during transfer procedure.

After housing
The period of the first 48 hours after housing the egg layers is a critical period. Close supervision and observation are required to ensure the normal behaviour of the entire flock. The following points should be noted:

• Water consumption – normal drinking habits, within 6 hours after arrival.
• Temperature – ideally 15°C. 18°C is the maximum temperature. It is important that birds do not become chilled but they must have fresh air.
• Feed consumption – increasing appetite/intake.
• General attitude of the flock – at first it will be quiet, but should gradually become more active and ‘talkative’, but not frenetic or hyperactive.
• If slats are incorporated in the house, the egg layers have to be encouraged to perch during the dark night period. This may take 3 to 7 days to occur prior and during lights off.
• Keep nest boxes closed until 7 days prior to the expected onset of lay, or until you see the first egg.
• Open them almost 2 hours before the main house lights, and keep open until late afternoon.
• Light intensity must be high – please consult your breed representative on housing but it should be gradually reduced to the recommended levels shown.
• Dim the light gradually at light off – please consult your breed representative for advice.
• It is recommended egg layers are kept on the system for a few days if they are not reared on a partly slatted house (according to local regulations).

Laying Period

Body weight after 16 weeks
After 16 weeks, the hen’s body weight development is critical for a good start to production:

• Avoid unnecessary stress to the birds during this time
• House the hens before 17 weeks
• Give a prelay diet but ensure the birds are on the layer feed before production starts

Changes in diet are dependent on the production level, body weight, and feed intake - and not on age of the bird.

Feeding

• Deviation from body weights and feed amounts may occur due to season, housing system, feed composition, transport and health status of the flock.
• The feeding programme should be synchronised with the lighting programme to bring the flock into production in a good condition and at the desired age. Feed intake should be measured.
• From 16 to 21 weeks it is critical that the feed intake increases, in order to let the birds grow to achieve target body weight.
• It is good practice to empty the feeders during the middle part of the day. This encourages good feeding behaviour, allowing a good crop of feed to be consumed before the dark period and ensures the whole ration is consumed. Care should be taken to avoid restriction – the birds should be working for the last bit of feed in the pan, track or trough rather but not to the point it is bare. Uniform feed distribution is important in this respect and it may be necessary to feed twice in quick succession after the feeding gap.
• Ideally changes in diet, including raw materials used, should not be made between peak and 40 weeks. Ensure the flock is on a suitable diet to take them through to post 40 weeks by the time peak is reached.
• After 6 weeks, mash is the favoured feed presentation rather than crumbs or pellets. It also allows more granular forms of calcium which help provide this nutrient at the right time for shell formation.
• Birds have a strong preference for coarse particles – they tend to leave the fine part of the feed. Consequently, the feed needs to be uniform with a maximum of 10% coarse particles above 3.2mm and 15% maximum of fine particles below 0.5mm. Too high proportion of coarse particles will lead to feed sorting, uneven body weight and laying performance, too high proportion of fine particles will decrease feed consumption.
• Birds also do not like variation in feed presentation. Similarly to fine particles, variation in feed presentation decreases feed consumption.
• Addition of 1% oil to mash layer feed is recommended

to improve feed presentation. Oil sticks the finest particles and makes them easily ‘eatable’.

• In the case when the feed intake is very low or the feed presentation is poor, crumbs can be used, they are easy to take by beak and each particle is nutritionally balanced. Crumbs increase water intake and wet droppings

and a change from crumbs to mash can decrease feed consumption.

• Feed distribution during the time that egg laying is intensive increases dirty eggs and floor eggs.

Fibre for layers
Birds have a specific requirement for fibre. Deficiency in fibre can lead to feather pecking. Poor feathering observed in a flock without feathers visible on the floor could be a sign of a lack of fibre. A good supply of fibre improves feathering, decreases mortality, improves gut health and digestion.

Fibre provided to layer flocks must be insoluble and as much as possible of a coarse presentation.

Fibre could be provided through the feed by oilseed meal

(sunflower/rapeseed), alfalfa (or lucerne) and oats. Cereal by-products could provide a good amount of fibre in the feed, but their presentation is usually too fine to have ‘structure effect’ on the digestive tract.

In alternative systems fibre could be provided directly in the building. We advise the use of a coarse fibre such as straw, alfalfa (or lucerne), wood shavings, rice/oat husk, silage etc. These materials must be available in the building through round feeders or directly as a ball on the scratching area.

Birds must have a free and ad libitum access to fibre sources. We advise to not spread fibre directly on the floor. To prevent floor eggs, fibre supply must be introduced after peak production when the birds are well trained to use the nest.

Water
The water is the most critical nutrient for the poultry. The daily control of water consumption is essential. If a hen does not drink, it will not eat and cannot produce.

Water quality
Good quality drinking water is very important for production animals. Hens must always have easy access to the drinking water, the water must be fresh and bright. Taste and smell seem to be of less importance to the birds, but are indicators for the water quality.

Monitoring water quality
The value of any analysis depends on when, where, and how the sample has been taken (where it enters the house or at the end of the system). You should not forget that an analysis only refers to the quality of the water at the time, when the sample was taken, and is never a guarantee of its quality at another time.

Where farms have their own water supply, it is necessary to take a sample at least twice a year (once at the end of winter, the other at the end of summer). On farms using the mains supply, an annual measurement should be adequate. In addition, if egg layers are or have been treated with medication, or vitamins through the water system, take care to avoid a build-up of bio-film. It is important to realise that the sodium thiosulphate contained in the flasks, supplied by the laboratories carrying out bacteriological tests on water, only neutralises chlorine or bleach. It has no action on quaternary ammonium compounds.

Water consumption
Water consumption depends on ambient temperature. Above 20°C, consumption increases to enable the bird to maintain body temperature (respiratory evaporation). The actual consumption depends on temperature and humidity of the ambient air. The following shows the relationship between water and feed consumption according to house temperature:

Water to feed ratio according to temperature in rearing and laying period

Temperature
Although the laying hen can tolerate a wide range of temperature variation, and still perform well, excessive fluctuations in environmental temperatures are detrimental to productivity and efficiency. At the beginning of the production period, the ideal house temperature is between 21-24°C, slowly increasing as the hen ages. Temperatures below 12°C and above 28°C will negatively affect performance. Lower house temperatures will increase feed consumption and lead to a larger egg size. Higher house temperatures can slow egg size increase and limit feed consumption early in lay. Higher house temperature can be utilised later in lay to control feed consumption and prevent excessive egg size.

Air quality
It is necessary to maintain good air quality – minimum ventilation rates should be maintained at all times. All areas of the house should have some level of air movement. A minimum ventilation rate of 1.5m3/hour/kg of body weight should be maintained.

Light intensity
A uniform distribution of light is recommended.

Floor system flocks may be reduced to 6 lux once peak lay has been reached.

Collecting floor eggs
It is important to start collecting floor eggs as soon as the lights in the house are switched on. This reduces the number of floor eggs, and trains the hens to lay in the nest boxes. To reduce the number of floor eggs, it is also crucial to have a good nest box:

• The nest box should be free of draught.
• Entrance to the nest should be clearly visible to the birds.
• Nest boxes should be easily accessible and preferably be located in the centre of the house.

To prevent floor eggs, the water lines are ideally positioned near to the nest boxes, so that all the hens will have to visit that area, and be encouraged to explore the nest boxes.

• Open the nest boxes with nest box lights switched on 7-10 days before start of production. Do not disturb the birds during the main laying period.
• When floor eggs are found just after lights go on, open the nest boxes earlier, or place small light bulbs in the centre of the house and light these light bulbs ½ hour to 1 hour before normal lights go on.
• Collect floor eggs several times per day.
• Do not disturb the birds during laying. Minimise feeding times from between 3 and 6 hours after lights go on.
• Diminish the number of dark spots in the house, because dark spots can increase the number of floor eggs.
• Place obstacles in places where birds continue to lay floor eggs.

General management

Good bio-security practices should be maintained at all times. Visitors should be restricted and those that are necessary should be provided with clean boots and overalls. Hand washing should be enforced before and after contact with the livestock. Feed spills should be cleaned up promptly, and the site should generally remain tidy and free from vermin refuges.

Houses should be wild bird proof and pets kept from contact with the poultry. Floor system birds should be regularly wormed. Red mites, flies, and other vermin should be monitored and populations kept under control. Management of the ranging area for free range and organic flocks is a wide and complex subject but it is crucial to success.

In particular, the area of close proximity to the house should be well drained and its use rotated. Between crops it should be ideally turned and re-seeded. Fencing should be maintained, in order to prevent losses to predators.

For further information on nutritional guidance, please ask your breed representative for our comprehensive Nutrition Guide.

General principles of lighting programmes during the production period

In production, as well as in rearing, the lighting programme greatly influences feed consumption. In addition, during all their life, hens remain sensitive to changes in the duration of illumination. The objective of the lighting programmes during the production period is:

• To encourage growth at the start of lay
• To counteract the harmful effects of decreases in natural day length
• To control the livability through the light intensity management
• To improve eggshell quality

Other lighting programmes can also be introduced during the production period, to adapt the egg weight to market demand, to improve eggshell quality, or to control feed intake for some breeds. Do not change the lights-off time once the flock is in lay. In practice, this means that we advise to fix the lights-off time as soon as possible after housing and to increase the day length by adding light in the morning.

Light intensity in production

The light intensity required is low. No significant differences have been found in the different trials with today’s breeds. But as stated for the rearing period, we encourage an increase in light intensity for a few days from the transfer time, in order to help the hen to discover its new environment and to easily find water and feed systems. Thereafter, the light intensity can be reduced step by step, to a minimum of 0.5 lux at the feeder level in the dimmest areas of the laying house, as long as during the rearing stage, light intensity doesn’t exceed 10 lux.