Parent Stock Management Manual ROSS308

Transcription

1 Parent Stock Management Manual ROSS308

2 This Manual The aim of this manual is to assist farm staff and owners of Ross broiler parents to achieve the highest possible performance from their stock. It is not intended to provide definitive information on every aspect of stock management, but draw attention to important features that if overlooked may depress flock performance. The management techniques contained in the manual are considered to be the most appropriate to achieve good performance consistent with maintaining the health and welfare of the birds. In this connection due regard has been paid to the welfare recommendations for livestock detailed by the UK Department of the Environment, Food and Rural Affairs (DEFRA). Aviagen also encourages owners and managers of Ross stock worldwide to adopt a similar policy in this respect. Performance Performance can be influenced substantially by many factors including flock management, health status and climatic conditions. Data contained in the manual indicate those levels of performance which can be achieved under good management and environmental conditions, where the breeder strategy is to have 5% production at 23 weeks. Every attempt has been made to ensure the accuracy and relevance of the information presented. However, Aviagen accepts no liability for the consequences of using the information for the management of chickens. Variations may occur for a variety of reasons. For example, feed consumption can be affected significantly by form of feed, energy level and house temperature. Data presented in this manual should not, therefore, be regarded as Specifications but as Performance Objectives. Technical Services For further information on the management of Ross stock please ask your local Technical Service Manager or contact the Technical Services Department. Aviagen Limited Newbridge Midlothian EH28 8SZ Scotland UK tel +44 (0) fax +44 (0) infoworldwide@aviagen.com Aviagen Incorporated Cummings Research Park 5015 Bradford Drive Huntsville Alabama USA tel fax info@aviagen.com March ROSS308 1

3 INTRODUCTION Aviagen produces a range of genotypes suitable for different sectors of the broiler market. All of Aviagen products are selected for a balanced range of parent stock and broiler characteristics. The range of Ross genotypes allows users to select the Ross product which best meets the needs of their particular operation. In the broiler house, all Ross broilers are fast growing, feed efficient and have excellent liveability. The broilers have been selected to be vigorous with strong legs and robust cardiovascular systems. In the processing plant, Ross broilers are designed to have high carcase yield and meat yield with low numbers of downgrades. As parent stock all Ross genotypes are selected to produce the maximum number of vigorous day-old chicks by combining high egg numbers with good hatchability and fertility. This is achieved by mating together male lines which are fast growing, feed efficient and have high meat yield with female lines which lay high numbers of eggs which will produce broiler chicks with specific broiler qualities. This manual summarises best practice in parent stock management for Ross 308. Ross 308 is aimed at producers who require high numbers of feather sexable broiler chicks which will be used in a range of different end products. The Ross 308 broiler is very fast growing with exceptional FCR and high meat yield. It therefore satisfies the needs of broiler producers who require versatility to produce a range of chicken products (e.g. whole bird, portions and further processing). Integrators worldwide favour the Ross 308 because it continues to add value to all aspects of their business. USING THIS MANUAL Finding a topic Printed tabs appear on the right-hand side of the Manual. These allow readers immediate access to those sections and topics in which they are particularly interested. The contents list presented here gives the title of each section and subsection. There is also an alphabetical Key Words Index at the rear of the manual. Key Points Where appropriate, key points have been included which emphasise important aspects of husbandry and management. They are highlighted by a red heading and red ticks in the left-hand margin alongside the text. Certain danger points have been given emphasis using this sign and bold text. Performance Objectives Performance Objectives have been reproduced as a separate booklet which is enclosed at the rear of the manual. This will allow for regular updating. 2

4 Section 1 Rearing Days (0-15 Weeks) MANAGEMENT REQUIREMENTS FOR MALES AND FEMALES 6-8 BROODING 8-13 BODYWEIGHT CONTROL AND FEEDING 14 MEASUREMENT OF BODYWEIGHT AND UNIFORMITY CONTROL OF FEEDING TO MANAGE BODYWEIGHT GRADING TO MANAGE UNIFORMITY Section 2 Management into Lay Days (15-30 Weeks) MANAGEMENT OF FEMALES 105 DAYS (15 WEEKS) TO LIGHT STIMULATION MANAGEMENT OF MALES 105 DAYS (15 WEEKS) TO LIGHT STIMULATION 25 MANAGEMENT PROCEDURES MANAGEMENT OF FEMALES PRE-PEAK PERIOD, LIGHT STIMULATION DAYS (30 WEEKS) MANAGEMENT OF MALES PRE-PEAK PERIOD, LIGHT STIMULATION DAYS (30 WEEKS) Section 3 Management in Lay Days (30-64 Weeks) MANAGEMENT OF FEMALES POST-PEAK PERIOD DAYS (30-64 WEEKS) MANAGEMENT OF MALES POST-PEAK PERIOD DAYS (30-64 WEEKS) Section 4 Specific Environmental Requirements HOUSING AND ENVIRONMENT NUTRITION LIGHTING CARE OF HATCHING EGGS HYGIENE AND HEALTH APPENDICES INDEX OF TABLES 82 INDEX OF DIAGRAMS 83 KEY WORD INDEX

5 CRITICAL AGE OBJECTIVES In order to achieve the maximum numbers of vigorous day-old chicks, it is essential to understand the requirements of the Parent Stock flock at each stage of its life. Critical age objectives for Parent Stock are summarised below:- AGE KEY OBJECTIVES 1-3 days Appetite development 3-28 days Achievement of target bodyweights at 7, 14, 21 and 28 days 28 days Grade. Target is < 12 CV% at 28 days to permit 2 way grading days Control growth within each graded population days Stabilise populations to achieve correct incremental growth 70 days Re-draw bodyweight targets (if required) days Achieve correct incremental growth 105 days Increase feed to stimulate growth Re-draw bodyweight targets (if required) days Achieve correct incremental growth days Give first light increase days Achieve correct incremental growth emphasising uniformity of sexual maturity days Increase feed in response to egg production, bodyweight gain and egg weight gain 210 days-depletion Control bodyweight gain and egg weight by removing feed. Manage males by observation of bird condition. Remove nonworking males to maintain mating ratios. 4

6 Section one Rearing Section one Rearing Days (0-15 Weeks) page Contents 6 Management Requirements for Males and Females 8 Brooding 14 Bodyweight Control and Feeding 14 Measurement of Bodyweight and Uniformity 16 Control of Feeding to Manage Bodyweight 18 Grading To Manage Uniformity ROSS308 5

7 MANAGEMENT REQUIREMENTS FOR MALES AND FEMALES Objective To provide male and female parent stock with their requirements during each stage of rearing, in order to prepare them for sexual maturity. Principles Ross broiler parents exhibit the same inherent rapid growth and feed efficiency characteristics as the broiler generation. Growing the Ross broiler parent to the target growth curve allows males and females to achieve optimum lifetime performance and welfare. To achieve the objectives of the rearing period, the birds must be grown to the target bodyweight-for-age, maintaining accurate control by careful sample weighing and adjustments of feed allowances. Accurate and appropriate grading will aid good uniformity. Diagram 1 shows how the bird grows in phases, with development of different organs and tissues occurring in sequence as the birds age. In each phase of growth, the stock attendant must consider the organ or tissue that is developing at that time. Diagram 2 (page 7) indicates the important management considerations at each age and follows the phases of growth shown in Diagram 1. The principles for managing males and females in the rearing period are the same, although the target bodyweights are different. Although males constitute a small percentage of the flock in terms of bird numbers, they will form 50% of the breeding value. Males therefore are just as important as females. Throughout the rearing period, however, the management of males will require more effort to achieve a successful result. The most successful users of Ross parent stock grow males and females separately from day old to mating at days (20-22 weeks) of age. Where it has been traditional practice to mix males and females at young ages, the growth and development varies according to their different abilities to compete for feed within the single population. Although the practice can be successful, it does not allow the growth and uniformity of males and females to be controlled separately and generally does not allow the maximum potential for chick production to be achieved. If, for organisational reasons, it becomes necessary to mix the sexes early, this should never be done before 42 days (6 weeks) of age, so that males achieve the correct skeletal development. In flocks of mixed sexes, it is the female bodyweight in relation to target that will be used subsequently to determine overall feed levels. DIAGRAM 1: PHYSIOLOGICAL DEVELOPMENT 6

8 Physiological objectives are detailed in Diagrams 1 and 2 (pages 6 and 7). Objectives To ensure good early development of skeletal size, immune system, cardiovascular function, feather growth and appetite. To obtain the best possible uniformity. Principles REARING FROM 0-28 DAYS (0-4 WEEKS) The Ross bodyweight targets in the early stages of rearing can only be achieved by ad libitum feeding of a good quality ration from day old. Feed intakes should be recorded from day old, so that a smooth transition can be achieved from ad libitum to controlled feeding. Feed allowances should never be reduced. In order to maximise performance, birds should be on or over target bodyweight by 7-14 days. Flocks that fail to achieve target tend to lose uniformity. Subsequently bodyweights are difficult to achieve and uniformity deteriorates further. To ensure that chicks achieve target bodyweight a Starter 1 diet, in crumb form, should be provided for the first 14-21days (2-3 weeks). (See Nutrition, page 48). Once the birds are 20-40g over target bodyweight, the Starter 2 can be introduced. Twice weekly weighing of birds must be undertaken to monitor results during the transition from Starter 1 and Starter 2, and where target bodyweight is not being achieved. A useful method for giving early indication of development of appetite is to assess the proportion of chicks that have fed by monitoring the number of chicks with full crops. By 3 days of age 100% of the chicks should have full crops. If there is any evidence that birds are not growing to target bodyweight, then the age at which constant daylength will be achieved can be delayed. Flock uniformity can also be improved later in this period by providing frequent small increases in feed allowances, rather than by making changes weekly. Bodyweight falling behind target weight-for-age at any stage during the early rearing period, or signs of failure of appetite development require immediate action. Action taken at this stage will prevent difficulties at later stages in dealing with the consequences of poor uniformity and poor development of essential physiological functions. DIAGRAM 2: MANAGEMENT PROGRESSION 7

9 Physiological objectives are detailed in Diagrams 1 and 2 (pages 6 and 7). Objective To bring the whole flock to standard bodyweight-for-age, prior to 70 days (10 weeks). Principles REARING FROM DAYS (4-10 WEEKS) The period from days (4-10 weeks) is one of rapid growth and development of the broiler parent. Good control of bodyweight gain using increasing quantities of feed is essential. During this stage, small changes in the quantity of feed consumed, can have large effects on bodyweight. Therefore, monitoring of bodyweight is important. The feeding programme is only a guide to the amount of feed required. Changes to quantities of feed required should be calculated using the deviation from target bodyweight curves and the amount of feed currently allocated. allowed to grow to target. Small increases in feed quantity may be necessary (1-2g/bird/day). In situations where birds are more than 100g ahead of the bodyweight targets, a new target line should be drawn parallel to the recommended line (see Post Grading Management, page 20). These birds should achieve the same incremental growth as birds on the target line. In males, sexual organs begin to develop from 70 days (10 weeks). Stress or interruption in growth over this period will affect growth of the testes and reduce adult fertility. Key Points Grow males and females separately until mating (18-23 weeks). Achieve early bodyweight targets to facilitate successful rearing. Ensure that birds achieve weekly bodyweight targets. Use small but regular feed increases to promote good early uniformity. Both sexes may need to be graded within this period (see Grading to Manage Uniformity, page 18). The different colonies established at grading should be managed separately with the aim of creating a single population of birds for each sex by 70 days (10 weeks) of age. The period days (6-13 weeks) is crucial in the development of males. During this period there is rapid development of legs (i.e. muscles, ligaments and bones). Any deviation from the target growth profile may cause subsequent problems with liveability and performance of adult males. Physiological objectives are detailed in Diagrams 1 and 2 (pages 6 and 7). Objective REARING FROM DAYS (10-15 WEEKS) To maintain the appropriate growth profile and flock uniformity throughout the period in preparation for the transition to sexual maturity. Objectives To ensure a strong growth progression from day-old through to 7 days, to achieve target bodyweight by 14 days (2 weeks), and to ensure that this is maintained on a smooth growth curve through to 28 days (4 weeks). To achieve the successful establishment of the flock from day-old, to develop appetite, to promote feather growth and to maintain uniformity across the flock. Principles BROODING Chicks must be provided with the correct temperature profile, relative humidity, air quality, good quality feed and water and appropriate stocking density. Subsequent high levels of performance in the laying period are dependent upon achieving high standards of management in the early stages of the birds lives. CHICK PROCESSING Principles Growth during this phase is relatively unresponsive to changes in quantity of feed provided. Birds should be The lifetime welfare of the flock can be improved by certain procedures carried out either at the hatchery or in the first few days of life. These include dubbing, 8

10 de-toeing or de-spurring of breeder males and beak trimming of males and females. The necessity for any of these procedures should be reviewed frequently, and requirements specified for each flock. Hatchery Processing of Male Parent Stock To prevent damage to the female at mating it is generally advisable to remove the claw of the rear toe on each foot (i.e. dew claw) of the male chick and cauterise at the hatchery. The presence of undubbed males facilitates earlier, effective separate sex feeding. This will also help maintain fertility in older flocks. Males with complete combs are less susceptible to heat stress. Complete combs can, however, be more susceptible to damage from equipment and when males fight. De-spurring and dubbing (i.e. comb removal) of male chicks is not necessary. the chicks arrive. (See also, Hygiene and Health, page 60). Temperatures should be checked at chick level. If insufficient time is allowed for floor temperature to reach house temperature, there is a danger that chicks will become chilled. Chick behaviour is the most important indicator of temperature. Livestock attendants must respond quickly to changes in chick behaviour. Fresh litter should be laid to a depth of 10cm (4in) except where floor feeding is to be practised, when litter depth should not exceed 4cm (1.5in). Excessive litter can create a problem of litter subsidence leading to accidental burial of chicks. Drinker height should be adjusted in response to litter subsidence. BROODING AREA PREPARATION Beak Trimming Beak trimming is not recommended for males or females unless there is clear indication that suffering would be caused in the flock if it were not carried out. In exceptional circumstances, beak trimming may be undertaken at 4-5 days of age using a precision beak trimmer. It is preferable to allow chicks to settle and to be feeding before beak trimming, than to attempt this procedure at the hatchery. Beak trimming requires a high level of skill, concentration and precision and should always be carried out by trained personnel. The objective should always be to remove the least amount of beak, minimising stress on the chicks in the short- and long-term. A similar amount should be trimmed from the beak of each bird. Two basic systems of temperature control are used: - Spot Brooding - Whole House Brooding Brooding down the centre of the pen is most likely to achieve uniform chick distribution. This principle applies to both radiant and hot air systems. A typical spot brooding layout for 1,000 day old chicks is shown in Diagram 3. DIAGRAM 3: TYPICAL SPOT BROODING LAYOUT (1000 CHICKS) FOR DAY ONE Uniformity problems can be caused by variation in quality of beak trimming Great care must be taken to ensure perfect cauterisation when beak trimming, to reduce the possibility of infection. It is essential that only properly trained staff, using the correct equipment should be employed for beak trimming and it should be carried out in consultation with a veterinary adviser. HOUSE PREPARATION Houses and equipment must be cleaned, disinfected and set up in time for the brooders to be started and temperatures to reach the desired level 24 hours before Chick placements should be planned so that chicks from different aged donor flocks can be brooded separately. Chicks from very young donor flocks will catch up with the others if kept separate for the first days (2-3 weeks). It is good practice to allocate areas into which to grade birds before the chicks arrive. (See Grading to Manage Uniformity, page 18). 9

11 Chicks must be placed in the brooding area immediately after they arrive. Full chick boxes should never be stacked within the brooder house. Empty chick boxes should be removed from the building and destroyed as soon as possible. Great care must be taken in allocating equal numbers of chicks to each brooder area. The requirements for vaccination and provision of competitive exclusion products are discussed in Hygiene and Health (page 60). DIAGRAM 4: SPOT BROODING - AREAS OF TEMPERATURE GRADIENTS On arrival at the farm, the chicks require drinking water and fresh feed. Birds given early access to feed and water have been shown to have better early growth and uniformity than birds in which feeding was delayed. A maximum of one day s supply of feed should be provided daily to avoid problems associated with stale food. Small amounts of feed should be given frequently (i.e. 5-6 times per day), to encourage eating. To encourage even distribution of chicks, the brooder light should be raised initially, followed 2-3 days later by switching on the adjacent rows of house lights. BROODING TEMPERATURES Chick behaviour must be continuously and carefully observed during the brooding period, as this is the best indicator of the correct temperature. (See Diagram 5). Thermometers should be placed at bird height throughout the house to validate automated systems. Uneven chick distribution is a sign of incorrect temperature or draughts. DIAGRAM 5: BIRD DISTRIBUTION UNDER BROODERS The house must be at required brooding temperature 24 hours before the chicks are due to arrive. TEMPERATURE TOO HIGH TEMPERATURE CORRECT Spot Brooding The initial temperature under the brooders should be C (88-91 F). Thereafter, temperature under the brooders should be reduced by an average of C ( F) per day. (See Table 1). Initial house temperature should be C (75-80 F). House temperature should be reduced in line with brooder temperature to achieve a final house temperature of C (68-72 F) by days. Diagram 4 illustrates the areas of temperature gradients under conditions of spot brooding. TABLE 1: BROODING TEMPERATURES WHOLE HOUSE SPOT BROODING Chicks make no noise Chicks pant, head and wings droop Chicks away from brooder TEMPERATURE TOO LOW Chicks crowd to brooder Chicks noisy, distress-calling Chicks evenly spread Noise level signifies contentment DRAUGHT This distribution requires investigation Influenced by draught - uneven light distribution - external noises Age Temp C Age Temp C (days) (days) Brooder Edge 2m House A B C D/O 29 D/O Brooding surrounds may be used to control early chick movement. The area contained by surrounds should be expanded gradually from 3 days of age until 5-7 days, when surrounds should be removed. For the first hours, illumination should be continuous, depending on chick condition and behaviour, after which day length and light intensity should be controlled. (See Lighting, page 50). The only house illumination necessary will be in the form of circles of light 4-5m ( ft) diameter per 1,500 chick capacity. The light should be bright, lux 10

12 ( foot candles). The remainder of the house should be darkened or dimly lit. The illuminated area of the house should be increased in proportion to the stocked area. For the first hours, illumination should be continuous, depending on chick condition and behaviour, after which day length and light intensity should be controlled. (See Lighting, page 50). Whole House Brooding Where a whole house brooding system is used, the initial brooding temperature at chick level should be C (84-88 F). House temperature should be reduced gradually, in response to bird behaviour and condition, to achieve a final temperature of C (70-72 F) by days. (See Table 1, page 10). It is less easy to use chick behaviour as an indicator of satisfactory temperature than with spot brooding, because there are no obvious heat sources (see diagram 6). Often, the noise made by the birds may be the only indication of distress. The birds will, given the opportunity, congregate in the areas where the temperature is closest to their requirements. Some care is needed in interpretation of chick behaviour. DIAGRAM 6: TYPICAL BEHAVIOUR OF CHICKS IN WHOLE HOUSE BROODING AT DIFFERENT TEMPERATURES TOO HIGH CORRECT TOO LOW begin to dehydrate, causing negative effects on performance. In such cases action should be taken to increase RH. Poor performance and loss of uniformity can result from low relative humidity in the first week. If the house is fitted with spray nozzles (i.e. foggers) for cooling in hot climates, then these can be used to increase RH during brooding. Chicks kept at appropriate humidity levels are less prone to dehydration and generally make a better, more uniform start. As the chick grows, the ideal RH falls. High RH from 18 days onwards can cause wet litter and its associated problems. As liveweight increases, RH levels can be controlled using ventilation and heating systems. INTERACTION BETWEEN TEMPERATURE AND HUMIDITY All animals will lose heat to the environment by evaporation of moisture from the respiratory tract and through the skin. At high RH, less evaporative loss occurs increasing the animals apparent temperature. The temperature experienced by the animal is dependent on the dry bulb temperature and RH. High RH increases the apparent temperature at a particular dry bulb temperature, whereas low RH decreases apparent temperature. The temperature profile in Table 1 (page 10) assumes RH in the range 60-70%. Table 2 shows the predicted dry bulb temperature required to achieve the target temperature profile over a range of RH. The information in Table 2 can be used in situations where RH varies from the target range (60-70%). If RH is outside the target range, the temperature of the Humidity Relative Humidity (RH) in the hatcher, at the end of the incubation process will be high (approx. 80%). Houses with whole house heating, especially where nipple drinkers are used, can have RH levels as low as 25%. Houses with more conventional equipment (i.e. spot brooders, which produce moisture as a by-product of combustion and bell drinkers, which have open water surfaces) have a much higher RH, usually over 50%. To limit the shock to the chicks of transfer from the incubator, RH levels in the first 3 days should be around 70%. RH within the parent rearing house should be monitored daily. If it falls below 50% in the first week, chicks will TABLE 2: DRY BULB TEMPERATURES REQUIRED TO ACHIEVE TARGET APPARENT EQUIVALENT TEMPERATURES AT VARYING RELATIVE HUMIDITIES Age Conv. Temperature at RH% (days) Temp C RH% Ideal range

13 house at chick level can be adjusted to match that given in Table 2 (page 11). At all stages, chick behaviour should be monitored to ensure that the chick is experiencing an adequate temperature. If subsequent behaviour indicates that the chicks are too cold or too hot, the temperature of the house should be adjusted appropriately. When RH falls below 50% during brooding, action to increase RH is required to prevent chicks becoming dehydrated VENTILATION Chicks must be kept at the correct temperature with an adequate supply of fresh air. It is good practice to establish a system of minimum ventilation during brooding. This should replenish oxygen and remove carbon dioxide and noxious gases produced by the chicks and possibly the heating system. The minimum ventilation requirements are given in Appendix 6 (page 77), (see also Housing and Enviroment, page 40). Excessive chick noise is a sign of incorrect temperature Poor air quality due to under-ventilation at brooding may cause damage to the surface of the lung, making the bird more susceptible to respiratory disease. If the chicks are too warm in the first 10 days, then they will not start well. Food intake and therefore early growth will be depressed and feathering will be patchy and slow. HIGH AMBIENT TEMPERATURES STOCKING DENSITY 0-28 DAYS (0-4 WEEKS) Bird floor space allowance should be increased progressively so that by 28 days (4 weeks) birds are stocked at 4-7 birds/m 2 ( ft 2 /bird). See Table 3. TABLE 3: STOCKING DENSITIES Under conditions of high ambient temperatures, acclimatisation enables birds to function well at operating temperatures (see below for definition) up to C (82-86 F), provided that consideration is given to stocking density, air speed/ventilation and humidity. Evaporative cooling pads, high pressure fogging and/or the operation of in-house fans are used to reduce house temperature. (See Housing and Environment, page 40). Rearing days (0-20 weeks) Males birds/m 2 (ft 2 /bird) Females birds/m 2 (ft 2 /bird) 3-4 ( ) 4-7 ( ) Production days (20-64 weeks) Males and Females birds/m 2 (ft 2 /bird) ( ) In open-sided or curtained houses in areas with high diurnal temperature fluctuations, situations arise where brooding temperatures may move out of the range given in Table 1 (page 10). In such cases, it is acceptable for temperatures to be reduced by C/day from 1-10 days. However, from days the daily reduction should be limited to 0.3 C. Operating temperature is defined as the minimum house temperature plus 2 /3 of the difference between minimum and maximum house temperatures. It is important where there are significant diurnal temperature fluctuations. e.g. OPERATING TEMPERATURE Minimum house temperature 16 C. Maximum house temperature 28 C Operating temperature = [ (28-16) x 2 /3 ] + 16 = 24 C FEEDING AND DRINKING SPACE An allowance of 5cm (2in) of track space per bird, or 1 chick feeder per birds should be provided in the first 2-3 days. The first feed should be given on feeder trays or paper occupying up to 25% of the brooding area. The 5cm feed space allowance is suitable up to 35 days, 10cm (4in) to 70 days and thereafter 15cm (5.5in) will be required. See Table 4 (page 13). Feed should be given in crumb or mash form for the first 21 days (3 weeks). It is good practice to monitor the feeding activity of chicks. An indication of feeding activity is given by the extent of crop fill. By 24hrs after placement > 80% of chicks should have full crops. By 48hrs after placement > 95% of chicks should have full crops. By 72 hours 100% of chicks should have full crops. If these levels of crop fill are not being achieved then something is preventing the chicks feeding and action to resolve this is required. 12

14 Females Age TABLE 4: FEEDING SPACE Feeding Space 0-35 days (0-5 weeks) 5cm/bird days (5-10 weeks) 10cm/bird 70 days (10 weeks)-depletion 15cm/bird Males Age Feeding Space 0-35 days (0-5 weeks) 5cm/bird days (5-10 weeks) 10cm/bird days (10-20 weeks) 15cm/bird days (20-64 weeks) 18cm/bird If more than one feeder track is used, then tracks should operate in opposite directions. Feed distribution time can be reduced by placing a satellite bin containing sufficient feed to fill half of the track, halfway round the feeder loop. Feed depth, distribution time and eating-up time should be monitored routinely at several points. Water is essential for growth and development. Chicks should have unlimited access to water. Adequate drinking space for 1,000 day old chicks is provided by 5-6 standard bell drinkers each measuring 40cm (15.7in) diameter, plus mini supplementary drinkers each measuring 15-20cm ( in) diameter. Drinkers should be positioned strategically to ensure that chicks do not have to travel more than 1 metre for access to water in the first 24 hours. Water should be clean and fresh; at brooding temperatures bacteria can multiply very rapidly in open water. Key Points Prepare, clean and disinfect houses and equipment well in advance of chick arrival. Ensure that house reaches correct temperature and Relative Humidity 24 hours before chicks arrive. Ensure that chicks have immediate access to fresh water and feed. Use chick behaviour as an indicator of satisfactory brooding temperature. Replenish feed frequently during the brooding period. Monitor crop fill to ensure chicks are feeding Check and adjust feeders and drinkers at least twice a day. Check the chicks at regular intervals throughout the day. Beak trimming, if necessary, should be performed by trained, competent personnel and be properly supervised If any abnormality in chick behaviour should occur or if mortality exceeds 1% by 7 days, then all management factors should be rechecked and arrangements made for a veterinary examination as soon as possible. The supplementary drinkers should be replaced gradually from 3-4 days onwards. From 21 days drinking space is provided by: Automatic circular or trough drinkers Nipples Cups } 1.5cm/bird one for every 8-12 birds one for every birds See table 5 TABLE 5: DRINKING SPACE Rearing Period Production Period Automatic circular or trough drinkers 1.5cm/bird 2.5cm/bird Nipples one/8-12birds one/6-10birds Cups one/20-30birds one/15-20birds Nipple or cup systems plus supplementary drinkers can be used very successfully from day old. 13

15 Objectives To control the development of the parent throughout the rearing phase so that maximum reproductive performance is achieved. To establish and maintain target bodyweight-for-age and good flock uniformity by means of accurate control of feed allowances and feed distribution. Objective To obtain an accurate measurement of bodyweight and variability of each population, so that appropriate decisions can be made on feed allowances. Sample Weighing BODYWEIGHT CONTROL AND FEEDING MEASUREMENT OF BODYWEIGHT AND UNIFORMITY Growth and development in a flock are assessed and managed by weighing representative samples of birds and comparing them with target bodyweights-for-age. Several types of scales are available that can be used to weigh birds to an accuracy of 20g. Conventional mechanical or dial scales are more labour intensive and require records to be kept and calculations to be made manually. Electronic scales are available which record individual bird weights and calculate flock statistics automatically. Either type can be used successfully but only one type should be used for repeated measurements on an individual flock. Automatic weighing systems that are placed in the house will give daily records of bodyweights but these must be regularly calibrated and cross-checked with manual scales. All measurement systems require calibration and standard weights should always be available to check that scales are weighing accurately. A calibration check should be made at the beginning and end of every sample weighing. Sample weighing should be carried out weekly starting at day old. At 0, 7 and 14 days (0, 1 and 2 weeks) of age, samples can be weighed in bulk, birds at a time. The total sample must not be less than 5% of the flock. In flocks having early growth problems, more frequent weighings may be necessary. From 21 days (3 weeks) of age, randomly selected samples of birds should be weighed individually. Groups of 50 to 100 birds per colony should be caught using catching frames and individually weighed. All birds rounded up as a sample must be weighed in order to eliminate any selective bias. If the colony exceeds 1,000 birds, 2 sample weighings must be taken from different places in the colony. Birds should be weighed on the same day each week and at the same time, preferably 4-6 hours after feeding. The objective is to obtain a true representation of the flock growth and development by accurate sampling. When manual scales are being used, individual bird weights should be recorded on a weight recording chart as the birds are weighed. (See Diagram 7, page 15). Immediately after weighing, the following parameters should be calculated: - Flock average bodyweight - Flock weight range - Flock weight distribution - Coefficient of Variation % (see later for method) The average bodyweight should be plotted on the bodyweight-for-age graph. All decisions on feed allowances must be based on the deviation of average bodyweight from target bodyweight. COEFFICIENT OF VARIATION The coefficient of variation (CV%) is a mathematical method of expressing the uniformity or evenness of a flock. The precise method of calculation is as follows: Standard Deviation Average Weight Standard deviation may be calculated using an electronic calculator, or from electronic scales. In the absence of an electronic calculator, the following simple formula can be used to estimate CV%. Weight Range x 100 Average Weight x F x 100 = CV% = CV% Range is defined as the difference in weight between the heaviest and the lightest birds. F is a constant and depends on the size of the sample, as shown in Table 6 (page 16). One method of calculation should be used consistently throughout the rearing period, because the numerical result obtained will differ slightly depending on the method used. 14

16 DIAGRAM 7: ROSS BODYWEIGHT RECORDING CHART FARM BREED HOUSE PEN SEX AGE DATE NUMBER WEIGHED AVERAGE WEIGHT TARGET WEIGHT 2 3 F 35 November 01 UNIFORMITY % Sample + 10% of Av Coefficient of Variation % WEIGHT WEIGHT g NUMBER OF BIRDS g NUMBER OF BIRDS COMMENTS (20%) Light Birds (CV% ~ 6.9%) Cut off point Normal (CV% ~ 7.8%) N.B. Average Weight = Range = CV% = % Sample± 10% Age = Target Weight = Average Weight = 540g 360g 35 days 560g 540g Total Birds Weighed = % of Sample = 24 Cut off point 480g or below Approximate CV% of Light Population = 6.9% Approximate CV% of Normal Population = 7.8% Two way grading only 360 x x 5.02 = 13.28% 65 x 100 = 54.2%

17 TABLE 6: SAMPLE SIZE AND F VALUES SAMPLE SIZE F VALUE SAMPLE SIZE F VALUE > A second method of measuring evenness is to express it in terms of percentage of birds within the range of the average weight, plus or minus 10%. Whilst this method gives an accurate indication of the numbers of birds close to the average weight it does not, unlike the CV%, take into account the very light and heavy birds. Table 7 illustrates the approximate relationship between CV% and ±10% of the average weight in populations with a normal (i.e. bell-shaped) weight distribution. TABLE 7: RELATIONSHIP BETWEEN CV% AND ±10% OF AVERAGE WEIGHT OF POPULATIONS WITH A NORMAL WEIGHT DISTRIBUTION CV% % UNIFORMITY ±10% If a sample weighing produces data inconsistent with previous weighings and expectations, a second sample should be weighed immediately as a check before making a decision upon feed allowances. This will identify specific problems, e.g. feed allowance errors, drinker failures, pen number variation, disease etc. Key Points Start sample weighing at day-old and continue at least weekly throughout the rearing period. Weigh individual birds during sampling from 3 weeks onwards. Weigh birds at the same time each week. Use accurate bird weighing equipment. Calculate average bodyweight and uniformity. Record and plot using a bodyweight-for-age graph. Calculate feed allowances based on deviation of average bodyweight from target bodyweight. Use the feeding programme as a guide only. Objectives To achieve target bodyweights throughout the life of broiler parents. To ensure correct growth and development allowing the birds to achieve uniform and coordinated sexual maturity, both within and between sexes. To minimise variation within flocks thereby creating flocks which are easier to manage. Principles CONTROL OF FEEDING TO MANAGE BODYWEIGHT Bodyweight corrections are achieved through adjustment of feed allowance. Feed allocation can either be maintained or increased. Feed allowances must never be decreased during the rearing period. Good feed distribution, which allows all the birds to have access to feed at the same time, is absolutely essential because the birds are fed at less than ad libitum. Good uniformity is as important as achieving target bodyweights. One of the first indications of problems during rearing of parent stock is often an increase in variability. Another important aspect of uniform growth is good skeletal development. Onset of sexual maturity is dependent on body composition. Flocks with uniform bodyweight but variable skeletal size will have variable body composition. Birds in such flocks will not respond in a uniform way to changes in lighting pattern and feed allowances. 16

18 Failure to achieve early bodyweight targets will result in non uniform flocks with poor skeletal development and poor feathering. These flocks will not respond predictably to stimulation and are unlikely to achieve potential performance. Procedures CONTROL OF FEED ALLOWANCES All decisions on feed allowances should be based on pen average bodyweight in relation to target bodyweight. Feed allocation can either be maintained or increased. Feed allowances must never be decreased during the rearing period. Accurate feed weighing equipment is essential to permit calculation of feed allowance per bird to the nearest gram. TABLE 8: FEEDING SPACE ACCORDING TO AGE AGE FEEDING SPACE < 35 days 5 cm/bird days 10 cm/bird > 70 days 15 cm/bird Adequate feeding space must be provided during the rearing period as shown in Table 8. Where pans are being used it is essential to ensure that birds have unobstructed access to feeding points. Pans should be spaced so that birds feeding in adjoining pans do not obstruct access. To maintain good uniformity in young flocks, the birds must be fed ad libitum for long enough to achieve or exceed the 14-day target weight. This must be followed by small regular feed increases, as shown in Table 9. e.g. Between 1 and 21 days of age birds should not remain on the same amount of feed for more than 4 days. TABLE 9: MAXIMUM NUMBER OF DAYS ON CONSTANT AMOUNT OF FEED ACCORDING TO AGE AGE (DAYS) MAXIMUM (DAYS) Daily feed allocation must be recorded per bird, to monitor feed consumption. Feed allocation per colony should also be monitored, to take into account changes in colony size. Feeder layout should be such that each category of bird can be fed to its separate requirement. Feeding equipment should be capable of distributing feed to each separate colony, taking no more than 3 minutes per colony. As an alternative to conventional feeder systems, floor feeding of pelleted feed can offer certain advantages. These include rapid and even distribution of feed, increased flock uniformity, improved litter condition and reduction of physical damage to legs. Feed can be distributed by hand, or by using a spinner system. As with all feeding systems and techniques, management practice of a high standard is required to allow the full potential of floor feeding to be achieved. The following points should be considered when feeding on to the floor: - From days (2-6 weeks), the floor feeding area should be gradually expanded using good quality pellets of diameter 2.5mm and length 3-4mm. - From 42 days (6 weeks), good quality pellets of diameter 4mm and length 5-7mm should be fed on to the floor, spread evenly by hand or spinner. - High intensity light i.e. 20 lux minimum (1.85 foot candles) should be used for the feeding period. - Litter depth should not exceed 4cm (1.5in) and good litter condition must be maintained. - Birds should be using the laying feeders by 140 days (20 weeks) to minimise stress of the changeover during lay. Excluders (i.e. grids) should be removed from the feeders for the first few days after the change from floor feeding to tracks. Ideally, birds should be fed every day. However, sometimes this can be difficult because of feed distribution problems. Situations can arise when the volume of the feed that is required by the birds to support the correct growth rate is too small to achieve uniform feed distribution throughout the feeder system. Feed must be evenly distributed to minimise competition and maintain bodyweight and flock uniformity. This can be achieved by the accumulation of sufficient feed on the feed day supplemented with a scratch feed on the intermediate days. The most frequently used feeding schedules are shown in Table 10. TABLE 10: EXAMPLES OF FEEDING SCHEDULES IN PREFERRED ORDER SCHEDULE EVERY DAY 6 AND 1 5 AND 2 4 AND 3 FEED REQUIREMENTS PER DAY MON TUE WED THUR FRI SAT SUN Key - Complete Feed - Scratch Feed 17

19 The signs of poor feed distribution generally appear between 4 and 8 weeks of age. The switch from daily feeding should not occur before grading. The change to or from daily feeding needs to be gradual. The feeding of hard grain (Salmonella free) or pelleted feed as a scratch feed is permissible up to a maximum rate of 0.5kg (1lb)/100birds/day. A reduction in the amount of regular feed should be made so that scratch feeding represents a balanced part of the total diet and not an addition. The level of medication in the ration, e.g. coccidiostat, should be such that each bird s daily intake of feed provides the specified amount. Birds should gradually be returned to every day feeding starting at 105 days (15 weeks) with the change being complete by 126 days (18 weeks). The change over to every day feed should be gradual with progression from 4 and 3, to 5 and 2, to 6 and 1 as appropriate. Key Points period, which will result in good whole flock uniformity at point of lay. Principles A uniform flock will be much easier to manage than a variable one, because the majority of the birds will be in a similar physiological state and will respond to changes in levels of feed or light when necessary. A uniform flock will react predictably to increases in feed and will produce good results consistently. Flock uniformity can be optimised by applying high standards of management in the first 4 weeks. DIAGRAM 8: UNIFORMITY AND DISTRIBUTION OF BODYWEIGHTS Average Weight Day 1 ~ CV% 8-9 Average Weight Control bodyweight by adjustment of feed allowance. Never decrease feed allowance during rearing. Feed allowance should either be maintained or increased. Day 21 ~ CV% Average Weight Use accurate feed weighing equipment. Give birds the correct feeding space. Distribute feed, taking no more than 3 minutes per colony. Day 42 ~ CV% > 15 CV% = percentage coefficient of variation The switch from daily feeding to a feeding schedule should not occur before grading. The change to or from daily feeding needs to be gradual. GRADING TO MANAGE UNIFORMITY At day old, bodyweights of the flock will follow a normal (i.e. bell shaped) distribution, with a low CV%. (See Diagram 8). As the individual birds grow within a flock, their different responses to vaccination, or disease, and their differing competitiveness for feed will tend to increase the CV%. An increasing number of small birds tend to produce a skewed weight distribution. The reasons for this skewed distribution are numerous and can include: Objective To sort the flock into 2 or 3 sub-populations of different average weight at 28 days (4 weeks) of age, so that each group may be given the management during the rearing - chick quality - feed distribution - feed quality - temperature - humidity - vaccination 18

20 - beak trimming - disease The poor competitiveness of the small birds may allow a further population of heavy birds to emerge. In order to create a uniform flock, small birds should be identified and penned separately. All birds are then fed to achieve the target bodyweight by 63 days (9 weeks). The aim must be for a uniform flock, rather than many uniform small pens. If colony sizes in lay are likely to be larger than they were in the rearing period, and birds will have to be mixed at transfer, it is especially important to manage the pens of birds towards a common target bodyweight at the expected age of transfer. Procedures Grading is best carried out when the flock is aged 28 days (4 weeks), at which time the uniformity of the flock is usually within the range 10-14%. Grading is generally not permanently effective if carried out much before 28 days (4 weeks). If undertaken later than 35 days (5 weeks) the time available in which flock uniformity can be restored i.e. up to 63 days (9 weeks) becomes too short. In most cases, grading will be undertaken when the flock CV% is around 12. The practical requirements of grading must be considered at the planning stage, before the stock is placed. The easiest way to grade is into pens or possibly houses, which have been left empty at placement for this purpose. To allow for extreme cases (ie. CV%>12), the housing space allocated for both the male and female flocks must be capable of being divided into 3. Where the entire population of a house is to be graded within that house, 2 adjustable partitions will be required. To accomplish successful grading, certain procedures should be undertaken: - Within the flock to be graded all colonies must be sample weighed. - All the individual weighings should be consolidated into a single distribution. - Two-way grading is preferable, provided that the flock CV% is <12 at grading. If the CV% is >12, then a 3-way grading will be required and management practices from 0-4 weeks should be examined closely, so that improved CV% can be achieved with subsequent flocks. - Flock CV% should be calculated. Cut-off points must be set to achieve consistent stocking densities allowing for differences in pen size. Table 11, (page 20) indicates the typical percentages in light, medium and heavy populations to achieve populations with CV % less than 8 for 2- or 3-way grading. Cut off points should be set to achieve the required percentage of the population in each colony (see Diagram 9). DIAGRAM 9: FLOCK UNIFORMITY PRE-GRADING 12 CV% Light Medium Heavy Estimated % of Flock - 25% Calculated CV% of Light Birds - 9.5% Calculated CV% of Medium Birds - 6.0% Estimated % of Flock - 8% Calculated CV% of Heavy Birds - 5.0% Flock Bodyweight Distribution Light Medium Heavy Adjusted CV% 7.5 Revised % of Flock - 21% Adjusted CV% 7.0 Revised % of Flock - 69% Adjusted CV% 6.5 Revised % of Flock - 10% Revised Cut-Off Bodyweight Estimated Cut-Off Bodyweight 19