The Art of Male Management O.B.T

Introduction The stockman who pays attention to detail, observing and reacting to bird behavior will be rewarded with a successful result. Bruce Evans, Regional Technical Manager, Aviagen Limited, Newbridge, Scotland. To achieve good fertility requires management of the bird to ensure; correct skeletal size, uniformity and testes development, control of male feed distribution the correct mating ratios and fleshing of the bird at the different stages of its life.

Housing It is very much easier to grow males to a bodyweight profile if they are grown separately to females. Often when they are however, males are placed at the far end of a house out of sight. Aviagen Technical Managers advise that males are placed in a pen at the front of the house, where observing and managing them during the growing period is made much easier. In day-old to death rearing systems it is advisable to remove slats as they put stress on the bird's leg joints in the critical period of muscle and tendon/ligament development between 6 and 12 weeks. As the males grow, they naturally require more space and attention must be paid to providing the correct stocking density and feeding space for their age.

Early Growing Period One of the key factors is getting the chicks off to a good start. The first 72 hours of a chick's life will not only determine the bird's ability to withstand disease challenge, develop the cardio vascular system and feather cover, but most importantly will determine skeletal development.  If males are to be able to mate effectively throughout the laying period, they need to have good skeletal development in rearing.

Early Growing Period To get birds off to  a good start and make sure that this profile is achieved in the first 14 days, many producers use a broiler ration (without coccidiostat). If beak trimming is carried out at day-old or in the first week, extreme care must be taken, as poor beak trimming is still one of the biggest causes of poor uniformity in flocks. After 14 days the biggest factor in influencing the uniformity of the flock will be the males' ability to access and consume the amount of feed they require.  Uniformity of the male is critical and to maintain it, the feed system must be capable of providing accurate feed amounts to all males at the same time.  Bird behaviour, especially during the change over period from manual to automatic feeding, should be monitored to ensure uniform feed distribution and uniform development of the flock.

Early Growing Period As well as achieving the correct bodyweight profile, uniformity of the male population should be between 80-85% from day 35 onwards so that sexual maturity will be similar at the point of housing and mating up. By eight weeks of age, 85% of the skeletal development of the bird will be complete. Therefore it is important to achieve or even exceed early bodyweight.  If not, the mature frame size of the male will be smaller than the optimum.   Without a good frame size a male will tend to become over fleshed, fat and have poor conformation in later life, limiting his ability to mate successfully.

Early Growing Period The main points which will help in achieving the correct skeletal size of males are: Achieve target weight of 140 g at 7 days (if necessary by feeding a higher-specification pre-starter) Grade the birds at four weeks of age, at which point the very smallest birds should be culled. Achieve specified target bodyweights for the breed by eight weeks of age at the latest. Perform a final selection at 10 weeks, redrawing the bodyweight profile if necessary and do not move the males again until they are mated up. Make sure that the males are not overstocked (3-4 males/m2), have enough feeding space (15cm/bird) and that feed distribution is fast enough (maximum of 2-3 minutes/pen).

Testes Development Testes development starts in the period between 10 and 15 weeks During this time it is important to maintain weekly bodyweight gain as in this period loss of weight can impair development and thus semen production in later life. From 15 weeks onwards, rapid development of the reproductive system takes place so the bodyweight profile must be maintained through to lay and at the critical period of housing and mating up. For this reason, stocking rates and feed distribution are critical in the stage 10 weeks - mating up.

Laying Period The most critical factors during the laying period are to continue to maintain control over bodyweight and to ensure that males remain in good physical condition to carry out mating. Feeding males separately to females is the only way to maintain close control over male bodyweight during the laying period and while there are a number of different systems available, some basic advice applies to them all. Retaining a full comb on the male is one of the best ways of excluding males from the female feeding system. With a full comb males will not be able to steal feed from the female feeder and will be excluded completely from around 24 -26 weeks.

Laying Period cont’d Any male feeding system for the laying house must provide uniform feed levels to all males and prevent females and dominant males stealing from other males. It must also allow the males to feed quickly and be adjustable enough to maintain feeding space per bird at a constant level as male birds are culled throughout lay. In the early laying period males should be encouraged to eat solely from the male feeder by making sure that: There is enough feed space, which is distributed evenly throughout the house. The feeder height is adjusted so that the males are stretching for feed, but not having to jump up.

Laying Period cont’d The flock should be monitored carefully to make sure that the male feeders are high enough to make it difficult for the females to reach.  It may help to run the female feeding system in the dark until one full circuit has been completed. Then, when the lights come on, feed is immediately accessible to every female, reducing the need to steal from male feeders. After 24 to 26 weeks when males are excluded, the female feeders should be run first to encourage females away from the male feeder.  The choice of equipment to exclude males from the female feeding system is very important.

Laying Period cont’d A grill fitted to the feed track is probably the most wide spread and effective system used. Such a grill must be well manufactured to a height of 55mm and so that the width of the gaps is all the same. With adjustable grill, these gaps should be 45mm wide from 24 to 30 weeks of age and 48 mm wide from 30 weeks onwards. Grills should be checked daily at feeding time to ensure that males are being effectively excluded and that females are gaining easy access. The birds should be observed at feeding time, to ensure that all the grid remains correctly fitted, the corner wheels are still in place and that the male feeder height is still correct.

Laying Period cont’d Feed pans with multi-gap setting are also extremely effective at excluding the male from the female feeder in the laying period. However, every female must have enough space to eat from. No more than 9 females per pan (standard 30cm diameter) are recommended, and females must have enough room to stand back to back between each pan. Whatever systems are used for both males and females, they must deliver feed uniformly throughout the house and their effectiveness should be monitored throughout the life of the flock. Both males and females should be weighed weekly and their weight plotted on a graph to give a pictorial record of bodyweight changes and allow for precise adjustments in feed allocation to be made.

Laying Period cont’d Where slats are used in the laying house, it is important to observe female behaviour carefully.  If the females are hiding under the nest boxes or staying up on the slats while males remain on the floor area, there will be little mating activity, resulting in poor hatchability. Poor slat construction can also lead to bumble foot and joint tendon issues in the flock. Slats should never be more than 30 cm (12 inches) from the floor to avoid damage when birds jump up and down from them. It is a myth that stocking densities can be increased where slats are used as feed space is the key factor and slats tend to mean less room is available for feeding systems.

Mating Ratios Mating up offers the opportunity to handle and select every male. Birds should be selected on the basis of their physical appearance as well as their bodyweight and breast conformation (fleshing) appropriate to their age. Selected males should have bright eyes, straight toes, a good shank length, and a good comb colour, as well as a straight back, good foot pad condition and no damage as a result of beak trimming. The best opportunity for assessing conformation or fleshing is when birds are being handled for their weekly weighing. A general observation can be made before picking the bird up and then after capture, by running a hand up the length of the male's breast from crop to thigh, a subjective fleshing score can be assessed. (Diagram 1 illustrates fleshing characteristics)

Fleshing Profiles In open sided housing, males will tend to mature more quickly and to avoid females becoming shy of the males, they should be introduced gradually, starting from around 21 weeks when 5% males to females can be added. These males must be sexually mature and further males should be added up to a flock age of 25 weeks, until a maximum of 10% male to female ratio is reached. In closed or dark out housing, if light proofing in the rearing period has been effective then males and females should reach sexual maturity at the same time.

Fleshing Profiles Mating up can therefore take place over a shorter period of time, aiming to introduce 10% males to the female population by 23 weeks of age. Where a flock is reared in different housing and then moved to the laying house, best practice is to house the males two or three days before the females. This is to allow time for the males to familiarise and adjust to their new home and will ensure that all the birds know where to find feed and water. During the life of the flock, males should be inspected and their number reduced by culling regularly.

Fleshing Profiles If a severe problem has occurred with the flock and male condition and thus fertility is badly affected, spiking or replacement of males can offer a solution. However while multi-age complexes with defined health status may benefit from this practise there is a health risk to the flock if birds have to be moved between farms. Spiking within a house (intra -spiking) can be beneficial when using small pens.  Rotating 30% of males from pen to pen from 40 weeks onwards can have the effect of stimulating mating activity.

Fleshing Profiles In conclusion, managing the male population in a flock is as important a factor in determining chick output as managing the females. Following the appropriate weight profile recommended for the breed and managing skeletal growth, testes growth, mating ratios and feed distribution, will give the best possible chance of producing a uniform flock of males with the right conformation and maturity at mating up. Feeding males and females separately during the laying period of the flock will allow effective control of bodyweight.  The stockman who pays attention to detail observing and reacting to bird behaviour will be rewarded with a successful result. Courtesy of Asian Poultry, January/February 2004