標題: The Art of Male Management 種公雞的管理藝術(shù) [打印本頁] 作者: monica 時間: 2007-10-8 23:04 標題: The Art of Male Management 種公雞的管理藝術(shù) The Art of Male Management
種公雞的管理藝術(shù) The key factors for effective male breeder managment are achieving the correct skeletal size and uniformity; testis development; correct mating ratios and even feed distribution. - Dr Dinah Nicholson, Regional Technical Maanger, 對種公雞有效的管理，關(guān)鍵是要有適當?shù)墓趋莱叽绾途鶆蚨?，睪丸的良好發(fā)育，正確的配種頻率，還包括飼料分配。
The performance of the parent female has improved steadily over the last 5 years. For example, in Ross flocks depleted in the UK in 2002, average output per hen housed to 60 weeks was 161.6 hatching eggs. However, there was still a wide range in hatchability, and improving this parameter from bottom to top quartile would yield an extra ten chicks per hen house. In many cases, lower hatchability was associated with poorly managed separate sex feeding. In these cases, better hatchability could have been achieved by paying more attention to male management.
Good fertility can be achieved under a range of conditions across the world. Key management factors in achieving it include:
Correct skeletal size & uniformity
Testis development
Correct mating ratios
Male feed distribution
Skeletal Size & Uniformity 骨骼尺寸和均勻度
If males are to mate effectively throughout the laying period of the flock, they need to achieve good skeletal development during the period 0-20 weeks. The growth of the birds in the flock should be controlled to match the breeding company's bodyweight profile, and the flock should be as uniform as possible so that sexual maturity will be even at the point of housing and when males and females are mixed, around 20 weeks.
By 8 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 targets. 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.
Follow your breeder's advice. 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 4-5 weeks, at which point the very smallest birds should be culled
Achieve target bodyweights of 1080g at 6 weeks and 1670g at 10 weeks
Perform a final grade & selection at 10 weeks, after which the males are not moved 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 3 min/colony)
Testes Development
Testes development starts in the period between 10 and 15 weeks and accelerates after 15 weeks. During sexual development, it is extremely important to maintain weekly bodyweight gain because any loss of weight can restrict testes development and hence semen production in later life. For this reason, stocking rates and feed distribution are critical in the stage 10 weeks to mating up. Stocking density should not exceed four males per square metre in this later stage of rearing.
The photograph shows a group of well reared males.
Mating Ratio 配種率
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.
Ideally, at transfer about 0.5% extra males should be moved, with the objective of achieving 8.5-9.0% (8.5-9 males per 100 females) at 22 weeks by selecting out the poorer birds. Thereafter, about 0.1% per week need to be removed, to achieve 6.5% males by 55 weeks. Males should be inspected & culled little and often; irregular culling of larger numbers will leave some females unmated and risks depressing fertility for a while.
In closed houses, when the males have been very well reared, low mating ratios (7-7.5% at 22 weeks) can give excellent results. The males stay active and in good condition, and there is then no need for any culling beyond natural wastage.
It is good practice to move the males into the laying house two or three days before the females. This allows time for the males to familiarise themselves with and adjust to their new home and will ensure that they all know where to find feed and water.
Feed Management & Distribution 飼料的管理及分配
The most critical factors during the laying period are to maintain control over bodyweight and to ensure that males remain in good physical condition to carry out mating.
Providing separate feeding systems for the females and the males is the only way to maintain close control over male bodyweight during the laying period. While there are a number of suitable systems available, some basic advice applies to them all.
Retaining a full comb on the male makes it very much easier to exclude 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 it by around 24 to26 weeks.
Any male feeding system for the laying house must fulfil the following criteria:
provide uniform feed levels to all males
prevent females stealing
prevent dominant males stealing from other males
allow males to feed quickly and easily
offer the option to remove feeders as male birds are culled throughout lay, to maintain feeding
space per bird at a constant level
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 should be distributed evenly throughout the house. It is also important that the feeder height is adjusted so that the males are stretching for feed, but not having to jump up
The flock should be watched 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.
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 sexes 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.
It is important to observe the females. If they 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. Caught early, such behaviour can be corrected by removing surplus males and using an afternoon scratch feed on the litter area to encourage the pullets down.
In conclusion, managing the male population in a flock is as important a factor in determining chick output as managing the females. Following the breeding company's weight profile and managing skeletal growth, testis 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 and regular observation of bird behaviour will show whether effective mating is taking place.
The stockman who pays attention to detail and makes every effort to understand and monitor what is going on in the chicken house will be rewarded with a successful result.