Controlling male bodyweight and condition is one of the most critical aspects of maintaining fertility and hatch persistency as broiler breeder flocks age. From 30 weeks of age onwards, primary males should gain bodyweight slowly to maintain activity and reduce incidence of testicular regression. This demands applying proper feeding techniques and conducting the right regimes.
By Winfridus Bakker, GP and PS specialist, Cobb-Vantress, USA
While spiking younger males into the flock and inter-spiking by moving males between houses to increase mating activity are good tools, better long-term results can be obtained by taking care of the primary males in the flock. Proper feeding systems and male management programmes are essential to establish and maintain males in the proper condition.
Improper feeding of the males is one of the primary causes of too much culling, overweight or underweight males and excessive fertility drops after 40-45 weeks of age. Good husbandry requires the manager to take time observing the feeding of the males and females at least once a week from housing to peak production. When management issues arise, adjustments can then be rapidly made before permanent damage is done to the flock. This visual observation of the flock is a crucial management tool. Several types of feeders will work well to assure uniform male flocks.
Manually-fed male systems
When a tubular feeder or pan system is used, calculate eight males per pan. Ensure that all males have easy access to the feeder at the proper height so feed is readily available to them. Photo 1
shows a manually-fed male feeder with counter weight attached under the pan. This wide open pan feeder gives easy access from all sides for males with mature combs. This feeder is deep enough to hold more feed volume without females gaining easy access.
shows a design of a plastic feeder that does not work well during the production period. Males with large combs will need to eat sideways, reducing space availability for the other males. Equal feed distribution around all sides can also be a problem if the feed volume is low. Photo 3
is an efficient manual feeding trough. An anti-perch device of a 10 cm (4 in) wide PVC pipe cut in half lengthwise is installed 15 cm (6 in) above the trough. This allows easy filling of the feeder but restricts females from stealing by preventing them from jumping on the feeder or fitting in between the trough and the PVC hood.
shows a manually-filled male feeder pan that is designed well, but illustrates improper feed distribution within the pan. Male access to the feed is easy from one side but more difficult from the other side, and severely limits the amount of feeder space available to the males. This is a very common problem seen in the field, and easily corrected when discovered through regular observation.
Automatic feeders should be filled while suspended above and out of reach of the birds (Photo 5
). This enables the manager to see how uniformly the feed is distributed in all the pans. If the feeder line must remain at male level all the time, close observation during feed distribution is critical, especially between 20 and 30 weeks of age. One method that can be used is to distribute the feed in the dark for females and males. This is possible when feeding very early in the morning or in solid side production houses.
Even if the females and males are being fed one hour after the lights come on, the lights can be switched off for 3-4 minutes when the feed is distributed for females and males. This is the only time when feeding problems can be identified and quickly corrected. Feed distribution problems during the weeks when the males are developing and maturing can permanently affect male testicular development and overall flock fertility. Males with large combs will have problems accessing certain automatic feeder pans with a central cone (Photo 6
). Be sure to take the comb size into account when determining which male feeder line would be ideal for your conditions.
As can be observed in this pan feeder, the males need to position themselves partly sideways to be able to eat. This restricts the feeder space per pan to less than eight males. The male feeder design of Photo 7
is very close to ideal. We could grade this male feeder on several basic criteria, from 0 to 3 (0 being the worst and 3 being the best score) as given in Table 1
. The same 15 total points from this table can be given to the easy accessible male pan feeder in Photo 8
Male feeding techniques
To train the males to recognise their feeder, they should if possible be moved to the production house a minimum of three to four days before the females. After the females are transferred, the female feeder should be started a few minutes ahead of the male feeder, or filled in the dark before lights come on, to draw the females to their feeder and to discourage them from stealing from the males.
The height of the male feeders must be closely monitored, especially during the first weeks in the production housing when the height needs to be adjusted often as the males develop sexually. Attaching a vertical wooden stick to a pan on the feeder line can provide a cheap and effective indicator of the correct height above the litter when lowering the system for feeding. Another method could be a metal “V” bar that is adjustable in height (Photo 9
If the litter depth is excessive, the feeder height from the top of the litter could become uneven. In the period from 20 to 30 weeks of age, it is better not to exceed 5 cm (2 in) of litter depth in the scratch area. However, the type of climate during the start of production and type of floor (concrete or dirt) also play a role in deciding litter depth. The height of the feeder above the litter is normally between 46 and 52 cm (18 to 20 in), depending on the height of the males.
Proper feed distribution
During feeding, also notice how the pans tilt (Photo 10
) and whether the feeder swings. If the pan is tilted when males eat, it is a clear indication that the feeder is too high. This will cause feed to shift in the feeder, resulting in poor feed distribution and an overall reduction of feeder space.
Also, the pan openings in all the male feeders should be calibrated so that the feed amount is properly distributed among all available pans. Males could be stealing feed from the female feeders. The grill openings may be too wide or too tall, allowing easier access by the smaller, less developed males. Or, the males may not have been trained to use their own feeder line. This happens when males are uneven, either in size or comb development, or when spiking males have been added to a flock. At any time, a reduction in male bodyweight, monitored through regular check weighings, could be a clear indication that the feeding system or distribution is not working properly.
Strong economic impact
One percent hatch improvement on a complex processing one million birds per week has an economic impact of US $33,000 a year (US data reporting service, June 2011). In addition to using feeding techniques to control the male bodyweight and condition, attention to fine detail will enhance the long-term health and activity of the breeding male.
This can make a big difference to the financial returns since each male can have 9-10 times as much impact on hatch as each female. Close observation and attention to these details will provide a good return through improved performance.