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Male Management

Male Management 1

What is the optimal male ratio starting from 20 weeks to 28 weeks to prevent male aggression; I have a flock with male aggression from mix until 19 weeks of production. What causes this condition?

The major problem for male aggression is “sexual synchronization of females and males”. 
Cobb recommends a Male/Female ratio at HH or at the start of production at 8% with synchronized female/male maturity
One of the major reasons of male aggression is the males have matured earlier than females due to overweight males during the growing period or after mixing by stealing female feed.
Ensure synchronized maturity, well managed sex separate feeding, and the ratio at 20 weeks should be 9% -10% and at 25-28 week should be 8%

How much does fleshing and nutrients impact the proliferation of seminiferous tubules in males at the age of 15-25 weeks?

We know there is an effect of fleshing and nutrition that allows the proliferation of the seminiferous tubule of males from 15-25 weeks. The nutrient quantification is at a cellular level and has not been studied in detail. However, we know that following Cobb body weight standard and fleshing targets plus nutrition specifications optimizes the male genetic potential.

What is the cause of crooked toes in Cobb males?

Crooked toe is not happening in a specific breed only; There are reports of crooked toes in other breeds as well. There are several causes of crooked toes:
- Not enough feed intake. There is a lot of calcium in the residual yolk of the chick so even if the chicks don’t eat feed, they absorb calcium from yolk and deposit it in the bones. However, the tendons don’t get enough amino acids to form the collagen.  This means bones and tendons will not synchronize growth, and the tendon will stretch, pulling the toes.
- Insufficient/imbalanced amino acid intake during rearing period
- Vitamin B deficiency

Male Management 2

Why does bodyweight increase very fast if we use the feed allocation in Cobb supplements?

The feed guide in our supplement is NOT a feed standard and must be adjusted based on male bodyweight and fleshing, etc. Feed intake in our supplement is developed based on Cobb feed specifications in their comfort zone (18-28°C, or 64-82°F).
To answer your question, below are the possible causes:
- The actual feed nutrient you’re using is higher than Cobb specification (in energy and/or protein). You need to discuss/confirm this with your feed provider/nutritionist. In Cobb, we recommend customers to follow our feed nutrient specification to achieve optimal performance in both males and females.
- If house temperature is warmer than our “comfort zone” recommendation, the birds will convert excessive energy into bodyweight.
To prevent this issue, always use the previous weekly body weight gain as a main consideration for the coming week feed increment. For example, if the bodyweight is already above the standard, you don’t need to increase as much as the guide.
Cobb is selected for high performance at the broiler level (good FCR, ADG, weight). At the breeder level, Cobb is also very good at converting feed into bodyweight, so feed and feeding management (feed intake, nutrient, distribution) are really important.  

What are the causes and prevention of testicular regression in broiler breeder male?

The most common cause of testicular regression in breeder males is regression of body condition (bodyweight and fleshing). To prevent this, we need to make sure males never lose weight at any age.

Could you please elaborate more on new male spiking program?

New male spiking is the addition of younger males into an older flock to compensate for the decline in fertility that usually occurs after 40-45 weeks of age. This decline in fertility can be due to a decrease in mating interest (naturally after 35 to 40 weeks of age), a reduction in sperm quality (naturally after 55 weeks), lower mating efficiency (poor management leading to males with physical conditions such as weight or leg and feet disorders) and excessive male mortality resulting in a reduced male to female ratio.
Normally spiking is done by introducing 20-25% of younger males into the older flock at around 40 weeks of age. We need to consider using 20-25% of younger males to break the older males' dominant hierarchy behavior. The younger males should be around 4.0-4.2kg and are meant to replace the suboptimal older males that will be removed or increase the male ratio back to around 9% (or any ratio you are comfortable). Spiking once in the life of the flock is normally sufficient. Flocks can also be spiked twice on an 8-10 weeks interval if necessary (meaning first spike at 40 weeks, second spike at 48-50 weeks). Spiking is usually not economical beyond 55 weeks of age. The younger males should come from a single source flock and the source flock should be tested for any potential diseases such as mycoplasma 5-7 days before moving. What is more important is to monitor the fertility and hatchability results after you have done the spiking so that we can make the necessary adjustments and keep improving.

Male Management 3

What happen if we transfer males and females on together?

In most scenarios, we highly recommend moving males first, especially if feeder or drinking systems are different from rearing. Delay in water and feed consumption could lead to weight loss and affect testis development after photo stimulation. Moreover, separate sex feeding (SSF) requires males to learn and recognize their own feeder, reducing the chance to access the female feeder and subsequent excessive BW gain after mixing.  Even in a scenario where both male and female had different feeder systems, the males are still prioritized to move first to learn and recognize their own feeder.

- Most of the time males are reared on full litter. Once they move to production house, they must learn to drink with nipple line over slat. Therefore, males must be trained to jump onto slats with perching/slat training in rearing.

- Ideally, use the same type of feeder in rearing and production with perching/slat training in rearing. It’s ok to move males at the same time with females and incorporate the SSF concept to train in production house. If not, I highly suggest moving males first.

If males lose 100g-500g of bodyweight, testis weight will be also decrease and not be able to recover. Does this occur at all ages?

It occurs during the entire production period, so keeping good male bodyweight is very important.

If I found testicular regression earlier (24-30 week of production), what could cause testicular regression at this age? Can this be fixed, or should males be replaced with spike males?

Early testes regression is an indication of insufficient nutrient intake; We usually will see those males have lost condition as well.  Make sure that males gain enough weekly body weight.  When males don’t take enough nutrients, the reproductive system will be sacrificed first.  Males can lose condition due to poor feed distribution. Uneven feeding can lead some males to take more feed, while other males will take less. I suggest you check the bodyweight of the males with early regression. If the BW gain is below the standard, consider increasing the feed. Also visit the farm during the feeding time to ensure good feed distribution. Male spiking can help to maintain fertility level, but you need to make sure that male feeding management (feed nutrient, feed intake, feeder space, distribution practice, level of feeder etc.) are correct, otherwise those spiked males can easily lose condition as well.

Male Management 4

Is bodyweight the only key parameter to achieve the right testes size at the right age?    

No, we can’t rely on bodyweight per se to assess testes size, as comb color and development is an indication of maturity and testes development as well. In production period, to ensure good/working males, and check the fleshing score and body conformation. Upright standing males with fleshing scores of 2.5 – 3 and red full developed comb are ideal. If males lost their condition significantly but gained back weight, their bodyweight will be good, but their testis may not recover and will be small.

With spiking, we only replace 20-25% of males. How is the risk of fighting between old and new males?  

Male spiking (and intra-spiking) is an “option” to maintain/improve slightly the fertility level in the flock. Yes, we recommend replacing 20-25% old males with new or spiked males.  The idea is to break social hierarchy or pecking order in the pens and lead to more mating activity of new males and old males as well. Fighting between them is an indication that “social hierarchy” is actually breaking, which is normal just after spiking. It will be settled down and the mating activity will increase. To prevent further aggression, make sure that spiked males (new males) are mature with at least 4 kg bodyweight and a minimum of 25 weeks of age.  With intra-spiking, we only change males between pens, and will see some aggression but normally we don’t see injury since the age, size, and maturity levels of the exchanged males are similar. 

Can we expose males to light at higher intensity and for longer times to promote maturity if they are reared separately from females?  

Basically, you can do that, but you need to be careful since we don’t want to create aggressive males. Male / female sexual synchronization is the main objective of the male management, so all decisions should be based on your flock condition/observation. For example, if you noticed that your males are behind in maturity compared with females prior to mixing, you may start photo stimulation a week earlier for males to achieve male/female sexual synchronization.  Whereas, if you think that there is no issue in synchronization, there is no need to start male photo stimulation earlier.

Male Management 5

The recommended Ad-Lib feed time for Cobb breeder males was 2 weeks. What’s the recommended Ad-Lib feed time for breeder males now? If there is any reduction in the Ad-Lib feed time, would that limit gonadal development for the breeder males at the early stage?

1. With the continuous genetic selection, our males have become very efficient. The Ad-libitum feeding program can be done for at least 1 week but can be extended up to 2 weeks depending on male weight at 7 days. Even with ad-libitum feeding we also need to measure their daily feed intake.
2. Provided that the chicks have a good start, brooding, feed stimulation, weight, density etc., males should have good gonadal development at an early age.

What can we do to reduce bodyweight of overweight males with a chance of recovering the male for later use?

1. The male should not lose weight at any point of his life. Studies show that;
 A. Slight weight loss will cause the sperm to decline.
 B. If males lose 100 g in 5 weeks the sperm quality and volume decline.
 C. If males lose 500g in 5 weeks the semen production stops and sometimes does not recover.
2. Overweight/heavy males can be used to match with heavy females.
3. Overweight males can be used as spike males but with at least 4.5 kg with > 26 weeks of age.
4. Make sure to supply them enough feed so that they will not lose condition.

Tips in handling chain type of feeders in both males and females please.

1. Chain feeders are considered as one of the most popular and most convenient auto feeders in breeders. Some key points for operating chain feeders are:
 A. Use progressive feeder space in rearing until 12 weeks of age and older. At that point, the requirement is 15 cm of feeder space per female and 18cm for male with a chain/trough system.
 B. Progressively giving more feeder space will help to maintain uniformity, allow enough feeding space and enough feeder height in the chain feeder.  With 3 loops of chain feeders, the chicks are fed with one loop up to 3-4 weeks of age, from 4 weeks to approximately 12 weeks, two loops are used.  After 12 weeks and until transfer time, all 3 loops are used.
 C. Start running the chain feeder when the feed volume will be able to reach from one hopper to another.
 D. Make sure to check/adjust the hopper guide at least once a week to be able to make sure the thickness of the feeds are even throughout the length of the track.
 E. In general, if grills are used on the feeder chains, they should be installed at around 4-6 weeks of age. It will line up the birds, prevent accidents in corners, help control feed spillage and give a slightly better uniformity in rearing.

Male Management 6

During restaurant feeding, is it alright to release or open the net used for restaurant feeding after feed cleanup time of females around 2 to 3hrs after?

In a normal flock from the start of mixing (22-30 weeks of age) until peak production, the feed cleanup time of the females will be around 45-60 minutes. So, you can open the net/gate and release males after the female’s cleanup time. However, if the cleanup is extended to 1.5-2.5 hours after 30 weeks, you can release males after 1 hour for them to drink and since the male’s comb has been fully developed at this age, feed stealing would be very minimal.

How many additional DOC can be produced when spiking is done at 40 weeks?

It is quite hard to the determine the additional chicks you can get by spiking, but what I can tell is the positive response in terms of fertility.
Generally, if done correctly, spiking results in a 1-3% increase in fertility over a 5-10 week period and the spiked flocks should be able to maintain good fertility (>90%) through 60 weeks of age.
A good spiking program will be able to slow down the decrease of the hatch after 45weeks.

How much feed g/male increase per week is required to maintain good hatchability and good male condition?

Unfortunately, there is no direct answer to your question as it depends on the situation but what I can share with you are some tools to help you decide.
 1. Increasing or maintaining feed in production will depend on several factors such as bodyweight, weekly weight gain, fleshing.
 2. There are feeding concepts that you use as your guide and reference;
  A. Bodyweight and Fleshing – you can do random checks of fleshing 2 times a week from 25-35 weeks and once a week 35-60 weeks. Weigh bodyweight weekly.
  B. Energy & Protein concept – you can check this out on our male supplement.

How can we prevent feed choking?

Feed chocking or impaction has several causes:
1. Recheck male population and feed amount to ensure that there is no error in calculation or males that have migrated from neighboring pens. 
2. Calibrate feed scale and feeder setup to rule out equipment issues. 
3. If the above 2 points are fine, then I recommend running a trial with automatic lights on and allow birds to drink for 30-45 minutes before feed time. Then, lights off for 10-15 minutes to calm birds down before running feed in the dark to complete the loop in less than 3 minutes. Finally, lights on and let bird consume feed. 
4. If supplying water before feed time doesn’t help, then you may need to change to a skipped program. For example, from 4/3 down to 5/2 or 5/2 down to 6/1.  
5. Ensure that the water regulator is set up with the correct pressure to allow good flow or water source/bird is correct. 

Webinar Replay

Optimizing Male Fertility 

&Male Introduction to New Environment

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Dr. Kanjana Blumberg- Regional Technical Service Manager
August 26, 2020

Q & A Special: Male Management

Dr. Alvin Arucan- Regional Technical Service Manager
September 29, 2021

Pro Series

Male Fleshing

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