9/26/2012
Managing for fertility
 Weight, fleshing, and condition of the roosters
Factors Influencing Fertility
 Number of roosters per 100 hens
Jeanna L. Wilson
University of Georgia
 Hens influence on fertility
1957 verses 2012 6 week broilers
University of GA, 2012
Rearing Program
 Cockerels usually come to you as a smaller, weaker chick. They have been vent sexed, toes trimmed and maybe a comb trim.
 They may need a little extra encouragement to get up and eat the first few days especially in the wintertime. The best performance comes from those who give them TLC.
Focus on . . . Rearing Program
 Cocci is usually more of a problem for males than females. So be on the look out for those bloody droppings. Treat before you have high mortality.
 Blackhead can also be an issue in males – making worming programs extremely important. Again, blackhead will cost you roosters that you don’t want to lose.
 We need every male!
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Healthy cockerels with low mortality
Rearing Program
 Good house conditions from start to finish
 Clean facilities, no built up litter in rearing
 Good ventilation
 Good handling methods (two legs only)
 Sanitary vaccination of the birds (clean water source and equipment, clean needles and change them often, opportunity for bacterial entrance to the bird – poor sanitation)
 Males seem die more easily from the little stuff
 Need good ventilation – pullet house
 Tunnel ventilation, good dark out
 Evaporative cooling
 Dry litter conditions with excellent litter quality, this is not the place to save money
 Remember we build immunity during rearing not during lay, so all that vaccine is wasted if we stress them out with our ventilation, lack of cooling, or some other issue
Sex ratio
Where does this start?
 Good mixing of males and females tells you that the number of males to females is good.
 If the hen learns to run and tries to hide (slatting), you know you have too many males (prevent because reduces fertility).
So what causes foot pad issues?
Overly aggressive/poor sexual development
 Litter source
 Built up litter
 Poor ventilation – wet
 Excessive body weight
 Foot pad issues limit the effectiveness of those male, end up culling those roosters
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Poor matching of the ratio
 Overmating leads to excess feather loss, cut hens, down hens, fearful behavior
 High mortality
 Low fertility
Rooster numbers
 Number of roosters you need depends on your average rooster mortality in the hen house
 If you place 8.5 roosters and by 30 weeks of age you are down to 7.5, you will need to add 1 rooster per 100 hens as soon as you can
 Then at 40 weeks reevaluate, add another 1.5‐2 males per 100 hens
 In the highest mortality flocks add another 1‐2 males at 50‐54 weeks of age
Good mixing of the flock indicates the right rooster numbers
Rooster numbers
 So you would need = 5 roosters/100 hens for spiking
 By 45‐50 weeks you would like to be at 9 males/100 if you started with 8.5
 If your rooster quality is real good and mortality is low, you won’t need this many roosters
 The reverse is also true. You might need more.
 KEY = to anticipate and have the numbers you need. It doesn’t do us any good to have good egg production and low fertility.
Rooster numbers
Managing a spiking program – 3 ways
 You can never have too many roosters!
 Best is a separate stud farm to take your 21 week old roosters and put some weight on them for a 25‐26 week move
 Pen in the hen house, release roosters to get back up to 8.5 between housing and 25‐27 weeks (if you have more than you need – go to another farm), bring in other males to spike at 38 and maybe 45 weeks of age
 Keep spike males on the floor with the flock until 25‐
26 weeks then move to a flock that needs these spike males (32‐45 weeks of age)
 Suggest that you buy 14‐16 roosters per 100 hens
 Grow them sex separate with 2.5‐3 sq ft/bird
 Place 8‐10 good roosters/100 hens at 21 weeks of age
 Plan to add enough roosters to keep rooster numbers around 8‐9 rooster 3
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Managing a spiking program – 3 ways
Good body weights
 Stud farm – expensive, potential biosecurity risk, but produces a great spike male because independent management of these males
 Pen in the hen house – can be a good situation or a bad situation, depends on how the grower manages the pen. Need space (not on the slats) and enough feed to put on some extra weight. Don’t want to rob the hens
 Keep spike males on the floor with the flock – least desirable situation, because it is easy to have too high a ratio and slat hens, not really preparing a rooster to be a spike – lack control over these males
 Attentive to gains and losses in weight
Keys to a spiking program
 Increase rooster numbers and reduce average age of the roosters.
 Know your feed
 Know your houses and farm managers
 Those who are making the feed changes have to have a weight and knowledge of whether the roosters are gaining and how rapidly
 Can you end up with good males WITHOUT doing these things? Yes sometimes! Can you consistently –
NO!
Improve flock uniformity
 Look for ways to improve uniformity  Disease a major issue: blackhead, cocci
 These changes will increase overall mating frequency in the flock. Instead of hens being mated on average of every 8‐9 days they are being mated every 5‐7 days.
 Since mating activity decreases with age, flock will need slightly higher numbers of roosters as the flock ages to sustain mating frequency and fertility.
Good body weight management
 Feeder space and floor space in rearing– determine the right amount of feeder space a what age
 Filler in the diet – trend toward more filler to get the feed to more birds – 30 min feed clean up time tells that the more aggressive birds are get the majority of the feed
Trying to create and maintain these average roosters?
Breeding males
These males that are
responsible for most
of your fertile eggs.
too heavy
culls
Body weight
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Does management of the hen affect fertility?
Feather pecking
 Mortality/morbidity influence egg numbers
 With Leghorns it has been suggested that birds are not provided enough fiber to help them feel full and satisfied.
 Body weight, obesity reduces fertility
 Tend to have more over weight hens in flocks coming in during fall and winter –
push them to come into lay with feed
 When sources of fiber are added the pecking subsides.
 However, the quality of feed ingredients must always be checked when these symptoms are observed.
 And generally lower rate of lay equals higher early dead and lower fertility
Overweight hens
 Increased mortality Cottonseed meal diet vs Corn‐soy
 Carry too much abdominal fat and the fat infiltration around the oviduct
M. Lordelo, A. Davis, N. Dale, J. Wilson
 Poorer sperm storage
 Today’s high yielding hen tends to put on more breast fleshing than fat
 She acts more like a broiler than a hen, poor longevity of lay
 From 2‐18 weeks, breeder pullet rearing diet contained 20% cottonseed meal vs. standard corn soybean meal diet (2860 kcal/kg and 15.5% crude protein).
 Pullets were weighed weekly from 2‐32 weeks of age.
 Feeding the cottonseed meal diet allowed feed allocations to increase by 6‐12.5% to achieve similar growth during rearing. So, cottonseed meal allowed us to feed more volume with more fiber.
Diets – cottonseed meal
Feather licking and pecking – either sex
 Cottonseed meal fed pullets were more uniform than the corn‐soybean meal fed pullets (13 vs 16.5 CV)
 No differences in egg numbers through 32 weeks of age (peak egg production of 80% in CSM and 78% in SBM).
 No differences in fertility (range with natural mating of 87.1 to 98.8% from 25 to 32 weeks of age).
 No differences in hatchability (range of 56.8 to 89.6% from 25 to 32 weeks of age).
 No difference in egg weight.
 Fillers allow a more uniform consumption rate.
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Oat hulls used as filler
 Zuidhof (1995) reports that adding 15 to 30 % ground oat hulls to pullet and hen rations improved flock uniformity.
 Increased feed cleanup time through 12 weeks of age
 15% dilution increased egg production (164 vs 151 in undiluted diets)
Time of the year influences
 Roosters that were 12‐18 weeks old during the hottest part of the summer may not perform as well as those grown during the fall and winter, depending on your pullet housing
 Heat stress starts at 85‐90 F
 If this is routine for your operation, place 0.5 to 1 more male after peak egg production
 30% dilution in hen ration was too much bulk
Feather loss
Summary
 Good start with attention to detail in their management
 Healthy, sanitary environment – low mortality
 Rooster numbers – buy, grow, and place
 Spiking program – have what you need
 Body weight and uniformity management
Influence of feathering on fertility
 Leave the causes of feather loss to our next speaker
 As well as what we can do about feather loss in breeders
 But feather loss does negatively impact fertility –
these hens learn to avoid the scratch area and mating
Questions
Jeanna L. Wilson
University of Georgia
jeannaw@uga.edu
 So, feather loss caused a decline in flock fertility
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