MAXIMIZING FERTILITY WITH ROOSTER MANAGEMENT

Jeanna L. Wilson

University of Georgia

Some might ask – why we are having issues with fertility?

To answer that question let’s take a look back – 6 week old broilers, 1950’s vs 2012

University of GA, 2012

1957 verses 2012 cross section

University of GA, 2012

Full fed broiler breeder male. Restriction program is allowing only about 27% of full fed consumption level(33-35% on female).

First steps in excellent fertility – testes development

• Achieve maximum testicular development, 35-50 grams total testes wt

• By 28-30 weeks of age in feed restricted roosters

• Slow decline or regression after 30 weeks of age

First steps in excellent fertility

• We can influence testes size and maintenance through our management of the roosters.

• Poor management = faster decline in testes size, testosterone and libido or mating interest.

Relationship of body and testes weight

Body weight (pounds)

Body weight (grams)

Testes weight (grams)

Ratio of testes to body weight

11.57 5250 35.24 0.67110.56 4790 45.6 0.952

9.99 4530 35.83 0.79110.05 4560 32.52 0.71310.43 4730 29.12 0.61610.54 4780 36.14 0.75610.63 4820 32.02 0.66411.05 5010 28.34 0.566

9.94 4510 51.38 1.13911.40 5170 23.89 0.462

Relationship of body and testes weight

Body weight (pounds)

Body weight (grams)

Testes weight (grams)

Ratio of testes to body weight

11.57 5250 35.24 0.67110.56 4790 45.6 0.952

9.99 4530 35.83 0.79110.05 4560 32.52 0.71310.43 4730 29.12 0.61610.54 4780 36.14 0.75610.63 4820 32.02 0.66411.05 5010 28.34 0.566

9.94 4510 51.38 1.13911.40 5170 23.89 0.462

Regression – controlled by health and condition of the rooster

45 grams 10 grams

Good rooster management

• Small consistent body weight gains each week

• Small gains hard to measure, plot results and should see body weight increase slightly 2 weeks out of 4 weeks

• Uniform male flock

• Poor uniformity leads to overfeeding the top roosters and starving the bottom roosters

• Consistent daily feeding

Good rooster management

• Level floors

• Feed line charged or run all the feed out each day

• Keep the females out of the male

• Consistent daily feeding

• Measure gain and fleshing

At mixing or start of lay (21-23 weeks), don’t slat your hens by having too many roosters at housing (8-9 males/100)

Fearful hens learn to run and hide

• Slating the hens makes it more difficult for the rooster to compete the mating.

• Hen has to evert the oviduct for efficient semen transfer.

• The hens don’t really get over this fear, so reduces fertility for the life of the flock.

Want good mixing in the late evening.

When do birds mate?

• More than 50% of the mating takes place within 4 hours of the lights going out in the hen house.

• Ask the farmer where the birds are at 5-6pm.

• Go visit the flock, at 7-8pm. Where are the birds? Scratch area or in those hen groups?

• Go in and sit down. Do you see lots of mating in a 10-15 minutes or are the hens hiding?

So, if the hens are on the slats at 6pm ?

• The question is how do you draw them down?

• Hand broadcast cracked corn, oat or soy hulls in the litter at 5-6pm to draw the hens out. Gotten away from oyster shell because of Salmonella.

• New idea, to use male drinker line to draw them out, turn off water on the slats or near hen feeders at 5-6pm and lower male water line to draw the hen to the center of the house for mating.

Male numbers throughout the flock

• After peak egg production, bring roosters numbers up to 8.5-9 males/100

• Post 40-45 weeks of age, spike the flock with 26-28 week old males (good quality).

• After 40 weeks of age cull all pretty boys. They are no longer mating and preventing more moderate males from mating.

How do you accomplish the culling?

Culling program • To get the most from the moderate size males and the spike males – critical that you cull the big well feathered males, especially after 40 weeks of age.

• This will allow males more access to feed and females without the big males around.

• You will get far more from your spike males with a good culling program.

Increase male numbers as the flock ages (9-9.5 males/100 by 55-60 weeks of age)

There is also the natural decline that we are fighting against

• Natural relationship between bird behavior and physiology.

• Rooster less interested and able to complete matings.

• Hen physiologically needs to be mated more often to sustain same level of fertility.

Impact of age on flock fertility

• So, to get the same fertility level as you had a 35 weeks of age the older hen will have to be mated more often as she ages to sustain fertility.

• To sustain 98-96% fertility, a young hen needs to be mated once every 8-9 days, an older hen needs to be mated every 6-7 days

• Reason to spike and increase male number as the flock ages

A few other important facts in managing for excellent fertility

Good physical condition, improves mating activity

• Poor shaving quality or lack of shavings increases foot pad problems

• Provide the good ventilation and water management – wet floors cause problems

• Low slates reduces injury to males and females

• Nipple drinker line in scratch for males, reduces time he spends on slats

Feather loss can affect fertility – hens make their last set of three sets of feathers about peak egg production, then it’s maintenance of the feathers.

Prevent pecking – urates streaming from vent

Normal vent of mature rooster

Pecked vent of mature rooster

Cockerels (16-18 weeks) are maturing on 8 hours

What’s the cause?

• Have to say not sure.

• Usually have low body weight uniformity. Upper body weight group is maturing.

• Most likely being caused/driven by breast meat deposition. Heavier males maturing early with short day length. But body weight not totally out of line. Maybe have 10-25% of the flock involved.

• Perhaps these more mature males should be our spike males?

Sperm is deposited in vaginal area must reach infundibulum area of the oviduct for fertilization in the hen

vagina

infundibulum

Sperm has to travel to infundibulum for fertilization

• Hope that a portion of the sperm get in the sperm storage tubules located at the junction of uterus and vagina – for later release

• Could have a hard shelled egg in the oviduct –obstacle to sperm swimming up the oviduct, late afternoon and evening mating gives a better chance for high fertility

• Could have poor storage conditions in the sperm storage tubules or fat infiltration around tubules and sperm don’t get out as well or don’t survive storage

Formula for fertility

• Have excellent testicular growth

• Maintain testicular development, consistent daily feeding after getting to hen house

• Place just the right number of young, maturing cockerels

• Don’t ever slat hens, mentally discouraging mating

• Encourage good mating behavior, litter, ventilation, water

• Maintain body weight and breast fleshing without excessive breast fleshing in roosters, change the diets

• Spike aging flocks with young, mature roosters

• Increase roosters numbers as the flock ages

• Maintain feathers on the female

Questions

jeannaw@uga.edu