Re: Brooding hens that won't let me near the eggs

" Jill" <news@xxxxxxxxxxxxxxxxxxxxx> wrote in message
Farm1 wrote:
" Jill" <news@xxxxxxxxxxxxxxxxxxxxx> wrote in message

I am genuinely curious
We live and breed our birds in a place where force 8 gales are
not
remarkable, where we get over 7 ft of rain a year, and even in
the
middle of the summer [today!] can get downpours of 60mm/hr - as
we
have just had for the last hour. We can go from minus 5 to plus
10
in a winters 24 hour period. We have only 6-7 hours of daylight
in
the winter.
And yet we have pure breeds producing over 200 - 250 eggs a year
with 95% fertility

Whats tough?

But surely you must know that domestic birds (which are derived as
you
would know) from forest based birds, can stand those conditions
you
describe much more easily than they sruvive heat???????????????


Domestic fowl have not been Jungle fowl for over 4000 years - and
some say a
lot longer
The heat in the "jungle" they came from was much nearer your
temperature
than ours, so there is a greater degree adaptation to our climate
than
yours.

I'm was initially quite shocked at your ignorance but on reflection I
guess living in a hot counry makes me more aware of the problems than
you could be expected to be. Domestic birds suffer dramatically and
in many cases, fatally, from heat stress.

Here are a few cites but there are many more:
http://www.abe.iastate.edu/livestock/layh.gif
and in the following you will note that there is one sentence on birds
dealing with cold but how many paras on heat?????
http://www.traill.uiuc.edu/poultrynet/paperDisplay.cfm?ContentID=140
"Poultry respond physiologically to cold temperatures by mainly by
increasing internal metabolic rate to keep their body temperature
normal. During exposure to hot ambient temperatures, poultry have a
more difficult problem keeping themselves cool and maintaining
homeothermic body temperature. Since birds do not sweat, they must
rely on evaporative cooling (panting) to keep themselves cool. This
increased rate of panting produces what is called respiratory
alkalosis of the blood. This physiological response is characterized
by an increase in blood pH (more basic), along with a decrease in
blood CO2 concentration. This upsets the blood acid-base balance and
produces a decrease in blood calcium and bicarbonate which are
necessary for the production of strong egg shells. Thus, the ultimate
problem is a production of thin-shelled eggs produced by laying hens.
As for growing birds, heat stress affects them by depressing weight
gain mainly because feed intake is depressed. Figure 4 depicts the
response of poultry to extremes in environmental temperatures.

In our laboratory, we have conducted several studies in which we have
developed a system that is designed to replenish the CO2 lost in the
blood of poultry (laying hens) when they are exposed to high
temperatures and are panting. This system (Figure 5) provides the bird
with a constant source of carbonated drinking water. Previous results
in our laboratory have shown that egg shell quality could be improved
for layers exposed to high environmental temperatures (Odom et al.,
1985). In more recent work, we showed that egg specific gravity of
second-cycle hens maintained in a commercial-type facility during the
summer was improved by providing carbonated drinking water (Koelkebeck
et al., 1992) (Table 2). In another study, we showed that hens
provided carbonated drinking water had greater tibia bone strength
when sampled after exposure to six weeks of heat stress temperatures
(Koelkebeck et al., 1993) (Table 3). The work we have done on the use
of carbonated drinking water for heat-stressed layers seems to show
beneficial results.

In addition to our work with carbonated drinking water, we have
explored another avenue of heat stress relief for poultry. Another
means of losing body heat in poultry subjected to heat stress
temperatures is dissipation of heat through conductive heat loss via
the foot pad area. Physiologically speaking the bird reacts to high
temperatures by shunting blood towards the skin surfaces to dissipate
heat (peripheral vasodilation). Therefore, we hypothesized that if
there was a system to remove heat from the birds skin this would
effectively help keep the birds body temperature normal. Therefore, we
devised a system that allows for conductive heat transfer for broilers
subjected to high environmental temperatures. The system is designed
to remove body heat by allowing the birds to stand on a water-cooled
floor perch, and the perch acts as a heat sink to remove heat (Reilly
et al., 1991). The results showed that final body weight and total
body weight gain were improved for broilers exposed to heat stress
temperatures for 4 wk and provided with a water-cooled roost (Table
4). These results indicated that water-cooled perches may offer a
thermoregulatory and performance advantage to broilers exposed to a
hot environment.

More recent work in our laboratory has focused on the use of adding
supplemental ascorbic acid in the feed and examining its effect on
poultry subjected to heat stress and other concurrent stressors at the
same time. In the field, when poultry are subjected to one stressor
such as heat stress, usually they are also subjected to another
stressor at the same time. This results in an additive stress
situation which further hampers the ability of the birds to cope with
the stress. Since it has been shown previously that ascorbic acid can
improve performance of poultry during times of stress, we wanted to
examine the stress relieving effect of ascorbic acid on poultry
subjected to multiple concurrent stressors (McKee and Harrison, 1995).
In this experiment, broiler chicks were exposed to the multiple
stressors of beak trimming, coccidiosis challenge, and heat stress
from 10 to 17 days of age. Performance parameters and several
physiological factors were then measured.

Table 5 shows the effect of ascorbic acid on chick performance, plasma
corticosterone, and heterophil:lymphocyte ratios when chicks were
exposed to three stressors. These results showed that chicks fed an
ascorbic acid supplemented diet (150 ppm) gained more weight than
those fed 0 ppm or 300 ppm when exposed to heat stress. Plasma
corticosterone was also reduced for chicks fed the 150 ppm level of
ascorbic acid compared to those fed 0 ppm and exposed to a coccidiosis
challenge or heat stress. Heterophil:lymphocyte ratios decreased for
those chicks fed 150 or 300 ppm of ascorbic acid compared to those fed
0 ppm when exposed to either beak trimming, coccidiosis challenge, or
heat stress. When the number of stressors were examined simultaneously
(order), ascorbic acid supplementation had a positive effect on weight
gain and feed intake (Table 6).
Summary

In summary, physiological responses of poultry to the environment vary
tremendously depending on what type of environmental stressor is
imposed. Of the ones discussed herein, temperature, i.e., heat stress,
has the most devastating effect on physiological responses and
production performance of poultry. The research which we have
conducted on ways of alleviating negative effects of heat stress have
merit in the commercial poultry industry. Aside from this research,
there are some basic practices which a poultry complex manager must
follow in order to control in-house air temperatures. The following
items should be closely monitored:

Make sure fans operate effectively.
Make sure fans and air inlets are kept clean.
Inspect and/or replace fan drive belts when necessary.
Make sure thermostats and static pressure monitors are operating
effectively.
Provide clear cool water at all times.
Don=t overcrowd layers in cages or boilers in a house.
The above list is only a partial list for poultry producers to follow.
Following these and many other items will help reduce the devastating
effects of heat stress on poultry production performance.

Finally, the commercial poultry industry here in the U.S. has gone to
using evaporative cooling type houses as well as the use of tunnel
ventilation, especially for broiler houses. If these types of houses
are operated properly, then negative heat stress affects on poultry
performance should be minimized."

and heres a nice one from steamy, humid, hot Louisiana:
http://www.lsuagcenter.com/en/crops_livestock/livestock/animal_health/
poultry/Advice+on+Reducing+Heat+Stress+in+Poultry.htm
"Dealing with summertime heat is a great challenge for people in
Louisiana. LSU AgCenter poultry specialist Dr. Theresia Lavergne says
high heat and humidity combine to pose severe problems for all types
of poultry.

"Under conditions of severe heat stress, poultry will have a reduced
growth rate, decreased feed intake, poor feed conversion, decreased
egg production, reduced hatchability rate, reduced egg shell quality,
reduced egg size and reduced internal egg quality," Lavergne
explained. "Additionally, heat stress can cause increased mortality."

All types and ages of poultry are susceptible to heat stress, but
older poultry face a bigger risk. As poultry get older, they increase
in size as well as insulation (feathering). Lavergne says this makes
it harder for them to dissipate heat.

"The most obvious sign of heat stress in poultry is panting," the LSU
AgCenter specialist says. "Poultry do not have sweat glands that can
cool their skin, so instead they must use evaporation from their
throat and respiratory system as a means of cooling themselves."

Lavergne points out that panting takes a lot of energy which, in turn,
generates an appreciable amount of body heat for poultry.

"Ultimately, if poultry are not relieved of heat stress, their body
temperature can continue to rise and increase the possibility of
mortality," she stresses, "Fortunately there are several things you
can do to help your home poultry flock handle heat stress."
"etc.

and here's one on heat from cool old Canada:
http://www.canadianpoultry.ca/heat_stress.htm
"Although we have only seen a couple rays of sunshine, the forecast
warns us against a blistering summer. This heat may be a wonderful
change from the dreary weather of the Lower Mainland, but can cause an
increased amount of problems when dealing with poultry. In broilers,
heat stress can cause reduced growth rate, depressed feed intake, and
poor FCR. There can be a drop in egg production and a reduction in
shell and internal quality in egg laying birds. For all types of
poultry, heat stress can also cause increased mortality.

Heat stress is a bigger risk factor in older birds than younger
birds, due to their insulation and size. Older birds have better
feathering, which acts as insulation, making it difficult for the
birds to expel heat that they are producing. Additionally, older birds
are larger, making space in the barn minimal. This creates a denser,
warmer environment, increases the temperature at the floor level, and
decreases the birds ability to dissipate heat."

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&l
ist_uids=15742968&dopt=Abstract
"Superoxide radical production in chicken skeletal muscle induced by
acute heat stress.
Mujahid A, Yoshiki Y, Akiba Y, Toyomizu M.
Life Science, Graduate School of Agriculture, Tohoku University, 1-1
Tsutsumidori-Amamiyamachi, Aoba-ku, Sendai 981-8555, Japan.

Heat stress is of major concern for poultry, especially in the hot
regions of the world because of the resulting poor growth performance,
immunosuppression, and high mortality. "

Even the UK govt. recognises some of the problems with heat on birds:
http://72.14.203.104/search?q=cache:Sjgg3OVKgOQJ:www.defra.gov.uk/anim
alh/welfare/pdf/hstress05.pdf+poultry+%22heat+stress%22+mortality&hl=e
n&gl=au&ct=clnk&cd=3
and
http://72.14.203.104/search?q=cache:sZ7ojLN941cJ:www.defra.gov.uk/anim
alh/welfare/pdf/heatstresspoultry.pdf+poultry+%22heat+stress%22+mortal
ity&hl=en&gl=au&ct=clnk&cd=21

I've snipped a LOT of this one, but again, one sentence on cold and it
goes on forever on heat stress:
http://www.p2pays.org/ref/18/17815.htm
"Normally, the chicken's body temperature is 104-107oF, but will
fluctuate somewhat depending upon the temperature of its environment.
There is a lot of margin for error on the low side; in cold weather a
chicken's body temperature can drop as low as 73oF before death
occurs. However, there is much less flexibility on the high side. The
upper lethal limit on body temperature is 113-117oF. The chicken must
be able to get rid of excess body heat quickly or it is in trouble.

Although birds and mammals are homeothermic, birds have a number of
thermoregulation characteristics different from mammals. The most
obvious is feathers. Feathers are great insulation which is good for
cold weather but bad for hot weather. Feathers tend to hold heat in
and not let it escape easily from the chicken's body. Another
difference is that birds have no sweat glands. Most mammals perspire
when they are hot, and evaporation of this perspiration from their
skin is extremely effective in reducing body temperature.
Nevertheless, birds have a couple of special features that do help
them during hot weather. Their relatively high body temperature makes
it easier for them to lose heat to the air around them. Also the
bird's respiratory system is very effective at cooling. The air sacs
of the bird allow inhaled air (which is usually cooler than body
temperature) to reach deep into the abdominal cavity, and of course
when the bird exhales, heat is removed from its body. The bird also
has a panting mechanism (gular flutter) that it uses during hot
weather to evaporate water from its throat and reduce its body
temperature. Thus panting in birds is analogous to perspiring in
mammals and is extremely effective at cooling the bird."

And its been the same there in all the thousands of generations that
have
gone into creating the birds you have in Australia. Birds have been
breeding
in those conditions for

Pure supposition on your part. The birds are bred here just as in the
UK for your favoured "productivity" in terms of egg production and
table birds or a combination of both. If you bother to read the cites
you'll realise what heat affects the birds at a the level of their
blood metabolism. Breeders don't "do" blood because it has nothing to
do with Poultry Standards or appearance or egg or meat production.

And chooks will die in that heat MUCH easier than they
will from -5 and rain if they have halfway adequate shelter where
they
can stay out of the rain if they choose.

And you do not provide halfway adequate shelter/provision from your
heat? ;)

Of course. They live in an orchard and thier house is in the
permanent shade from evergreen trees, but you try surviving 40+C temps
for weeks and you'll realise how hard that is as human let alome a
chook with a permanent feather coverage. I was in Paris 2? years ago
during their heatwave when thousands of humans died from the heat and
it was not as hot as here (and I still have the blister scars on my
feet to prove it).


.

Relevant Pages

  • Bird Flu - Guardian Report
    ... wild birds are spreading the deadly H5N1 virus that's ... If you normally make a point of buying free-range poultry and eggs, ... farms of China and south-east Asia. ...
    (uk.business.agriculture)
  • So whos really to blame for bird flu? and why put yourselves at risk!
    ... So who's really to blame for bird flu? ... wild birds are spreading the deadly H5N1 virus ... that's wiping out poultry worldwide. ...
    (sci.agriculture.poultry)
  • China and Vietnam Report Flu Outbreaks
    ... warning that migratory birds from Europe and Asia could carry the virus ... The virulent H5N1 strain of bird flu has devastated Asia's poultry ... China's latest outbreak - the fourth in three weeks in the world's most ... Hiroko Tabuchi in Tokyo, Japan, contributed to this report. ...
    (soc.culture.cambodia)
  • Re: Culling by suffocation
    ... The poultry industry as a whole does on a daily basis ... The culling methods used during the AI crisis situation in the ... depended on the housing and the numbers of birds. ... that some birds will be exposed to low concentrations of gas or no gas at ...
    (uk.business.agriculture)
Loading