What is a "Normal" mortality rate?

Discussion in 'Emergencies / Diseases / Injuries and Cures' started by Organic Acres, Oct 8, 2013.

  1. Organic Acres

    Organic Acres In the Brooder

    Sep 8, 2013
    I have a flock of various breeds of chickens, which free range 100% of the time (unsupervised most of the time) on a large property. I have two white leghorns, 6 cross breeds and 4 "green legged partridge fowl", which are a heritage breed and are pretty wild and pretty immune to illness.

    I started out with 9 green legs and a greenleg rooster, then got the white leghorns.

    one of the hens has gone broody a few times and so I put a few eggs under her from the neighbour (2 of them hatched) and bought dayold mixed breed chicks when those ones hatched, to end up with 9 chicks.

    the second time she went broody (she is a bantam green leg) she had been stashing her own eggs in the haystack, and had 9 of them under her. I thought she had disappeared but I found her in there when taking out some hay. All 9 of those chicks hatched (a much better success rate than with an incubator), and those 9 chicks are now 2 weeks old.

    Anyhow, from my original 9 green leg hens, a few disappeared, presumably taken by hawks during the day, and 4 started to act sickly and then in a day or two just dropped dead with no visible symptoms of illness except a droopy head, disorientation, lethargy, etc (each time the behavior was different, so I don't think it was the same illness each time). This didn't happen to all 4 at the same time, it was one at a time at seemingly random intervals across the course of their teenage months.

    From the 6 cross breed hens that I bought and put under the broody hen as day olds, 2 have dropped dead in the last 2 months. The two that hatched are still ok and are now 4 months old (one of them is a rooster, unfortunately).

    I had also three broilers, two of which are ok and 14 weeks old now (time to chop them), but one of them dropped dead a week ago for no reason, and was not acting sick the day before.

    so, it means that over the course of one season (May to October), out of a total of around 22 chickens (not including the 9 that are now 2 weeks old), 6 of them died for unknown reasons and without symptoms other than behavior changes.

    I consulted with my neighbours, who mostly have confined or partly free range chickens, and they state that this mortality rate is normal and that they always lose a few chickens here and there. When they notice a chicken starting to act sickly, they cull it immediately, in fact.

    In researching large poultry farms, I find that there is such a thing as a "calculated mortality rate", basically chickens dying for seemingly no reason, and to combat this (and thus maximize their profits) they use antibiotics, steroids, high protein food additives and a variety of synthetic viatmins and other additives, hoping to reduce this mortality rate to nearly zero.

    My question is, is a mortality rate of 6 chickens (usually dying before reaching adulthood) out of 22 in the course of a year, in a natural free range situation, normal and acceptable?

    Please advise.
  2. Wyandottes7

    Wyandottes7 Crowing

    Jul 24, 2013
    I think I've read that a mortality rate of 5% per year is "normal". So, the amount of your chickens that have died is not exactly normal.
  3. Organic Acres

    Organic Acres In the Brooder

    Sep 8, 2013
    Yeah, my rate is 26 percent, so if 5% is the normal rate then something is horribly wrong. I wonder if the chicks I bought originally were inbred or something?
  4. babsbag

    babsbag Songster

    Jan 12, 2010
    Anderson, CA
    I have close to 50 chickens, most mixed breed, many home grown, that free range with my goats totally unsupervised. They have a coop at night. In the last year I have lost 3, maybe 4, for unknown reasons, all of those were well over a year old. There may be a few that have disppeared from hawks, but no sign of that, no pile of feathers. Your mortality rate is very high IMO. I do give antibiotics now and then if I see closed eyes but that is maybe 1 or 2 chickens a year. I don't vaccinate and I don't worm, and I don't treat for mites or lice. I am pretty hands off with my birds.
  5. Organic Acres

    Organic Acres In the Brooder

    Sep 8, 2013
    I am very hands off too. I don't give them medication and their feed is grown by me on my field, along with what they forage. their eggs are very deep colored (and awesome) and the chickens all look tough, strong and healthy. All of the ones that have died though have been ones that I picked up as chicks from other sources. the ones I am raising on the farm under the broody hen that actually hatched on my farm are so far ok. they are pretty young though.

    They have to be bringing in a previously extant illness or weak genes from the places I got them from. if it's not inbreeding, then what is it?

    a 26% mortality rate can't be normal.

    I'm not going to bring in any more chicks from off site; I will cross my green legs with the white leghorns, to create a cross breed because they are supposed to be more vigorous, and will then start to select for immunity. Perhaps I can selectively breed to the point that I have an adapted flock that does well in my location.

    Unless anyone has other ideas as to why these chickens keep keeling over on me like this?
  6. LMiller

    LMiller Chirping

    Apr 2, 2013
    You may have had something go through your flock. Could come from anywhere. The same disease may present quite differently in different chickens so many many chicken deaths are chalked up to unknown causes unless they are tested. The broiler probably dropped dead of being 14 weeks old. That happens with broilers and they are known for it. They aren't meant to last long. They can, but they need special and very restricted feeding to do so. Mine were processed at 8 weeks and weighed 9-10 lbs. I can't imagine 6 more weeks and they weren't fed 24/7 like my regular chickens. They also free ranged. Anyway I wouldn't count that one on your mortality list.

    You could have a plant on your property that doesn't agree with chickens. Sometimes they eat a piece of string and mess up their crop and die within a day. Little ones are more fragile and can go quickly from coccicida or other things. It's hard to say really. If you are really concerned you could send a carcass in for necropsy. Half the time they will tell you unknown causes killed your chicken :/.
  7. Organic Acres

    Organic Acres In the Brooder

    Sep 8, 2013

    after about 4 more adult birds that I had brought in, and an entire brood (about 9) of 11 week olds, died in the course of about 2 weeks, dropping like flies, by then I knew that this was a management issue and therefore something caused directly by me. My mortality rate was at over 50% over 3 months at the peak of this problem!!

    The only thing I could see that might be a problem was that the water was always dirty from the chickens rooting thru the dirt and poo with their beaks and then drinking from the waterers. Even if I cleaned it several times a day it was dirty again within an hour.

    I tossed out all my waterers, those plastic bottle things that let water out into a ring shaped trough at the bottom that runs around the bottom of the plastic tub, and installed a sealed water tank with a plastic water line going to waterer nipples, the nipples were installed into 3/4 x 3/4" square PVC pipe. The tank is 50 liters, which I think is about 12 gallons, and I fill it up once every 10 days or so. I'm gonna get a much bigger one though.

    The chickens figured out in about 8 seconds that they can get water from the nipples, and when they peck at them the little metal nipple moves up and water comes out. Because water is always flowing outwards, the nipples stay clean and infectious bugs can't grow on them.

    And guess what? the mortality rate immediately dropped to ZERO percent. I have not lost one single bird since then (several months now), even in sub zero weather.

    There must have been a bacterial infection or virus, or both, that was being passed from bird to bird by way of the waterer. Some of my birds were immune to it, or else lucky, or maybe the bacteria had to build up to a certain concentration in the water before it would kill one of the birds.

    Note that this was NOT coccidiosis, I had an autopsy done on several of the birds after they died, looking for this problem, and their digestive tracts were not affected by coccidiosis.

    I'm going to make some U-tube videos one of these days to explain my organic farm and all it's cool stuff. I'll do a section on this water system.

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