Induced Molting of Layer Birds
Biology
Senior Seminar
Goshen College,
Indiana
November 12, 2001
Natural molting and induced molting
III – Positive outcomes
a. Better egg quality
b. Profit per hen
c. Time management, cost distribution
d. Feed cost
IV – Negative outcomes
a. Salmonella enteritidis
b. Contamination of rats and mice with Salmonella
c. Overhead cost and planning
d. Mortality
e. Egg durability
a. Economical lost
b. Increase in farmers cost of egg production
VI – AVMA (American Veterinary Medical Association) stand point of view
a. Statement is confusing
b. Need for a rewording of statement
VII – Economics vs. Animal welfare
a. Birds nervous system of pain and consequences
b. Egg producers costs
VIII – My stand of view and how it should be controlled
Induced Molting of Layer Birds
Induced molting of layer birds is a practice done for economical benefits. These birds are put under great stress, which should not be allowed. Further studies of humane induced molting techniques should be done to replace those that are currently used and inhumane.
In nature birds undergo natural
molting. During a year birds will
replace all of their feather to maintain a good plumage, this usually occurs at
the beginning of winter when birds do not have chicks. They can concentrate their energies to stay
warm and to grow new feathers. (Animal Protection Institute, 1998) However, there also is induced molting,
which is done by human influence. The
later is practiced by 60% - 70% of the layer industry, so that a second cycle
of laying flocks is achieved. (Macri
et al., 1998)
Induced molting occurs when the bird’s organism is stressed by some source that alters their environment. The most common are: lack of food and water, decrease of light, and change in diet. Food withdrawal can be up to 10 days and of water up to 2 days. The change in diet usually is a low calcium, or low sodium and also feeding a diet high in dietary zinc. All of these methods can be done separately or in any combination with each other. (Alodan and Mashaly, 1998).
At the end of every laying cycle, egg quality and production are decreased. This is when induced molting is imposed to give a “rest” to the birds. After the “rest” period egg quality and production are increased when compared to the pre-molting period. There are several improvements to the egg at the post-molt period; there is a "better egg size, shell quality, internal egg quality and rate of egg production." (Alodan and Mashaly, 1998)
According to a study done by Alodan and Mashaly (1998), diet influences quality of egg in post-mold period. They compared the effects of different hen diets; the study groups were a diet in high dietary zinc, California method, conventional method, and a control group. After analyzing the data statistically using one-way analysis of variance (ANOVA), the authors concluded that the mortality rate was in the normal range for all groups; indicating that the molting program was not too severe. There was an increase of egg weight in molted hens when compared to the control but not significant. However, shell weight increased for all groups when compared to control, therefore, a better eggshell quality. This may be explained because involution of hens' uterus increases the efficiency of glandular epithelium. (Alodan and Mashaly, 1998) Among the groups, the zinc and California group had greater shell quality when compared to the conventional group. This is explained by the fact that the hens from the conventional group did not loose much weight and egg production was not completely stopped. The zinc group was the one to be out of production for the shortest time. Even if the rate of egg production, egg shell quality, and egg mass were better in the California group, economically zinc is the most favorable method to adopt. This is just one example of how induced molting can be beneficial.
The biggest reason for induced molting is the economical benefits off it. The poultry industry is pinched for money so any little improvement that can be done to improve their costs will be done. One of these improvements is the profit per hen. The cost of hens per dozen of eggs produced is reduced, for the fact that induced molting increases the length of egg production of a hen. For example, a conventional hen will lay in average 20 dozens of eggs and a new flock is purchased annually. Now with induced molting hens the average eggs laid is increased to 31 dozens and typically flocks are purchased three times in five years. (Carey and Brake, 1998)
According to Carey and Brake (1998), an egg producer can match egg supply according to market conditions. As mentioned before molted flocks (second-cycle) will produce larger eggs than first-cycle flocks. Usually during the summer higher prices or premiums are paid for larger eggs so molted flocks are desired. When prices are not much different between medium and large eggs it’s favorable to have first-cycle flocks, such lack of difference in prices usually occurs in the winter and spring. One of the biggest advantaged of induced molting is that it can be done any time during the year and the whole flock is molted at the same time. The egg producer can plan accordingly to the market prices and demand. (Ruszler, 1997) Carey and Brake (1998) reports that there will be a reduction of egg production by 7% during a five year period, but the key of induced molting is that the egg producer diminishes the time that the house in not producing. This allows a better income distribution throughout the year. (Ruszler, 1997)
Another positive consideration of induced molting is the feed requirement. The cost is reduced to bring the flock to a good egg production. (Ruszler, 1997) Greater time and feed are consumed when raising a new flock until egg production is optimum. (Bell, 2000)
However, not everything is perfect, there are several negative aspects of induced molting. The biggest negative outcome of induced molting is the increase contamination of the hens with Salmonella enteritidis (SE). Macri et al. (1998) has reported that his laboratory has shown that induced molting made hens more susceptible to SE. They also report that poultry are susceptible to several organism and that future studies should be done on induced molting hens and their increase susceptibility to other organisms.
According to Poultry.org referencing to Holt (1992) induced molting by removing feed or dietary restriction can modify humoral immunity (like in humans, rates, mice) and cell-mediated immunity. He also reports that “the number of circulating lymphocytes” were significantly decreased” when compared to the control groups. Poultry.org reported that according to Holt et al. (1995), there is a possibility of feed withdrawal diminishing intestinal flora, which would also unprotect the animal’s intentional track. This organization also reports that according to Fowler (1990) the use of antibiotic/antimicrobial therapy would destroy the intestinal flora, making the bird susceptible to Salmonella. Induced molting leads to a disturbance of the intestinal microflora, then the animal gets sick and antibiotics are used, which debilitates the intestinal microflora even more. Salmonella is then free to take over the flock.
The problem of SE infection to layer birds is just the beginning of the problem. Even with the decrease of production of feces when a hen is molting, there still is a large quantity of SE in the feces and a high probability of the whole flock to get contaminated, because of their immune debilitation. To make the situation worse yet, mice can carry and transmit SE in their feces. The presence of mice in a poultry establishment will maintain the cycle of SE. This occurs to the fact that if all hens are removed, killed and the establishment is cleaned and disinfected contamination with SE will reoccur. When those infected mice return with the presence of new hens, they will transmit SE to molting hens and the process starts all over.
Another negative aspect of induced molting is the overhead cost and planning. When hens are molting, there is a cost to maintain the establishment and the “health” of the hens when no eggs are being produced. With induced molting there is a much more complex planning to ensure that the method and time is the best for the outcome wanted. There is a higher cost to feed a hen during the post-molt period, because feed consumption is increased. Also there is a slighter higher mortality during the second cycle when hens have been molted, compared to the first cycle of non-molted hens. And finally another problem is that eggs need to be sold and consumed fast especially during hot weather, because eggs may only last for 5 to 6 months. (Ruszler, 1997)
There has been interest to ban induced molting in the United States. Britain has banned induced molting since 1987 (Animal Protection Institute, 1998) and also because of health concerns other European countries have banned induced molting. (Summer/Fall 1998 Poultry Press). According to Bell (2000) if induced molting were to be banned in the U.S. with the improvement of $0.17/hen it would cost $45 million for the U.S. and $4.25 million for the State of California. Bell (2000) also reports that with the ban of induced molting there would be an increase of the laying flock by 3%, which means that there is a need for greater number of establishments for these new flocks. There would be an increase in egg supply in the market by 4% to 5% because of the increase in the laying rate, which would reduce the egg price. This would lead to an increase of costs for the poultry industry running egg producers out of business.
Several negative outcomes would happen with the increased demand for flocks. Approximately 47% increase of chicks needing to be hatched, an equivalent to 200 million more chicks. This leads to more breeding farms and breeding flocks, which leads to more hatcheries, which leads to more male chicks being killed, about 200 million males. (Bell, 2000)
With the increase of flocks there will be an increase of eggs. The market already has problems with high quantities of medium and small eggs. The quality of these eggs would be reduced, since egg producers would push the limits beyond laying age, generating more cracked eggs. Egg producers would not be as flexible to adjust to the market’s demand. The U.S. in general would become less competitive to other countries or states that induced molting is still permitted. (Bell, 2000)
However, the good side of banning induced molting is that egg production would go up, needing less planning and skills required for induced molting hens. Poultry houses would be filled to their capacity and problematic flocks would be getting eliminated more often. (Bell, 2000)
There has been an article published by Journal of American Veterinary Medical Association (2001) urging for the American Veterinary Medical Association (AVMA) to reword its policy statement toward induced molting, which consists off:
“The process designed to bring the entire flock into a nonlaying and oviduct rejuvenation period (commonly called “induced molting”), is a management practice, that should be done under careful supervision and control. The once-practiced long-term total feed and water withdrawal that resulted in high levels of mortality is not acceptable. Under no circumstances should water be withheld. A carefully monitored and controlled program that may include reduced photoperiod (day length), controlled calorie intake through dietary restriction, and/or reduction in some nutrients essential for egg production (i.e., sodium) is acceptable. Feed restriction should be minimized. Careful monitoring of bird weights and weight loss, mortality, egg production, and behavior are needed to ensure that proper results are achieved humanely. Feather loss (molting) is not a reliable index of the progress and success of a resting and rejuvenation program. The goal is to improve the bird’s ability to produce a high quality egg with a good shell, not to replace the feathers. Additional research is needed to improve the welfare aspects of the molting process.” (AVMA, 2001)
According to AVMA (2001), “Veterinarians are obligated morally, ethically, and philosophically to promote the welfare of all animals, as defined by AVMA policy.” (75) The argument is that AVMA supports induced molting, while some veterinarians believe it to be inhumane, however, they believe that more research should be done to improve the animal welfare in reference to induced molting.
Those that are against induce molting, criticize the poultry industry to be using soft words towards their practice like induce molting is a period of “fast”, “pause” or “rest” (Poultry.org, Summer/Fall 1998 Poultry Press). The reality is that these laying birds are being starved, because they are not from their free will reducing their food intake, as it would happen in nature. Therefore, the terms fasting, resting and pausing can be used to represent the state of the laying bird for natural molting, but for induced molting the proper word would be starving.
Birds can experience pain, fear, and suffering. They have pain receptors, thermo-receptors, and physical-impact receptors. Birds like mammals also will “show a rapid increase in heart rate and blood pressure, and behavioral changes” (Poultry.org) when exposed to aversive stimuli, therefore, they should be treated as mammals are treated.
The problem is if animal welfare can survive with economics? It has been presented above that banning induced molting would generate higher costs to egg producers and even put them out of business. However, there also is the welfare issue that laying birds are dying from diseases and are suffering from induced molting.
The arguments made against induced molting are to a certain point valid. Any animal will react to a sudden change in its environment, like change in diet or a limited quantity of food; it all depends if the animal can adapt to such changes, without debilitating its organism. Induced molting by food removal or poor diet should be banned.
The arguments done in favor of induced molting are problematic. The poultry industry is suffering and currently the agriculture is in the worse place to be at the current economy. It is very true that with the ban of induced molting, there would be an increase of eggs in the market, which would make its price go down, putting egg producers out of business. There needs to be a change.
There are three changes to solve this ethical question for the benefits of both, the laying animal and for the egg producer. First of all, as the AVMA has said, further studies should be done so that layer birds are not harmed. There may be other ways to induced molting that does not decline the health of a layer bird. There are other methods to induced molting that do not depend in feed/water removal or limitation of these.
Secondly the government can subsidize egg producers. The government subsidies so many products, because the cost is so low, why not subsidize eggs or set a floor price for eggs being sold? This would mean that even if there would be an increase of egg supply the price could not go lower then the one established as a floor price. By doing so the government would allow time for more research to be done with induced molting and also would help the egg producer in economical difficult times.
Finally and third, there is the need of regulation. Egg producers should provide certificate of inspection, proving that the induced molting method used is not harmful. These birds should be closely monitored, maybe by a veterinarian. The establishment could get a health certificate as it is done for transportation of animals or food derived from animals.
It is possible for animal welfare and economics to coexist in the poultry industry. It may just take time for more research to be done. There is a need for people to be considerate to egg producers as they wait for new, more humane, techniques to be developed. Just after these our layer birds will be able to produce our needs for eggs without being exploited and harmed.
References:
Alodan,
M and M. Mashaly. “A Comparison of Induced Molting Programs on Production
Parameters of Laying Hens” University of Nebraska Cooperative Extension MP 70.
Institute of Agriculture and Natural Resources. Last visited on 09/09/2001 at http://www.ianr.unl.edu/pubs/poultry/mp70/mp70-15.htm
AVMA – American Veterinary Medical Association (2001). “Directory & Resource Manual” Division
of Membership and Field Services: Schaumburg, Il. 50th edition, pages 75-76.
Animal Protection Institute. “The Cruelty of Forced Molting”
(08/14/1998). Last visited on
09/09/2001 at http://www.api4animals.org/areas.asp?C=1&ID=432#Molting
Bell, Donal. “An Egg Economics
Update” Department of Animal Science, University of California. (12/13/2000)
Last visit on 09/22/2001 at http://animalscience.ucdavis.edu/extension/avian/eeuAPR00.htm
Carey, John B. and John T. Brake. “Induced Molting as a Management
Tool” Extension Poultry Science, North Carolina State University
(10/05/1998). Last visited on
09/09/2001 at http://www.ces.ncsu.edu/depts/poulsci/techinfo/4Pst09.htm#top
JAVMA - (09/01/2001). “Induced
molting resolution fails, but delegate support for alternatives grows.” Journal American Veterinary Medical
Association. Vol. 219, No. 5. Page 571 and 573.
Macri, Nicholas P., Robert E. Porter and Peter S. Holt. “The Effects of Induced Molting on the Severity of Acute Intestinal Infection Caused by Salmonella Enteritidis.” Tektran, United States Department of Agriculture, Agrucultural Research Service (12/18/1998). Last visited on 09/09/2001 at http://www.nal.usda.gov/ttic/tektran/data/000007/07/0000070701.html
Poultry.org, a Farm Sanctuary Campaign. “Forced Molting of Laying
Birds” Last visited on 09/09/2001 at http://www.poultry.org/molting.htm
Ruszler, Paul L. “The Keys to Successful Induced Molting of Leghorn-type Hens” Extension Poultry Scientist, Department of Animal and Poultry Sciences, Virginia Tech, Virginia State Univerty. Publication Number 408-026, January 1997. Last visited on 09/09/2001 at http://www.ext.vt.edu/pubs/poultry/408-026/408-026.html#TOC
Summer/Fall 1998 Poultry Press “Balancing Economics and Evil” Induced
Molting. Last visited on 09/22/2001 at http://www.upc-online.org/summer98/molting_econ_and_evil.html#top