Posted on February 6, 2012; Last updated on March 16, 2015
A vegetarian spares the lives of a certain number of animals each time he or she chooses to forgo meat for vegetables, fruits, grains, legumes and nuts. These animals, of course, are not necessarily ones who continue to live because a vegetarian chose not to eat them. The way a vegetarian saves animals is by reducing the demand for meat and causing fewer animals to be born into a harsh life owned by the meat industry, where callousness abounds and mercy is scant.
Exactly how many animals does a vegetarian save each year? Given the scale and complexity of animal agriculture today, this number is impossibly difficult to determine accurately. But, it is possible to estimate a conservative range—in this post, I will attempt such an estimate for a vegetarian in the United States.
First, a few preliminaries. To determine the number of animals saved by a vegetarian, we need at least two numbers: the total number of animals killed for food consumed in the US in a given year and the size of the US population during that year. But, estimating the number saved is not merely a matter of dividing the total number killed by the size of the population. Suppose there are only two people in the US: one regular meat-eater who eats 100 animals each year and one vegetarian who eats no animals. A reasonable conclusion is that the vegetarian saves 100 animals per year. But, if we merely divide the number killed by the population size, we will unreasonably conclude that a vegetarian saves only 100/2 = 50 animals per year. So, we have to divide the number killed by the size of the meat-eating population, as expressed in the following formula.
|Number saved by a vegetarian =||Total number of animals killed|
|Population size × ( 1.0 − v )|
where v is the fraction of the population that is vegetarian or vegan.
According to a study of current and former vegetarians and vegans conducted by the Humane Research Council, about 1.94% of the US population is vegetarian or vegan. Based on this study, I will use v as 0.0194. (Because of rounding, the results of additions and multiplications reported in this post may not be exact.)
In the following, almost all of the data for the number of animals killed is for the year 2013. Using data from the U.S. Census Bureau, I will use the resident population of the United States on July 1, 2013 (mid-year) as 314,886,749.
But wait. Don’t vegetarians also cause animals to die?
Yes, indeed. Even a vegan diet causes a certain number of deaths and some amount of suffering. Mice, moles and other small animals die in the cultivation of grains and pulses on modern farms. They get run over by agricultural equipment such as tractors or they die as a consequence of the disruption of their land. Many small animals also die from poisoning by pesticides.
- G. Matheny. Least Harm: A Defense of Vegetarianism from Steven Davis’s Omnivorous Proposal. Journal of Agricultural and Environmental Ethics 16:505-511, 2003. (link, accessed March 15, 2015)
- M. Bittman. Rethinking the Meat-Guzzler. The New York Times, January 27, 2008. (link, accessed March 15, 2015)
But, the animals we eat do not just exist in isolation waiting for us to eat them. They eat grains too. In fact, almost all the animals we eat are ones kept caged by us inside desolate barns and kept fed by us on grains we grow just for them. We grow soy, corn, wheat, barley, sorghum and other grains on vast tracts of land—all of which also cause large numbers of deaths. Meat consumption remains an inherently inefficient process in which we grow far more crops to feed to the animals we eat than we would need if we ate the crops directly ourselves.
So, while the cultivation of crops to feed a vegetarian does kill some animals, far more animals die in the cultivation of crops to feed the animals we eat. This post makes no claim that vegetarians do not cause any deaths of animals. This post is about how many animals a vegetarian saves—the same question as how many fewer animals have to die for a vegetarian.
- National Agricultural Statistics Service, USDA. Poultry Slaughter 2013 Summary. February 2014. (link, accessed March 15, 2015)
- National Agricultural Statistics Service, USDA. Livestock Slaughter 2013 Summary. April 2014. (link, accessed March 15, 2015)
- Economic Research Service, USDA. Livestock and Meat International Trade Data. March 2015. (link, accessed March 15, 2015)
The number of land animals slaughtered in the U.S. or imported minus the number exported determines the U.S. supply of meat in the market. Table 1 below lists these numbers. The table does not include cows used for dairy, hens used for their eggs or the male chicks killed by the egg industry because we are trying to find the number of animals saved by a vegetarian, not a vegan (a whole other topic for another post, another time).
Two annual reports produced by the USDA serve as our sources for the number who are slaughtered or condemned before slaughter: the Poultry Slaughter 2013 Summary report and the Livestock Slaughter 2013 Summary report. The import and export numbers come from the data on international meat trade made available by the USDA. In this table, conversion from carcass weights or pounds of meat to numbers of animals is based on data in the same two slaughter reports mentioned earlier.
for the U.S. supply of meat in 2013
|Slaughtered in the U.S.||Imported into the U.S.||Exported from the U.S.||Total slaughtered for U.S. supply of meat|
- C. Bono, et al. Dynamic Production Monitoring in Pig Herds III. Modeling and Monitoring Mortality Rate at Herd Level. Livestock Science, volume 168. October 2014. (link, accessed March 15, 2015)
- Animal and Plant Health Inspection Service, USDA. Mortality of Calves and Cattle on U.S. Beef Cow-Calf Operations. APHIS Info Sheet: Veterinary Services. May 2010. (link, accessed March 15, 2015)
- National Agricultural Statistics Service, USDA. Hatchery Production 2013 Summary. April 2014. (link, accessed March 15, 2015)
Mortality from other causes: A large number of animals in our factory farms die even before they reach the moment of slaughter. They die of untreated illnesses and injuries, rough transportation, and various skeletal and other problems caused by intense genetic selection for excessively rapid growth. Many of them also die during or after their use as breeders. Some die in research experiments serving the meat industry. Some live long enough to get to the slaughter plant but are condemned by federal inspectors during the required ante-mortem screening because they are too sick, injured, or otherwise unfit for human consumption.
In the following, for the most-used land animals, I will use conservative but documented estimates of the deaths in the meat industry from causes other than their slaughter for meat.
In a recent study of modern pig farms published in 2014, the authors report that the average pre-weaning mortality rate of piglets is 14.6% and the average post-weaning mortality rate is 1.9%, for a cumulative mortality rate of about 16.22%.
The pre-slaughter mortality numbers for bovines come from a 2010 USDA report on U.S. beef operations. About 3.5% of calves die before weaning. An additional 1.5% die after weaning, for a cumulative pre-slaughter mortality rate of about 4.95% for cows.
In the case of chickens, we know from the USDA’s 2013 summary of hatchery production that a total of 9,057,461,000 chicks of the type used for meat were hatched in 2013. But, from Table 1 above, only 8,648,756,000 reached slaughter. This yields 4.51% as an estimate of the percentage of chickens in the industry who die from causes other than their slaughter for meat.
for the per capita U.S. supply of meat in 2013
|Total slaughtered for U.S. supply of meat||Mortality rate from other causes||Total deaths for U.S. supply of meat||Total deaths per capita||Number saved by a vegetarian|
|Calves||788,600||3.50%||817,202||< 0.1||< 0.1|
|Sheep||4,816,359||—||4,816,359||< 0.1||< 0.1|
|Goats||689,200||—||689,200||< 0.1||< 0.1|
|Bison||57,200||—||57,200||< 0.1||< 0.1|
According to the same report on hatchery production, we know that 269,476,000 turkeys were hatched in 2013, but the number slaughtered in the U.S. in 2013 was only 239,386,000. This yields 11.17% as an estimate of the percentage of turkeys in the industry who die from causes other than their slaughter for meat.
For lack of better data on the mortality rate of ducks, I use the ante-mortem condemnation rate of 2.12% by federal inspectors inferred from USDA’s Poultry Slaughter 2013 Summary report. This is a conservative estimate—surely, many more ducks die before they reach the moment they are so unfit for human consumption that federal inspectors remove them from the slaughter line.
We kill over 7.7 billion land animals each year for our food. Using the formula mentioned earlier, we find that a vegetarian saves over 25 land animals each year, almost 24 of who are chickens. The following pie charts depict the numbers of these animals in the proportion we eat them.
for the average American consumer (total: 24.6)
for the average American consumer (total: 1.3)
- National Marine Fisheries Service. Fisheries of the United States: 2013. September 2014. (link, accessed March 15, 2015)
- National Fisheries Institute. Top 10 Consumed Seafoods. (link, accessed March 15, 2015)
- Counting Animals. The fish we kill to feed the fish we eat.. March 16, 2015. (link, accessed March 16, 2015)
Aquatic animals we eat come to us through at least four different means: commercial landings (caught in the wild, brought ashore and then sold), aquaculture (farmed aquatic animals), imports and recreational fishing. The sum of these minus the exports yields the total that enters the U.S. supply as food. The most recent compilation of this data can be found in the Fisheries of the United States (2013) report, released by the Fisheries Statistics Division of the National Marine Fisheries Service. Based on this data for 2013, but excluding US-produced aquaculture and recreational fishing, the National Fisheries Institute has released numbers on the per capita consumption of sea animals by United States residents.
US-produced aquaculture data are not yet released for 2013, but we can reach a reasonable approximation using the 2012 data from the Fisheries of the United States (2013) report. With this adjustment to the data from the National Fisheries Institute and using the conversion factors and the methodology employed in my post on the fish we kill to feed the fish we eat, Table 3 below estimates the number of sea animals killed for direct consumption by the US civilian resident population in 2013. The consumption is reported in terms of live weight, the weight of the whole animal while alive. The “other” category in the table reports fish caught during marine recreational fishing.
by U.S. civilian resident population in 2013
(all weights are in live weight, except for mollusks which are reported in the weight of meat excluding the shell.)
|Weight of U.S. supply (in 1,000 pounds)||Estimated mean weight (in pounds) of an individual animal||Number killed for U.S. supply||Number killed per capita for U.S. supply||Estimated number saved by a vegetarian|
- A. Mood. Worse Things Happen at Sea: The Welfare of Wild-Caught Fish. 2010. (link, accessed March 15, 2015)
- A. Mood and P. Brooke. Estimating the Number of Farmed Fish Killed in Global Aquaculture Each Year. July 2010. (link, accessed March 15, 2015)
- Food and Agriculture Organization of the United Nations. FAO Yearbook 2012: Fishery and Aquaculture Statistics. June 2014. (link, accessed March 15, 2015)
In Table 3 above, the mean weights of the individual fish are derived from the mid-point of the estimated means compiled in two reports produced by fishcount.org.uk: one on wild-caught fish and one on aquacultured fish. The mean weights used in the table are appropriately weighted by the estimated proportion of each species of animal used in our diet. For example, the mean weight of salmon in Table 3 is based on the mean weights of farmed Atlantic salmon and the mean weights of the most-caught Pacific salmon: pink salmon and chum salmon. As another example, the mean weight of tuna is similarly based on the proportional mean weights of the most-caught species of tuna: skipjack tuna, yellowfin tuna, bigeye tuna and longtail tuna. The assigned proportions rely on US production data reported in the Fisheries of the United States: 2013 document and on the total global fisheries production reported in the FAO Yearbook on Fishery and Aquaculture Statistics (2012).
Shrimp are sold categorized by the count of heads-off shrimp per pound, ranging from extra small at 61-70 count per pound to extra colossal at under 10 count per pound. The relative sales numbers of these categories are not recorded by any regulatory body, but the 26-30 and higher counts are among the most popular. The weight of the shrimp I use is conservatively estimated at 26 heads-off shrimp per pound, with a live weight to heads-off weight conversion factor of 0.6 (as also used in the Fisheries of the United States: 2013 document.)
by the average American consumer (total: 12.1)
by the average American consumer (total: 136.9)
The mean weights of shellfish (shrimp, clams, crabs, oysters, lobsters and scallops) are similarly obtained based on conservative (high) estimates of the weight of individuals of a species, weighted by the proportion of each species that enters the US supply. For example, the mean weight of clams is based on the mean estimated weight of Manila clams, Atlantic surf clams, quahog and ocean quahog clams and softshell clams, in the approximate proportion in which they enter the US supply (as reported in the Fisheries of the United States: 2013 document.)
As Table 3 makes apparent, in terms of the number of individual sea animals, we Americans eat the most of shrimp (about 126 shrimp per person per year). Besides about 129 shrimp, a vegetarian saves more than 12 fish and more than 10 shellfish.
The fish we kill to feed the fish we eat
It is important to not forget the wild fish we catch, then kill and process into fishmeal (ground up dried fish) and fish oil to feed to the fish, the shrimp, the pigs and the chickens we eat. Yes, we feed wild-caught fish products to the pigs and chickens we eat! In fact, according to the International Fishmeal and Fish Oil Organisation, 20% of the world's production of fishmeal in 2010 was used to feed weaning pigs and an additional 5% was used to feed day-old chicks in the poultry industry.
- C. J. Shepherd and A. J. Jackson, International Fishmeal and Fish Oil Organization. Global Fishmeal and Fish-Oil Supply: Inputs, Outputs and Markets. Journal of Fish Biology, volume 83, pp. 1046-1066. 2013. (link, accessed March 15, 2015)
The sea animals we kill to feed the pigs, chickens and aquacultured animals we eat is treated in detail in another of my posts: the fish we kill to feed the fish we eat. The aquacultured animals in the American diet who are fed fish products include shrimp, salmon, tilapia, pangasius, catfish and crabs. As derived here, American consumption of aquacultured fish and shrimp demands the capture and death of 45,513 million to 92,313 million wild-caught sea animals each year! Assuming a US resident civilian population of 314,886,749 in 2013, the number of wild sea animals captured and killed to feed the aquacultured animals eaten by the average US consumer is between 144.5 and 293.2 per year. While some of these animals are also used to feed pigs and chickens, it is the feeding of aquacultured animals that drives the demand for the wild-caught “feed fish”.
I reproduce here the pie chart which depicts the proportions of their numbers (amongst those species of which more than 150,000 metric tonnes per year were captured in 2012 worldwide).
aquacultured animals eaten by the average American consumer
(Total: Between 144.5 and 293.2)
Bycatch from wild-caught sea animals
The numbers we have calculated above do not include bycatch, the fish and the crustaceans we unintentionally catch and then throw back into the sea dead or dying. Dolphins caught in tuna nets and turtles hooked by fishing gear have garnered well-deserved attention, but large numbers of less popular fishes and crustaceans routinely encounter commercial fishing gear and end up hauled on ships and discarded. According to a comprehensive study published by the FAO and based on surveys of marine fisheries, about 8% of the total catch of sea animals is discarded dead and not brought ashore.
But, this bycatch rate is not uniform across all of the species of sea animals we capture. The most destructive are shrimp trawlers, which use enormous nets towed by ships to indiscriminately capture all species of animals in their path. According to the FAO study, 62.3% of the catch of shrimp trawlers is discarded. Most of these discards are small fish and crustaceans who are dragged along in the net unable to escape. They also include larger animals like turtles, stingrays and even sharks.
The impact of American consumption of sea animals is particularly harsh, given that shrimp is the top sea animal, both in terms of their numbers and the edible weight, that Americans eat. Because of the unusually oppressive impact of shrimp trawling and the high shrimp consumption in the United States, in this post I will compute the bycatch numbers for shrimp separately from the bycatch numbers for all other animals.
Based on estimates derived here, we know that 1,114 million pounds of wild-caught shrimp are eaten by American consumers (the rest being aquacultured shrimp). This suggests an estimate of the total bycatch from shrimp trawling for American consumption at 1,114 × 0.623 / (1 − 0.623 ) ≈ 1,844 million pounds.
As mentioned earlier, the estimated weight of the shrimp we eat is about 0.0641 pounds. It is a reasonable assumption that the mean weights of the species of animals unintentionally caught by shrimp trawlers are approximately the same or larger than the mean weight of the shrimp we intentionally catch to eat. Given that shrimp trawlers drag along animals of all species indiscriminately, the mean weight of the bycatch animals can be estimated as the mean weight of all sea animals we catch equal to or larger than the size of the shrimp we eat. Using the same sources as earlier, this mean weight ranges between 0.075 and 0.165 pounds. The total number of animals caught in the bycatch from shrimp trawling for US consumers, therefore, is between 11,156 million and 24,466 million. The per capita bycatch number for American consumption of wild-caught shrimp, therefore, is between 35.4 and 77.7.
Again from this study, the average bycatch rate for sea animals other than shrimp is about 6.03%. Using aquaculture production data derived here and from capture production worldwide reported in the FAO Yearbook on Fishery and Aquaculture Statistics (2012), we can infer that about 10,670 million pounds of fish and shellfish other than shrimp are wild-caught annually to serve American consumption (5,641 million pounds of which are “feed fish”).
The mean weight of sea animals unintentionally caught during commercial non-shrimp fishing can be reasonably estimated as the mean weight of all sea animals intentionally captured by commercial fisheries but who are larger than shrimp. Considering only the species of which 150,000 metric tonnes or more were caught in 2012 and using data from the FAO Yearbook on Fishery and Aquaculture Statistics (2012), this mean weight lies between 0.082 and 0.2058 pounds. The number of individual animals in this bycatch, therefore, lies between 3,325 and 8,346 million. The per capita number lies between 10.6 and 26.5. Adding this to the bycatch from shrimp trawling, the average American causes the unintentional capture of 46–104 sea animals who are discarded dead or dying.
Table 4 below summarizes the proportional impact, in terms of numbers of animals, of the American consumption of animals.
|Total number killed
|Number killed per capita||Number saved
by a vegetarian
|“Feed fish”||45,513 – 92,313||144.5 – 293.2||147.4 – 299.0|
|Bycatch||14,481 – 32,812||46.0 – 104.2||46.9 – 106.3|
|Total||114,631 – 179,762||364.0 – 570.9||371.2 – 582.2|
From the table above, a vegetarian saves 371–582 animals each year. Using the mid-point of the ranges in the table above, the pie chart below depicts the proportional numbers of animals killed in service of the American consumption of meat.
and indirect consumption of animals by the average American
Yes, a vegetarian saves at least an animal a day! As large as these numbers are, the larger scandal is not in how many animals we eat but in how much suffering we impose on them during their lives and during slaughter. On factory farms for chickens and pigs and on factory farms for fish, the animals live a dreary existence weighted by both physical and mental suffering. The vegetarian, by withdrawing her contribution to this grim industry, saves her conscience too.