April 20, 2016
We are what they eat: The deepening interconnections between feed-based animal diets and human health
By ERIC J. BROOKS
An eFeedLink Hot Topic
- Science-based connections between feed quality, animal performance and human health are casting a shadow over consumer marketing campaigns
- Feed-based livestock have higher levels of gut pathogens, which then require antibiotics, ultimately leading to antibiotic resistant infections in humans
- Low levels of vitamins C and E give feed-based meat a shorter shelf life, unattractive appearance, and make it less healthy to eat. Supplementation must be increased
- Feed-based meat's low omega-3 fat level impacts everything from cow productivity to child brain development, heart disease incidence to dementia rates
- Boosting supplementation of key vitamins, fatty acids faces technical challenges and in some cases, resource scarcity
- Algae can boost feed's omega-3 levels, boost livestock performance and significantly improve human health
- We are gradually restoring animal health and meat quality to the levels of forage-based, pre-industrial times
If the saying 'you are what you eat' applies to livestock, then 'we are what they eat' is equally true of people. Livestock raised modern feeds may look outwardly similar to their forage-based ancestors, but on a biochemical level, their meat's is profoundly different. Feed-induced changes in meat composition can impact human health as much as they do animal performance. These links can be easily seen in the interconnected cattle performance and human health outcomes associated with feed quality.
On one hand, due to amid scarce, limited pastureland and an ever growing human population, there is no way we can go back livestock relying exclusively on forage. In the early to mid-1940s, American farmers discovered that by substituting corn-based feed in place of forage, the time required for beef cattle to reach their 540kg (1,200lb) slaughter weight could be reduced by a considerable extent. From 4.0 to 5.0 years in the 1940s, superior genetics, innovations in supplements and the substitution of corn in place of forage have reduced beef cattle maturation time to a mere 1.1 to 1.3 years.While this profoundly improves cattle productivity, it comes at a significant cost to both human and animal health. Whereas pasture fed cattle have neutral stomach pH near 7.0, a corn-based feed diet induces acidic pH levels ranging from 5.0 to 6.5. Acidosis, as the condition is known, then occurs, causes cattle gut flora to change from beneficial to pathogenic species.
Untreated acidosis is accompanied by decreased appetite, the inability to digest the cellulose component of feed materials and higher rates of infection. The latter where traditionally kept in check by antibiotic growth promoters (AGPs). Even so, AGPs, while enabling cattle to endure feed-based diets and acidic guts, made sure the side-effects would impact human health.
When feed-based diets induce acidosis in cattle, the most immediate, visible impact on human health is its boosting of E. Coli levels in meat. In an article ("Grass Fed versus Grain Fed: You are What Your Food Eats", 16 July 2012) Bill Kiernan, director of Global AgInvesting Research & Insight, states, "A corn diet dangerously raises the acid level in the cow's stomach, creating health conditions such as acidosis, necessitating medications and antibiotics which create prime conditions for the existence of E. Coli."
As the accompanying chart shows, E. Coli bacteria concentrations are 315 times higher in the guts of feedgrain-based raised cattle than in those relying on pastureland. This has played a large role in the microbial evolution and outbreaks of E. Coli 0157:H7. Contaminating everything from supermarket beef to fast food hamburgers, E. Coli 0157:H7 has caused many cases of serious illness, human deaths and permanent organ damage.
According to Kiernan, "This very dangerous strain of E. Coli 0157:H7 was isolated in the 1980's and arose because cattle were being fed grain and not their natural diet of grass. When we hear of all too common re-calls of beef because of E. Coli contamination, it is because of the animal's [feed based] diet."It should also be noted that E. Coli concentrations are a benchmark indicator for overall livestock gut health: When E. Coli numbers skyrocket, so do concentrations of other pathogenic species, such as salmonella or listeria. To control the high pathogen concentrations and infection rates associated with acidic rumens, feed-based livestock became highly dependent on antibiotics.
Over time, antibiotics used to prevent cattle infections caused by an acidic, feed-based diet accelerated the evolution of antibiotic resistant bacteria strains. This has not only increased incidents of beef's bacterial contamination and food poisoning, it also made the curing of their human food poisoning infections highly problematic.
Alongside highly visible human and livestock infections, feed-based cattle diets also have less visible but highly serious effects on meat quality and ultimately, human health. Quality-wise, from feed-raised cattle either lacks or contains significantly lower levels of key antioxidants. Not only are vitamins such as A, C and E present in lower concentrations than in grass, the quantity within feed decreases with time.
The Canadian province of Alberta's agriculture ministry states that besides boosting cattle immunity and reducing the incidence of respiratory infections, "Vitamin E supplementation at 500 IU/day for the last 100 days on feed increases vitamin E concentration in meat and improves meat's color, fat stability and shelf life." Hence, without antioxidant supplementation, beef from feed-raised cattle decomposes more quickly, has a shorter shelf life and could lead to higher incidents of both food poisoning and degenerative diseases in people.
Boosting current supplement levels is obviously key to avoiding such outcomes: As the accompanying graph shows, while cattle given conventional vitamin E supplementation have higher levels than their other feed-raised counterparts, their meat's vitamin E concentration is still lower than in pasture-raised animals.
Moreover, supplementing vitamin C simultaneously with vitamin E has a synergistic impact on meat quality. According to supplement supplier DSM, "Ascorbic acid [vitamin C] can donate an electron to the tocopherol free radical, regenerating the reduced antioxidant form of tocopherol [vitamin E]."
Darren Macleod, researcher at Hoffman-Laroche Canada, concurs that, "There is a close synergism between ascorbic acid and vitamin E in that vitamin C can reduce the radical of vitamin E back to its active reduced state."
He also notes that vitamins C and E work synergistically to boost the animal performance and meat quality of monogastric livestock and also, "bolsters the immune response of dairy cows." In mature cows, additional supplementation may be necessary, as, "Lactating dairy cattle may be predisposed to subclinical ascorbic acid [vitamin C] deficiency."Along with safeguarding the meat's quality, appearance and shelf life, meat from such animals will contain significantly higher vitamin C and E levels. In humans, higher levels of these vitamins have been correlated with everything from human immune system health, the rate at which wounds heal to the incidence of cardiovascular diseases. This makes boosting the supplementation of feed equally advantageous for livestock farmers, their animals, consumers and those marketing meat.
Similarly, a feed-based diet causes a huge drop in beef's concentration of conjugated linoleic acid (CLA), a trace fatty acid that scientifically proven have anti-carcinogenic, anti-diabetic, anti-obesity and anti-atherosclerosis (heart disease) effects in human. According to Michael Pariza, the scientist who discovered CLA, "Few anti-carcinogens and certainly no other known fatty acids, are as effective as CLA in inhibiting carcinogenesis."
Moreover, in over 30 scientific studies, CLA was shown to have important body weight management properties and plays a key role in preventing obesity. Unfortunately for us, the concentration of CLA in grass fed cattle (22mg/g) is a whopping 467% higher than its minimal level in the beef from feedlot raised animals (3.9mg/g). Unless feed-raised cattle are given supplemental CLA, grass-fed beef will always enjoy an advantage in premium, high-end niche markets.Marketing considerations aside, perhaps the most important –and problematic– nutritional difference between pastureland and feed-raised beef is its fatty acid concentrations. Humans were designed to consume meat with an Omega-6 to Omega-3 fatty acid ratio of close to 1:1. Modern diets by comparison, have omega-6: omega-3 fat ratios in the range of 5:1 to 20:1. Much of this deterioration in human fatty acid ratios occurred over the last century.
According to Dr. Maurice Boland, Alltech's director of research, states that, "Humans originally consumed a diet rich in omega-3 fatty acids and low in saturated fatty acids because pasture based animals had much higher contents of omega-3 fatty acids than do the present-day commercial [feed-raised] livestock."
Boland explains that, "Omega-3 is related to enhanced cognitive function [IQ] and learning ability in children, including benefits for children with attention deficit and hyperactivity disorder (ADHD). In addition, DHA omega-3 improves the health of adults by lowering the risk of developing cardiovascular and Alzheimer's diseases, and lessening severity of depression. Adequate supplies of DHA are required for infant development. The content of DHA in breast milk is influenced by the [meat] diet of the mother."
Clearly, changes to livestock diets have boosted meat making productivity. Unfortunately, with levels of nutrients such as vitamins C, E, CLA and omega-3 fat in meat falling over the last half century, feed-based meat may have played a role in the rising incidence of degenerative diseases. Kiernan states that, "Feeding cattle on corn fundamentally changes the meat they produce." He explains that, "In the early decades of the 20th century, the diet of cattle was dramatically changed to corn and grains from grass, changing the levels of Omega-3s and Omega-6s, and drastically reducing the amount of CLA in beef. This paved the way for an epidemic explosion in rates of cancer, weight gain, diabetes, and heart disease."
His opinion is seconded by that of Dr. Patrick Wall, associate professor of public health at University College Dublin's School of Public Health, who states that, "This disproportionate [omega-6: omega-3] ratio may contribute to excess inflammation in the body, increasing the incidence of chronic disease." By comparison, "Plentiful levels of dietary DHA are linked to reduced risk of coronary heart disease, depression, cancer and age-related mental decline."
In response to such concerns, the number of grass-fed cattle raising operations in America skyrocketed from 50 in 2002 to over 2,200 today. Consequently, agribusiness is being forced to acknowledge deepening science based connections between feed quality, animal health, human diseases –and the shadow this issue casts upon their consumer marketing efforts. The problem is that boosting livestock omega-3 fat levels of livestock feed is far more challenging than raising vitamin or antioxidant supplementation levels. This is especially true of the omega-3 fats most essential to human health, EPA and DHA.Beyond forage, livestock's only major supply of omega-3 fats comes from anchovies. Unfortunately, wild catches of the pelagic fish from which EPA and DHA rich protein meals are derived have peaked and their supply has been declining for three decades.
Due to the substitution of feed in place of forage, mid-20th century agribusiness was keynoted by falling omega-3 fat levels in livestock. Now, with fishmeal's quantity and price going in opposite directions, the last two decades have seen EPA and DHA levels in aquaculture species such as salmon falling sharply.
Besides damaging the early development of species ranging from salmon to sea bass, farmed fish's falling omega-3 levels are undermining seafood's reputation for being 'healthy'. Becky Timmons, global technical director of Alltech Algae states, "The amount of DHA found in farmed fish has decreased due to the shift in raw materials used in aquaculture diets. There are no content guarantees on fish, so are we actually getting the nutrients in our food that we pay for?"
While everything from the genetically engineering feed crops to Antarctic krill has been proposed as new supplies of omega-3 fats, at this time, most aqua feed suppliers are merely substituting plant ingredients in place of soymeal. They have made innovations that make plant-based aqua feeds more digestible. The ultimate result has been farmed fish with lower levels of omega-3 oils, unusually high omega-6 fat level concentrations and dark implications for human health. Amid declining anchovy catches and fishmeal prices inflating from $250/tonne to over US$2,000/tonne in less than a decade, declining omega-3 fat levels are due to genuine natural scarcity.
At this point, algae may be the only alternative feed input that has the potential for reversing a longterm decline in feed's EPA and DHA levels. Rather than attempting to catch more of the cold water fish rich in omega-3 fats, Alltech is cultivating the algae from which salmon and pelagic fish obtain their EPA and DHA in the first place.
In an article authored by Boland on this subject ("Research: Feeding DHA omega-3 could benefit both health and reproduction") Boland states that, "Supplementation using DHA-rich microalgae sources has been used successfully in monogastric livestock such as pigs and poultry to produce DHA-enriched meat." He shares the results of an Italian study that used Alltech's proprietary, omega-3 fat-rich feed supplement, Algae STM: "Cows were allocated into two homogenous groups of 18 animals each. The treated group received supplementation (6 g/kg DMI) of the test product [Algae STM] for 84 consecutive days mixed into one component of the TMR [corn meal]. The control group had received the same amount of corn meal without a test product."Dairy cattle given Algae STM had a similar body condition scores and their live weights were nominally higher than those of control group cows. While levels of milk protein, lactose, urea and somatic cell count were unaffected, milk yields in cows given Algae STM supplemented feed were 5.4% (1.19kg/cow/day) higher, while milk fat content and fat production was reduced.
For dairy farms, this translates into approximately 420 litres of additional milk per cow annually from the same feed. The implied 4% to 5% increase in dairy cow productivity makes an investment in omega-3 rich algae-based feed supplements like Algae STM profitable, with a rapid investment pay off time.
These are not the only benefits to be gained from using algae-supplemented feed. Noting how constant commercial milk production strains cow reproductive systems, Boland adds, "Studies using DHA in lactating cows are aimed at enhancing the quality of their uterine epithelium, modifying and attenuating the release of prostaglandin F-2a and thus ensuring a higher pregnancy rate."
Best of all, algae-based feed supplements are as good for human health as they are for marketing milk, meat or fish grown with high omega-3 fat levels. In Alltech's Italian dairy study, cows given Algae STM saw their milk's DHA level rise from 0% to 0.37% of fatty acid content. Their milk's conjugated linoleic acid (CLA) concentrations also increased closer to those of pasture-based cattle.
Boland states that, "DHA inclusion in the diet will not only add benefits for animal and human health but also increase reproductive efficiency in the herd." By supplementing feed with algae-based derivatives, Timmons believes, "We can shift the [human] omega-6 to omega-3 ratio towards disease prevention levels through consumption of whole, natural foods instead of supplements or artificially-fortified foods."
Best of all, similar healthy results can be obtained from supplementing omega-3 fat rich algae derivatives into the diets of monogastric livestock. For example, as the accompanying charts show, supplementing algae-based feed compounds into broiler diets. It resulted in chicken breast meat having 1,129% more DHA, 834% more EPA+DHA than flesh from conventionally raised broilers.
While such positive results are described in just a few minutes and with a few hundred words, the technical challenge took millions of dollars and many years of research. Nor is raising feed's levels of scarce omega-3 fats the only challenge. Even efficient supplementation of easily made vitamins faces technical obstacles.
For example, traditional crystalline vitamin C, while suitable for monogastric animals, does not survive its journey through the guts of rumens like cattle and sheep. Due to its water solubility and continuous excretion, the constant injections of vitamin C required would themselves ruin ruminant health and meat quality.
Here too, the development of ascorbyl-2-polyphosphate by companies such as DSM has made it possible to supplement feed with a vitamin C compound that can be efficiently absorbed by ruminants such as cattle. In fact, while vitamin supplementation has been around for the better part of a century, it is only during the last decade that innovations like organic trace minerals have made it possible for feed to deliver vitamins with anything approaching the efficiency of natural forage.
Clearly, numerous technical hurdles remain before feed becomes anywhere near an ideal source of vitamins, minerals and enzymes as natural forage. It will take decades before all the enzymatic, vitamin and fatty acid deficiencies of domesticated livestock are identified –and even longer before domesticated beef, milk or salmon approximates the nutritional profile of their natural counterparts.
Agribusiness stakeholders may not want to hear it, but 20th century's gains in protein production and livestock efficiency produced came at the cost of increased animal suffering, poorer human health, lower quality meat and the evolution of antibiotic resistant bacteria. –In fact, historians may one day remember the 20th century as a time when the quality of protein ingested by humans hit rock bottom.
The good news is that progress is being made on all fronts. It will take time, but we can look forward to a world where animal health, livestock farming returns and meat's nutritional quality will all rise at the same time –and all of it will be clean and green, healthy and sustainable.
All rights reserved. No part of the report may be reproduced without permission from eFeedLink.
