Nutrition: A century's worth of progress in swine nutrition

Sunday, April 5, 2009

Test your knowledge with this quiz on the major advances that have taken place in swine nutrition over the past 100 years

by JANICE MURPHY 

The past 100 years have produced a wealth of information on the nutrition of weaner, grower and finisher pigs, and gestating and lactating sows. These research studies, carried out by academics and feed industry nutritionists, have progressively led to a better understanding of the pig's need for dietary energy, protein, amino acids, carbohydrates, fats, minerals and vitamins, and have helped to quantify the specific nutrient requirements of pigs at various stages of growth and reproduction.
In addition to this focus on the pig's needs, considerable research effort has been spent on evaluating the options available to the swine industry in assessing various feedstuffs, feeding strategies, growth promotants and carcass modifiers.
In celebration of the American Society of Animal Science's centennial, Gary Cromwell, a fixture at the University of Kentucky since 1967, recently summarized the past century's progress in swine nutrition. The following quiz touches on some of the major advancements to date.

Questions

Q1.
Today's standard ingredients, corn and soybeans, were the major crops used in feeding pigs 100 years ago.
True   
False

Q2.
The majority of mineral research over the past 50 years has focused on:
a) Magnesium
b) Potassium
c) Selenium
d) Calcium and phosphorus
e) None of the above

Q3.
What change in animal husbandry practices resulted in vitamins becoming increasingly important?
a)"ˆConfinement housing
b) Artificial insemination
c) Split-sex feeding
d) Computerized record-keeping
e) Liquid feeding

Q4.
What vitamin was the last to be discovered in 1948?
a) Vitamin A
b) Choline
c) Vitamin B12
d) Vitamin K
e) Niacin

Q5.
What technique, developed in Canada, contributed to the ability of researchers to assess amino acid digestibility?
a) Polymerase chain reaction (PCR)
b) Near infrared spectroscopy 
         (NIRS)
c) High performance liquid
         chromatography (HPLC)
d) Mass spectrometry (MS)

e) Ileal cannulation

Bonus Question. How many editions of the National Research Council's Nutrient Requirements of Swine have been published since the first one hit the shelves in 1944?
5   10   15    20    25

Answers:

Q1, False.

Although corn is and always has been a major crop in feeding swine, the same cannot be said for soybeans. The acreage, yield, and price of the two major crops currently fed to swine have undergone dramatic changes over the past century. Comparing the 1910 U.S. Census of Agriculture to numbers available from the National Agriculture Statistics Service in 2008 (see Table 1, page 35) shows that, thanks to technological advances, corn has realized tremendous strides in yield and value over the past 100 years.

On the other hand, soybeans were not even listed in the 1910 Census of Agriculture. It appears that the small amount of soybeans existing at the turn of the century might have been used for a green manure crop or as forage for cattle.

Small scale soybean crushing operations did not start until the 1920s. One event which boosted the use of soybeans was World War II. Prior to that, the United States imported nearly half of its edible fats and oil, but when edible oil supplies were cut off, interest turned to soybean oil. Over the past 50-60 years, soybean production has seen tremendous growth as its value as an oil source for humans was realized and it achieved widespread use as soybean meal, a high quality protein source for livestock and poultry.

Q2. d.

More swine studies have focused on calcium and phosphorus in the past 50 years than for any of the other major minerals. Researchers have used bone ash and bone breaking strength as response criteria, since they are very sensitive to adequate supplies of calcium and phosphorus, to establish requirements for all phases of production.

Some of the initial discoveries in mineral nutrition in the past century involved the identification of the roles of calcium, phosphorus and salt for pigs. This was followed by discoveries of the roles and necessity of the other macro-minerals and micro-minerals, along with the specific establishment of their requirements. However, one of the most important discoveries in mineral nutrition was the realization that selenium was an essential nutrient, despite its miniscule requirement, and not simply a toxic compound.

Q3. a.

Research has shown that vitamins A, D, E and many of the B-complex vitamins became especially important when the swine industry moved indoors into confinement facilities. As a result, pigs no longer had access to legume pasture, sunlight and other sources of vitamins. In addition, the move to fully slatted floors and sows being housed in stalls prevented animals from coming into contact with their feces, making it necessary to provide diets fortified with vitamins, like the B-complex vitamins and vitamin K, which are naturally synthesized by enteric microbes.

Q4. c.

Most nutritionists agree that the 1948 discovery of vitamin B12, the last of the vitamins identified, had more impact on the swine industry than any other single vitamin discovery. For many years, it was well known that there was some unidentified growth factor (now known as vitamin B12) at work in animal protein sources, and that growth in pigs and chicks was impaired if they were fed plant-only diets without the inclusion of fish meal, meat meal or other animal protein sources. The discovery of vitamin B12  was extremely important because it led to the successful feeding of simplified corn-soybean meal diets to swine and poultry, and it was closely associated with the discovery of chlortetracycline, an antibiotic important for its growth promotant effects in swine.

Q5. e.

As published in the Canadian Journal of Animal Science in 1962, Canadian researchers (Cunningham, Friend and Nicholson) developed ileal cannulation procedures which were subsequently implemented by researchers in Europe and the United States. The development of this technique led to many research studies that allowed quantification of the apparent and true digestible amino acid level in feedstuffs for swine. The information derived from ileal cannulation experiments, in combination with the concept of ideal protein (an ideal ratio of amino acids that closely matches the pig's requirements), has been widely accepted and implemented by the feed industry in formulating practical diets for pigs.

Bonus question. b.

The tenth edition of the NRC Nutrient Requirements of Swine was published in 1998. This latest edition of the publication features a mathematical model to estimate nutrient requirements. The growth model uses equations to partition energy and amino acid requirements for maintenance and lean growth rate of grower-finisher pigs. Sow models use equations to estimate energy and amino acid requirements for maintenance, potential litter size, number of pigs nursed and weight change during lactation. BP

Janice Murphy is a former swine nutritionist with the Ontario Ministry of Agriculture, Food and Rural Affairs who now lives and works in Prince Edward Island.