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PURDUE UNIVERSITY

THIS IS TO CERTIFY THAT THE THESIS PREPARED UNDER MY SUPERVISION

Hobart Beach G e u r i n _______________________

by_______________

e n title d

Protein Efficiency of Corn Oil M e a l , Other

Corn Products and Some Plant and Animal Protein Feeds For Swine Growth.

COMPLIES WITH THE UNIVERSITY REGULATIONS ON GRADUATION THESES

AND IS APPROVED BY ME AS FULFILLING THIS PART OF THE REQUIREMENTS

FOR THE DEGREE OF

Doctor of Philosophy

P

r o fe sso r in

H ead

June

of

Charoe

S chool

or

isBO

TO THE LIBRARIAN:-----IS THIS THESIS IS NOT TO BE REGARDED AS CONFIDENTIAL.

GBAI>. SCHOOÏI FORM 0—3 -4 0 — 1M

of

Th e s is

D epa rtm en t

PROTEIN EFFICIENCY OF CORN OIL MEAL, OTHER CORN PRODUCTS AND SOME PLANT AND ANIMAL PROTEIN FEEDS FOR SWINE GROWTH

A Thesis Submitted to the Faculty of Purdue University

by Hobart Beach Geurin

In Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy June, 1950

ProQuest N um ber: 27714146

All rights reserved INFORMATION TO ALL USERS The quality of this reproduction is d e p e n d e n t upon the quality of the copy subm itted. In the unlikely e v e n t that the a u thor did not send a c o m p le te m anuscript and there are missing pages, these will be noted. Also, if m aterial had to be rem oved, a n o te will ind ica te the deletion.

uest ProQuest 27714146 Published by ProQuest LLC (2019). C opyright of the Dissertation is held by the Author. All rights reserved. This work is protected against unauthorized copying under Title 17, United States C o d e M icroform Edition © ProQuest LLC. ProQuest LLC. 789 East Eisenhower Parkway P.O. Box 1346 Ann Arbor, Ml 48106 - 1346

ACKNOWLEDGMENT The writer wishes to express his very sincere appre­ ciation to Dr. J. A. Hoefer and Dr. W. M. Beeson of the Purdue Animal Husbandry Department for the opportunity to work on this problem and for their extremely helpful super­ vision and wise counsel In conducting the study.

He Is

especially grateful to the Corn Industries Research Founda­ tion for the very generous grants of both money and supplies necessary to carry on the project.

He Is also greatly In­

debted to his brother, Gilbert Geurin, who contributed in­ valuable personal labor during rush periods.

In addition,

he is extremely thankful to the Animal Husbandry Department as well as to the Veterinary Department and the Agricultural Chemistry Department for the use of the facilities and equip­ ment used in conducting the research.

In fact, the writer

has greatly benefited by, and is very thankful for, the large number of friends this study.

that he has encountered throughout

TABLE OP CONTENTS Page ABSTRACT

.......................

i

INTRODUCTION............................................... 1 REVIEW OP L I T E R A T U R E ...................................... 3 Various Methods of Determining Protein Quality Protein Efficiency Method

...

3

....................... 3

Nitrogen Balance M e t h o d ............................ 5 Amino Acid Analysis for Protein Q u a l i t y ........... 6 Purified Diets

7

Corn By-Products C o m Oil Meal

................................ 8 . f ...............................

C o m Gluten Meal

9

.................. 11

Corn S o l u b l e s ............

.*12

Other Protein S u p p l e m e n t s ........................ 13 FIRST FEEDING T R I A L ..................................... 16 Experimental P r o c e d u r e .......................

...

R e s u l t s ...................................

16 22

Supplements to the Original Corn Solubles Ration . 32 BIOTIN SUPPLEMENTARY TRIAL-............................... 35 Experimental Procedure

..................

35

Results

...........................

35

SECOND FEEDING T R I A L ..................................... 40 Experimental P r o c e d u r e ............................... 40 Results

...................

* ..............44

THIRD FEEDING T R I A L ...........................

ExperimentalP r o c e d u r e .............................. 51 R e s u l t s ............ DISCUSSION .

51

............................................ 59

S U M M A R Y .........................

66

LITERATURE C I T E D .................................

68

V I T A ................

92

LIST OF TABLES Table

Page

1.

Components of Experimental Rations . . . . . . . .

2.

Partial Analysis of the Protein Feeds Used (Air Dry B a s i s ) ..................................... 18

3.

Components of Mineral M i x t u r e .................. 20

4.

Components of Vitamin M i x t u r e .................. 21

5.

Components of Modified Corn Solubles Ration

6.

Rations Fed to Lot 3 Pigs After Failure on Corn Solubles R a t i o n ...........................

• .

17

. 23 24

7.

Results of Feeding Swine Rations Containing Either Dried Whole Egg, Corn Oil Meal or Corn Solubles as the Sole Source of Protein . . . . . . . . . 2 5

8.

Average Weight of Animals at 7-Day Intervals . . .

9.

Average Daily Feed Consumption of Animals at 7-Day I n t e r v a l s .......... -........................ .28

10.

Average Gain Per Pound of Protein Consumed at .................. . . 3 0 7-Day Intervals

11.

Results of Modifying the Original Corn Solubles R a t i o n ......................................... 33

12.

Components

26

of the Egg R a t i o n ....................... 36

13. .Average Growth and Feed Consumption at 7-Day Intervals ................... .. . . . .

37

14.

Results of Feeding Swine Rations Containing Dried Whole Egg With or Without Bio t i n .............. 39

15.

Components

16.

Partial Analysis of the ProteinFeeds Used (Air Dry B a s i s ) ..................................... 42

17.

Components

18.

Average Weight of Animals at 14-Day Intervals

19.

Results of Feeding Swine Rations Containing Either Dried Skim Milk, Corn Oil Meal, Soybean Oil

of Experimental Rations.

of Vitamin Mixture

.............. 41

.............. 43 . . 45

Meal or C o m Solubles and Soybean Oil Meal as the Sole Source of Protein .............. 46 20.

Average Daily Feed Consumption of Animals at 14Day Intervals ............. . . . . . . . . . . 4 8

. 22.

Average Protein Efficiency at 14-Day Intervals . . 50

23.

Average Weight of Animals at 14-Day Intervals

24.

Results of Feeding Swine Rations Containing Either Dried Skim Milk, Corn Oil Meal, Tankage or C o m Gluten Meal as the Sole Source of Protein . . . 55

25.

Average Daily Feed Consumption of Animals at 7-Day I n t e r v a l s .............. 56

26.

Average Protein Efficiency at 7-Day Intervals

21

Components,of Experimental R a t i o n s ................ 52 . . 54

. . 58

ABSTRACT This study, consisting of three feeding trials with growing swine, shows the protein efficiency values obtained when various natural protein feeds were fed as the sole source of protein in purified rations•

The protein effi­

ciency is expressed as pounds gained per pound of protein consumed.

The pigs were housed inside on raised wire screens

and fed individually twice daily. controlled.

Feed consumption was not

The trials were roughly from weaning to about

125 pounds live weight and were conducted in both summer and winter. The crude fat and crude fiber contents of each ration were equalized by adding corn oil and corn fiber when neces­ sary.

One per cent of dried whole liver was used to supply

unknown growth factors in the first trial, but in succeeding trials the liver was replaced by 0.1 and then 0.2 per cent of a commercial vitamin

concentrate.

The other ration

ingredients were 5 per cent of a complex mineral mix, 0.1 per cent of a commercial vitamin A and D oil and dextrose. Aliquots of a standard vitamin solution containing thiamin, riboflavin, niacin, pyridoxine, pantothenic acid, choline and menadione were fed daily on the evening feed. In the first trial dried whole egg was compared with corn oil meal and corn steep water solubles.

The respective

average daily gains were 1.19, 0.98 and -0.05 pounds while the protein efficiency values were 2.35, 2.14 and -0.15.

il After 21 days when it became apparent that the pigs receiving corn solubles would not live long, various nutrients were added to the ration.

Pure tryptophan added to the corn

solubles ration enabled the pigs to grow very slowly. Methionine, in addition to tryptophan, caused a slight fur­ ther increase .in pig growth.

When soybean oil meal replaced

one-half of the corn solubles protein, growth was much im­ proved.

When the pigs receiving dried whole egg were con­

tinued on the ration after the experiment closed, they soon . developed a severe deficiency syndrome characterized by loss of appetite, growth retardation, marked hair loss and sore, cracked feet.

In a later supplementary trial, biotin seemed

to prevent the occurrence of the deficiency syndrome. In the second trial dried skim milk was compared with corn oil meal, soybean oil meal and an equal parts protein mixture of corn solubles and soybean oil meal.

The average

daily gains were 1.44, 1.13, 1.16 and 0.66 pounds respec­ tively.

Likewise, the protein efficiency values were 2.42,

2.62, 2.18 and 1.71. A third trial was also conducted in which dried skim milk was compared with corn oil meal, tankage and corn gluten meal.

The pigs gained respectively 1.57, 1.32, 0.87

and 0.59 pounds per day.

Comparable protein efficiency

values were 2.64, 2.51, 1.65 and 1.25.

PROTEIN EFFICIENCY OF CORN OIL MEAL, OTHER CORN PRODUCTS AND SOME PLANT AND ANIMAL PROTEIN FEEDS FOR SWINE GROWTH

INTRODUCTION The nutritive value of proteins for swine is of fundamental importance both from the standpoint of rapidity of growth and economical production♦

Swine rations are made

up mainly of the common farm grown cereal grains which al­ though excellent as a source of energy are inadequate in both quantity and quality of protein.

One of the big prob­

lems therefore, is to add sufficient high quality protein to swine rations to properly meet the animals1 requirements. In order to make practical recommendations, it is essen­ tial that we understand in detail the special protein quali­ ties of each of the important natural protein feeds fed to swine.

Such an under s tan ding of the advantages and limita­

tions of a feed can be secured only through carefully planned experiments on animals in which each feed is studied as the sole source of nutrient in question when all other nutrients are optimum.

Also, from an economic standpoint, due to the

actual limited supply of high quality protein feeds, there is a very definite need to investigate thoroughly every potential source of high quality protein. The purpose of the investigations described here, using young weanling pigs as the experimental animals, has been to derive more fundamental information concerning the nutri­ tive value of the proteins of corn oil meal, corn steep water

solubles and corn gluten meal when compared with, dried whole egg, dried skim milk, soybean oil meal and tankage.

3 REVIEW OF THE LITERATURE Various Methods of Determining Protein Quality The nutritive value of a protein depends on the kind and amount of amino acids it supplies to the animal body. The evaluation of the relative nutritional quality of a feed protein is an exceedingly complex problem.

Proteins

vary considerably in their digestibility and in the extent to which the end products of their digestion are absorbed from the digestive tract and utilized for various body functions. Three main approaches to the determination of protein quality are (a) the determination of the ratio of gain in weight to protein intake for growing animals (commonly called protein efficiency) , (b) the determination of the amount of nitrogen retained by animals using the nitrogen balance procedure and (c) the determination of the amino acid content of the feed protein by either chemical or microbiological methods.

The three methods have been reviewed extensively

by Fixen (1935), Hegsted and Worcester (1947), Mitchell (1943, 1944) and Swanson and Herman (1943).

It is well to

keep in mind that each of the methods for determining protein quality 'is subject to criticism, and there are definite advantages and limitations for each one. Protein Efficiency Method.

Osborne et al. (1919) were the

first to propose the protein efficiency method in which the ratio of gain in body weight to protein consumed was the

4 comparative measure.

In this method growing rats were fed

ad libitum a diet In which the protein was the only nutritive factor limiting growth.

It was originally demonstrated and

later subs tantiated (Almquist 1947, Deuel et al. 1946, Harte et al. 1948a, Hutchinson et al. 1943 and Kade and Sheperd 1948) that the numerical expression for protein efficiency depends partially on the level of protein in the ration, and that a maximum protein efficiency could be obtained by in­ creasing the concentration of protein up to the point where protein is not limiting growth. In actual practice most investigators have employed only one arbitrarily selected protein level, usually the 10 per cent level, which is low enough to actually make protein the limiting factor and bring out differences in quality (Draper and Evans 1944, Harte et al. 1947, McCollum et al. 1981 I, II, III, IV, V, Rhian et al. 1942, Stewart et al. 1943 and Woods et al. 1943). .Some investigators have modified the original method in order to equalize feed intake of all the test proteins (Harte et al. 1947, Jones and Widness 1946 and Marshall and Davis 1946b).

It is argued that protein efficiency is not

a true efficiency ratio since part of the protein consumed Is used for maintenance and therefore not completely indica­ tive of relative protein quality unless the amount of total protein consumed is the same for each protein assayed.

How­

ever, since protein efficiency is really a measure of gross biological utilization, most investigators feel that part of

5 the differences of feed intake are directly attributable to differences in protein quality resulting in greater growth and consequent greater feed requirements (Cannon 1948, Harte et al. 1948b", Marais and Smuts 1940a and __________

1949a).

Also, whenever growth is limited by restricting the normal food intake the original hypothesis of making protein the sole limiting nutrient is forsaken (Barnes et al. 1945, Murray 1948 and Osborne et ai. 1919). It is well to keep in mind that in measuring protein quality by the growth method the experiment should be con­ ducted during the period of growth when the protein content of the gains is not only at a maximum but also is not changing greatly.

For swine this period is roughly from weaning time

to about 195 pounds liveweight (Atkinson and Klein 1946, Hammond 1932, Maynard 1937 and Mitchell and Hamilton 1929) . Nitrogen Balance Method.

A method was proposed by Thomas

(1909) to determine the efficiency of utilization of the nitrogen which was actually absorbed.

The method was first

adapted to the growing rat by Mitchell (1924a) to include the value of dietary protein in covering the requirements for nitrogen during maintenance and growth.

The basic prin­

cipal of the protein assay is a comparison of nitrogen metabolism based on nitrogen balance data whereby information is obtained on both digestibility and metabolic utilization. Biological value by Mitchell 's (1924a) method is the numeri­ cal term denoting the percentage of absorbed nitrogen which is retained by the body for repair or construction of

6 nitrogenous tissue (Smuts 1935, St. John et al* 1932 and Sure and House (1948) . The method as used today is probably the most accurate quantitative means of comparing protein quality for growth. The level of protein fed, usually 10 per cent, must be high enough so that growth will actually result as indicated by a positive balance; yet, it must not be in excess of the amount needed to cause maximum growth because the protein must be the limiting nutrient factor in the ration (Crampton 1939)*

Workers using the nitrogen balance method usually

follow Mitchell fs pattern and control the feed intake (DuToit and Smuts 1941 and VanLandingham et al. 1945).

The

balance method takes into account that fraction of daily nitrogen loss, endogenous and metabolic nitrogen, which has actually been utilized by the body even though it appears in the excreta (Bricker et al* 1948, Mitchell et al. 1945 and Murlin et al* 1944). Amino Acid Analysis for Protein Quality*

This method has

been broadened to include not only the difficult chemical procedures (Beach et al. 1943, Block and Bolling 1943 and Osborne and Clapp 1907) but also microbiological methods of determining the amino acid composition of feeds (Kuiken and Lyman 1949 and S a u b e r ü c h et al. 1947). - For the most desir­ able usage, the content of all of the essential amino acids should be presented. The amino acid analysis of a feed sets the upper limit of the protein usefulness of the feed (Mitchell 1944).

It

7 la possible to derive much, useful preliminary knowledge from chemical analysis which may be correlated with subsequent growth studies (Almquist 1935, 1941, Evans 1945, Evans et al. 1944 and Grau 1946), but caution should be used since in practice the chemical picture is inevitably altered by biological factors♦ An inspection of the amino acid make-up of a protein yields information as to maximum protein quality if compared with animal amino acid requirements.

Although information

as to requirements is still fragmentory, Rose and coworkers (Rose 1937, 1949, Rose et al. 1939, 1943 and 1948) have contributed greatly to our knowledge of the requirements of various species of animals by feeding the amino acids in pure form.

Other workers (Bauer and Berg 1943, Beeson et al.

1949, Benditt et al. 1947, Christensen et al. 1948, Cox et al. 1947, Greenberg and Winnick 1948, Hall and Sydenstricker 1947, Kinsey and Grant 1944, Mertz et al. 1949, Salmon 1948, Schweigert and Pearson 1948, Woolley 1945 and Wintrobe et al. 1945) have also contributed invaluable information concerning amino acid utilization and requirements of animals.

Purified Diets The use of purified rAtions has led to much greater accuracy in actually making protein the limiting nutrient while other nutrients in the ration are optimum.

In fact

only by using a purified diet may a test feed be satisfac­ torily fed as the sole source of protein in the ration.

In

8 theory, the test feed supplying a certain level of protein is supplemented With pure sources of carbohydrates, fats, minerals and vitamins at levels

sufficient tomake the ration

adequate in all respects except protein. A pure synthetic ration will not produce normal growth in swine because the pig requires small amounts of some un­ known growth factors such as those present in crude liver concentrates (Ershoff 1947, Hughes 1937, McRoberts and Hogan 1942, 1944 and Russell et al. 1948).

Liver itself may be

expected to supply a good balance of amino acids (Beach et al. 1943); however, since only small amounts are fed, many investigators-feel that the protein thus obtained will, at the most, influence the response of the test protein to only a slight degree (Hove and Harrell 1943, Hove et al. 1945, Rose 1949 and Rose et al. 1948). e

Very recently, various APP (animal protein factor)

con­

centrates supplying only negligible amounts of protein have been used successfully as sources of unknown growth factors (Beeson and Bloss 1949, Bosshardt et al. 1949, Bowland et al. 1948, Emerson et al. 1949, Hartmen et al. 1949, Hogan and. Anderson 1949, Johnson and Neuman 1949, Schweigert 1949 and Stokstad et al. 1949).

Corn By-Products Corn is generally regarded as an inadequate source of protein for growing animals because it is definitely limited by its low tryptophan and lysine content (Csonka 1939, Jones

9 et al. 1942, Marais and Smuts 1940b, McCollum et al. 1917, Mitchell and Smuts 1932 and Morgan 1931).

Zein, constituting

from 40 to 50 per cent of the protein of corn is well known to contain little or no tryptophan and to be very low in ly*

sine (Jones et al.' 1948, Osborne and Mendel 1914, Showalter and Carr 1922 and Viets 1945). A little over 500 million bushels of corn, or about 17 per cent of the total corn crop, are processed industrially each year in the United States (__________ 1949b) .

About

one-fourth of this total- is returned to the farms in the form of by-product feeds. Corn Oil Meal.

The corn germs, which are removed by flota­

tion after cracking and soaking the kernels in the wet mill­ ing process, are dried and run through expellers which by heat and pressure remove most of the oil (__________

1949b) .

The cake residue, when ground, is called corn oil meal (Mor­ rison 1949 and Quackenbush 1944) .

Corn germ meal is the

ground defatted embryo of corn produced by the dry milling process, and is likely to contain more of the B vitamins than corn oil meal (Crampton and Ashton 1943a). Corn oil meal has about 22-24 per cent crude protein and about 10 per cent crude fiber.

It has a high water

absorbing capacity (Smith 1947) and is fairly bulky for a protein supplement.

Several workers have presented an amino

acid analysis of corn oil meal (Block and Bolling 1943 and Mitchell and Block 1946).

By comparing these analyses with

other analyses of leading proteins, the apparent quality of

10 protein in corn oil meal seems fairly high. (Vickery 1944). This is possible since the germ makes up only about 12 per cent of the kernel (Hopkins 1913) and a high per cent of the total-kernel lysine and tryptophan is concentrated in the germ.

However, as is shown below, under actual experimenta­

tion the results Of feeding corn oil meal have varied tre­ mendously. In some of the earlier feeding trials with swine, corn germ meal (dry milled) has been of value in supplementing corn only when fed along with some other high protein feed such as tankage (Crampton and Ashton 1943b, Hogan 1917, Robison 1920, 1921 and Skinner and Starr 1918).

In a series of mis­

cellaneous feeding trials with swine, the Iowa workers (Evvard and Culbertson 1925a, 1925b, Evvard et al. 1925a, 1925b, 1925c and Shearer et al* 1926) have successfully in­ corporated corn oil meal into a complex protein mixture at levels of 15 to 20 per cent. Osborne and Mendel (1918) noted that the protein con­ tained in the corn embryo was fairly efficient in promoting rat growth.

Stare and Hegsted (1944) have shown corn germ

and dried skim milk protein to be equal in value for main­ tenance in the adult dog.

Corn germ meal (Morris and Wright

1955) and c o m oil meal (Hart and Humphrey 1916) have been shown to have a high biological value for steers, while corn oil meal (Draper 1944) has been a poor supplementary protein for a cereal ration when fed to both rats and chicks. In recent protein experiments using rats fed purified

11 diets, the protein efficiency of corn germ meal has compared very favorably with whole egg (Beeson et a l • 1947), dried skim milk and soybean flour (Jones and Widness 1946) •

Hove

et a l , (1945) showed that the protein efficiency of corn oil meal was just below dried skim milk, was higher than soybean oil meal, and considerably above cottonseed or lin­ seed oil meal.

Mitchell and Beadles (1944) reported equal

biological values for corn germ meal and beef round, both of which were slightly higher than the value for soybean oil meal. Corn Gluten Meal.

Corn gluten meal comes from the wet mill­

ing industry and consists chiefly of the gluten layer which is located in the kernel just under the hull.

After the

embryo has been removed from the kernel, the remainder is then ground and run through a sieve to remove the hulls. The starch then settles out from the gluten in passing through a shallow trough (__________ 1949b) .

The largest part of the

protein in the corn kernel is in the gluten fraction which contains 40 per cent or more protein and is about 30 per cent zein (Osborne and Mendel 1917). The amino acid analysis of corn gluten meal shows that it is definitely limiting in lysine and tryptophan, but in­ dicates a good balance of the other essential amino acids (Block and Bolling 1943, Block and Mitchell 1946, Kratzer 1944 and Schweigert 1947).

Corn gluten meal as the sole

protein was adequate for rat growth if supplemented with pure lysine and tryptophan (Osborne and Mendel 1917).

12 Corn gluten meal protein is very highly digested (Schulz and Thomas 1949b and Turk et al . 1935) , but has a rather low biological value (Olson and Palmer 1940, Ringrose et al. 1939, Schulz and Thomas 1949a and VanLandipgham et al. 1942).

Although corn gluten meal has been inferior to soy­

bean oil meal in poultry rations, it has been able to replace a part of the soybean oil meal with good results (Clark et al. 1949, Hammond 1944, Ringrose et al. 1943 and Slinger et al. 1944). Corn Solubles.

In the wet milling of corn, the clean ker­

nels are steeped in tanks of warm water to which sulfurous acid has been added to prevent fermentation (Cox et al. 1944 and Fulfrey et al. 1940) and in this manner the whole kernels may be softened and the hulls loosened (__________

1949c).

The resulting steep water is called corn solubles since it contains the soluble nutrients removed from the grain in the soaking process (Morrison 1949).

Corn solubles is different

from dried corn distillers solubles (Synold 1945 and Fair­ banks et al. 1944) which is the soluble material after yeast fermentation of ground corn.

Corn solubles is generally

mixed in with gluten feed or used as an excellent source of nutrients in the production of yeast or penicillin (Bowden and Peterson 1946, Knight and Frazier 1945 and White et al. 1945). Corn steep water solubles contains little or no trypto­ phan, but is a fair source of all the other essential amino acids (Cardinal and Hedrick 1948).

Corn solubles has around

13 30 per eent protein (Liggett and Koff 1er 1948) of which, about one-fifth is non-protein nitrogen (Cardinal and Hedrich 1948 and Hart and Bentley 1915) .

Although it is very highly di­

gestible, it has a very low biological value for rats (Schulz and Thomas 1949b)• Other Protein Supplements.

In the proteins of whole egg we

have an amino acid mixture that is very highly digestible and almost perfectly utilisable (Allison et al* 1948, Block and Mitchell 1946, Hawley et al* 1948, Hoagland et al* 1948, Lehrer et al. 1947 and Mitchell and Carman 1924).

The spray

drying of whole eggs apparently causes no significant destruc­ tion of any of the important nutrients (Cruishank et al. 1945 and Klose et al. 1943).

Raw, unhatched, incubated eggs

have been fed to pigs from weaning to market weights with good results (Tomhave and Hoffman 1945 and Willman et al. 1942) . Although it is well known that egg white contains a protein (avidin) which forms an undigestible complex with biotin in the intestine (Cunha et al. 1946, Kennedy and Palmer 1945 and Waisman et al. 1945), there is considerable doubt as to whether the egg yolk contains a sufficiently high level of biotin to adequately compensate for the loss due to the biotin-avidin complex (Hertz 1946 and Okey et al. 1947). Dried skim milk may not always be the most economical swine protein supplement to use, but it is certainly one of the most palatable and efficient protein feeds (Harrow 1946,

14 Hart and Humphrey 1915, Marshall and Davis 1946a, 1946b, Marshall et al. 1946, Mitra and Mlttra 1942, Morrison 1949, Pearce et al. 1946 and Sure 1948).

The protein of milk is

composed of roughly four parts casein to one part lactalbumin. Both of these have very good amino acid balance (Beach et al. 1941 and Block and Mitchell 1946).

Apparently there is no

measurable loss of protein value incurred in drying the skim milk (Henry et al. 1944 and Eon 1943). A dried skim milk, purified diet has produced excellent growth with young pigs (Weybrew et al. 1949) while the pro­ tein of dried skim milk has given very high values with rats (Hove and Barrel 1943 and Rapp et al. 1946). Tankage, a by-product of the meat packing industry, is an extremely rich source of protein and contains considerable calcium and phosphorous.

For swine feeding, tankage has not

only produced excellent results but also has been generally used as a standard of comparison for other protein supple­ ments in experiment station tests (Evvard et al. 1931, Ferrin 1946, Hughes and Hart 1934, Morrison 1949 and Vestal 1926).

Actually tankage has tended to be of somewhat lower

value inerecent years due to removal for other uses of hearts, livers, kidneys and glandular materials, all of which contain good quality protein (Cunha et al. 1948b). Soybean oil meal is a very common and widely used pro­ tein supplement for swine feeding.

It contains a large

amount of very highly digestible protein (Bricker and Mitchell 1947, Cahill et al. 1944 and Cheng et al. 1941),

15 but is low in calcium and has a sub op t iimim amount of the unknown growth factors (Geurin et a l • 1950, Heuser et al. 1946, Neuman et al. 1948, Richardson et al. 1949, Robison 1947 and Shrewsbury and Vestal 1937) • Methionine is not only the limiting amino acid in soy­ bean oil meal (Almquist et al. 1942, Bell et al. 1950, Clandinin et al. 1947, Fritz et a l . 1947 and Kuiken and Lyman 1949) but tests also show that the methionine in soybean oil meal is hydrolyzed in vitro at a considerably slower rate than any of the other essential amino acids. Although the protein efficiency of soybean oil meal for rats is high, it was slightly below dried skim milk or casein at both the 9 and 15 per cent levels of protein (Jones and Divine 1944). The above review of literature brings out the point that the protein quality of a feed may be critically tested by using the protein efficiency method.

The work reported

on corn oil meal is somewhat conflicting in that reports indicate the protein is of good quality, but results of corn oil meal experiments with swine are certainly far from favorable.

No research has been reported pertaining to the

quality of protein of corn solubles for swine.

16 FIRST FEEDING TRIAL

Experimental Procedure The quality of protein in the various experimental feeds was tested by a modification of the rat growth method originally proposed by Osborne et al. (1919) .

In this

method the protein efficiency is expressed as pounds gained per pound of protein eaten.

Dried whole egg served as the

control source of protein. Fifteen Duroc pigs obtained from the Purdue Experi­ mental Swine Farm were used in this experiment. had just been weaned and were about 8 weeks old.

The pigs Pairing

into stratas of three pigs each was accomplished by con­ sidering litter, sex and weight.

The pigs in each strata

were then randomly placed on one of the three rations.

The

experiment was started on November 28, 1948. The rations fed to the three lots of pigs are presented in table 1 and a partial analysis of the individual protein feeds is presented in table 2.

The experimental variable

in each ration was the source of protein.

The 11 per cent

protein level in each ration is considerably below the op­ timum for young growing pigs.

The test protein supplied

10.5 per cent and the dried whole liver used as a source of unidentified growth factors supplied about 0.5 per cent protein. The crude fat and crude fiber contents of each ration

17

TABLE 1.

Ingredient

COMPONENTS OP EXPERIMENTAL RATIONS

Lot number and protein feed used 2 3 1 Corn Corn oil Egg meal solubles

Protein source^*

22.1

45.5

33.4

Dextrose

67.5

41.1

48.7

Corn oil

——

7.3

7.4

Corn fiber

4.3

Whole liver powder

1.0

1.0

1.0

Mineral mixture

5.0

5.0

5.0

Vit. A and D oil^

0.1

0.1

0.1

Vitamin mixture3

*

*

*

4.4

--

^Ttie dried whole egg was obtained from Armour & Company; the corn oil meal was a solvent extracted meal from Clinton Industries, Inc.; and the corn steep water solubles was a dried product from American Maize-Froducts. ^Fortified cod liver oil (Nopco XX) contains 3000 units of A and 400 units D/gram. ^A water-alcohol solution of vitamins was mixed in the evening feed of each pig. See table 2.

18

TABLE 2.

PARTIAL ANALYSIS OP THE PROTEIN FEEDS USED (AIR DRY BASIS)

Corn oil meal

Com solubles-*"

5.2

11.9

9.7

Crude protein

47.5

23.1

31.5

Ether extract

35.0

0.8

0.8

Powdered whole egg

Crude fiber

1.5

H O * H

Mois ture

0.7

Ash

3.3

1.4

13.3

Nitrogen free extract

7.5

52.7

44.0

^*Corn solubles in the dry state is very hygroscopic and becomes sticky when moisture is absorbed.

19 were equalized*

Since whole egg containing 35 per cent

crude fat contributed 7*7 per cent fat to the ration, corn oil was added to the other rations as needed to equalize all the test rations at this level*

In a similar manner

corn fiber was added to the corn solubles and egg rations to equalize the crude fiber at 4*6 per cent of the rations* The qther ingredients of the rations included 1 per cent of dried whole liver to supply sufficient unknown growth factors, 5 per cent of a complex mineral mixture as presented in table 3, 0.1 per cent of a commercial vitamin A and D oil and the balance dextrose*

The complete rations

were mixed twice weekly by hand. Ten milliliters per pig daily of a standard vitamin mixture as presented in table 4 was mixed in with the even­ ing feed*

The vitamins were mixed and made to volume in an

alcohol water solution with a few drops of acetic acid added to get the calcium pantothenate into solution.

The levels

of vitamins fed were as recommended by Heinemann et al. (1946)* The pigs were placed on raised wire screens and housed individually in indoor pens ( 4 x 7 feet) *

They were fed

and watered twice daily in built up troughs that were wired down to prevent overturning.

Feed consumption and live

weight records were taken weekly throughout the experiment. The individual feed and growth data were treated statis­ tically.by analysis of variance as outlined by Snedecor (1946).

20

TABLE 3.

COMPONENTS OP MINERAL MIXTURE

Component Potassium chloride

Per cent 6.7

Dicalcium phosphate

46 «3

Sodium chloride

13.5

Calcium carbonate

16.9

Magne s ium carbonate

8.5

Potas s ium phospha te

5.7

Iron pyrophosphate

2.1

Manganese chloride

0.02

Copper sulphate

0.02

Zinc oxide

0.016

Cobalt carbonate

0.016

Potassium iodide

0.228

21

tfÂBLE 4.

COMPONENTS OP VITAMIN MIXTURE

Mg. daily per 100 lb. live w t . Thiamin hydrochloride Riboflavin Niacin Pyridoxine hydrochloride Calcium pantothenate Choline chloride Alpha tocopherol^ Menadione1 ^Milligrams per pig daily.

18 5 55 9 23 450 50 2

22

When it became obvious after 21 days of treatment that the 5 pigs receiving the corn solubles as a sole source of protein would not long survive under that dietary regime, it was decided to supplement the corn solubles with various nutrients in an effort to improve the results and perhaps •find out what is lacking in corn solubles. The ingredient composition of the substitute rations fed to the corn solubles pigs is presented in table 5 while the schedule or period of feeding the rations is presented in table 6.

Amino acid supplementation (rations 3A, 3B, 3F,

3G) was used in an attempt to verify the limiting amino acid that had been previously identified with rats (Geurin et al. 1949).

The level of protein was raised to 20 per cent (3D,

3F, 3G) in order to obtain an indication of the extent to Which the limiting amino acid was present in corn solubles. Various natural protein feeds were used to replace one-half of the protein of corn solubles (30, 3E, 3H, 31 and 3J) in order to compare possible supplementary relationships. Results The results obtained in the first feeding trial are summarized briefly in table 7.

Dried whole egg protein

supported faster growth of young weanling pigs than did either corn oil meal or corn solubles protein (See table 8). Corn solubles pigs in fact lost weight and had to be removed from the experiment after 21 days.

Since the source of pro­

tein was essentially the only known variable between the corn

23

*"3 to

COMPONENTS OP MODIFIED CORN SOLUBLES RATION

H to

w to

to

m

O

G>

1 1

1 1

i ■

i i

1 1

o • 02 02

o

1 1

1 1

1 1

i i

i i

1 1

to • rH 02

1 1

I I

i i

i i

1 1

to • to to

02

to

o-

in •

02 • •

o to rH

1 1

O • 02 to

1 1

• to H

1 1

rH • H to

xh «

02

'sh

02 to

o

1 1

I l

co 02 rH

1 1

i i

i i

1 1

o

to •

o

1 1

o>

• o

to

1 1

1 1

1 1

1 1

1 1

i i

i i

i i

i i

i

i

i

i

1 1

1 1

1 1

03 to to •

o

m

i—1 • C-

§ § O •H

-P

-o

P g5 u > ctf M 03 Q

03 to *

O o • Th

H i—1 • ■st

to O) • to

"3* r4

m 03 •

00 H • '41

r4 03 •

r4 r4 • St

H ,sh

to

st i—1

to

03

O in • to

43 i —1

n ■—i

43 i—1

T’ART.Tü 25.

AVERAGE DAILY FEED CONSUMPTION OF ANIMALS AT 7-DAY INTERVALS