Parakeratosis: A Nutritional Disease of Swine

Similar documents
Preventing Selenium Poisoning in Growing and Fattening Pigs

South Dakota State College

Swine: Feeding 1. Randy Walker 2

Commercial Supplement Versus a Home-Mixed Supplement Plus Corn Free Choice for Finishing Swine

Whey-Grown Yeast as a Protein Source for Baby Pigs

EFFECT OF ADDED FAT ON PERFORMANCE OF GROWING-FINISHING PIGS IN COMMERCIAL CONDITIONS

Vitamin A and Carotene Nutrition of Lambs

Algaroba Bean Meal. 1n Turkey Rations. C. I. DRAPER, Associate Poultry Husbandman

Lamb Feedlot Nutrition

Barley and Fat for Corn

Clif Little, Associate Professor/Extension Educator, Guernsey/Noble Counties Wayne Shriver, Manager, EARS & Staff

Effect of Formulating Diets to Reduce Excess Amino Acids on Performance of Growing and Finishing Pigs

EC Swine Ration Suggestions

Evaluation of Wet Distillers Grains for Finishing Cattle

EC1496 Revised 1951 Poultry Rations and Feeding

EC1496 Revised 1950 Poultry Rations and Feeding

The Value of Peanuts and Peanut Meal in Rations for Chickens

Fattening Pigs. A Simple Mineral Mixture. AGRICULTURAL EXPERIMENT STATION of the ALABAMA POLYTECHNIC INSTITUTE. BULLETIN No.

EFC-01 Fall Feeding Distiller Grains to Hogs. Ron Plain 1

Exercise 6 Ration Formulation II Balance for Three or More Nutrients 20 Points

Ohio State University Eastern Agriculture Research Station Belle Valley, Ohio Male vs Female Confinement Lamb Finishing

Procedures in Feed Formulation

USE OF CORN, BARLEY, AND WHEAT WITH OR WITHOUT. FAT IN BROILER RATIONS By G, H. Arscott

Effects of varying creep feeding duration on proportion of pigs consuming creep feed and preweaning

UNIVERSITY OF HAWAII COOPERATIVE EXTENSION SERVICE EMERGENCY RATIONS FOR SWINE

IMPACT OF PRE-SLAUGHTER WITHDRAWAL OF VITAMIN SUPPLEMENTS ON PIG PERFORMANCE AND MEAT QUALITY. conditions was not addressed in the present study.

nutrition, vitamin levels in other ingredients and level of metabolic precursors in the diet. Summary

EFFECTS OF INCREASING DRIED DISTILLER S GRAINS ON FEED INTAKE

FOR years eggs have been studied as a

FATS AND PELLETS IN BROILER RATIONS. G. H. Arscott

INFLUENCE OF FEED PREPARATION AND NUMBER OF PIGS PER PEN ON PERFORMANCE AND OCCURRENCE OF ESOPHAGOGASTRIC ULCERS IN SWINE 1

Swine Day. trn sz% f., 4,. c) 4 Reluvred.,. Sixth Annual. Sitoadoltece. o 79. 0, * V'1' /''' Si 17 I E

THE EFFECTS OF POULTRY MEAL AND FISHMEAL ON GROWTH PERFORMANCE OF WEANLING PIGS 1

Evaluation of Beta-Glucan and Antibiotics on Growth Performance and Carcass Traits of Weanling and Finishing Pigs

Supplementing Market Broiler Rations with Lactobacillus and Live Yeast Culture. R.F. Burkitt, R.H. Thayer and R.D. Morrison.

EVALUATION OF DIFFERENT SOY PROTEIN CONCENTRATE SOURCES ON GROWTH PERFORMANCE OF WEANLING PIGS 1

EFFECTS OF INCREASING CA:P RATIO IN DIETS CONTAINING PHYTASE ON FINISHING PIG GROWTH PERFORMANCE

EFFECTS OF COPPER SULFATE, TRI-BASIC COPPER CHLORIDE, AND ZINC OXIDE ON WEANLING PIG GROWTH AND PLASMA MINERAL CONCENTRATIONS 1

Feeding the Doe Herd. Lyle W. McNichol PAg. Lyle McNichol Livestock Consulting Services

Beef Cattle Handbook

Guidelines for Feeding Broiler Litter to Beef Cattle

Industry. Feeding Swine. Energy. US Per Capita Meat Consumption. Gain (Tissue accretion) Maintenance ME

POTENTIAL FOR EGG PROTEIN AND PORCINE SPRAY-DRIED BLOOD AS A REPLACEMENT FOR PLASMA PROTEIN (AP-920) IN EARLY- WEANING PIG DIETS

EFFECTS OF PELLETING AND PELLET CONDITIONING TEMPERATURES ON WEANLING PIG PERFORMANCE 1

THE INFLUENCE OF DIETARY FAT LEVEL AND CRYSTALLINE AMINO ACID ADDITIONS ON GROWTH PERFORMANCE OF 25- TO 50-LB PIGS 1

Effect of Dietary Salmon Protein Concentrate on Growth Performance of Weanling Pigs

THE occurrence of blood spots in eggs

COMPARISONS OF LYSINE BIOAVAILABILITY IN SPRAY-DRIED BLOOD MEAL, BLOOD CELLS, AND CRYSTALLINE LYSINE IN NURSERY PIGS

EFFECTS OF INCREASING GLYCEROL AND DRIED DISTILLERS GRAINS WITH SOLUBLES ON THE GROWTH PERFORMANCE AND CARCASS CHARACTERISTICS OF FINISHING PIGS 1,2

The Evaluation of Dehulled Canola Meal as a Replacement for Soybean Meal in the Diets of Growing and Finishing Pigs

EFFECTS OF CORN SOURCE AND FAT LEVEL ON GROWTH PERFORMANCE OF GROW-FINISH PIGS REARED IN A COMMERCIAL FACILITY 1

EFFECTS OF CERTAIN ANTIBIOTICS AND VITAMIN B12 ON PANTOTHENIC ACID REQUIREMENTS OF GROWING- FATTENING SWINE 1, -"

POULTRY NUTRITION BRETT KREIFELS NEBRASKA EXTENSION DOUGLAS-SARPY COUNTIES

HORSE FEED. Available in 50# Bags

RATIONS FOR BEEF CATTLE

EFFECT OF THE CALCIUM-PHOSPHORUS RELATIONSHIP OF THE RATION ON GROWTH AND BONE FORMATION IN THE PIG '

FOWL POWER. Available in 50# Bags

16% HOG RATION Feed as a Complete Growing & Finishing Ration

Log on to your PUCC account and set up your Brill diet formulation files. You need to do the following. Your TA will guide you through the process.

THE ph OF SPRAY-DRIED BLOOD MEAL DOES NOT INFLUENCE NURSERY PIG PERFORMANCE 1,2

LYSINE REQUIREMENT OF PHASE 2 NURSERY PIGS FED KARL HARD RED WINTER WHEAT BASED DIETS

Evaluating Vitamin Premixes for Swine

CONTENTS. Energy Feeds for Swine Recommended Protein Levels... 4 Excessive protein intake... 5 Inadequacy of protein feeding standards...

A COMPARISON OF WHEY PROTEIN CONCENTRATE AND SPRAY-DRIED ANIMAL PLASMA IN DIETS FOR WEANLING PIGS 1

Lesson 2 Meeting the Nutritional Needs of Animals

T.B. Morillo, S.D. Carter, J.S. Park, and J.D. Schneider. Story in Brief. Introduction

Meeting the Nutritional Needs of Animals

Rice bran in beef cattle fattening rations

THE INFLUENCE OF CORN SILAGE HYBRID VARIETY ON BEEF STEER GROWTH PERFORMANCE. Department of Animal and Poultry Science, University of Guelph

Section 2 Feed Management

Effects of different feed mills and conditioning temperature of pelleted diets on nursery pig performance and feed preference from 14 to 50 lb

ARSANILIC ACID AS A THERAPEUTIC AND PROPHYLACTIC AGENT FOR HEMORRHAGIC DYSENTERY

VitaFerm + Creep Feed = Easy Transition and Efficient Gain

6 Nutrients Essential for Life

hogs ALL SUNGLO HOG FEEDS CONTAIN:

EFFECTS OF REPLACING WHEY PROTEIN CONCENTRATE WITH CRYSTALLINE AMINO ACIDS ON WEANLING PIG PERFORMANCE

COMPARISON OF INTERNATIONAL PROTEIN CORPORATION 740 FISH MEAL AND SPECIAL SELECT MENHADEN FISH MEAL IN NURSERY PIG DIETS

SUPPLEMENTATION OF L-CARNITINE AND PAYLEAN IMPROVE GROWTH PERFORMANCE OF PIGS IN A COMMERCIAL FINISHING FACILITY

Summary. Procedures. (Key Words: Sorghum, Distillers Grains, Waxy, Endosperm, Finishing Pigs.) Introduction

Evaluation of a Commercial Pro biotic Culture in Broiler Rations. A. A. Alyaseen, E. E. Murray, R. D. Morrison, R. H. Thayer and G. W.

Efficiency of Utilization of Dietary Phosphorus By Caged Turkey Breeder Hens When Fed Rations Supplemented With Live Yeast Culture

Sand and Sage Round-Up SWINE STUDY GUIDE Junior and Intermediate Division (Ages 8-13 as of December 31)

VITAMIN A requirements of growing

Meeting the Nutritional Needs of Animals

J. M. Benz, M. D. Tokach, S. S. Dritz 2, J. L. Nelssen, J. M. DeRouchey, and R. D. Goodband

NUMEROUS investigations have

EFFECTS OF HEMICELL ADDITION TO NURSERY DIETS ON GROWTH PERFORMANCE OF WEANLING PIGS. Authors: Story in Brief

Niacin for Growing Sheep and Steers

Comparative effects of dietary copper, zinc, essential oils, and chlortetracycline on nursery pig growth performance

EFFECTS OF AMINO ACID SUBSTITUTIONS FOR WHEY PROTEIN CONCENTRATE ON WEANLING PIG PERFORMANCE. Authors: J. Chung, S.D. Carter and J.C.

EFFECT OF WHEY PROTEIN CONCENTRATE SOURCE ON GROWTH PERFORMANCE OF NURSERY PIGS

EFFECTS OF SOYBEAN MEAL SOURCE AND LEVEL ON GROWTH PERFORMANCE OF WEANLING PIGS

EFFECTS OF VITAMINS AND MINERAL PROTEINATES ON GROWTH PERFORMANCE AND PORK QUALITY IN FINISHING PIGS

INFLUENCE OF NUTRIDENSE LOW PHYTATE 1 CORN AND ADDED FAT ON GROWING-FINISHING PIG GROWTH PERFORMANCE

Feedlot Performance of Cattle Program Fed Supplemental Protein

DETERMINING THE THREONINE REQUIREMENT OF THE LACTATING SOW 1

EFFECTS OF INCREASING AMOUNTS OF TRUE ILEAL DIGESTIBLE LYSINE ON THE GROWTH PERFORMANCE OF GROWING-FINISHING PIGS REARED IN A COMMERCIAL FACILITY 1

The Effect of Varying Levels of Monensin in Finishing Rations for Beef Cattle

Introduction. Hypothesis

Sand & Sage Round-Up SWINE STUDY GUIDE Senior Division Age 14 and over as of December 31

Transcription:

South Dakota State University Open PRAIRIE: Open Public Research Access Institutional Repository and Information Exchange Agricultural Experiment Station Circulars SDSU Agricultural Experiment Station 4-1957 Parakeratosis: A Nutritional Disease of Swine R. C. Wahlstrom South Dakota State University Follow this and additional works at: http://openprairie.sdstate.edu/agexperimentsta_circ Recommended Citation Wahlstrom, R. C., "Parakeratosis: A Nutritional Disease of Swine" (1957). Agricultural Experiment Station Circulars. Paper 134. http://openprairie.sdstate.edu/agexperimentsta_circ/134 This Circular is brought to you for free and open access by the SDSU Agricultural Experiment Station at Open PRAIRIE: Open Public Research Access Institutional Repository and Information Exchange. It has been accepted for inclusion in Agricultural Experiment Station Circulars by an authorized administrator of Open PRAIRIE: Open Public Research Access Institutional Repository and Information Exchange. For more information, please contact michael.biondo@sdstate.edu.

FIJ.E. COPY CIRCULAR 137 APRIL 1957 Zinc treatment far 32 days brought this pig from 86 pounds (top photo) to 160 pounds ANIMAL HUSBAND RY DEPARTMENT AGRICULTURAL EXPERIMENT STATION South Dakota State College, Brookings

Pox-like lesions (left) is one of the earlier symptoms of parakeratosis. Crusty, scablike lesions (right) develop later. 2

PARAKERATOSIS a nutritional disease of swine RICHARD C. 'vv AHLSTROM A skin disease of swine called parakeratosis has become increasingly prevalent in South Dakota and throughout the United States during the past few years. Minnemta investigators first described parakeratosis in 1953 and suggested that it was of nutritional origin. Recent research at several experiment stations has sho,vn that high levels of calcium and phosphorus in the ration were associated with the disease and that the addition of zinc had a curative effect. Swine affected by parakeratosis have reduced appetite, fail to grow normally, and often exhibit diarrhea during the early stages of the disease. The skin lesions appear almost simultaneously with these early symptoms. The condition is first noted by the reddening of the skin on the underline followed by poxlike lesions on the abdomen and between the front and rear flanks. Within a short time the crusty scablike lesions develop on the legs, ears, tail, and, in severe cases, cover the entire body. This often causes the skin to form large folds or wrinkles. There are great individual differences in the severity of the symptoms and duration of the disease. 3 On the same rations, some animals may not show any symptoms of the disease while others show mild or severe symptoms. Death losses are quite low but there is often an economic loss due to poor growth and poor feed efficiency. Parakeratosis has occurred at the South Dakota Experiment Station at different times during the past few years. The condition has appeared most frequently in rations supplemented by plant proteins. It has been most prevalent from weaning age to 100 pounds during fall and winter feeding trials. \i\lhen these trials were conducted it had not been observed at this station in pigs fed cereal grain and protein supplement free-choice. The following experiment was designed to study the occurrence of parakeratosis on different type rations and to study the effect of calcium and zinc on the development of this disease. THE EXPERIMENT This experiment consisted of two trials, the first conducted during the winter of 1955-56 and the second during the summer and fall of 1956. Dr. Wahlstrom is associate animal husbwdman, South Dakota Agricultural Experiment Station.

4 South Dakota Experiment Station Circular 137 Thirty-three weanling pigs averaging almost 20 pounds were separated into four lots of eight or nine pigs each i n the first trial. They were allotted as equally as possible according to breed, litter, weight, and sex. All pigs were kept in a barn with concrete floored pens and had access to outside runways. The rations, shown in table 1, were selffed and an automatic water supply was provided. For trial 2, the pigs were allotted in a manner similar to trial 1. They were separated into 10 lots of six pigs each. Each of the five rations shown in table 2 was feel to two lots of pigs. Rations 1, 2, and 3 were complete mixed rations that were similar to those used in trial 1. Ration 4 was similar to 2 and 3 except that the mineral supplement was fed free-choice instead of being mixed into the ration. Shelled corn and protein supplement feel freechoice made up ration 5. B-vitamin and antibiotics were added as indicated in footnotes to tables 1 and 2. It has been reported that soybean oil meal is often consumed in excessive quantities when fed as the only source of protein supplement. One recommendation that has been given to prevent excessive consumption is to add 10 to 12 percent of a mineral mixture to the soybean meal to reduce its palatability. Therefore, ration 5 was designed to see if adding this amount of limestone and steamed bone meal would cause parakeratosis by increasing the calcium content of the protein supplement. The housing and management conditions were similar to those described for trial 1. The trial was conducted for 77 clays and then zinc was added to the ration of four of the pigs showing the most severe symptoms of parakeratosis. These pigs were continued on this curative treatment for an additional 32 clays. Table 1. Composition and Chemical Analyses of Rations Used in Trial 1 (Percent)* Lot I Lot2 Lot3 Lot4 Ground corn ---------------------------------------------- 79.5 81.0 85.5 79.5 Soybean oil meal --------------- ----- ---------------- 17.0 17.0 3.0 17.0 Tankage ---------------------------------------------------- 10.0 Steamed bone n1eal. 2.0 0.5 0.5 2.0 Ground limestone ------------------------------------ 1.0 1.0 0.5 1.0 Trace mineral salt 0.5 0.5 0.5 Zinc carbonate ------------------------------------------ 0.011 Crude protein -------------------------------------------- 15.1 15.1 15.4 15.1 Calcium ------------------------------------------------------ 1.00 0.65 1.13 1.10 Phosphorus ------------------------------------------------ 0.52 0.39 0.58 0.54 All rations were supplemented with the following vitamins and antibiotics per pound of ration: vitamin A, 500 USP units; vitamin D, 62.5 USP units; niacin, 4.5 mg.; pantothenic acid, 2 mg.; riboaavin, I mg.; vitamin B.,, 4.5 mcg.; and penicillin-streptomycin, 10 mg. 0.5

Parakeratosis-A Nutritio11al Disease of Swine 5 RES UL TS AND DISCUSSION Trial 1. The results of the first trial are presented in table 3. Only three cases of parakeratosis were observed and these were all in lot 1, which received the plant protein ration containing a high level of calcium. Two of these pigs were only mildly affected while one had a severe case of parakeratosis. After 8 weeks on this tric1l the pigs in lot 1 averaged 87.1 pounds compared with 101.1, 92.8, and 102.7 pounds for the pigs in lots 2, 3, and 4, respectively. Although at this time the pigs in lot 3 averaged about 10 pounds less than those in lots 2 and 4, there was no evidence of parakeratosis. The slower growth of this lot may have been due to a poorer quality of protein in this ration. As these. Table 2. Composition and Calculated Analyses of Rations Fed in Trial 2 (Percent)* Ration No. 2 3 4 5 Ground corn ---------------------------- 83.75 80.8 79.5 83.0 t Soybean oil meal. 10.0 17.0 17.0 17.0 Tankage ------------------------------------ 5.0 Steamed bone meal 0.25 1.0 1.0 Ground limestone -------------------- 0.5 2.0 Trace mineral salt 0.5 0.5 0.5 Crude protein -------------------------- 15.3 15.2 15.0 15.3 40 Calcium -------------------------------------- 0.63 0.64 1.13 3.97 Phosphorus ---------------------------------- 0.49 0.48 0.48 0.88 *Rations I, 2, 3, and 4 were supplemented with a B-vitamin supplement at the rate of 2 pounds per ton and chlortetracyline (Aureomycin) at the rate of IO gm. per ton. The protein supplement in ration 5 was supplemented with these ingredients at a rate of 6 pounds and 60 gms. per ton, respectiv.cl ' i Shelled corn and protein supplement fed free-choice. The protein supplement consisted of soybean oil meal 88, ground limestone 8, stearn.ed bone meal 2, and trace mineral salt 2. +A mineral supplement consisting of 2 parts steamed bone meal, 2 parts ground limestone, and I part trace mineral salt was fed free-choice. 0.7 Table 3. Results of Trial I (Winter 1955-56) Lotl Lot2 Lot3 Lot4 No. of pigs 8 Av. initial wt., lb. 27.6 Av. 8-week wt., lb. 87.1 Av. final wt., lb. 203.0 Av. daily gain, lb. 1.54 Av. daily feed per pig, lb.. 4.31 Av. feed per cwt. gain, lb. 280 No. of pigs showing symptoms. 3 9 27.6 101.1 212.8 1.59 4.08 257 0 8 29.l 92.8 213.8 1.59 4.62 267 0 7* 26.3 102.7 223.3 1.70 4.63 274 0 one pig died of unknown cause.

6 Soutb Dakota Exp:1ri111ent Staticn Circular 137 pigs became older and their requirements less critical, they grew at a more satisfactory rate. In fact, there was essentially no difference in rate of gain of lots 1, 2, or 3 at the end of the trial. The affected pigs in lot 1 recovered without treatment. A slightly lower rate of gain was evident in this lot at the end of trial, but it was due almost entirely to the one pig that had done very poorly for several weeks. Slightly more feed was required per unit of gain for this lot too, although all lots were efficient in their feed conversion. The pigs in lot 4, which received the same high calcium level ration as lot 1 plus 62 parts per million of zinc ( 100 grams of zinc carbonate per ton), gained 0.16 pound per day faster than lot 1 and 0.11 pound per day faster than lots 2 or 3. Zinc supplementation completely counteracted the harmful effects of the high calcium level. Trial 2. A summa1y of the results of the second trial is given in table 4. Rations 1 and 2, which contained essentially the same amount of calcium and phosphorus but differed in the source of these elements, supported very good gains. The slighth slower rate of gain for the pigs fed ration 2 can be attributed entirely to the slower gain of the one pig in this lot that developed parakeratosis early in the trial. Five definite cases of parakeratosis were observed in lot 3. The ration fed to these pigs was similar to ration 2 except that it contained 1.3 percent more ground limestone which increased its calcium content about 0.5 percent. A reduced growth rate was noted in most of the pigs fed ration 3, although some of them did not show visible signs of parakeratosis. This trial points out quite clearly that the level of calcium in the ration must definitely be considered or a good ratie,n may become a poor one just by excessive calcium supplementation. Ration 4 also consisted of ground corn and soybean oil meal, bt1t the mineral supplement was fed freechoice rather than being mixed in the feed as it was in rations 2 and 3. The pigs fed this ration made fast Table 4. Results of Trial 2 (Aug. 14-0ct. 30, 1956) Ration No. 2 3 4 No. of pigs... 12 12 12 12 Av. initial wt., lb. 31.4 31.4 31.2 31.2 Av. final wt., lb... 164.7 161.3 119.2 166.2 Av. daily gain, lb... 1.73 1.68 1.14* 1.75 Av. daily feed per pig, lb. 5.27 5.13 3.78 5.31 Av. feed per cwt. gain, lb. 304 304 331 303 No. of pigs showing symptoms ---------------------- 0 5 0 significantly less than lots I, 2, or 4 at the I% level and lot 5 at the 5% level. tsignificantly less than lots I or 4 at the I% level and lot 2 at the 5% level. 5 12 31.2 142.9 l.45t 4.42 305 0

Parakeratosis-A N111ritional Disease of S1vi11e 7 and efficient gains and did not show signs of parakeratosis. There was no indication of parakeratosis in the pigs fed ration 5, where limestone and steamed bone meal were added to the soybean meal, but their rate of gain was significantly reduced compared with that of the pigs fed rations 1, 2, or 4. The feed consumption of the pigs fed ration 5 was also reduced. This may have been due to the high content of minerals present in the soybean meal although the supplement was consumed in adequate amounts to balance the ration in protein content. Four of the pigs that developed severe symptoms of parakeratosis when fed ration 3 were used to study the curative effect of adding zinc to the ration. Fifty grams of zinc carbonate were added to 1,000 pounds of ration 3. This is equivalent to 62 parts per million of zinc. An immediate improvement in appetite was noted when the zinc was added to the feed. Although these pigs had gained an average of 0.76 pound per day previous to treatment, their rate of gain for the week prior to treatment was 0.50 pound per day. During the first week on the zinc ration these pigs gained 2 pounds per day and their average gain for the 32 days they were on this ration was 2.3 pounds per day. The disappearance of the skin lesions was gradual but marked improvement was noted by the end of the 32 days on the curative ration. In recent trials at this station on another experiment, parakeratosis developed in pigs fed com or oats free-choice with a protein supplement. The protein supplements fed in these trials contained 30 to 40 percent meat and bone scrap but no added limestone or steamed bone meal. Meat and bone scrap is high in calcium and phosphorus. Therefore, it appears that parakeratosis may occur whether the pigs are fed free-choice or complete mixed rations. A protein supplement containing 3.5 percent or more of calcium could result in parakeratosis since excessive calcium is a predisposing factor in the incidence of parakeratosis. SUMMARY AND CONCLUSIONS Two trials were conducted to study the development of parakeratosis in pigs fed rations varying in the amount and source of calcium. Another purpose was to detem1ine the value of zinc as a preventive or cure for the disease. In all, 93 weanling pigs were used. Feeding of a corn-soybean meal ration containing approximately 0.65 percent calcium resulted in good growth, however, a 5 percent incidence of parakeratosis was noted. This type of ration, containing 1 percent or more of calcium, resulted in poorer growth and a 40 percent incidence of parakeratosis. Adding zinc to this high calcium ration at a level of 62 parts per million prevented symptoms of parakeratosis and increased growth rate. Where symptoms were already present, zinc supplementation resulted in a marked increase in growth rate and an alleviation of the skin lesions.

8 So111b Dakota Expel"iment Station Circular 131 Rations containing an animal protein and a calcium content of 0.63 and 1.13 percent supported good growth with no incidence of parakeratosis. However, recently we have observed several cases of parakeratosis in pigs fed rations containing animal protein. There was no incidence of parakeratosis when the mineral supplement was feel free-choice with a mixture of ground corn and soybean oil meal. Adding 12 percent of ground limestone, steamed bone meal, and trace mineral salt to soybean oil meal and feeding this mixture ( 4.0 percent calcium ) free-choice with corn resulted in poor growth; however, no symptoms of parakeratosis were observed. The symptoms of parakeratosis observed in these trials were reduced appetite, poor growth, scouring, and skin symptoms. The skin lesiojjs were first noted on the underline as red pox-like areas. Crusty scab-like lesions developed on the hocks, ears, and tail. In severe cases thickening of the skin and formation of folds or wrinkles over the the body was apparent. The skin of some pigs also became cracked, with an oozing of fluid from the cracked area. This resulteel in matted hair and accumulation of dirt and a dark, dirty, greasy appearance. The results of these trials indicate the importance of avoiding excessive calcium supplementation of rations, at least for the young growing pig. Since many protein supplements may contain 3.5 percent or more of calcium, it is possible that vvhen these supplements are used to make a mixed ration the total calcium content may approach 1 percent. The same could be true when the supplements are fed freechoice. Parakeratosis oft e n develops when rations this high in calcium are fed; sometimes it occurs on rations of lower calcium content. Thus, it appears that the addition of zinc to rations for young growing swine is a practical way of eliminating swine parakeratosis. In these trials a level of 62 parts per million of zinc as zinc carbonate gave excellent protection and completely cured all symptoms. Other work indicates that 20 parts per million of zinc will also give good results in preventing parakeratosis. The effective level may vary with the calcium content of the ration.