Effect of Linoleic Acid Reserves on Essential Fatty Acid Deficiency of the Chick

Effect of Linoleic Acid Reserves on Essential Fatty Acid Deficiency of the Chick DAVID A. ROLAND, SR. AND HARDY M. EDWARDS, JR. Poultry Science Department, University of Georgia, Athens, Georgia 30601 (Received for publication June 26, 1971)

ABSTRACT Experiments were conducted to study the influence of EFA-deficiency on growth and development of male and female chicks and to determine the influence of linoleic acid reserves and age on susceptibility to essential fatty acid deficiency. When the birds were fed the basal essential fatty acid deficient diet, the females grew faster than the cockerels. After 7 months there was very little difference in the weight of the females on the experimental diets (basal 2,588 grams vs. basal + 5% corn oil 2,679 grams), but there was considerable difference between the males (basal 2,497 grams vs. basal + 5% corn oil 3,814 grams). In experiment 2 there were 5 dietary treatments: the basal, the basal supplemented with 5% corn oil or the corn-soy diet were fed for 12 weeks. The other two treatments were such that the corn-soy diet was fed for the first 4 weeks followed by the basal or basal 4- 5% corn oil for the next 8 weeks. Experiment 3 had S dietary treatments. Two treatments consisted of feeding the basal diet or the corn-soy diet for 8 weeks. In the other 3 treatments the corn-soy diet was fed for the first week, first 2 weeks, or first 4 weeks, followed by the basal diet. The weight of the birds fed the corn-soy 0 to 4 weeks, basal 4 to 12 weeks diet was not significantly different from the birds fed the corn-soy 0 to 12 weeks diet and the triene-to-tetraene ratio of 0.30 in the testes of the birds fed the corn-soy 0 to 4 weeks, basal 4 to 12 weeks diet both indicated that these animals were not EFA deficient. The same ratio of these fatty acids in liver lipid from birds fed the corn-soy 0 to 4 weeks, basal 4 to 12 weeks diet was 0.79, only slightly above the 0.4 ratio which indicates normal EFA status in rats. The growth rate and triene-to-tetraene ratio of liver tissue in experiment 3 also indicated that birds fed EFA-deficient diet after 4 weeks of age were not EFA deficient and would grow normally for 8 to 12 weeks. The birds fed the corn-soy diet less than 4 weeks and then fed the basal diet were EFA deficient when 12 weeks of age. Thus the increase in growth rate and the decrease in the triene-to-tetraene ratio are proportional to the number of days the chicks are fed a fat-supplemented diet before being fed a fat-deficient diet. POULTRY SCIENCE 51: 382-389,

M

ANY problems involved with essential fatty acid (EFA) deficient animals are due to the difficulty of depleting their EFA stores and creating uniformly deficient animals. Nugara and Edwards (1970) observed a wide range of response in individual chicks fed EFA-deficient diets. Bieri et al. (1969) noted many contradictory reports in the literature regarding the effects of EFA deficiency in rats. They presented evidence that predepleting lactating mothers and their suckling young of their EFA stores caused the depleted young to have more severe deficiency symptoms when fed the EFA-deficient diet for 26 weeks compared to rats from dams that were not depleted and fed the EFA-deficient diet after they were weaned. Ahluwalia et al. (1967) reported that classical

1972

EFA-deficiency symptoms could be obtained in 10 weeks when rabbits were fed deficient diets at 3 months of age. In the chicken, evidence has been presented by Menge et al. (1964) and Edwards (1967) that the fatty acid content of the diet of the laying hen may influence the performance of their progeny when fed an EFAdeficient diet. Age and species are important in developing an EFA-deficient animal, and excellent reviews on EFA-deficiency in general are in the literature (Aaes-Jorgensen, 1961; and Alfin-Slater, 1968). The experiments reported in this paper were conducted to study the influence of essential fatty acid deficiency on growth and development of male and female chickens and to determine the influence of lin-

382

383

ESSENTIAL FATTY ACID DEFICIENCY

oleic acid (18:2) reserves an age on susceptibility to essential fatty acid deficiency. EXPERIMENTAL PROCEDURE

Three experiments were conducted with young chickens obtained from a local hatchery. Day-old White Plymouth Rock chicks were used in experiments 1 and 2, and day-old Single Comb White Leghorn chicks were used in experiment 3. Chicks were identified with wing bands and housed in electrically heated battery brooders equipped with wire-mesh floors. They were weighed by lot at the initiation of the experiment and individually thereafter at two-week intervals for at least 8 weeks. Feed and water were supplied ad libitum. There were two dietary treatments in experiment 1: the basal diet (Table 1) and the basal diet supplemented with 5% corn oil. Eighty chickens, 40 of each sex were fed the diets for 24 or 30 weeks. Chicks of each sex were divided into 4 groups of 10 chicks per group and fed the 2 diets so that each treatment was duplicated within each sex. In experiment 2 there were 5 dietary treatments: the basal, the basal supplemented with 5% corn oil or the corn-soy diet, a regular practical diet,1 was fed for 12 weeks. The other 2 treatments were such that the corn-soy diet was fed for the first 4 weeks, followed by the basal or the "The composition of the corn-soy diet used in these experiments was as follows: (g./lOO g. ration) ground yellow corn, 67.62; S.B.M. (50% protein), 15.00; limestone, 5.63; poultry by-product meal, 5.00; dehydrated alfalfa (17%), 3.75; defluorinated phosphate, 1.25; poultry fat, 1.00; salt, 0.50; vitamin mix, 0.15; trace minerals, 0.10. The vitamin mix contained per kg. of diet: riboflavin, 2.2 mg.; Ca pantothenate, 4.4 mg.; niacin, 9.9 mg.; choline CI, 99 mg.; vitamin A, 2200 I.U.; vitamin D2, 880 I.C.U.; vitamin Bi2, 6.6 u.g.; 1, 2-dihydroxy-6ethoxy-2,2,4 trimethyl quinoline, 125 mg. The mineral mix contained ( % ) ; Ca, 26.0; Mn, 6.0; Fe, 2.5; Zn, 2.0; I, 0.12; Cu, 0.2; Co, 0.04.

TABLE 1.—Composition of the basal diet1 Ingredient Glucose monohydrate Casein, commercial grade Gelatin, commercial grade Methionine hydroxy analogue Cellulose2 Choline CI (70%) NaCl KC1 MgC0 3 Defluorinated phosphate (18% P) CaC0 3 1,2 Dihydroxy-6-ethoxy-2,2,4-trimethyl quinoline Vitamin mixture43 Mineral mixture

g./ioo g. 65.41 18.37 9.19 0.28 1.00 0.30 0.75 0.60 0.25 3.33 0.18 0.03 0.11 0.20

1 All diets that contained fat were calculated to be isocaloric with a part of the glucose monohydrate being replaced with cellulose. 2 Solka Floe, Brown Company, Berlin, New Hampshire. 3 The vitamin mixture supplied the following (in mg. or units/100 g. of diet): vitamin A, 550 I.U.; vitamin E, 5.51.U.; vitamin D 3 , 50 I.C.U.; thiamine •HCl, 2.0; riboflavin, 2.0; Ca pantothenate, 3.3; pyridoxine-HCl, 1.0; niacin, 8.0; folic acid, 0.7; bio tin, 0.3; vitamin B12, 0.003; menadione sodium bisulfite, 0.5. 4 The mineral mixture supplied the following (in milligrams/100 g. of diet): Zn, 10; Mn, 7; Fe, 8; I, 0.05; Mo, 0.5; Se, 0.02; Ca, 50.6, Cu, 0.8.

basal + 5% corn oil for the next 8 weeks. Each dietary treatment was fed to 3 groups of 10 male chicks each. At the termination of the experiment, liver, testes and adipose tissue samples were taken from 6 birds fed each dietary treatment and immediately frozen. All samples were individually analyzed for their respective fatty acid content. All values for fatty acid composition data were obtained by gas liquid chromatography analysis according to the methods described by Nugara and Edwards (1970). Experiment 3 had S dietary treatments. Two treatments consisted of feeding either the basal diet or the corn-soy diet for 8 weeks. In the other 3 treatments the cornsoy diet was fed for the first week, first 2 weeks, or first 4 weeks, followed by the basal diet. Four pens of 10 birds each were given one of the dietary treatments for a period of 8 weeks. Four chickens from each

384

D. A. ROLAND, SR. AND H. M. EDWARDS, JR.

2.000.

1.600

< o : 1.20Q

I

800

// /

I

o 400

0

2 4 6 5 10 12 WEEKS FED EXPERIMENTAL D I E T S

FIG. 1. The effect of composition of diet on growth rate of male and female chicks. Legend: A B C D

• • X X

• • X X

Males, basal + 5% corn oil Females, basal + 5% corn oil Females, basal Males, basal

dietary treatment were sacrificed at the termination of the experiment. Liver and adipose tissue samples were taken and immediately frozen for individual fatty acid analysis. The data were subjected to statistical analysis and tested for significance by the multiple range test of Duncan (1955) as modified by Kramer (1956). RESULTS

Experiment 1 was conducted to determine the influence of essential fatty acid deficiency on growth of male and female chicks. Both the male and female birds fed the basal + 5% corn oil diet were definitely heavier than the birds fed the basal

diet at 12 weeks (Figure 1); however, when the birds were fed the basal diet, the female chicks grew faster than the cockerels. This difference in growth due to sex became evident within two weeks of the experiment and the effect became increasingly apparent as the experimental period progressed. By 7 months there was very little difference in the weight of the females on the different experimental diets (basal 2,588 grams vs. basal + 5% corn oil 2,679 grams) but there was considerable difference between the males (basal 2,497 grams vs. basal + 5% corn oil 3,814 grams). Cockerels receiving the basal diet had pale combs and wattles that were not as large as the combs and wattles of birds fed the corn oil-supplemented diet. An abnormally high death rate was observed in the EFA-deficient males and females. Within 12 weeks 45% of the males and 25% of the females were dead; however, this was not observed in the other 2 experiments. The birds fed the basal diet developed a severe necrosis of the feet in approximately 20 weeks. Experiment 2 was designed to determine the influence of linoleic acid reserves and age on susceptibility of growing cockerels to essential fatty acid deficiency. The effect of the composition of the diet on the growth rate is shown in Figure 2. The growth rate of the birds fed the basal diet was significantly less (P < 0.05) than that of the birds fed the other 4 dietary treatments. The weight of the birds fed the corn-soy 0 to 4 weeks, basal 4 to 12 weeks diet was not significantly different from the birds fed the corn-soy 0 to 12 weeks diet. The birds fed the basal + corn oil 0 to 12 weeks diet were significantly smaller (P < 0.05) than the birds fed the corn-soy 0 to 12 weeks diet. The liver weights, expressed as a function of body weight, of birds fed the basal 0 to 12 weeks diet were significantly greater (P < 0.05) than the liver weights

385

ESSENTIAL FATTY ACID DEFICIENCY

from birds receiving the other dietary treatments (Table 2). The average weight of the testes from birds fed the corn-soy 0 to 12 weeks diet, expressed as a percent of body weight, was more than double the weight of those from birds fed the basal 0 to 12 weeks diet; however, the difference was not statistically significant (Table 2).

2.400.

TABLE 2.—The influence of dietary treatments on liver and testis weight1 Dietary treatment

Chick Liver weight weight

Basal 0-12 weeks B a s a l + 5 % corn oil 0-12 weeks Corn-soy 0-4 weeks Basal 4-12 weeks Corn-soy ~0-4 weeks B a s a l + 5 % corn oil 4-12 weeks Corn-soy 0-12 weeks

Liver as% body weight

Testis weight

Testis as% body weight

g.

%

g.

%

41.6

3.01b

0.369

0.024a

41.0

2.14a

0.593

0.034a

48.2

2.05a

0.734

0.032a

45.7

1.98a

0.621

0.025a

47.0

1.79a

1.346

0.055a

1

Figures in the same column followed by the same letter(s) are not significantly different (P <0.05).

The linoleic acid content of the liver was lowest in the birds fed the basal diet for 0 to 12 weeks and highest in that of the birds fed the basal + 5% corn oil diet for 0 to 12 weeks (Table 3). The linoleic acid content of the liver from the birds fed the basal 0 to 12 weeks and corn-soy 0 to 4 weeks, basal 4 to 12 weeks was significantly lower (P < 0.05) than the linoleic acid content in the liver of the birds fed the other diets. The arachidonic acid (20:4) content of the liver in the birds fed the corn-soy 0 to 4 weeks, basal 4 to 12 weeks diet was 8 times greater than that in the birds fed the basal 0 to 12 weeks diet;

0

2 4 6 ' A 10 12 WEEKS FED E X P E R I M E N T A L DIET

FIG. 2. The effect of composition of diet on the growth rate of males. Means bordered by the same adjacent vertical line are not significantly different (P<0.05). Legend: A • B X C • D X E

• Corn-soy 0-12 weeks X Corn-soy 0-4 weeks, basal 4-12 weeks • Corn-soy 0-4 weeks, basal -+- 5% corn oil 4-12 weeks X Basal + 5% corn oil 0-12 weeks Basal 0-12 weeks

TABLE 3.—The fatly acid composition of liver lipids of 12-week old chicks as affected by dietary treatment1 Dietary treatments Fatty acid 2

16: o 16: l

is: o

18: l 18:2 20:3 20:4 22:6

Basal (0-12 wks.)

%

21.8 8.4 17.7 39.0 2.2a 9.3c 0.7a 0.0

B a s a l + 5 % Corn-soy Corn-soy (0-4 wks.) (0-4 wks.) co-n-soy corn oil Basal Basal+5% (0-12 (0.12 (4-12 corn oil wks.) wks.) wks.) (4-12 wks.)

%

17.4 0.6 23.5 10.9 21.9c 0.5a 18.5b 2.6

%

22.2 7.0 18.1 35.5 3.5a 4.7b 5.9a 2.4

%

23.0 1.8 23.6 18.7 17.7b 0.7a 13.6b 0.3

%

23.1 1.8 24.4 17.0 20.5bc 0.0a 12.8b 0.00

1 Figures in the same row followed by the same letter(s) are not significantly different (P <0.05). 2 First number is chain length; second, t h e number of double bonds.

386

D. A. ROLAND, SE. AND H. M. EDWARDS, JR.

TABLE 4.—The fatty acid composition of the

testes of 12-week old chicks as affected by dietary treatment1 Dietary treatments Fatty2 acid

Basal (0-12 wks.)

n a olA-so? la+;,/o corn oil l , , wks J '

14:0 is: l i6:o 16: l 17:0

0.6 1.1

%

% 0.6

% 0.7

2.0

1.5

0.4 0.9

0.6 1.4

15.9

19.6

22.3

21.9

20.4

13.8 30.1 1.2a 10.3b 1.6a

16.8 16.5 5.2b 1.7a 13.4c

15.2 29.3 0.9a 2.6a 8.5b

17.1 17.7 7.1b 2.0a 14.2c

15.2 21.2 9.9c 1.5a 12.0c

is: o

is: l 18:2 20:3 20:4 20:5 22:2 22:3 22:4

3.8 1.1

4.1 0.8

14.0 0.0

1.4 1.7

7.7 0.8 0.1 9.2

Corn-soy Corn-soy (0-4 wks.) (0-4 wks.) Corn-soy Basal+5% (0-12 Basa, (4-12 corn-oil wks.) wks.) (4-12 wks.)

3.9 1.3

2.7 1.4 0.0 9.2

%

2.0 0.9

6.6 0.0 0.0 8.6

%

2.2 1.6

4.6 0.0 0.0 8.4

'•2 See footnotes Table 3.

however, it was not significant. The basal + 5% corn oil fed birds had the highest content of arachidonic acid. Feeding the corn-soy 0 to 4 weeks, basal 4 to 12 weeks diet reduced the eicosatrienoic acid (20:3) content to approximately 50% of that in the liver of birds fed the basal 0 to 12 weeks diet. The typical effect of the deficiency upon fatty acid pattern of testes lipids was noted (Table 4). There was a definite trend to increase the fatty acids of the oleate family and decrease those in the linoleate family. There was an increase of oleic acid (18:1), eicosatrienoic acid and docosatrienoic acid (22:3) and a decrease in linoleic, arachidonic and docosatetraenoic acids (22:4). The eicosatrienoic acid content of the testes of the birds fed the basal diet was significantly higher (P < 0.05) than that from the testes of birds fed the other diets. There was no significant difference in the linoleic acid content of the testes between the birds fed the basal 0 to 12 weeks and corn-soy 0 to 4 weeks, basal 4 to 12 weeks diet. The eicosatrienoic acid content of the testes of the birds fed the corn-soy 0 to 4 weeks, basal 4 to 12 weeks diet was significantly lower (P < 0.05) and the arachi-

donic acid content was significantly higher (P < 0.05) than that of the birds fed the basal 0 to 12 weeks diet. There was no significant difference in the linoleic acid content of the adipose tissue of birds fed the basal diet and the corn-soy 0 to 4 weeks, basal 4 to 12 weeks diet, but the linoleic acid content of the adipose tissue from the birds fed these 2 diets was significantly lower than that of the adipose tissue of the birds fed the other 3 diets • (Table 5). Since there was no significant difference in the growth rate of the birds fed the cornsoy 0 to 4 weeks, basal 4 to 12 weeks, and the corn-soy 0 to 12 weeks diet, a third experiment was designed to determine the period of time required for adequate storage of essential fatty acids for normal growth when the birds are fed an EFA-deficient diet. In this trial there were no significant differences in the growth rate between the birds fed the corn-soy 0 to 8 weeks diet and the corn-soy 0 to 4 weeks, basal 4 to 8 weeks diet, but the growth rate of the birds fed the corn-soy diet was significantly greater (P < 0.05) than the growth rate of the birds fed the other 3 dietary treatments (Figure 3). The growth rate of the birds fed the corn-soy 0 to 4 weeks, basal 4 to 8 weeks diet was not significantly different TABLE S.—The fatty acid composition of the adi-

pose tissue of 12-week old chicks as affected by dietary treatments1 Dietary treatments acid IcW

H:O

14:1 16:0 16:i 18:0 18.1 1812

Basal

(0-12 wks.)

% 1.3

0.4 24.7 11.8b 38.3 51.6 1.4a

Ttasal-I-S% Corn-soy Corn-soy corn oil (0-4 wks.) (0-4 wks.) Corn-soy C ?n „ Basal Basal+5% (0-12 { (4-12 1" (*rl2 c°r?°« ^ wks.) wks.) (4-12 wks.)

% 1.1

% 1.2

% 0.9

0.1

0.4

0.0

0.8 0.1

22.4 2.7a 12.5 30.9 26.2b

30.7 10.4b

23.7 3.5a

19.7 4.2a

48.7 1.5a

34.7 28.0b

35.9 29.2b

••« See footnotes Table 3.

6.9

9.3

%

8.9

387

ESSENTIAL FATTY ACID DEFICIENCY

from the growth rate of the birds fed the corn-soy 0 to 2 weeks, basal 2 to 8 weeks and corn-soy 0 to 1 week, basal 1 to 8 weeks diet. The fatty acid pattern in the adipose tissue from the birds fed the deficient diet reflect the same general trend as that in the previous experiment (Table 6). The levels of linoleic acid correspond directly to the length of time the birds were fed the experimental treatments. The linoleic acid content of the adipose tissue of birds fed the corn-soy 0 to 4 weeks, basal 4 to 8 weeks diet was significantly higher (P < 0.05) than birds fed the corn-soy diet for a shorter period. 800

TABLE 6.—The fatty acid composition of the adipose tissue of 8-week old chicks as affected by dietary treatment1 Corn-soy Corn-soy Corn-soy tatty2 Fatty Basal Corn-soy (0(0-1 wk.) (0-2 wks.) (0-4 (0-4wks.) wks.) acid (0-8 wks.) (0-8 wks.) Basal fincnt Tiiicfl] Basal Basal Riicnl (1-8 wks.) (2-8 wks.) (4-8 wks.)

%

14:0

0.5

H:I 1610

o.o 24.5

16:1 18:0 18:1 18:2

10.lb 5.5 59.5 O.Oa

%

0.6 0.0 20.6 4.7a 6.1 36.8 30.2c

%

0.8 0.1 24.3 11.2b 5.4 58.0 0.2a

%

0.8 0 0 25.7 9.2b 7.1 56.2 1.0a

%

0.7 0.0 27.7 11.9b 5.3 50.9 3.5b

'• 2 See footnotes Table 3.

The linoleic and arachidonic acid content of the liver lipids from birds fed the cornsoy 0 to 2 weeks, basal 2 to 8 weeks and corn-soy 0 to 4 weeks, basal 4 to 8 weeks diet was significantly higher (P < 0.05) and the eicosatrienoic acid was lower than in the birds fed the basal 0 to 8 weeks diet (Table 7). DISCUSSION The growth rate of chicks fed an essential fatty acid-deficient diet was depressed more in males than in females (Figure 1). This difference in growth rate due to sex was apparent within two weeks after the birds were fed the deficient diet. After prolonged feeding of the deficient diet, the female chicks were able to overcome the growth depression; however, in male chicks a much more pronounced difference in body weight occurred. The observed difference

o ~i

5

5 4

i

i

V e

WEEKS FED E X P E R I M E N T A L DIETS

FIG. 3. The effect of composition of diet on growth rate of males. Means bordered by the same adjacent vertical line are not significantly different (P < 0.05). Legend: A B X C • D X E •

Basal 0-8 weeks X Corn-soy 0-1 week, basal 1-8 weeks • Corn-soy 0-2 weeks, basal 2-8 weeks X Corn-soy 0-4 weeks, basal 4-8 weeks • Corn-soy 0-8 weeks

TABLE 7.—The fatty acid composition of liver lipid of 8-week old chicks as affected by dietary treatment1 Dietary treatments Fatty acid 2

16:0 16: i

i8:o

is: l 18:2 20:3 20:4 22:6

Corn-soy Corn-soy Corn-soy Basal Corn-soy (0-1 wk.) (0-2 wks.) (0-4 wks.) (0-8 wks.) (0-8 wks.) Basal Basal Basal (1-8 wks.) (2-8 wks.) (4-8 wks.)

%

19.9 6.4c 17.3 43.8 O.Oa 10.3c O.Oa 2.0

%

22.2 0.5a 26.8 11.1 20.2d 0.1a 15.9c 1.4

'•2 See footnotes Table 3.

%

14.3 4.7b 18.8 41.4 l.Oab 9.4c 1.9a 8.2

%

18.3 5.7bc 19.7 41.9 2.6bc 6.6b 3.0ab 2.0

%

21.9 6.6c 19.7 33.8 4.8c 6.3b 5.6b 1.0

388

D. A. ROLAND, SR. AND H. M. EDWARDS, JR.

due to sex after a prolonged deficiency could be explained by increased production or secretion of hormones as the birds become older, since sex hormones are usually considered to have little effect on young chicks. Roland aand Edwards2 have shown a 10-fold increase in size of testes between the second and third month in control birds and only a 3-fold increase in size of testes in EFA-deficient birds during the same period. A greater increase in size of testes in the deficient birds occurred after 3 months, but maximum size of the testes still was only half that of the controls. This increase in size of testes in the deficient birds, although reduced and delayed, indicates that increased production or secretion of hormones does occur, which may explain the more drastic changes after the birds become older. Ostwald and Lyman (1968) concluded that the need for more structural phospholipids by the faster developing male rat necessitated synthesis of phospholipid in which eicosatrienoic acid replaced the normal arachidonic acid. Lyman et al. (1966) ascribed the sex differences in rats to the female and to a more direct influence of estradiol on the formation or maintenance of phospholipids rich in arachidonate. The faster growth rate of the female chicks over the male chicks in this experiment indicates that size is not responsible for the more severe effect noted in the males when fed the fat-deficient diets. Roland and Edwards3 also found no relation between severity of EFA-deficient symptoms and growth rate in coturnix quail, where the female grows faster than the male but the male still appears to be affected to a greater extent by the EFA defi2

Roland, D. A., Sr. and H. M. Edwards, Jr. (1970) (unpublished results). 3 Roland, D. A., Sr. and H. M. Edwards, Jr. (1970) (unpublished results).

ciency. This again suggests that sex hormones are responsible for the observed difference in EFA-deficient chicks. However, whether these differences are due more to male or to female sex hormones is still not known. The severe necrosis of the feet developed by EFA-deficient birds was thought to be due to the prolonged period of time they were kept in the grower batteries with wire floors. This could have caused increased pressure on the feet resulting in cuts or scratches which became infected and developed into a type of dermatitis. Experiments 2 and 3 indicate that the ability to deplete essential fatty acids and create deficiency symptoms in birds is related to the EFA stores in the body. Normal growth and normal triene-to-tetraene ratios are directly proportional to the number of days chicks are fed the fat-supplemented diet before they are fed the fat-deficient diet. At least 4 weeks were required for adequate storage of EFA's to maintain the previous two criteria for at least 8 weeks when fed the deficient diet. Aaes-Jorgensen (1961) suggested that EFA's are necessary for active growth (i.e., formation of new tissues accompanied by relatively large metabolic losses). Adults do not develop new tissue in the sense of true growth but rather use EFA's primarily in the synthesis of replacement components of older tissues, i.e., the EFA's already present may be reutilized, thereby decreasing the demand for dietary EFA. This may explain why older animals with adequate storage of EFA's are more difficult to make deficient. The rapid depletion of linoleic acid from all tissues analyzed indicates that birds have little ability to conserve this fatty acid. In the testes (Table 4) the high levels of arachidonic and docosatetraenoic acid in the birds fed the corn-soy diet for 4 weeks

389

ESSENTIAL FATTY ACID DEFICIENCY

and then fed the deficient diet suggest that the ability of chicks to conserve these fatty acids is much greater than their ability to conserve linoleic acid. REFERENCES Aaes-Jorgensen, E., 1961. Essential fatty acids. Physiol. Rev. 4 1 : 1-51. Ahluwalia, B., G. Pincus and R. T. Holman, 1967. Essential fatty acid deficiency and its effects upon reproductive organs of male rabbits. J. Nutr. 92: 205-215. Alfin-Slater, R. B., and L. Aftergood, 1968. Fatty acids reinvestigated. Physiol. Rev. 48: 758-784. Bieri, J. G., K. E. Mason and E. L. Prival, 1969. Essential fatty acid deficiency and the testis: Lipid composition and the effect of pre weaning diet. J. Nutr. 97 : 163-172. Duncan, D. B., 1955. Multiple range and multiple F tests. Biometrics, 11: 1-42. Edwards, H. M., Jr., 1967. Studies of essential

fatty acid deficiency of the growing domestic cock. Poultry Sci. 46: 1128-1133. Kramer, C. Y., 1956. Extension of multiple range test to group means with unequal number of replications. Biometrics, 12: 307-310. Lyman, R. L., R. Ostwald, P. Bouchard and A. Shannon, 1966. Effect of sex and gonadal hormones on rat plasma lipids during the development of an EFA deficiency. Biochem. J. 98: 438-450. Menge, H., E. C. Miller and C. A. Denton, 1964. Effect of a fat-free maternal diet on the fatty acid composition of the progeny. Poultry Sci. 43: 164-168. Nugara, D., and H. M. Edwards, Jr., 1970. Changes in fatty acid composition of cockerel testis due to age and fat deficiency. J. Nutr. 100: 156-160. Ostwald, R., and R. L. Lyman, 1968. Influence of sex and gonadal hormones on lipid metabolism in essential fatty acid-deficient rats. Lipids, 3 : 199-211.

Characterisation of Staphylococci Isolated from Poultry L. A. DEVRIESE, 1 A. H. DEVOS,1 J. BEUMER2 AND R. MAES 1 (Received for publication June 28, 1971)

ABSTRACT The characteristics of staphylococci isolated from arthritis-synovitis lesions in broiler breeding stock, and strains isolated from poultry without known history of staphylococcal disease, were investigated. All lesion-strains were coagulase positive, produced a haemolysin, lysozyme, phosphatase, acetoin from glucose, fermented mannitol in anaerobic conditions, split galactose, maltose, lactose and mannose. The majority of them produced DNase, gelatinase and urease, cleared egg yolk- and milkagar, and hydrolysed Tween 80. None was fibrinolysin positive. Coagulase positive non-lesion strains showed similar characteristics. The S. epidermidis strains investigated, could not be inserted with certainly in one of Baird-Parker's subgroups. Sixty-two percent of the S. aureus strains were typable with the international set of basic typing phages, most of them only at the RTD X 1000 dilution. It was suggested that strains derived from poultry may be different from strains isolated from other animals or humans. Minimum inhibitory concentrations (M.I.C.) were determined for the S. aureus strains. Eighty percent of the strains produced penicillinase. Fifty percent of the strains were resistant to tetracycline and ten percent to streptomycin. Six strains (8%) showed complete cross-resistance when tested for susceptibility to the marcolide antibiotics and lincomycin. The same strains also showed a slightly decreasd susceptibility for the peptolide antibiotic virginiamycin. POULTHY SCIENCE 51: 389-397,

DISEASE condition characterised by inflammation of the tarsal joints and particularly of the tendon sheats in the tarsal region, appeared in Belgian poultry flocks during 1968. This disease, which affected almost exclusively broiler breeding stock, appeared to be rather similar to the

A

1972

condition described by Jungherr and Plastridge (1941). 1

Faculty of Veterinary Medicine, State University of Ghent, Casinoplein 21, B 9000 Ghent, Belgium. 2 Institut Pasteur du Brabant, rue du Remorqueur 28, B 1040 Brussels, Belgium.