The effect of Antibiotic Supplementation on the Response of Poults to Dietary Corn Oil1

RESEARCH NOTES

areas showed a greater weight increase than the birds with one open thigh area. An evaluation of the data by analysis of variance and Duncan (1955) multiple range and multiple F test indicates that these differences were statistically significant ( 1 % level). Opening the thigh areas forms a pocket through which chill water may reach the inter-muscular spaces of the pelvic area and may seep into sub-dermal locations forming the often observed bubbles and "blisters" between the thigh and breast. A consideration of the type of cut used to eviscerate must therefore be made when evaluating water absorption from any source during processing and marketing.

227 SUMMARY

Broiler chickens whose abdominal cavities were opened during evisceration by cutting the skin between the thigh and the rib cage on one or both sides of the bird picked up significantly greater amounts of water during slush-ice chilling than did broilers in which the thigh areas were not opened. Therefore, when moisture absorption of eviscerated poultry is evaluated, the type of cut used for opening the body cavity should be noted. REFERENCES Bailey, R. L., G. F. Stewart and B. Lowe, 1948. Ice slush cooling of dressed poultry. Refrigerating Engineering, 55(4): 369-371. Duncan, D . B., 1955. Multiple range and multiple F tests. Biometrics, 11(1): 1-7.

THE EFFECT OF ANTIBIOTIC SUPPLEMENTATION ON THE RESPONSE OF POULTS TO DIETARY CORN OIL1 W . C. SUPPLEE Department of Poultry Husbandry, University of Maryland, College Park, Maryland (Received for publication July 27. 1959)

Markedly different results were obtained in a recent experiment when poult diets containing increasing levels of corn oil were fed with and without an antibiotic. On the premise that antibiotic effects are due to modification of intestinal microflora, the results illustrate the potential influence of microflora status in studies of dietary fat effects. The basic 4% corn oil diet is shown in Table 1. Diets containing 8.4, 13.3 and 18.7% corn oil were prepared by increasing the corn oil and correspondingly decreasing sucrose on the basis of their productive energy values. As 2.2 parts of 1

Scientific Article No. A783, Contribution No. 3048 of the Maryland Agricultural Experiment Station (Department of Poultry Husbandry).

TABLE 1.—Composition of 4% corn oil diet Parts Drackett C-l assay protein Sucrose Corn oil (refined) DL-methionine Glycine Choline chloride Antioxidant (Santoquin) Minerals 1 Vitamins 2

47 40 4 0.7 0.5 0.33 0.02 7.69 0.28

1 Minerals, % of diet—\.9 CaC0 3 , 3.2 Ca 3 (P0 4 ) 2 , 0.9 K 2 HP0 4 ,0.4 KCl, 0.45 MgS0 4 - 7H 2 0, 0.7 NaCl, 0.05 FeS0 4 -7H 2 0, 0.04 MnS0 4 -H 2 0, 0.025 ZnCl2, 0.01 KA1(S0 4 ) 2 -12H 2 0, 0.05 Na 2 Si0 3 -9H 2 0, 0.004 KI, 0.002 CuSO„-5H 2 0, 0.002 NaBr, 0.001 Na 2 MoCv2H 2 0, 0.001 H 3 B0 3 , 0.002 CoSCv7H 2 0. 2 Vitamins, mg./lOO g. of diet—6.0 alpha-tocopherol acetate (from Myvamix), 0.003 Bi 2 ,100 inositol, 1.0 vitamin K (Menadione), 0.5 para-aminobenzoic acid, 0.04 biotin, 0.8 folacin, 3.0 pyridoxine HC1, 10.0 niacin, 4.0 calcium pantothenate, 2.0 riboflavin, 2.0 thiamine, 2.0 ascorbic acid. Also per 100 g., vitamin A (from Nopcay "250") 1,400 I.U. and vitamin D (from Nopdex "15") 160 I.C.U.

228

RESEARCH N O T E S

TABLE 2.—Growth responses, nutrient efficiencies and intestinal weights of poults fed diets containing various levels of corn oil with and without an added antibiotic (—) Antibiotic Corn oil level (%)

4

2

Corn oil Relative renutrient sponse, effi% ciency

21-day gain (g.)1

13.3 '

18.7

.78

.040

av. 384

338 (12) 346 (12) .79

.037

av. 411

374(11) 364 (12)

.88

14

.034

7

.84

20

.030

20

.81

25

.033

16

.79

27

.031

463 (12) 457 (12) 10

.80

.037

av. 460

348 (12) 352(12)

423 (12) 467 (12) 4

av. 350

—'

405 (12) 416 (12) 2

av. 369

I. wt.

393 (12) 374 (12) —

av. 342

Corn oil Relative Antirenutrient biotic' sponse, sponse, effi% ciency %

21-day gain (g.)

I. wt.5

328(11) 343 (11) av. 336

8.4

( + ) Antibiotic 4

.74

.039

av. 445

1 Replicate pens of 12 mixed sex, day-old Midget Bronze X Maryland Medium White poults started. Surviving poults in ( ). 2

3

4

6

Corn oil response=

treatment gain—4% diet gain

Antibiotic response=

4% diet gain

X100.

(+) antibiotic gain— (—)antibiotic gain

X100.

(—) antibiotic gain treatment gain

Relative nutrient efficiency =

weight of treatment diet Xfeed consumed (g.) weight of 4% diet

/ intestinal wt 1 . wt. = intestinal weight per unit body weight I \ body wt.

sucrose were deleted for each p a r t of corn oil added, the diet weights decreased and nutrient densities increased as corn oil level increased. A portion of each diet was supplemented with 50 mg. of oleandomycin phosphate per kg., and the two series thus obtained were fed to replicate groups of day-old, Midget Bronze X M a r y land M e d i u m White poults for three weeks. At the termination of the feeding period, one group from each t r e a t m e n t was fasted for 24 hours, weighed individ"

Data from one group only. •

>

ually, and sacrificed for intestine weight comparisons. The intestines were removed (gizzard to ceca), rinsed, freed of excess water, and weighed. Intestine weight per gram of body weight was calculated for each poult and averaged. The experimental d a t a are shown in Table 2. T h e maximum growth response to corn oil increase was 2 0 % in the presence of the antibiotic and 1 0 % in its absence. T h e response to antibiotic supplementation increased from 14% with the 4 %

RESEARCH NOTES

corn oil diet to 27% with the 18.7% diet. The apparent interaction between corn oil and antibiotic growth effects was statistically significant (P<.05). It is noteworthy that these results were obtained in the absence of any apparent morbidity, and where growth without antibiotic supplementation was excellent. Discounting the aberrant result with the 18.7% diet, the efficiency with which nutrients were converted to body weight tended to increase slightly with increased growth rate in the absence of the antibiotic. With the antibiotic-supplemented diets, the data indicated even more definitely a decrease in efficiency with increased growth. Such an anomalous trend could result if the antibiotic effect led to progressively greater overconsumption,

229

and, consequently, to an unusual fattening effect. Further study, including carcass analyses, is in progress to confirm these data and to clarify their significance. The effect of antibiotics in lowering intestinal weight is well established; our interest in collecting the data shown here was, rather, with the possible effect of increased corn oil level. Although the highest intestine weight value in each series was obtained with the 4% diet, there was no apparent trend toward lowered weight as the corn oil level increased. In view of the great individual variability in intestine weights within groups, no significance could be attached to any of the differences noted.

THICKNESS OF TURKEY SHELL MEMBRANES JAMES B. COOPER Poultry Department, South Carolina Agricultural Experiment Station, Clemson, South Carolina (Received for publication August 10.1959)

There is very little information in the literature on thickness of shell membranes. Hays and Sumbardo (1927) working with chicken eggs reported that inner shell membranes varied from 0.0129 mm. to 0.0173 mm. and outer shell membranes varied from 0.0411 mm. to 0.0560 mm. They gave the method of preparation of membranes and how measured but did not state from what place in the egg the membranes were taken. Romanoff and Romanoff (1949) listed the thickness of the shell membranes of turkey eggs to be 0.09 mm. for the outer and 0.017 mm. for the inner shell membrane. It might be assumed that the large end of the egg was the location for taking the measurements since the membranes are normally already separated in this locality.

METHOD AND MATERIALS

There was no attempt made to measure the two different shell membranes. Measurements were made with micrometer calipers with a ratchet stop to provide uniform pressure. The report is for measurements made in 1946 and 1959. Measurements were made toward the small end of the egg just below the line where the turkey embryo would likely break (out of) the shell when hatching. The eggs were from trap-nested Broad Breasted Bronze and Beltsville Small Type White turkeys. In 1946 collections were made from January 9-16. All eggs were broken on the same day with no eggs being over 10 days old. In 1959 the eggs were saved from January 19 to February 2. The eggs were incubated for