Table 2 Effects of the experimental treatment on anatomy and blood physiology.

From: Elevated levels of the stress hormone, corticosterone, cause ‘pessimistic’ judgment bias in broiler chickens

Measure1

Control

CORT

Inferential statistics

N

Mean

SE

N

Mean

SE

Test statistic and df2

P-value

Significance

Weight gain (g)

10

326.80

15.02

12

314.42

23.03

t(18.3) = 0.45

0.658

 

Heart (g)

11

8.11

0.30

12

8.34

0.45

F(1,20) = 0.012

0.912

 

Liver (g)

11

46.05

3.10

12

62.08

3.20

F(1,20) = 39.00

<0.001

*

Spleen (g)

11

1.88

0.16

12

1.48

0.12

F(1,20) = 9.37

0.006

*

Blood pH

7

7.36

0.04

9

7.41

0.02

t(8.57) = −0.96

0.362

 

Blood pCO2 (mmHg)

7

41.11

4.51

9

39.10

1.49

t(7.32) = 0.42

0.684

 

Blood Na+ (mmol/l)

7

145.43

0.69

9

143.78

0.22

t(7.27) = 2.29

0.054

 

Blood glucose (ng/dl)

7

237.71

3.94

9

266.78

12.97

t(9.44) = −2.14

0.059

 
  1. Notes: 1With the exception of Weight gain, which was measured between days 11 and 17, all measures were taken at the end of the experiment on day 17. 2For Weight gain, pH, pCO2, Na+ and Glucose the test was a two-sample t-test; for Heart, Liver and Spleen, the test was an ANCOVA with weight on day 17 included as the covariate. *Indicates a P-value ≤ 0.006.
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