This study evaluated the effects of heat stress and supplementation with ascorbic acid and acetylsalicylic acid on broiler chicks. 100 chicks were divided into 5 groups - a control, 2 heat stressed groups, and 2 heat stressed plus supplemented groups. Results showed that heat stressed groups had poorer feed conversion ratios and immune responses compared to control and supplemented groups. Supplemented groups maintained better organ weight ratios under heat stress. The study concluded that ascorbic acid and acetylsalicylic acid supplementation had beneficial effects on performance and immunity in broiler chicks exposed to heat stress.

1. Ascorbic Acid &
Acetylsalicylic Acid
Performance of Broiler Chicks Exposed To Heat Stress

2. Materials and Methods
› 100 day-old broiler chicks were divided into five groups, containing 20 birds each, on
14th day of age.
1. Group A: control
2. Group B: heat stressed at weeks 3 and 4
3. Group C: heat stressed at weeks 3 and 4 + supplementation
4. Group D: heat stressed at weeks 5 and 6
5. Group E: heat stressed at weeks 5 and 6 + supplementation

3. Vaccination
› All the birds were vaccinated against Newcastle disease (ND) virus (Lasota strain)
on days 1 and 14.

4. Evaluation
1. Feed conversion ratio (FCR) was calculated on 42nd day of age.
2. Geometric mean haemagglutination inhibition (GMHI) titres against NDV were
determined on days 1, 14, 28 and 42.
3. Five birds from each group were slaughtered on days 28 and 42 of age for
pathological examination of bursa, thymus and spleen.
4. Bursa/body weight ratio (BBWR)
5. Thymus/body weight ratio (TBWR)
6. Spleen/body weight ratio (SBWR) were also calculated on days 28 and 42

5. Results
Groups FCR on day 42
ND GMHI titre (log 2) on day
1 14 28 42
A 1.40 5.25 7.0 7.38 4.75
B 1.57 5.25 7.0 5.25 3.88
C 1.44 5.25 7.0 6.38 4.13
D 1.90 5.25 7.0 7.31 2.50
E 1.59 5.25 7.0 7.35 3.00

6. Results
Day Organs Group A Group B Group C Group D Group E
28
Bursa 1.512 0.995 1.307 1.505 1.508
Thymus 3.467 2.989 3.056 3.458 3.463
Spleen 0.698 0.517 0.548 0.692 0.695
Day Organs Group A Group B Group C Group D Group E
42
Bursa 0.597 0.488 0.536 0.306 0.419
Thymus 1.902 1.573 1.737 0.778 1.351
Spleen 0.829 0.709 0.78 0.399 0.648

7. Conclusion
› This study indicated that ascorbic acid and acetylsalicylic acid supplementation
during heat stress had beneficial effects on:
1. FCR
2. Serum antibody development
3. Ratio of weight of bursa, thymus and spleen to body weight
› It is concluded from this experiment that ascorbic acid and acetylsalicylic acid has
expressed themselves as an anti-heat stressor and an immunopotentiating agent
under heat stress conditions in broiler chicks.