Abstract

Abstract
Stress to slaughter and quality of meat in cattle and broiler
Slaughter is mean stressor factor for livestock animals. Its severity depends on conditions of
slaughter and genetics of the animal. It affects negatively the organoleptic and health qualities
of the meat. Our study had assessed firstly, the response to the slaughter stress of two cattle
populations: Prim‘Holstein and autochthonous beef cattle. After that, the study concerns three
lots of broilers of ISA strain with fast growing trait and different weights.
The physiological parameters (body temperature, heart rate and respiratory rate) were
measured in pre-slaughter stage, at slaughterhouse for cattle species and in farms before
delivery of broiler chicken then at their arrival to slaughterhouses. The following cattle
biochemical indices were measured on blood samples harvested at pre-slaughter: cortisol,
catecholamines, ACTH, testosterone and glucose. Furthermore, urinary cortisol and glucose
were essayed. In post-slaughter, investigations on meat are carried out at different times (2h-
12h and 24h), for cattle (pH, temperature and color), and for chicken (pH of breast fillets and
thighs, exudates losses, cooking yieldandthe sensory analysis of the color on the sixth day)
The results of physiological parameters on cattle species (temperature, heart rate and
respiratory rate) show greater variability (p <0.05) at 12h AM (after animal’s unloading) for
the imported breed, in males and in younger animal. The pH measurements on 24h PM
carcass are higher in imported cattle (6.09 vs. 5.9), in females (6.24 vs. 5.87) and in
olderanimals (5.93 vs. 6.12). A significant difference (p <0.05) in cortisol levels measured at
20 min ante mortem; is recorded in the indigenous animals (26.8 ng / ml vs. 8.6 ng / ml).
However the average rates of urinary parameters; do not show significant differences
according tothe sex, breed and age (p> 0.05).
IN other hand, physiological indices of broilers showed stressful conditions of transport and
unloading. Hyperthermia (42.55 ° c ± 0.28), bradycardia (28.78bpm ± 1.96) and respiratory
rate (24.89mvt / min ± 2.75) confirm the established constitution. These parameters are
significantly correlated with muscle acidity (p <0.01). In post-slaughter the ultimate thighs pH
at 24h PM; are significantly higher (p <0.05) than those of breast fillets (6.19 ± 0.09 vs. 6.11
± 0.10), leading to high losses by spontaneous discharge (11% ± 1.45 and 6% ± 2.80), and by
cooking yield (78% ± 0.06 vs. 90% ± 0.06) of breast fillets and thighs,
respectively.Individualvariability (intra-batch) at all measurement times and for the two
muscles; indicates a genetic influence on the response to slaughter stress (P <0.001).
Exudates losses are negatively correlated with pHu (r = -0.75 and -0.69, p <0.001), and with
technological efficiency (r = -0.90 and -0.84, p <0.001). Furthermore, significant effect of the
live weight of slaughtered chickens on pHu was established, especially of the thigh (r = -
0.59; p <0.05). Generally; the sensory analysis of the color confirmed that slaughter stress
affects cattle and broiler carcasses; leading to the expected effects (Dark, Firm and Dry meat:
dark firm and dry).
Key Words: - Algeria- Broiler – Chicken- Cattle – Genetics – Quality -Meat- Slaughter -
Stress.

Information

Item Type:	Thesis
Divisions:	» Production animales, biotechnologie et sante » Institute of Agricultural and Veterinary Sciences
ePrint ID:	2477
Date Deposited:	2020-12-22
Further Information:	Google Scholar
URI:	https://www.univ-soukahras.dz/en/publication/article/2477

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