Quality of Broilers Carcasses

Introduction

The chicken meat quality on the market is increasingly valued by consumers. The achievement of the physical integrity of animals during transport and slaughter is claimed by associations of animal welfare. Many authors have reported that the transport conditions and slaughter can lead to significant economic losses and negatively affect the sanitary quality of products (Gregory and Austin, 1992; Berri, 2002; Nunes, 2004). In poultry production, there has been trauma during the carcasses inspection. These are mostly bruises and fractures. Nevertheless, the effect of the stages prior to slaughter (harvest and transport) has been few studied. Therefore, the main objectives of this study, focused on a survey conducted at the poultry slaughterhouse of Batna (Algeria) on three batches of 3000 broilers ISA 15, is to assess the frequency and characteristics of external lesions observed on chicken carcasses before and after slaughter and the condemnation rate.

Materials and Methods

The study was conducted at the poultry slaughterhouse in the Batna city (Algeria). The survey was carried out on 3 flocks of 3000 broiler chickens ISA 15 aged between 49 and 56 days to determine the impact of collection, transport and unloading of animals. The characteristics of the animal state description are performed on a batch of 350 chickens. They are based on the description of the color of damaged tissue, the presence or absence of edema and traumatic observations (bruises, fractures and wounds). Each type of injury has been described in terms of its nature, its location and its severity.

Chickens are manually suspended on the slaughter without shock. The time of suspension, before the bleeding, is estimated at 1 minute. The 3 groups of broiler chickens from different farms were slaughtered in the same conditions. For each batch of animals the condemnation rate was calculated. It is based on the results of the ante and post mortem. The causes of sanitary condemnation included in this study were: cachexia, congestion, skin lesions, ascites, abnormal color or odor.

Statistical Analysis

The results were presented by calculating the mean and standard deviation (SD). Statistical analyses were performed by SPSS 15.0. The differences were tested by analysis of variance (ANOVA), they are considered significant at P <0.05.

Results and Discussion

Characteristics of lesions observed on broiler chickens carcasses: Each type of injury has been described in terms of its nature, its location and the degree of severity (Table 1). There are 3 types of lesions: superficial, intermediate and deep lesions. Unopened fractures, mean bruises located on the wing, thigh, or the filet are the main superficial lesions. Intermediate lesions are mainly represented by open fractures of the wing or elbow. Most lesions are characterized by deep tissues tumefaction in the whole carcass.

The frequency of lesions in the 3 groups before slaughter is 12.43% of bruises, 3.73% of fractures and 2.71% of wounds (Table 2). The bruises prevalence varied significantly between the 3 groups (10.0 VS to 15.0 and 12.3% p< 0.05). Indeed, the transport conditions were different. The birds of groups 2 and 3 were transported in small vehicles. No significant differences were observed between groups with fractures (3.6 VS 4.2 VS 3.4%).

2.71% chickens has presented wounds, a significant difference was observed between groups 2, 3 and 1(4,2 VS 1,3 and 2,6%). This is caused by the conditions of collection and unloading of unskilled workers.

Estimating the condemnation carcasses frequency at slaughterhouse level is based on prospective observation of lots of animals from their receipt to the slaughterhouse to the sanitary inspection. The condemnations prevalence varied significantly between the group 2 and groups 1, 3 (11.2 VS 6.8 VS 7.2% p<0.05) (Figure 1). For each group, the carcasses removed from the food chain have been accrued by reason of regulatory condemnation.

The main reasons for condemnation were cachexia, congestion, ascites but some associations between skin lesions, abnormal conformations and the color or odor. The carcasses were seized mainly for the following reasons in increasing order (Figure 2): congestion (30%), skin lesions (28%), cachexia (25%), ascites (8%), abnormal coloration (4%), arthritis (3%) and conformation (2%).

Table 1: Characteristics of lesions observed on carcasses of chickens

Quality of Broilers Carcasses and Condemnation Rate during the Veterinary Control in the Batna Slaughterhouse - Image 1

Table 2: Prevalence of lesions before slaughtering (%)

Quality of Broilers Carcasses and Condemnation Rate during the Veterinary Control in the Batna Slaughterhouse - Image 2

Studies of catching conditions, transport and discharge of poultry are rare in Algeria. Barbuat and Andrea, 1974, showed that the transport conditions have led to many lesions in poultry (wing bruises, fractures, dislocation). However, Gregory and Wilkins, 1992, reported that the beating of wings of birds in cages transport cause the appearance of bruises, fractures and trauma. The condemnation frequency observed in our experiment is lower than that reported by Bremner, 1994; Herrenda D and O Jakal, 1994, and by Lupo et al., 2007. However, the causes of seizure were heterogeneous in their work. This first study in Algeria, has demonstrated an association of several risk factors leading to a depreciation of the carcass quality and assessment of different condemnation causes.

The losses with contusions, fractures and dislocation can be reduced by improving the management of harvesting and transportation as well as the adjustment of the equipment used in slaughterhouses. The sanitary control of slaughterhouse should be improved, since it is crucial and have direct effects on the quality of the final product.

Fig. 1: Condemnation of chicken carcasses after veterinary control for each group (%).

Quality of Broilers Carcasses and Condemnation Rate during the Veterinary Control in the Batna Slaughterhouse - Image 3

Fig. 2: Major causes of sanitary condemnation in slaughterhouse (%).

Quality of Broilers Carcasses and Condemnation Rate during the Veterinary Control in the Batna Slaughterhouse - Image 4

Conclusion

These results show that many carcasses lose their quality during transport and the slaughter process and can be removed from consumption. Therefore, drastic measures must be applicated before, during and after the slaughtering process for best performance and to minimize the economic losses and guarantee best meat quality for the consumers.

References

Gregory NG, Austin SD (1992). Causes of trauma in broilers arriving dead at poultry processing plant. Vet. Rec., 131 (22): 501-503.

Berri C (2002). Variability of sensory and processing qualities of poultry meat. World's Poult. Sc. J., 56: 209-224.

Nunes F (2004). Pre-slaughter management the first step towards yield and quality. World Poult. 20 (9): 32-35.

Barbuat G, Andrea B (1974). Influence des conditions de productions et d'abattage sur la présentation du poulet. Doc., ITAVI, 54 p.

Gregory NG, Wilkins LG (1992). Skeletal damage and bone defects during catching and processing. Bone Biology and Skeletal disorders in poultry, 313-328, Abington, UK.

Bremner AS (1994). Post mortem condemnation returns from poultry slaughterhouses in England and Wales. Vet. Rec., 135 (26): 622-623.

Herrenda D, Jakal O (1994). Poultry abattoir survey of carcass condemnation for standard, vegetarian, and free range chickens. Can. Vet. J., 35 (5): 293-296.

Lupo C, Chawin C, Balaine L, Petetin I, Perast J, Le Bouquin S (2007). Saisie sanitaire lors de l'inspection des poulets de chair à l'abattoir.VII eme J.R.A., Tours, France, 500-504.

This article was originally published in the Journal of Veterinary Advances 2012, 2 (1): 70-73. Engormix.com thanks for this contribution.