2 Department of Animal and Poultry Science, University of Saskatchewan

Ascites, a condemnable condition when accompanied by other systemic affects, has become one of the major causes for total broiler carcass condemnations in Canadian Registered Establishments. Because of a steady increase in the condemnation rates, the problem of ascites has received considerable attention over the last several years. However, data on its extent at the slaughter level has not been compiled. The following presentation is based on the veterinary condemnation records from 1986 to 1994, provided by the Meat and Poultry Division of Agriculture & Agri-Food Canada.

Historically, the condemnation rate due to ascites has changed considerably during the last decade. In 1986 ascites ranked #6 among the health related condemnation categories (Table 1). Categories such as emaciation, bruising, cyanosis, and leg deformities were 2 to 4 times more prevalent than ascites.

Table 1. Major condemnation categories in 1986. Values represent national average.

Total slaughter figures: 331, 115, 176.

There has been a drastic increase in condemnations due to ascites in recent years. Fig. 1 shows relative changes between 1986 and 1994 in total slaughter, total condemnations, dead on arrival (DOA) and ascites condemnation. These variables were analyzed concurrently as they are mutually dependent and had influence on the relative change in incidence of ascites. In order to better visualize changes, all data from 1986 was assumed as 1. During the analyzed period the number of broilers slaughtered in Canada increased by 36%, whereas the percentage of total condemnations and DOA did not change significantly (p>0.5) since 1986. On the other hand, ascites has increased 5.76 fold between 1986 and 1994 (Fig. 1). Among western provinces, British Columbia has experienced the greatest increase in ascites condemnations (19.2 fold) followed by the Manitoba-Saskatchewan region (13.1 fold) and Alberta, where 6.4 fold more ascitic birds were deemed unfit for human consumption in 1994 than in 1986 (Fig. 1).

Fig. 1 Relative change (1986 vs. 1994) in number of chickens slaughtered, total condemnations, dead on arrival (DOA) and condemnations due to ascites.

Interestingly, the ascites condemnation rate in 1986 was comparable with the arthritis rate. At present arthritis is of negligible significance, whereas ascites, over the last 9 years, from the obscurity, moved to the top of the condemnation list, being in 1994 marginally surpassed by cellulitis (Table 2). Currently, ascites is a major economic concern in the broiler production sector.

Table 2. Comparison of major condemnation categories between 1986 and 1994. The selected conditions represent health related problems, which relatively increased during analyzed period. Values represent national average.

For calculations of the ratios, the values for condemnations were first expressed as % of slaughter. Total slaughter figures: 1986; 331, 115, 176; 1994; 449, 962, 563.

Noteworthy, British Columbia has almost doubled its chicken production (98% increase) over the past 9 years, and at the same time British Columbia recorded the most noticeable change in percentage of ascites birds, being 0.014% in the 1986 and close to 0.27% in 1994 (Fig. 2). In 1986, the condemnation rate in the province of Alberta was 5,9 and 4,3 fold higher than in British Columbia and Manitoba-Saskatchewan respectively.

Growing trends in ascites have been observed in all western provinces since 1986. In 1994, based on the percentage values, the province of Alberta leads in ascites condemnations (0.53%), followed by British Columbia (0.26%) and the Manitoba-Saskatchewan Region (0.24%).

Fig. 2. Changes in ascites condemnations in the western provinces from 1986 to 1994.

Very regular seasonal trends in the incidence of ascites condemnation were observed in the present work. For each consecutive year, the ascites condemnation rate was the highest during the first quarter, which corresponds with the coldest months of the year. Then they gradually declined, reaching the lowest point during the third quarter (July, August, September) just to spike up again in the colder months of the fourth quarter. The injurious effects of cold on the occurrence of ascites have been reported by many authors. The present data further illustrates the significance of cold as a factor predisposing to ascites.

Overall, there has been a steady nearly linear (R²=0.98) increment in the national rates of ascites condemnations. Using appropriate statistical techniques it is possible, based on the historical data, to mathematically forecast the future trends in ascites condemnations. If the present trend continues, the ascites condemnation rate will reach 0.5 to 0.6% level by the year 2000 (Fig.3).

Fig. 3. Trends in the incidence of ascites condemnations in Canada between 1986 and 1994. Values represent national yearly average.

At present, ascites condemnations account for almost 19% of total condemnations. In 1994, there were close to 1.6 million broilers condemned due to ascites. In addition, some 1 to 1.3 million chickens dead on arrival had ascites. It is estimated that in Canada in 1994, between 2.6 and 2.9 million market age broilers were lost due to this condition at the plant level. The condemnations in the western provinces accounted for almost 31% of total national condemnations (Fig. 4).

Fig. 4. Estimated number of market age broilers with ascites. Data represents 1994 national figures and values for the western provinces.

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