Istihalah and Porcine DNA Detection in Chickens Fed with Pig-Derived Feed: Real-Time PCR Assessment of Purification Timeline

Abstract

The purification of animals from prohibited dietary substances (al-jallalah) through the process of “istihalah” is critical for ensuring halal compliance. However, the appropriate duration of quarantine required for chickens that have consumed pig-derived feeds to be considered purified remains unclear. This study hypothesised that a short-term quarantine of three days would be insufficient to eliminate porcine DNA from the chickens. To evaluate this, eighty broiler chickens were divided into control and treatment groups. Only two chickens from each group were analysed per day across three consecutive days after the feeding phase. Detection of porcine DNA was conducted using real-time PCR and gel electrophoresis. The results revealed the presence of porcine DNA in several intestinal and faecal samples, with Cq values ranging from 22.6 to 34.7. These findings indicate that the three-day quarantine period was inadequate to fully remove detectable porcine DNA. This study underscores the importance of extending the “istihalah” period and provides scientific support for establishing purification timelines in halal animal husbandry practices.