Detection of foot-and-mouth disease virus in raw milk in Menofia Governorate and its effect on reproductive hormones and physiochemical properties of milk

Abstract

Background and Aim: Foot-and-mouth disease (FMD) is an extremely contagious viral disease that affects domestic and wild cloven-hoofed animals. In Egypt, FMD has been enzootic since the 1950s and caused great economic losses in cattle and buffalos over the past few years. This study aimed to detect FMD virus (FMDV) in serum and raw milk samples collected from infected and adjacent cattle and buffalos from different localities in El Menofia Governorate, Egypt. Materials and Methods: Blood and milk samples were collected from apparently diseased and adjacent 100 cows and 100 buffalos. Serum samples were prepared and used for the detection of FMDV using a non-structural protein enzyme-linked immunosorbent assay, while real-time reverse transcription-polymerase chain reaction (rRT-PCR) was used for the detection of FMDV in milk samples. Reproductive hormones were estimated using radioimmunoassay kits. Milk constituents were determined by Lactoscan. Results: Of the 200 examined serum samples (100 cows and 100 buffalos), 56% and 44% were seropositive for FMDV non-structural protein antibodies in cattle and buffalo, respectively. Real-time reverse transcription-polymerase chain reaction results confirmed that all examined milk samples collected from seropositive animals were positive for FMDV. Estrogen and progesterone levels in the serum of seropositive and seronegative animals were measured, and FMDV was proven to significantly elevate estrogen and reduce progesterone levels in both non-pregnant and pregnant animals during different stages of pregnancy. The effect of the virus on milk composition and somatic cell count (SCC) was also studied, revealing that FMDV infection significantly decreased the level of milk fat, protein, and lactose but did not significantly affected minerals, pH, and conductivity. Moreover, it significantly increased the SCC. Conclusion: Data recorded in this study indicates a widespread occurrence of FMDV in cattle and buffalo all over Menofia Governorate, Egypt. Infected raw milk is of poor quality and, if put for commercial sale, may have health risks for consumers and play a significant role in spreading the virus. Moreover, FMDV may disturb some reproductive hormones, which could adversely affect cattle and buffalo productivity. Therefore, preventive programs and accurate diagnosis are essential for successful disease control.