Body condition scores, fluke intensity, liver pathology, and carcass quality of different dairy cattle genotypes infected with Fasciola species at high throughput abattoirs in South Africa

Milk is an essential commodity whose demand far exceeds supply. However, dairy animal productivity is constantly hampered by parasitic diseases such as fasciolosis, affecting milk production. Despite the negative impact of liver fluke on milk production, there is little information on liver fluke infection and associated abattoir losses (body weight, condition score, liver pathology, and carcass quality) in culled dairy cattle. This study aimed to determine body condition scores, fluke intensity, liver pathology, and carcass quality of different cattle genotypes infected with Fasciola species at three commercial abattoirs. A longitudinal study was conducted from September 2019 to October 2020 to determine body condition score, liver fluke intensity, liver pathology in 3065 dairy cattle slaughtered in CA1, CA2, and CA3, of the Eastern Cape Province South Africa. Liver fluke intensity significantly increased with cattle age (P < 0.0001). Cattle >= 7 years old (59.93 +/- 6.42) and those 4 to 6 years old (49.78 +/- 9.98) had higher infection than those 2 to 3 years old (27.55 +/- 13.68). The liver fluke infection was significantly (P < 0.001) the highest when sampling was conducted in summer, followed by autumn and winter, and least for spring. The differences in carcass weights or body condition scores decreased by 0.99 units (P < 0.0001) or 0.97 units (P < 0.0001) respectively. Therefore, this study suggests that fluke infection could be responsible for considerable economic and production losses mainly due to condemnation and weight loss in dairy cattle. This study recommended a combination of holistic and grazing management to control infection rates in dairy herds.

Automated summary

Milk is in high demand, but parasitic diseases like fasciolosis can have a negative impact on dairy animal productivity. This study investigated the effects of liver fluke infection on body condition scores, fluke intensity, liver pathology, and carcass quality in different cattle genotypes. The results showed that liver fluke intensity increased with cattle age and varied with seasons. The differences in carcass weights and body condition scores were also affected by fluke infection. The study suggests that fluke infection can lead to significant economic and production losses in dairy cattle and recommends a combination of holistic and grazing management to control infection rates.