Liver fluke infections in cattle and sheep

The trematode, Fasciola hepatica, is a cosmopolitan parasite of temperate regions that can infect a wide variety of wild and domestic mammalian species, including man. Host-responses differ amongst different species and this article focuses on the contrast between cattle and sheep, the two classes of livestock in which fasciolosis assumes the greatest economic importance. In the sheep, acute fasciolosis resulting from parenchymal damage to the liver and haemorrhage caused by migrating juvenile flukes is a severe and potentially fatal disease. In contrast, the parenchymal stages have limited effects in cattle and the acute form of the disease is extremely rare. Though there is no evidence for a functional, acquired immune response to Fasciola hepatica, cattle provide a less hospitable environment, probably due to the profound changes in parasitised bile ducts, which render them as unsuitable habitats for feeding fluke. Consequently, in untreated cattle, many liver fluke die within 18 months of infection, though some can survive for 2 years or more. In the sheep, essentially, the fluke can live as long as the sheep; up to 11 years has been reported. These differences lead to the need for different treatment approaches in cattle and sheep with respect to juvenile fluke, but do also provide some opportunities for novel control approaches, based on the relative tolerance of cattle and their ability to limit parasitic damage to the liver parenchyma

Grassland management and helminth control on cattle farms

Farmers manage their pastures and grazing animals primarily to ensure that swards provide adequate, quality nutrients to support animal performance, but it is also possible to provide useful levels of parasite control without compromising production. On cattle only farms the easiest options for the control of parasitic gastroenteritis in young cattle revolve around the avoidance of high risk pastures from July onwards. On many farms, silage/hay aftermaths that have not been grazed by cattle for 12 months or more can provide low risk fields on which cattle can thrive with minimal reliance on anthelmintics

Erasing the orbital angular momentum information of a photon

Quantum erasers with paths in the form of physical slits have been studied extensively and proven instrumental in probing wave-particle duality in quantum mechanics. Here we replace physical paths (slits) with abstract paths of orbital angular momentum (OAM). Using spin-orbit hybrid entanglement of photons we show that the OAM content of a photon can be erased with a complimentary polarization projection of one of the entangled pair. The result is the (dis)appearance of azimuthal fringes based on whether the \which-OAM" information was erased. We extend this concept to a delayed measurement scheme and show that the OAM information and fringe visibility are complimentary