| dc.description.abstract |
Control of gastrointestinal nematode (GIN) parasites has traditionally been based on the premise of chemotherapeutic control with the resultant consequence being the development of anthelmintic resistance by GIN. An alternative premise to the management of GIN parasites is to improve the resistance and resilience of sheep to GIN infection by manipulating the nutritional environment at key periods of a sheep's life. One key period, is the periparturient phase in the reproductive cycle when ewes experiences a temporary loss, or diminution, of immunity to GIN parasites. This phase is associated with an increased requirement for both metabolisable energy (ME) and metabolisable protein (MP). The increased requirement being greater for MP. The loss of immunity to GIN is associated with a diminished cell-mediated immune response in the gut mucosa, the magnitude of which can be regulated by protein nutrition, or more specifically the supply of MP. Experimental studies that have increased MP supply, in housed and grazing periparturient ewes, have demonstrated significant improvements in resistance to GIN infection. Positive gut immune responses to an increased MP supply are believed to occur because the increased MP supply counters the combined pathological consequences of GIN infection |
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