1a.Objectives (from AD-416)
To examine forage systems for year round gastrointestinal nematode (GIN) control, exploit resistant sires, bucks, and breeds to integrate into organic flocks/herds, and examine on-farm use of integrated GIN control.
1b.Approach (from AD-416)
Studies will be conducted at USDA, ARS, LSU, FVSU, and on-farm using pastures in transition and organic principles to examine forages and genetics to minimize the use of anthelmintics (antibiotics) to control GIN. A number of approaches will be used to evaluate producer's use of strategic control.
A long-term study was initiated to examine the long-term effects of using sericea lespedeza and copper oxide wire particles in sheep and goats for parasitic worm control. The infection level, amount of required deworming, production (weight gains and lamb/kid production), and blood parameters are being examined to determine the benefits and consequences of these alternatives to chemical deworming. This information is essential to sheep and goat producers who have no effective chemical dewormers.
Selecting sheep resistant to gastrointestinal nematodes will diminish parasite challenges in pastures, leading to reduced infections. A study was initiated in 2009 and continued in 2010 and 2011 with additional funding to examine the relationship between fecal egg counts (FEC) in the ewe during lambing and her offspring. There was a positive relationship between FEC of lambs at 90 days of age and dams at 30 days post-lambing, and FEC of lambs at 120 days of age and dams at 60 days post-lambing. There was a negative relationship between FEC of dams at 60 days post-lambing and weight of offspring at 60 days of age. These relationships will help develop selection strategies for producers and reduce the reliance on chemical dewormers.