Segregation of natural and experimental gastrointestinal nematode infection in F2 progeny of susceptible Suffolk and resistant Gulf Coast Native sheep and its usefulness in assessment of genetic variation

Veterinary Parasitology
J E MillerR A McGraw

Abstract

Gastrointestinal nematode parasitism is a concern to small ruminants worldwide. Productivity has been compromised because such nematodes, particularly Haemonchus contortus, have developed resistance to available anthelmintics. Some sheep breeds and lines within breeds are relatively resistant to infection, a trait that may be useful for developing control strategies. Suffolk sheep, which are susceptible to infection, were crossed with Gulf Coast Native sheep, which are more resistant to infection, to produce F1 progeny. F1 rams were bred to F1 ewes which produced 227 F2 offspring. These F2 offspring were evaluated for variability in infection levels, based on fecal egg count (FEC) and blood packed cell volume (PCV), under two natural infection conditions (one at weaning and another after a summer grazing period) and one experimental infection. The range of both FEC and PCV was large for all three infection periods with annual variation. Overall, the range for the three infection periods, respectively, were 167-149,933, 0-31,400 and 17-114,667 eggs per gram (EPG) of feces and 8.7-37.0%, 7.3-33.0% and 8.3-36.0%. This segregation of infection is what would be expected of F(2) progeny from susceptible and resistant parent breeds. H...Continue Reading

Citations

May 9, 2012·Animal : an International Journal of Animal Bioscience·H A SaddiqiM A Shahzad
Aug 16, 2011·Parasitology Research·Hafiz A SaddiqiAasif Shahzad
Sep 14, 2010·Trends in Parasitology·David PiedrafitaEls Meeusen
Oct 1, 2008·Veterinary Parasitology·B F SilvaA F T Amarante
Aug 1, 2012·PloS One·James W KijasNoelle Cockett
Feb 8, 2020·The Veterinary Clinics of North America. Food Animal Practice·Joan M Burke, James E Miller

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Anthelmintics or antihelminthics are a group of antiparasitic drugs that expel parasitic worms (helminths) and other internal parasites from the body by either stunning or killing them and without causing significant damage to the host. Discover the latest research on anthelmintics here.

Anthelmintics (ASM)

Anthelmintics or antihelminthics are a group of antiparasitic drugs that expel parasitic worms (helminths) and other internal parasites from the body by either stunning or killing them and without causing significant damage to the host. Discover the latest research on anthelmintics here.