In this study, AUGrazier sericea lespedeza (AUGSL) leaf meal pellets which have a higher concentration of condensed tannin, was evaluated, as a supplement pelleted feed, for affect on naturally acquired Haemonchus contortus infection in grazing ewes. The study had 2 phases, one during parturition/lactation and another during summer grazing. Results indicated that suplementation did not affect fecal egg count (FEC), blood packed cell volume (PCV), FAMACHA score or survival/developement of larvae in feces during the peri-parturient period. During the summer grazing period, there was no effect on FEC, PCV or FAMACHA, but there was a reduction of larval survival/development in feces. For both periods there was a reduction in survival/development of Haemonchus larvae in AUGSL leaf meal supplemented ewes. Results were disseminated to scientific and producer groups via producer workshops, the Southern Consortium for Small Ruminant Parasite Control web page (SCSRPC.org), and various scientific and extension publications.
Infection with gastrointestinal nematode (GIN) parasites, particularly Haemonchus contortus, a blood-feeder, is the most important constraint to profitable small ruminant production in the southeastern US and worldwide. Weanlings are especially susceptible to infection during their first grazing season. Infection with H. contortus can rapidly lead to lost production and even death. Over use of anthelmintics (dewormers) has resulted in high levels of dewormer resistance in GIN throughout the southeast and other regions where H. contortus is a problem. The problem has become so severe that it is threatening viability of small-scale and limited-resource small ruminant farm operations in this region despite continued high demand for sheep and goat products. A more sustainable approach to parasite control involves integrating targeted, limited use of anthelmintics with non-chemical alternative control methods that reduce GIN numbers in the host animal and lower pasture contamination with eggs and larvae. Grazing sericea lespedeza [a condensed tannin containing forage] and feeding whole plant (AUGrazier cultivar) hay and pellets in confinement has been shown to effectively reduce GIN infection in sheep and goats.
Determine the effect of AUGSL leaf meal pellets, fed as a supplement, on Haemonchus contortus infection in grazing ewes during the parturition/lactation and summer grazing periods.
For Phase I of the study, 25 naturally infected pregnant crossbred (Suffolk x Gulf Coast Native) ewes were randomly allocated to 2 groups based on FEC and PCV. Group 1 (control, n = 13) and Group 2 (treatment, n = 12) were supplement fed with alfalfa pellets and AUGSL leaf meal pellets (2 pounds per head per day), respectively. Diets were fed starting 2 weeks before the start of lambing and continued through weaning. Each week, feces (for FEC) and blood (for PCV) were collected and FAMACHA scores were recorded to monitor infection level. Residual feces from each group were cultured for recovery, enumeration and identification of infective larvae. For Phase II of the study, 23 of the same ewes (now open) were re-allocated to 2 groups based on FEC and PCV. Group 1 (control, n = 11) and Group 2 (treatment, n = 12) were supplement fed with alfalfa pellets and AUGSL leaf meal pellets, respectively. Diets were fed (2 lbs per head per day) starting 4 weeks after their lambs were weaned and continued through the summer grazing season. Each week, feces (for FEC) and blood (for PCV) were collected and FAMACHA scores were recorded to monitor infection level. Residual feces from each group were cultured for recovery, enumeration and identification of infective larvae.
In Phase I, there was no difference (p > 0.05) in FEC between groups through week 6, at which time the FEC of both groups exceeded 2000 epg and it was decided to administer a strategic treatment of COWP. The efficacy of that treatment was 73% (p < 0.05). Subsequently, there was no difference (p > 0.05) in FEC between groups for the remainder of Phase I. There was also no difference (p > 0.05) between groups for PCV or FAMACHA score. Fecal cultures showed that there was no difference (p > 0.05) in percent development and survival of larvae between groups. Percent Haemonchus was similar between groups on week 0, but there was a 57% reduction for Group 2 at week 2 and remained consistently reduced by 9-43% throughout Phase I. Overall reduction of Haemonchus larvae was 29%. Throughtout Phase II, there was no difference (p > 0.05) between groups for FEC, PCV or FAMACHA score. No dewormings were necessary. Fecal cultures showed that there was a 52% percent reduction in development and survival of Group 2 larvae which was significant (p < 0.05). Percent Haemonchus was similar between groups on week 0, but there was a 36% reduction for Group 2 at week 2 and remained consistently reduced by 6-53% throughout Phase II. Overall reduction of Haemonchus larvae was 33%.
Educational & Outreach Activities
No publications to date. Results were included in various professional and producer oriented venues: Integrating FAMACHA, drugs and other alternative measures for controlling worms. GoatCamp, October 28, 2008, Lohn, TX; Integrated parasite control. Tuskegee University Goat Field Day, April 18, 2009, Tuskegee, AL; Integrating FAMACHA, drugs and other alternative measures for controlling worms. Southern University Goat Field Day, April 25, 2009, Baton Rouge, LA; Small ruminant integrated parasite control. Trinidad and Tobago University Workshop, May 4-6, 2009, Trincity, Trinidad; Managing parasites – Current status and thoughts for the future. Katahdin Hair Sheep International, September 11, 2009, Eugene, OR; Integrating FAMACHA, drugs and other alternative measures for controlling worms. USDA ARS Small Ruminant Field Day, October 23-24, 2009, Booneville, AR; Integrating FAMACHA, drugs and other alternative measures for controlling worms. Goat producer meeting, November 19, 2009, Jonesville, LA; Parasite control in small ruminants. LSU/SU small ruminant field day, April 24, 2010, Baton Rouge, LA; Integrating FAMACHA, drugs and other alternative measures for controlling worms. Louisiana Meat Goat Association meeting, September 11, 2010, Crowley, LA; Small ruminant integrated parasite control. GoatCamp, October 26, 2010, Lohn, TX; Small ruminant integrated parasite control. Goat producer meeting, January 2, 2011, St. Martinville, LA; USDA SCC-81/American Society of Animal Science-Southern Section, February 1-3, 2009, Atlanta, GA; Trinidad and Tobago University Small Ruminant Parasite Workshop. May 4-6, 2009, Trincity, Trinidad; SCSRPC Workshop, May 21-22, 2009, University of Georgia, Athens, GA; USDA NCERA-190, June 8-9, 2009, LSU, Baton Rouge, LA; USDA SCC-81/American Society of Animal Science-Southern Section, February 7-9, 2010, Orlando, FA; SCSRPC Workshop, May 24-25, 2010, Auburn University, Auburn, AL; USDA NCERA-214, June 14-15, 2010, University of Kentucky, Lexington, KY; SCSRPC meeting, October 21-22, 2010, Fort Valley State University, Fort Valley, GA.
It was expected that Group 2 supplemented ewes would have reduced FEC (specifically the peri-parturient rise in FEC during Phase I) and worm burden, which in turn would be beneficial in reducing pasture contamination for subsequent reinfection or for grazing lambs that may be put on that pasture. It was also expected that Group 2 supplemented ewe feces would have fewer infective larvae to migrate onto pasture forage, thus helping to further reduce pasture infectivity. Results did not indicate that supplementing (at the level provided) grazing parturition/lactation ewes with AUGSL leaf meal pellets was effective in reducing FEC or the total number of larvae that survived and developed in feces. However, Haemonchus larvae were reduced. Similarly, supplementing summer grazing open ewes did not reduce FEC. But, there was a consistent reduction in both total and Haemonchus larvae surviving and developing in feces, which in itself may help to reduce some issues with Haemonchus. Overall, under the conditions of this study, the level of AUGSL leaf meal pellet supplementation that was used did reduce Haemonchus survival and development in feces, but was not adequate (by itself) for control of GIN in grazing ewes.
Although a didactic economic analysis was not done, reducing pasture contamination and subsequent availability of infective larvae should result in reduced re-infection and an economic advantage over time.
It is anticipated that producers will take advantage of supplementing their small ruminants with AUGSL especially when the pellet formulation becomes available. It should be noted, however, that such supplementation should not be relied on as a sole means for control.
Areas needing additional study
There is a need to determine the effect of long-term supplementation with the AUGSL feed pellet supplement.