Progress report for LNE21-418
Problem and Justification: Production and animal losses due to gastrointestinal nematode (GIN) infection, especially by the blood sucking Haemonchus contortus, is a major constraint not only to profitability, but also to sustainability of United State (U.S.) small ruminant operations. In the absence of vaccines, the only mode of control of GIN is the use of anthelmintics/dewormers. However, decades of relying on dewormer treatments for parasite control has led to the emergence of multi-drug resistant (MDR) parasites which pose a significant challenge to parasite control on small ruminant farms world-wide. Hence, there is an urgent need to identify novel approaches to control and reduce the impact of drug-resistant GIN on sheep and goat farms.
Solution and Approach: The recent release of a new product in the U.S., BioWorma® and Livamol® with BioWorma® (International Animal Health Products, Australia), containing the fungus, Duddingtonia flagrans, offers an opportunity to reduce GIN on pastures and subsequently reinfection in grazing animals. BioWorma® contains only D. flagrans while Livamol® with BioWorma® is a feed supplement containing 2.2% of the fungus. Duddingtonia flagrans is a nematophagous fungus that is able to control GIN infections by capturing and killing immature larval stages before they migrate from feces to pasture, prohibiting their consumption by grazing animals. Utilizing this fungus in an integrative parasite control approach will help producers reduce parasite loads in their flock/herd significantly and limit their reliance on dewormer for parasite control. However, the current cost of feeding this product as recommended (at least sixty days during the transmission period) is a deterrence to most small ruminant farmers ($18 for a single 50 lb. lamb). Therefore, the overall objective of this project is to educate farmers on integrated parasite control strategies and demonstrate how best to utilize D. flagrans to reduce parasite infections and losses on sheep and goat farms. To achieve this objective, several outreach avenues will be used to present current research-based education on integrated parasite control strategies including the most effective treatment approaches. Additionally, research will be conducted on university and producer farms and results used to demonstrate different, possibly, more cost-effective, approaches to utilizing D. flagrans for effective GIN control.
Five hundred producers will attend field days and workshops both virtually and face-to-face to learn about dewormer resistance and parasite control in order to improve small ruminant productivity and increase profitability. One hundred will adopt the use of integrative parasite control (Five Point Check® system) on their farms. Another 20 producers will utilize BioWorma® on their farms to help reduce parasite loads. Adoption of techniques and the use of BioWorma® to control parasite loads will be utilized in 2,000 or more sheep and/or goats, saving an estimated $28.00 per head and reduce chemical dewormer usage.
The meat goat industry plays an important role in livestock production worldwide and is an industry with potential for high profitability as the market demand exceeds the current supply in the U.S. (Knight et al., 2006; Ibrahim et al., 2017). The growth in U.S. goat production has been attributed primarily to the high demand for goat meat by immigrant population, including ethnic groups, that consume goat meat and use goats for religious customs and ritual slaughters (Nettles and Bukenya, 2005; Knight et al., 2006; Okpebholo and Kahan, 2007; Ibrahim et al., 2017). Additionally, health conscious individuals are inclined to consume goat meat, as it is a lean source of red meat with favorable nutritional qualities (Ibrahim et al., 2017). The increasing need to meet this demand provides an industry with the potential for high profitability to limited resource and beginning farmers in the U.S. This is due mainly to the opportunity that goat producers have for direct marketing of goat meat at higher prices compared to other red meats (Glimp, 1995; Solaiman, 2007). Additionally, goats have high reproductive rates, low cost of breeding, and the ability to utilize native pasture unsuitable for other types of livestock (Haenlein, 1992). Unfortunately, worldwide production and animal losses due to GIN infection, especially by H. contortus, is a major constraint not only to profitability, but also to sustainability of small ruminant operations.
Infections with GINs are generally controlled by the use of broad-spectrum anthelmintic drug treatments (Miller, 1996). However, decades of relying on the use of available anthelmintics has increased the prevalence of anthelmintic resistant H. contortus (Mortensen et al., 2003), which is reported globally for all three major classes of anthelmintics (Kaplan, 2004; Kaplan and Vidyashankar, 2012). Additionally, large regional surveys conducted in the south (Mortensen et al., 2003), southeast (Howell et al., 2008; Schoenian et al., 2017) and Mid-Atlantic (Crook et al., 2016; Schoenian et al., 2019) regions of the U.S. confirmed that there is a high prevalence of multiple-anthelmintic resistance on sheep and goat farms, with increasing numbers of farms showing resistance to all available anthelmintics. Incorporating the novel biological control agent, D. flagrans, into a parasite management plan may greatly improve the likelihood of reducing parasite loads and contamination with resistant parasites on small ruminant farms.
Nematode trapping fungi are found naturally in soil and while many have been identified, only a few have been studied for their use in controlling GIN in animals (Healey et al., 2018a). One such fungi that has been extensively studied is D. flagrans.Duddingtonia flagrans, has the ability to survive passage through the gastro-intestinal tract of animals, germinate and grow rapidly in fresh feces then capturing and killing immature larvae before they migrate from feces to pasture where they are consumed by the grazing animals (Waller et al., 1994; Larsen et al., 1997; Baudena et al., 2000). Feeding of D. flagrans has been shown to reduce overall worm burdens of T. circumcincta (54.8%) and H. contortus (85%; Wright et al., 2003). Additionally, several other studies have found D. flagrans to be effective in reducing fecal egg counts in field trials in sheep (Knox and Faedo, 2001; Fontenot et al., 2003; Santurio et al., 2011). A new product introduced just recently into U.S. markets (Livamol® with BioWorma®) contains chlamydospores of a new isolate of D. flagrans (strain IAH 1297) and is sold as a nutritional supplement for the natural biological control of GIN larvae in the manure of grazing animals. Studies in Australia have demonstrated that this product significantly reduced larval counts when fed to grazing sheep, goats, cattle, and horses over an 8-week period (Healey et al., 2018a; Healey et al., 2018b). These results provide compelling evidence that BioWorma® offers a biological means of parasite control in grazing animals.
Currently, manufacturers recommend feeding continuously when the environment is conducive to GIN activity, however, this protocol is not cost-effective for most producers with the current prices ($0.60/100 lbs animal/per day). Consequently, use of D. flagrans remains limited and additional alternative approaches are required. However, targeted short-term use could provide important benefits in certain situations. Therefore, this project will evaluate and demonstrate the targeted short-term use of Livamol® with BioWorma® and BioWorma® inclusion in a cheaper feed/supplement alternative, to offer farmers cheaper but still highly effective methods of achieving successful control of GIN on sheep and goat farms. This project will positively impact the knowledge of extension personnel, producers and students by providing education on a new and effective way of controlling parasites on pasture. Emphasis will be placed on dissemination of results and information to producers, cooperative extension agents, animal scientists, veterinarians, veterinary parasitologists and other clientele at state, regional, national, and international levels.
Hypothesis 1: Feeding Livamol® with BioWorma® fourteen days each month (1/2 current recommendation) for a period exceeding sixty days will improve FAMACHA scores, reduce fecal egg counts and reduce GIN larvae on pasture.
Hypothesis 2: A locally developed BioWorma® mineral/feed supplement will be more cost-effective and as effective as Livamol® with BioWorma® in controlling GIN infection in sheep and goats.
Objective 1: Evaluate the efficacy of feeding Livamol® with BioWorma® for fourteen days out of every month during high parasite months on GIN infection indicators and pasture larval levels in small ruminants.
Treatments: For objective 1, animals will be allocated to one of three treatments. These will include: group 1 (BIO1) which will be dewormed according to the protocols suggested by the manufacturer’s recommendation and fed Livamol® with BioWorma® daily for four months; group 2 (BIO2) which will be fed Livamol® with BioWorma®for fourteen days in each month for four months; and group 3 (CON) which will receive no fungal supplementation for four months.
Methods: Objective one will be completed on two university farms (DSU and VSU) and validated on six producer farms. Each participating producer farms must have at least 15 animals (sheep or goat) that can be used in the project. Animals will be allocated to one of three treatment groups and fed Livamol® with BioWorma® mixed in feed at a rate of 1 g/kg of BW daily (BIO1), Livamol® with BioWorma® mixed in feed at a rate of 1 g/kg of BW for fourteen days in each month (BIO2), or receive no fungal supplementation (CON) for four months. Dosage of fungus will be based on the largest animal’s body weight (BW) in each group and no addition to feed in CON group.
Data Collection and Analysis: Every 14 days throughout the study period, animal BW, FAMACHA© scores and fecal samples will be collected. At the beginning, middle and end of the study, grass samples will also be collected. Body weight will be measured and recorded to monitor growth or body weight maintenance on the study. FAMACHA© scores will be measured to determine anemia indicative of a possible contortus infection. Goats will be dewormed if FAMACHA© scores are 4’s and 5’s or 3’s with other visual signs of parasitism. Fecal samples will be taken rectally from each animal and placed in a labeled Ziploc® bags on ice to prevent premature egg hatching and larval development until analyzing. In order to do the FEC at least 1-4 g of fecal matter is needed from each animal. Individual samples will be used to determine FEC using the modified McMaster technique (Henricksen and Aagard, 1986). Pooled fecal samples will be collected from each group bi-weekly to conduct fecal culture and larval identification according to a modified version of the guidelines put forth by Zajac and Conboy, 2012. Briefly, pooled fecal samples from animals will be collected and mixed with vermiculite at a 1:1 ratio to provide aeration and maintain moisture in a 500 ml beaker. Distilled water/PBS will be used to dilute feces and to enable mixing with the vermiculite until a uniform consistency is achieved and incubated at 27 oC for seven days with distilled water added to samples when necessary to prevent samples from drying out. After seven days, samples will be harvested using a Baermann apparatus into two 50 ml conical tubes. The centrifuge tubes will be centrifuged at 2500 rpm for 5 minutes and the supernatant in both tubes removed prior to combining pellets in one tube. The centrifuge tubes will be heated at 55o C in a heat block for 10 – 15 minutes and stained with 50% Lugol’s iodine to immobilize the larvae. After which, the solution containing the larvae will be transferred to a standard slide and counted for differential percentages of GIN species present. One-hundred worms will be counted and data calculated as a percent of each worm species within the sample population on the slide. Grass samples will be collected to conduct pasture larval count to determine level of third-stage larval infectivity and to identify the types of third-stage larvae most predominant on pasture. Samples (500 g each) will be collected randomly from each paddock in a zig-zag pattern with each sample containing a small amount of forage from at least six different collection points in each paddock. After collection, plant samples will be washed in water containing a non-ionic detergent overnight with moderate agitation and then parasites harvested using a modified Baermann method. Final counts will be tabulated and reported as L3/kg of dry matter and identifications will be reported as a percentage of L3 counted. FAMACHA© scores and fecal egg count data will be analyzed using the MIXED procedure of SAS (SAS Institute, Carey, NC) for repeated measures. Class variables will include treatment and day while the model will test main effects and the interaction of treatment and day (Littell et al., 1998). All FAMACHA© and fecal egg count data will be log transformed: ln(FEC, PCV or FAMACHA© + 1) for analysis and inferences will be made on Deworming frequency data will be analyzed using the PROC FREQ procedure of SAS (Chi Square analysis).
Farmer Input: This project objective was conceived from conversations with small ruminant producers and queries as to whether or not reducing the recommended dose/treatment days could still be effective in controlling GIN in small ruminants. Six farmers will participate in this objective by validating university research results in commercial/on-farm settings.
Objective 2: Develop a feed/supplement, with BioWorma incorporated and evaluate its cost and efficacy to Livamol®with BioWorma®.
Treatments: For objective 2, animals will be allocated to one of three treatments. These will include: group 1 (BIO), which will be fed Livamol® with BioWorma® mixed in feed at a rate of 1 g/kg of BW daily for 4 months; group 2 (NBIO), which will be fed the locally made feed/supplement with BioWorma® at recommended 0.06 g/kg rate daily; and group 3 (CON), which will be fed no fungal supplementation (control) for four months.
Methods: Objective two will be conducted on two university farms (DSU and VSU). Animals will be allocated to one of three treatment groups and fed Livamol® with BioWorma® mixed in feed at a rate of 1 g/kg of BW daily (BIO1), locally made feed/supplement with BioWorma® at recommended 0.06 g/kg rate daily (NBIO), or receive no fungal supplementation (CON) for four months. Animals in group 1 will be dewormed according to the protocols suggested by the manufacturer’s recommendation for feeding BioWorma®. Dosage of fungus will be based on the largest animal’s body weight (BW) in each group and no addition to feed in CON group. A feed company that can/will make feed (mineral supplement) containing BioWorma© has been approached and if they receive their EPA certification will be making feed supplement for this project. If the company is unable to receive EPA certification, the PI and co-PI will purchase mineral and mix the BioWorma© into mineral to carry-out the project.
Data Collection and Analysis: Protocol for sampling and analysis will be conducted similar to protocols described above in objective one.
Farmer Input: Similar to objective one, this project objective was conceived from conversations with small ruminant producers and queries as to whether or not it would be more cost-effective to create a feed/supplement with BioWorma® that will be as effective in reducing GIN infections when compared to feeding Livamol® with BioWorma®. Even though no farmers will participate in this objective, findings will be shared at Field Days conducted on producer farms during the final year of the project.
In order to gain knowledge of how this project will work on the university farm, a preliminary study was conducted to see the effects of feeding Livamol® with BioWorma® for fourteen days in each month. However, due to the late start time, this project was only conducted for 42 days before it became too cold to continue. Therefore, the full project will be conducted in the summer of 2022. Based on the data collected, there was no differences in body weight, fecal egg count, or FAMACHA scores between treatment (Meat Goat Kids Fed Livamol® With Bioworma® Daily (BIO-A), Livamol® With Bioworma® For Fourteen Days in Each Month (BIO-B), Or No Fungal Supplementation (CON)) over the 42 day period of the study. The data indicated that the most predominant parasite in each paddock was Haemonchus contortus.
Not totally completed as yet and so the conclusion could not be made.
The proposed project seeks to educate producers on integrated parasite management (IPM) strategies while demonstrating through research how best to utilize the biological control agent D. flagrans, contained in BioWorma®. This approach willmaximize our ability to achieve long-term sustainable success in reducing parasite loads on small ruminant farms. Integrated parasite management is a method of parasite control that uses multiple approaches in a coordinated application that takes social, economic and environmental aspects of production into account (Maqbool et al., 2016). This approach limits the use of dewormers and improve management practices (pasture management, genetic selection, targeted selective treatment, etc.), hence, increasing productivity, reducing development of dewormer resistance, and lead to a more sustainable approach to combat parasites on small ruminant farms (Maqbool et al., 2016). An alternative method to dewormers that has been proven to effectively control internal parasites is the nematode trapping fungus, D. flagrans. Duddingtonia flagrans, has the ability to survive passage through the gastro-intestinal tract of animals, germinate and grow rapidly in fresh feces then capturing and killing immature larvae before they migrate from feces to pasture where they are consumed by the grazing animals (Waller et al., 1994; Larsen et al., 1997; Baudena et al., 2000). Feeding of D. flagrans has been shown to reduce overall worm burdens of T. circumcincta (54.8%) and H. contortus in dairy goats (85%; Wright et al., 2003). Other studies have found D. flagrans to be effective in reducing fecal egg counts in sheep as well (Knox and Faedo, 2001; Fontenot et al., 2003; Santurio et al., 2011). BioWorma® contains chlamydospores of a new isolate of D. flagrans (strain IAH 1297) and studies in Australia have demonstrated that this product significantly reduced larval counts when fed to grazing sheep and goats over an 8-week period (Healey et al., 2018a; Healey et al., 2018b). However, regardless of efficacy, neither BioWorma® nor Livamol® with BioWorma® is affordable and practical for many small ruminant producers at its current price ($345 for 10 lb pail and $150 for a 30 lb. pail, respectively). Specific and more cost-effective recommendations need to be developed if this product is to become mainstream and included in IPM strategies. The results above provide compelling evidence that in the wake of dewormer resistance, educating producers on IPM, including the most cost-effective application of BioWorma®, offers an exciting and highly effective strategy for future parasite control in grazing sheep and goats.
Producers will learn about workshops, webinars, and/or field days on integrated parasite management, research projects on BioWorma® and activities outlined in this proposal through email, face to face, and social media communications and advertisements. These advertising methods will reach a minimum of 1,000 producers yearly.
Approximately 300 producers will indicate their interest in project objectives and willingness to receive additional information on outreach and educational programs conducted yearly as part of the project objectives.
Producers will register for workshops and 75 will attend integrated parasite management (IPM) workshops at both DSU and VSU yearly to learn about utilizing FAMACHA© scoring, the Five Point Check© system, pasture management, selective deworming, breed selection, nutrition, and natural/alternative dewormers to control GIN infections.
Producers participating in IPM workshops will volunteer and participate in on-farm studies to evaluate the efficacy of an alternative, more cost-effective method of feeding Livamol® with BioWorma® in controlling GIN infections in sheep and goats.
Producer will attend field days on producer farms in Delaware, Maryland and Virginia to learn IPM strategies and research project results on BioWorma®. Final year of project.
Producers will respond to follow-up surveys on changes in their GIN control strategies since training, their utilization and perceived benefit of BioWorma®, and challenges/successes from total project participation (response from all events held throughout the project).
Due to the time the accounts were setup at the university, we did not have enough time to get things going forward.
Performance Target Outcomes
Use of integrative parasite control (Five Point Check® system) and/or utilization of BioWorma® on their farms to help reduce parasite loads.
Adoption of techniques and the use of BioWorma® to control parasite loads will be utilized in 2,000 or more sheep and/or goats.
Saving an estimated $28.00 per head and reduce chemical dewormer usage.