Progress report for LNE23-464
Project Information
Problem or Opportunity and Justification: Gastrointestinal nematodes (GIN) are associated with increased mortality and reduced performance in pasture based small ruminant (SR) operations. Although young animals are susceptible to GIN infections, breeding females are particularly susceptible during the transition period due to the sudden emergence of GIN that have overwintered in an arrested state within the ewe. Although SR producers have readily adopted several important IPM tools, there has been limited adoption of the use of estimated breeding values (EBVs) for parasite resistance through the National Sheep Improvement Program (NSIP) to identify animals that are genetically less susceptible to GIN infection. With the significant increase of new SR producers, continued education and adoption of IPM practices with an emphasis placed on utilizing genetics to select for resistant stock is warranted to ensure the profitability, sustainability and resilience of SR operations in the northeast. This project will increase the number of SR producers utilizing EBVs for parasite resistance to improve on-farm productivity and to enhance breeding decisions.
Solution and Approach: We have a three pronged approach towards assisting SR producers with GIN control: 1) Online and in-person IPM/FAMACHA© anemia certification program; 2) Virtual and in-person workshops to promote of the use of EBVs for parasite resistance and; 3) Research into alternative strategies for control of parasites in ewes during the periparturient period (PPP) and their offspring to provide additional effective tools for GIN parasite control. There will be increased effort to reach more producers, particularly from underserved communities, more effectively and equitably and provide them with resources they need to be successful. To this end we will utilize the following strategies to increase our engagement with SR producers in the Northeast and to remove barriers to adoption of the use of EBVs for genetic selection of parasite resistance.
- Coordination with Northeast extension agents and SR veterinarians who visit SR producer farms to identify new communication channels and program delivery options particularly for SR producers with technological limitations.
- Hold in-person workshops in English and Spanish as needed to support the Spanish speaking community.
- Develop a regional mentoring hub with NSIP producer/mentors to facilitate all aspects of collecting, entering and interpreting data with NSIP.
- Provide financial support, as needed, to support participation of underserved communities in this project.
- Launch a genetic selection breeding demonstration project that will be used to showcase the financial benefit that can be achieved from the use of EBVs for economically important traits.
- We will evaluate the effect of feeding a β-glucan supplement derived from mushrooms to ewes and their offspring during the periparturient period when GIN are a greater challenge. This product, if proven effective, would be suitable for use by conventional as well as organic SR producers.
Fifty small ruminant producers will utilize estimated breeding values (EBVs) for parasite resistance across 4,200 ewes and 6,300 lambs. Because of this practice, they will realize a financial gain of $432,088 over 3 years.
Gastrointestinal nematodes (GIN) are associated with increased mortality and reduced performance in pasture based small ruminant (SR) operations. This problem is compounded as parasite resistance to commercially available dewormers continues to develop with the lack of viable alternatives to help strengthen an animals’ ability to mount a robust immune response. Although SR producers have readily adopted several important IPM tools, there has been limited adoption of the use of estimated breeding values (EBVs) for parasite resistance through the National Sheep Improvement Program (NSIP) to identify animals that are genetically less susceptible to infection (<11% of enrolled sheep). With the significant increase of new SR producers, continued education and adoption of IPM practices with an emphasis placed on utilizing genetics to select for resistant stock is warranted to ensure the profitability, sustainability and resilience of SR operations in the Northeast. This project aims to increase the number of SR producers utilizing estimated breeding values for parasite resistance, in addition to other important heritable production traits, to improve on-farm productivity and to enhance breeding decisions.
We have a three pronged approach towards assisting SR producers with GIN control: 1) Online and in-person IPM/FAMACHA© anemia certification program, now available in both English and Spanish, to teach producers how to identify and selectively deworm animals susceptible to to barber pole worm, the most pathogenic GIN responsible for the majority of production losses in SR; 2) Virtual and in-person workshops to promote of the use of EBVs for parasite resistance to improve on-farm productivity and enhance breeding decisions and; 3) Research into alternative strategies for control of parasites in ewes during the periparturient period (PPP) and their offspring to provide additional, effective tools for GIN parasite control. These three approaches have been very effective in providing SR producers with best management practices essential for the control of GIN parasites in SR and will be the foundation that we continue to build upon moving forward. Additionally, there will be increased effort to reach more producers, particularly from underserved communities, more effectively, and equitably, and provide them with resources they need to be successful.
Cooperators
- (Educator and Researcher)
- (Researcher)
- (Educator and Researcher)
- (Educator and Researcher)
- (Educator)
Research
Hypothesis: The inclusion of β-glucans into the diet of ewes and/or her lambs during the periparturient period (PPP, -8 weeks through weaning) will enhance overall performance and health.
Objective 1: Determine the effect of β-glucan supplementation during the PPP on the immune response and overall performance and health of ewes with varying GIN exposure and reared in different production environments and management systems.
Objective 2: Determine the effect of β-glucan supplementation of the ewe and/or her lambs on lamb performance and health.
Treatments:
In each study described below, ewes and/or their lambs will be supplemented with β-glucans extracted from mushrooms. Supplementation of prebiotic β-glucans, have been found to have beneficial effects on livestock species, including sheep, improving host immunity, growth, nutrient digestion, milk composition, lipid homeostasis, and beneficially affecting the rumen microbiome (deVries et al., 2020; Khalkhane et al., 2013; Ząbek et al., 2013) structure within β-glucans differ by source and this structural difference will affect their immunomodulating effects. Using β-glucans from mushrooms have advantages over yeast β-glucans due to increased solubility and lectin compounds that can confer additional anti-parasitic activity. To date, there has been no evaluation of mushroom β-glucan supplementation during the periparturient period in ewes. Understanding the effects of β-glucans during this period is key as it could be utilized by producers to improve overall ewe and lamb performance and health while reducing GIN. In the studies described below we will feed ewes one of two diets: 0.25 grams (g) of mushroom β-glucan/day or control. The β-glucan will either be top-dressed daily onto their daily pelleted grain supplement or the β-glucan will be incorporated into the pelleted grain supplement and fed to the ewes at a rate to ensure consumption of at least 0.25 g/day/ewe. Results from these studies will potentially yield an effective, affordable, commercially available product that will help ensure the sustainability and resilience of small ruminant operations.
Methods:
Ewe and lamb studies will be conducted at URI and the USMARC (Clay Center, NE).
YR 1 URI: Twenty Dorset ewes, naturally infected with GIN from the previous grazing season will be used for the periparturient study in YR1. Eight weeks (-8) prior to parturition (0) ewes will be assigned to treatment groups and individually fed 0.25 g of mushroom β-glucan (n=10) or control (n=10) from -8 through 8 weeks (wk) of lactation with groups balanced for parity, ewe BW weight, number of expected lambs and susceptibility to parasites. Fecal egg counts (FEC), fecal cultures and body weight (BW), FAMACHA© anemia scores will be determined at -8, -1, weekly from 0 through 8 wk lactation. Packed cell volume (PCV) will be determined at -8, -4, 0, 1, 2, 4, 6 and 8 wk to monitor for anemia due to emerging GIN infections. Additional blood will be taken at the same interval for determination of the immunological response to β-glucan supplementation by measurement of total immunoglobulin G (IgG) and IgG production specific to parasites (whole worm antigen). Milk components and somatic cell count will be measured using milk samples collected at birth (week 0) and weekly until weaning (week 8). Lamb BW, girth, crown-rump length and height measurements will be measured every two weeks beginning at birth until 12 wks of age. Ultrasound measurement of loin eye area and backfat thickness will be determined at 8 and 25 wk of age.
YR 2 URI: Twenty Dorset and Shropshire ewes, naturally infected with GIN from the previous grazing season will be used for the periparturient study in YR2. Eight wks prior to parturition, ewes will be assigned to treatment groups and fed as described for YR 1 from -8 through 8 wks of lactation with groups balanced for parity, breed, weight, number of expected lambs and susceptibility to parasites. At lambing, the ewes and their lambs will be split into two additional treatment groups with lambs supplemented with BG grain or control grain in the nursery/creep areas (inaccessible to the ewes;n=5 ewes/group and approximately n=9 lambs/supplementation group). Sampling will be as described for YR1.
YR 2 USMARC: Forty Polypay ewes with genetic linkages through NSIP, uninfected by GIN and maintained in confinement will be used for the periparturient study in YR2. Eight weeks (-8) prior to parturition (0) ewes will be assigned to treatment groups and fed 0.25 g of mushroom β-glucan (n=20) or control (n=20) from -8 through 8 weeks (wk) of lactation with groups balanced for service sire, production trait EBV, parity, BW, and number of expected lambs. Blood will be sampled at -4, -2, 0, 4, 8 wks of lactation for measurement of antibody response to tetanus vaccination administered at -4 wk. Milk samples will be obtained at 0, 2, 4 and 8 wk of lactation for determination of milk components and somatic cell count and BW will be measured at the same interval. Lamb BW will be measured every two weeks beginning at birth until 12 wk of age as well as additional body measurements mentioned in YR1 Ultrasound measurement of loin eye area and back fat thickness will be determined at 8, 25 wks of age. A portion of lambs from each dam treatment group will be harvested at a commercial abattoir and carcass traits will be recorded.
YR 3 USMARC: Forty Katahdin ewes with genetic linkages through NSIP, with a naturally acquired GIN infection from the previous grazing season brought in off of pasture at -2 wk will be used for the periparturient study in YR3. Eight weeks (-8) prior to parturition ewes will be assigned to treatment groups and fed 0.25 g of mushroom β-glucan (n=20) or control (n=20) from -8 through 2 wks of lactation with groups balanced for service sire, production trait and FEC EBV, parity, BW and number of expected lambs. At 2 weeks of lactation, the ewes and their lambs will be returned to pasture. FEC, fecal cultures, FAMACHA© anemia scores, PCV and BW will be determined at -8, -1, 0, 2 and weaning at 12 wk of lactation. Additional blood will be taken at the same interval for determination of the immunological response to β-glucan supplementation by measurement of total immunoglobulin G (IgG) and IgG production specific to parasites (whole worm antigen). Milk samples will be obtained at 0, 1 and 2 wk of lactation for determination of milk components and somatic cell count. Lamb BW will be measured at birth, 2, 12 and 25 wk of age. FEC, FAMACHA© anemia scores and PCV will be determined at weaning. Ultrasound measurements and carcass traits will be performed as described in YR2 USMARC.
Data Collection and Analysis:
Fecal samples will be analyzed for FEC, using the Mini-FLOTAC method with a sensitivity of 5 eggs per gram, using 5 g feces and a standard sodium nitrate flotation solution (Cringoli et al., 2010). Fecal samples will be cultured to determine larval development and characterization of GIN populations following standard protocol (Zajac and Conboy 2012). Blood samples will be analyzed for antibody IgG levels using an ELISA Kit following standard operating procedures. Packed cell volume will be determined by the micro-hematocrit centrifuge method. Milk samples will be analyzed for protein, fat, solids, SCC and milk urea nitrogen (Dairy One Inc., Ithaca, NY). Data will be analyzed using SAS (Cary, NC) and analysis will be performed using varying models, GLM procedures with repeated measures, Student t-tests, and one way ANOVAs as appropriate.
Farmer Input: Small ruminant producers are eager for additional tools to use in their integrated parasite management program. If the results from the studies at URI and USMARC are analyzed and the feeding of β-glucan to ewes and/or their lambs found highly efficacious and funding is available, a small pilot study with one of the Advisory Council producers will be initiated.
Annual Report 1: During December 2023, a 16% sheep pellet containing the mushroom β-glucan supplement was developed to facilitate the feeding of the study animals. This pellet plus a control pellet will be used in the upcoming studies at USMARC and URI during the winter of 2024.
Annual Report 2: Studies were commenced at URI and USMARC during early to mid winter 2024.
URI YR 1: Treatment groups were balanced for parity, body weight, number of expected lambs, and annual fecal egg count (FEC) prior to the start of the study. Dorset ewes were individually fed 0.25g of ImmuOligo incorporated into pelleted grain (BG; n=10) or control pelleted grain (CON; n=10) 8 weeks prior to parturition through 8 weeks of lactation. Feces were collected weekly (-8 to 8 wks) for analysis of FEC utilizing the mini-FLOTAC method and coprocultures were conducted to determine larval development and characterization of GIN profile. Blood was collected weekly (-8 to 8 wks) for packed cell volume (PCV) analysis and determination of peripheral IgG production. Milk was collected weekly after parturition (parturition to 8 wks) for analysis of protein, fat, solids, milk urea nitrogen and somatic cell count. Lamb body weight, girth, crown-rump length, and height measurements were measured every two weeks beginning at birth until weaning, 8 weeks of age. In conclusion, dietary supplementation of ImmuOligo® in periparturient ewes did not significantly affect fecal egg counts or the growth of lambs. However, there was a slight increase in milk fat and solids at week 4, suggesting a potential area for further exploration. Ongoing analyses, including coproculture identification, quantification, and IgG analysis, will provide more insights. Based upon the results from this study, the ImmuOligo® dose will be increased to 0.5 grams/ewe/day for 2025 studies.
USMARC YR1: Three weeks prior to the start of lambing 60 mature, pregnant Katahdin ewes were assigned to treatment (30 CON and 30 BG). The ewes were balanced equally between CON and BG groups based on age (2-4 yr), body weight, and Estimated Breeding Value (EBV) for maternal weaning weight (high vs. low), and number of lambs born (high vs low). Body weights, body condition scores (BCS), FAMACHA, blood (serum and CBC), and fecals were collected. During the initial supplementation period one of the automated feeders distributing the feed supplement to the ewes broke down with computer issues serious enough that the feeder had to be shipped to another state for repair. Additionally, only 66% of the control ewes and < 50% of the BG ewes were routinely using the supplement feeder. The end result is that supplementation had to be abandoned after 3 weeks. Samples continued to be taken to add to the dataset of mastitis/blood cell parameters associated with ewe and lamb performance in general and to determine whether milk components differ between ewes of high or low maternal weaning weight EBV and how that corresponds to differences in lamb growth.
Education
- Dahlia O’Brien, Ph.D., Small Ruminant Extension Specialist at Virginia State University, Petersburg, VA. Dr. O’Brien will advise us on effective methods of reaching out to underserved communities of SR producers as this is a focus of her work on complementary grants and an institutional focus of 1890’s institutions.
- Melanie Barkley Penn State Univ (PSU) Senior Extension Educator for Bedford Co. and Camren Maierle, PSU Extension Educator for Mercer Co. bring expertise as Small Ruminant Specialists and NSIP producers that routinely engage with PA SR producers during workshops and farm visits. In particular, they both routinely visit and interact with the underserved populations of Amish, Mennonite and German Baptist SR producers.
- Tom Hodgeman, M.S., a forage-based seedstock producer of Katahdin Sheep in Winterport Maine. Tom has been active since 2007 in genetic selection for parasite resistance using EBVs. Tom has been involved with LNE15-342 as workshop speaker and was one of the NSIP producer/moderators for our virtual NSIP workshops for LNE19-381.
- Joan Burke, Ph.D. Research Animal Scientist, USDA, ARS Dale Bumpers Small Farms Research Center, Bonneville, AR. Dr. Burke is extensively involved with numerous Katahdin producers interested in increasing parasite resistance within their breed using EBVs. She will provide guidance on engaging with Katahdin and other breed organizations.
- Rachael Gately, DVM, Small Ruminant Veterinarian, Tufts Veterinary Field Service, Woodstock, CT. Dr. Gately will help facilitate interactions with small ruminant practitioners to create new channels to reach SR producers with notice of the educational components of this project.
Project Advisory Committee (PAC) members have been integral to the development of the Educational Program proposed in this grant proposal particularly in regards to best practices for reaching the underserved SR producers and supporting all project participants with mentoring, educational material and financial support appropriate for their particular circumstances. PAC meetings will occur primarily via virtual Zoom meetings held every other month for 1 hour of compensated time. There will be other opportunities to interact with PAC members individually through grant activities and at other scientific meetings.
Milestones
- Dahlia O’Brien, Ph.D., Small Ruminant Extension Specialist at Virginia State University, Petersburg, VA. Dr. O’Brien will advise us on effective methods of reaching out to underserved communities of SR producers as this is a focus of her work on complementary grants and an institutional focus of 1890’s institutions.
- Melanie Barkley Penn State Univ (PSU) Senior Extension Educator for Bedford Co. and Camren Maierle, PSU Extension Educator for Mercer Co. bring expertise as Small Ruminant Specialists and NSIP producers that routinely engage with PA SR producers during workshops and farm visits. In particular, they both routinely visit and interact with the underserved populations of Amish, Mennonite and German Baptist SR producers.
- Tom Hodgeman, M.S., a forage-based seedstock producer of Katahdin Sheep in Winterport Maine. Tom has been active since 2007 in genetic selection for parasite resistance using EBVs. Tom has been involved with LNE15-342 as workshop speaker and was one of the NSIP producer/moderators for our virtual NSIP workshops for LNE19-381.
- Joan Burke, Ph.D. Research Animal Scientist, USDA, ARS Dale Bumpers Small Farms Research Center, Bonneville, AR. Dr. Burke is extensively involved with numerous Katahdin producers interested in increasing parasite resistance within their breed using EBVs. She will provide guidance on engaging with Katahdin and other breed organizations.
- Rachael Gately, DVM, Small Ruminant Veterinarian, Tufts Veterinary Field Service, Woodstock, CT. Dr. Gately will help facilitate interactions with small ruminant practitioners to create new channels to reach SR producers with notice of the educational components of this project.
Project Advisory Committee (PAC) members have been integral to the development of the Educational Program proposed in this grant proposal particularly in regards to best practices for reaching the underserved SR producers and supporting all project participants with mentoring, educational material and financial support appropriate for their particular circumstances. PAC meetings will occur primarily via virtual Zoom meetings held every other month for 1 hour of compensated time. There will be other opportunities to interact with PAC members individually through grant activities and at other scientific meetings.
Milestone Activities and Participation Summary
Educational activities:
Participation Summary:
Learning Outcomes
Performance Target Outcomes
Target #1
50
Producers will utilize estimated breeding values (EBVs) for parasite resistance.
4,200 ewes and 6,300 lambs
Producers will realize a financial gain of $432,088 over 3 years.