{"id":{"repo_id":"sask","oai_identifier":"oai:harvest.usask.ca:10388/18807"},"canonical_url":"https://search.dev.ndltd.org/etd/sask/oai:harvest.usask.ca:10388/18807","repository":{"repo_id":"sask","name":"University of Saskatchewan","base_url":"https://harvest.usask.ca/server/oai/request"},"display":{"title":"ELUCIDATING DIFFERENT CLOSTRIDIUM PERFRINGENS TYPE D VACCINE PROTOCOLS IN EWES AND LAMBS","abstract":"Enterotoxemia caused by Clostridium perfringens type D epsilon toxin (CptD ETX) is a major cause of sudden mortality in lambs. Protection of neonatal lambs relies heavily on maternally derived antibodies (MDA) transferred through colostrum; however, these antibodies may also influence the lamb’s immune response to vaccination. Therefore, the present study aimed to: (1) evaluate the effect of pre-lambing booster vaccination timing on ewe antibody responses and colostrum antibody transfer, (2) evaluate the transfer of passive immunity (TPI) in lambs, and (3) determine how lamb age at vaccination and maternal booster timing influence lamb vaccine antibody responses. Three trials were conducted in ewes and lambs, using a multivalent clostridial vaccine (Glanvac® 6, Zoetis Canada Inc., Kirkland, QC, Canada). In ewes, booster vaccinations were performed as follows: in trials 1 and 3, ewes were boosted 42-or-14 days (42d or 14d) pre-lambing; in trial 2, ewes were boosted 14d pre-lambing or received no booster. All ewes had a known primary and booster CptD vaccination history in previous years. A competitive ELISA was used to determine serum CptD ETX titers as inhibition %. CptD ETX were measured pre-vaccination, 14-days (-14d), and 7 days (-7d) pre-lambing, and at lambing (d 0). Lambs born to ewes in each trial were vaccinated at 3, 14, or 33/35 days (3d, 14d, 33/35d) of age, and serum CptD ETX antibody responses were monitored longitudinally up to 8-12 weeks from the day of vaccination. In ewes, booster at 42 d significantly (p<0.01) increased serum antibody titers at -7d compared with no booster (88.60% vs. 61.23%), although there was no difference at d 0 (p=0.34). Antibody responses were comparable between 42d and 14d groups (in trial 1 and 3) at both -7d and at d 0 (p=0.15 and p=0.07, respectively), and titer fold change from vaccination to -7d and d0 were also similar between booster groups (p=0.43 and p=0.13, respectively). Colostrum quality, assessed using Brix refractometry, was not influenced by any vaccination treatment (Brix % range: 28.53(± 4.75) to 31.52(± 3.17); lowest p=0.59). Likewise, TPI in lambs, evaluated at 36-48 hours of age, was not significantly different between lambs from different maternal booster groups in any trial, measured as serum total protein (TP) (lowest p=0.23), Brix% (lowest p=0.24), and ETX inhibition % (lowest p=0.08). Within each maternal booster group, lamb age (3 or 33 d in trials 1 and 2; 14 or 35d in trial 3) at primary vaccination did not significantly influence antibody titers at vaccination (lowest p trial 1: p=0.16; trial 2: p=0.36; trial 3: p=0.50) or over time (lowest p trial 1: p=0.36; trial 2: p=0.17; trial 3: p=0.39). However, among lambs from non-boosted ewes, antibody response trajectories differed between those vaccinated at 3d and 33d of age (p=0.02). When comparisons were made to see the effect of maternal booster timing, in trial 1 and 2, lambs vaccinated at 3d of age had a significantly lower antibody titers at pre-vaccination however, these lambs had a significant immune response following vaccination compared to lambs vaccinated at 3d but born to ewes booster-vaccinated at 42d (largest p=0.02, p<0.01, respectively). Interestingly, in 5 out of 6 comparisons, lambs from 42d boosted ewes had significantly higher circulating antibody concentrations pre-vaccination (largest p=0.04) compared to lambs from ewes boosted closer to lambing or not boosted at all. Pre-lambing booster vaccination enhanced maternal antibody responses regardless of timing. Colostrum quality and transfer of passive immunity were not affected by booster timing, providing producers with evidence-based flexibility in ewe vaccination scheduling. Importantly, maternal antibody levels influenced lamb vaccine responses in a dose-dependent manner: lambs with high pre-vaccination titers (>88% inhibition) showed minimal active responses, while those with moderate titers (~70%) mounted significantly stronger responses when vaccinated early (3 days of age). These findings support prioritizing ewe booster vaccination at 42 d pre-lambing as the cornerstone strategy, while early lamb vaccination (3 d) is recommended when maternal booster coverage is incomplete, allowing producers to tailor vaccination programs to their specific flock circumstances","abstract_html":"Enterotoxemia caused by Clostridium perfringens type D epsilon toxin (CptD ETX) is a major cause of sudden mortality in lambs. Protection of neonatal lambs relies heavily on maternally derived antibodies (MDA) transferred through colostrum; however, these antibodies may also influence the lamb’s immune response to vaccination. Therefore, the present study aimed to: (1) evaluate the effect of pre-lambing booster vaccination timing on ewe antibody responses and colostrum antibody transfer, (2) evaluate the transfer of passive immunity (TPI) in lambs, and (3) determine how lamb age at vaccination and maternal booster timing influence lamb vaccine antibody responses. Three trials were conducted in ewes and lambs, using a multivalent clostridial vaccine (Glanvac® 6, Zoetis Canada Inc., Kirkland, QC, Canada). In ewes, booster vaccinations were performed as follows: in trials 1 and 3, ewes were boosted 42-or-14 days (42d or 14d) pre-lambing; in trial 2, ewes were boosted 14d pre-lambing or received no booster. All ewes had a known primary and booster CptD vaccination history in previous years. A competitive ELISA was used to determine serum CptD ETX titers as inhibition %. CptD ETX were measured pre-vaccination, 14-days (-14d), and 7 days (-7d) pre-lambing, and at lambing (d 0). Lambs born to ewes in each trial were vaccinated at 3, 14, or 33/35 days (3d, 14d, 33/35d) of age, and serum CptD ETX antibody responses were monitored longitudinally up to 8-12 weeks from the day of vaccination. In ewes, booster at 42 d significantly (p<0.01) increased serum antibody titers at -7d compared with no booster (88.60% vs. 61.23%), although there was no difference at d 0 (p=0.34). Antibody responses were comparable between 42d and 14d groups (in trial 1 and 3) at both -7d and at d 0 (p=0.15 and p=0.07, respectively), and titer fold change from vaccination to -7d and d0 were also similar between booster groups (p=0.43 and p=0.13, respectively). Colostrum quality, assessed using Brix refractometry, was not influenced by any vaccination treatment (Brix % range: 28.53(± 4.75) to 31.52(± 3.17); lowest p=0.59). Likewise, TPI in lambs, evaluated at 36-48 hours of age, was not significantly different between lambs from different maternal booster groups in any trial, measured as serum total protein (TP) (lowest p=0.23), Brix% (lowest p=0.24), and ETX inhibition % (lowest p=0.08). Within each maternal booster group, lamb age (3 or 33 d in trials 1 and 2; 14 or 35d in trial 3) at primary vaccination did not significantly influence antibody titers at vaccination (lowest p trial 1: p=0.16; trial 2: p=0.36; trial 3: p=0.50) or over time (lowest p trial 1: p=0.36; trial 2: p=0.17; trial 3: p=0.39). However, among lambs from non-boosted ewes, antibody response trajectories differed between those vaccinated at 3d and 33d of age (p=0.02). When comparisons were made to see the effect of maternal booster timing, in trial 1 and 2, lambs vaccinated at 3d of age had a significantly lower antibody titers at pre-vaccination however, these lambs had a significant immune response following vaccination compared to lambs vaccinated at 3d but born to ewes booster-vaccinated at 42d (largest p=0.02, p<0.01, respectively). Interestingly, in 5 out of 6 comparisons, lambs from 42d boosted ewes had significantly higher circulating antibody concentrations pre-vaccination (largest p=0.04) compared to lambs from ewes boosted closer to lambing or not boosted at all. Pre-lambing booster vaccination enhanced maternal antibody responses regardless of timing. Colostrum quality and transfer of passive immunity were not affected by booster timing, providing producers with evidence-based flexibility in ewe vaccination scheduling. Importantly, maternal antibody levels influenced lamb vaccine responses in a dose-dependent manner: lambs with high pre-vaccination titers (>88% inhibition) showed minimal active responses, while those with moderate titers (~70%) mounted significantly stronger responses when vaccinated early (3 days of age). These findings support prioritizing ewe booster vaccination at 42 d pre-lambing as the cornerstone strategy, while early lamb vaccination (3 d) is recommended when maternal booster coverage is incomplete, allowing producers to tailor vaccination programs to their specific flock circumstances","abstract_has_math":false,"creators":["Muthukumara, Suren"],"institution":"University of Saskatchewan","degree_name":"Master of Science (M.Sc.)","degree_level":"Masters","degree_discipline":"Large Animal Clinical Sciences","degree_department":null,"school":null,"contributors":[],"advisors":["Uehlinger, Fabienne Dominique"],"committee_chairs":[],"committee_members":["Dadrwal, Dinesh","de Oliveira Costa, Matheus","Van Cleef, Eric"],"year":2026,"date_issued":"2026-07-09","date_published":"2026-07-09","updated_at":"2026-07-24T04:26:54Z","subjects":["sheep","Clostridium perfringens type D","booster vaccination","antibody concentrations"],"languages":["en"],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://hdl.handle.net/10388/18807","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Uehlinger, Fabienne Dominique"]},{"key":"dc:contributor.committeemember","label":"Committee Member","values":["Dadrwal, Dinesh","de Oliveira Costa, Matheus","Van Cleef, Eric"]},{"key":"dc:creator","label":"Author","values":["Muthukumara, Suren"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2026-07-09T15:35:06Z"]},{"key":"dc:date.issued","label":"Date","values":["2026-07-09"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Large Animal Clinical Sciences"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Masters"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science (M.Sc.)"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Saskatchewan"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["sheep","Clostridium perfringens type D","booster vaccination","antibody concentrations"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["en"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://hdl.handle.net/10388/18807"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Enterotoxemia caused by Clostridium perfringens type D epsilon toxin (CptD ETX) is a major cause of sudden mortality in lambs. Protection of neonatal lambs relies heavily on maternally derived antibodies (MDA) transferred through colostrum; however, these antibodies may also influence the lamb’s immune response to vaccination. Therefore, the present study aimed to: (1) evaluate the effect of pre-lambing booster vaccination timing on ewe antibody responses and colostrum antibody transfer, (2) evaluate the transfer of passive immunity (TPI) in lambs, and (3) determine how lamb age at vaccination and maternal booster timing influence lamb vaccine antibody responses. Three trials were conducted in ewes and lambs, using a multivalent clostridial vaccine (Glanvac® 6, Zoetis Canada Inc., Kirkland, QC, Canada). In ewes, booster vaccinations were performed as follows: in trials 1 and 3, ewes were boosted 42-or-14 days (42d or 14d) pre-lambing; in trial 2, ewes were boosted 14d pre-lambing or received no booster. All ewes had a known primary and booster CptD vaccination history in previous years. A competitive ELISA was used to determine serum CptD ETX titers as inhibition %. CptD ETX were measured pre-vaccination, 14-days (-14d), and 7 days (-7d) pre-lambing, and at lambing (d 0). Lambs born to ewes in each trial were vaccinated at 3, 14, or 33/35 days (3d, 14d, 33/35d) of age, and serum CptD ETX antibody responses were monitored longitudinally up to 8-12 weeks from the day of vaccination. In ewes, booster at 42 d significantly (p<0.01) increased serum antibody titers at -7d compared with no booster (88.60% vs. 61.23%), although there was no difference at d 0 (p=0.34). Antibody responses were comparable between 42d and 14d groups (in trial 1 and 3) at both -7d and at d 0 (p=0.15 and p=0.07, respectively), and titer fold change from vaccination to -7d and d0 were also similar between booster groups (p=0.43 and p=0.13, respectively). Colostrum quality, assessed using Brix refractometry, was not influenced by any vaccination treatment (Brix % range: 28.53(± 4.75) to 31.52(± 3.17); lowest p=0.59). Likewise, TPI in lambs, evaluated at 36-48 hours of age, was not significantly different between lambs from different maternal booster groups in any trial, measured as serum total protein (TP) (lowest p=0.23), Brix% (lowest p=0.24), and ETX inhibition % (lowest p=0.08). Within each maternal booster group, lamb age (3 or 33 d in trials 1 and 2; 14 or 35d in trial 3) at primary vaccination did not significantly influence antibody titers at vaccination (lowest p trial 1: p=0.16; trial 2: p=0.36; trial 3: p=0.50) or over time (lowest p trial 1: p=0.36; trial 2: p=0.17; trial 3: p=0.39). However, among lambs from non-boosted ewes, antibody response trajectories differed between those vaccinated at 3d and 33d of age (p=0.02). When comparisons were made to see the effect of maternal booster timing, in trial 1 and 2, lambs vaccinated at 3d of age had a significantly lower antibody titers at pre-vaccination however, these lambs had a significant immune response following vaccination compared to lambs vaccinated at 3d but born to ewes booster-vaccinated at 42d (largest p=0.02, p<0.01, respectively). Interestingly, in 5 out of 6 comparisons, lambs from 42d boosted ewes had significantly higher circulating antibody concentrations pre-vaccination (largest p=0.04) compared to lambs from ewes boosted closer to lambing or not boosted at all. Pre-lambing booster vaccination enhanced maternal antibody responses regardless of timing. Colostrum quality and transfer of passive immunity were not affected by booster timing, providing producers with evidence-based flexibility in ewe vaccination scheduling. Importantly, maternal antibody levels influenced lamb vaccine responses in a dose-dependent manner: lambs with high pre-vaccination titers (>88% inhibition) showed minimal active responses, while those with moderate titers (~70%) mounted significantly stronger responses when vaccinated early (3 days of age). These findings support prioritizing ewe booster vaccination at 42 d pre-lambing as the cornerstone strategy, while early lamb vaccination (3 d) is recommended when maternal booster coverage is incomplete, allowing producers to tailor vaccination programs to their specific flock circumstances"]},{"key":"dc:format.mimetype","label":"Dc Format Mimetype","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["ELUCIDATING DIFFERENT CLOSTRIDIUM PERFRINGENS TYPE D VACCINE PROTOCOLS IN EWES AND LAMBS"]}]}],"canonical_facts":{"dc:contributor.advisor":["Uehlinger, Fabienne Dominique"],"dc:contributor.committeemember":["Dadrwal, Dinesh","de Oliveira Costa, Matheus","Van Cleef, Eric"],"dc:creator":["Muthukumara, Suren"],"dc:date.accessioned":["2026-07-09T15:35:06Z"],"dc:date.issued":["2026-07-09"],"dc:description.abstract":["Enterotoxemia caused by Clostridium perfringens type D epsilon toxin (CptD ETX) is a major cause of sudden mortality in lambs. Protection of neonatal lambs relies heavily on maternally derived antibodies (MDA) transferred through colostrum; however, these antibodies may also influence the lamb’s immune response to vaccination. Therefore, the present study aimed to: (1) evaluate the effect of pre-lambing booster vaccination timing on ewe antibody responses and colostrum antibody transfer, (2) evaluate the transfer of passive immunity (TPI) in lambs, and (3) determine how lamb age at vaccination and maternal booster timing influence lamb vaccine antibody responses. Three trials were conducted in ewes and lambs, using a multivalent clostridial vaccine (Glanvac® 6, Zoetis Canada Inc., Kirkland, QC, Canada). In ewes, booster vaccinations were performed as follows: in trials 1 and 3, ewes were boosted 42-or-14 days (42d or 14d) pre-lambing; in trial 2, ewes were boosted 14d pre-lambing or received no booster. All ewes had a known primary and booster CptD vaccination history in previous years. A competitive ELISA was used to determine serum CptD ETX titers as inhibition %. CptD ETX were measured pre-vaccination, 14-days (-14d), and 7 days (-7d) pre-lambing, and at lambing (d 0). Lambs born to ewes in each trial were vaccinated at 3, 14, or 33/35 days (3d, 14d, 33/35d) of age, and serum CptD ETX antibody responses were monitored longitudinally up to 8-12 weeks from the day of vaccination. In ewes, booster at 42 d significantly (p<0.01) increased serum antibody titers at -7d compared with no booster (88.60% vs. 61.23%), although there was no difference at d 0 (p=0.34). Antibody responses were comparable between 42d and 14d groups (in trial 1 and 3) at both -7d and at d 0 (p=0.15 and p=0.07, respectively), and titer fold change from vaccination to -7d and d0 were also similar between booster groups (p=0.43 and p=0.13, respectively). Colostrum quality, assessed using Brix refractometry, was not influenced by any vaccination treatment (Brix % range: 28.53(± 4.75) to 31.52(± 3.17); lowest p=0.59). Likewise, TPI in lambs, evaluated at 36-48 hours of age, was not significantly different between lambs from different maternal booster groups in any trial, measured as serum total protein (TP) (lowest p=0.23), Brix% (lowest p=0.24), and ETX inhibition % (lowest p=0.08). Within each maternal booster group, lamb age (3 or 33 d in trials 1 and 2; 14 or 35d in trial 3) at primary vaccination did not significantly influence antibody titers at vaccination (lowest p trial 1: p=0.16; trial 2: p=0.36; trial 3: p=0.50) or over time (lowest p trial 1: p=0.36; trial 2: p=0.17; trial 3: p=0.39). However, among lambs from non-boosted ewes, antibody response trajectories differed between those vaccinated at 3d and 33d of age (p=0.02). When comparisons were made to see the effect of maternal booster timing, in trial 1 and 2, lambs vaccinated at 3d of age had a significantly lower antibody titers at pre-vaccination however, these lambs had a significant immune response following vaccination compared to lambs vaccinated at 3d but born to ewes booster-vaccinated at 42d (largest p=0.02, p<0.01, respectively). Interestingly, in 5 out of 6 comparisons, lambs from 42d boosted ewes had significantly higher circulating antibody concentrations pre-vaccination (largest p=0.04) compared to lambs from ewes boosted closer to lambing or not boosted at all. Pre-lambing booster vaccination enhanced maternal antibody responses regardless of timing. Colostrum quality and transfer of passive immunity were not affected by booster timing, providing producers with evidence-based flexibility in ewe vaccination scheduling. Importantly, maternal antibody levels influenced lamb vaccine responses in a dose-dependent manner: lambs with high pre-vaccination titers (>88% inhibition) showed minimal active responses, while those with moderate titers (~70%) mounted significantly stronger responses when vaccinated early (3 days of age). These findings support prioritizing ewe booster vaccination at 42 d pre-lambing as the cornerstone strategy, while early lamb vaccination (3 d) is recommended when maternal booster coverage is incomplete, allowing producers to tailor vaccination programs to their specific flock circumstances"],"dc:format.mimetype":["application/pdf"],"dc:identifier.uri":["https://hdl.handle.net/10388/18807"],"dc:language.iso":["en"],"dc:subject":["sheep","Clostridium perfringens type D","booster vaccination","antibody concentrations"],"dc:title":["ELUCIDATING DIFFERENT CLOSTRIDIUM PERFRINGENS TYPE D VACCINE PROTOCOLS IN EWES AND LAMBS"],"dc:type":["Thesis"],"thesis:degree_discipline":["Large Animal Clinical Sciences"],"thesis:degree_level":["Masters"],"thesis:degree_name":["Master of Science (M.Sc.)"],"thesis:institution_name":["University of Saskatchewan"]},"updated_at":"2026-07-24T04:26:54Z"}