title: Can an increased intake of metabolizable protein affect the periparturient relaxation in immunity against teladorsagia circumcincta in sheep?
abstract: Within the overall hypothesis that the periparturient relaxation of immunity (PPRI) to gastrointestinal parasites has a nutritional basis, we studied whether an increased intake of metabolizable protein (MP) could affect the expression of immunity to Teladorsagia (Ostertagia) circumcincta of twin-bearing and -rearing Greyface ewes. Two sets of iso-energetic diets were formulated to provide either 85% (L-) or 130% (H-) of the MP requirements during the last 6 weeks of pregnancy (-P) and the first 6 weeks of lactation (-L). Thirty ewes were allocated to LP or HP. Six ewes of each group were slaughtered after lambing (S(0)); the remaining 24 ewes of each group were allocated to either LL or HL, thus creating four treatment combinations during lactation (LP/LL, LP/HL, HP/LL and HP/HL; n=12). Six ewes of each treatment combination were slaughtered at Week 3 (S(3)) or at Week 6 (S(6)) in lactation. The HP ewes were heavier at lambing, produced heavier lambs, had lower faecal egg counts (FECs), a lower concentration of plasma pepsinogen, a higher concentration of plasma albumin during late pregnancy and more abomasal globule leukocytes (GLs) but similar worm burdens at S(0) compared to the LP ewes. The LP/HL and HP/HL ewes had a higher calculated milk production than the LP/LL and HP/LL ewes. FECs increased for each treatment combination during the first 3 weeks of lactation. This increase concurred with fewer abomasal GLs at S(3) compared to S(0). The LP/HL and HP/HL ewes had a higher proportion of immature worms and more abomasal GLs than the LP/LL and HP/LL ewes at S(6). The FECs continued to increase during the second 3 weeks of lactation for the LP/LL ewes only, which concurred with an elevated plasma pepsinogen concentration and an absence of abomasal GLs at S(6). The plasma pepsinogen concentration decreased rapidly for the LP/HL ewes during lactation. We conclude that an increased intake of MP could enhance the expression of immunity to T. circumcincta of twin-bearing and -rearing Greyface ewes.
authors.affiliation: Animal Nutrition and Health Department, Animal Biology Division, Scottish Agricultural College, Kings Buildings, EH9 3JG, Edinburgh, UK. j.houdijk@ed.sac.ac.uk
authors.forename: J G
authors.initials: JG
authors.lastname: Houdijk
authors.forename: I
authors.initials: I
authors.lastname: Kyriazakis
authors.forename: F
authors.initials: F
authors.lastname: Jackson
authors.forename: J F
authors.initials: JF
authors.lastname: Huntley
authors.forename: R L
authors.initials: RL
authors.lastname: Coop
mesh_terms: D000821:Animal Feed; D000818:Animals; D001798:Blood Proteins / Q000032:analysis; D004044:Dietary Proteins / Q000008:administration & dosage / Q000494:pharmacology*; D002149:Energy Intake; D005260:Female; D008297:Male; D010028:Ostertagia / Q000276:immunology*; D010029:Ostertagiasis / Q000276:immunology / Q000662:veterinary; D020116:Pepsinogen A / Q000097:blood; D011247:Pregnancy; D015597:Pregnancy Complications, Parasitic / Q000276:immunology*; D012756:Sheep; D012757:Sheep Diseases / Q000276:immunology*
chemical_list: D001798:Blood Proteins; D004044:Dietary Proteins; D020116:Pepsinogen A