Effect of peptidoglycan-polysaccharide complex on reproductive efficiency in sheep.
OBJECTIVE
Spontaneous mastitis or induced infections mimicking mastitis reduce pregnancy rates in ruminants. The effect of immunization with either a mastitis-related pathogen component, peptidoglycan-polysaccharide (PG-PS), or killed Streptococcus pyogenes on pregnancy outcome was investigated.


METHODS
Ewe lambs were immunized with PG-PS (n = 50) or killed bacteria (n = 50) or were not immunized (control, n = 100). Titers of PG-PS immunoglobulin G (IgG) were detected by enzyme-linked immunosorbent assay (ELISA). Ewes were bred by rams at synchronized estrus. All immunized ewes and half of the ewes not immunized were challenged with PG-PS on day 5 after breeding. Pregnancy maintenance was evaluated.


RESULTS
Although the proportion of ewes pregnant at day 42 after breeding did not differ among treatments, the probability of pregnancy decreased with total dose of PG-PS (P < 0.05).


CONCLUSIONS
Immunization of ewe lambs with PG-PS or killed S. pyogenes did not improve pregnancy maintenance. Furthermore, the toxic streptococcal component decreased pregnancy rate in immunized sheep in a dose-dependent manner.
Holásková
Ida
I
Division of Animal and Veterinary Sciences, West Virginia University, Morgantown, WV 26506-6108, USA.
Lewis
Gregory S
GS
Elliott
Meenal
M
Blemings
Kenneth P
KP
Dailey
Robert A
RA
D000818:Animals; D005260:Female; D007114:Immunization; D010457:Peptidoglycan / Q000276:immunology*; D011134:Polysaccharides / Q000276:immunology*; D011247:Pregnancy; D011256:Pregnancy Outcome; D011270:Pregnancy, Animal / Q000276:immunology* / Q000502:physiology; D012098:Reproduction / Q000276:immunology* / Q000502:physiology*; D012756:Sheep / Q000502:physiology*
D010457:Peptidoglycan; D011134:Polysaccharides