Improving the uterine environment

Previous studies have shown that improved uterine environments during pregnancy can improve postnatal growth and health performance of offspring. Indonesian researchers hypothesized that an improved uterine environment might also improve offspring's resilience to Haemonchus contortus. They evaluated the resistance and resilience to H. contortus of lambs born to ewes injected with pregnant mare’s serum gonadotropin (PMSG) prior to mating.

A total of 16 lambs, regardless of sex, at the age of 5 months were assigned into a 2 × 2 factorial experiment with 4 replications. The first factor was PMSG injection, consisting of two levels: 1) lambs born to ewes without PMSG injection (Non-PMSG lambs) and 2) those born to PMSG-injected ewes (PMSG lambs). The second factor was the infection of lambs with H. contortus at the age of 5 months, consisting of two levels: 2) lambs without infection (Non-infected lambs) and 2) lambs infected with H. contortus (Infected lambs).

Compared to non-PMSG lambs, PMSG lambs tended to have better prenatal growth indicated by greater birth weights. The improved prenatal growth during pregnancy improved the postnatal growth and health performance of the lambs. Three months after infection of H. contortus, non-PMSG lambs and PMSG lambs had similar worm counts. However, the PMSG lambs showed significantly higher resistance to H. contortus as indicated by the lower fecal egg counts 6–10 weeks after infection. The higher resilience of the PMSG lambs was shown by the positive growth rate during infection, while non-PMSG lambs had negative growth after infection. The increased resilience was also reflected in the eosinophil and lymphocyte parameters.

The researchers concluded that improvement of the uterine environment during pregnancy could be used to produce superior offspring with high resistance and resilience to the infection of H. contortus. Source: Small Ruminant Research. Volume 167. October 2018