Impact of insulin treatment during post-insemination mid-luteal phase on luteal profile and conception rate in buffaloes

Abstract

The aim of present trial in buffaloes was to test the impact of subcutaneous administration of insulin (long acting purified bovine insulin @ 0.2 IU/kg body weight/day) during post-insemination mid-luteal phase (days 8–12) on luteal profile and conception rate. A set of 22 estrus synchronized (2 PGF2α injections 11 days apart) post-partum buffaloes were assigned to insulin (n=12) or control (n=10) group. All the buffaloes were artificially inseminated (AI) 8–12 h after the onset of estrus and thereafter AI was repeated once at 12 h interval. Transrectal ultrasonography and jugular vein blood sampling was carried out on day 0 (day of last AI), 5, 8, 12, 15, 21 and 40 post-AI. First service conception rate was assessed by transrectal ultrasonography on day 40 post-AI. Data of insulin group showed no alteration in corpus luteum size (P>0.05), although post-treatment plasma progesterone and first service conception rate was higher (P<0.25) in insulin group compared to control group. In summary, insulin administration during post-AI mid-luteal phase may have a beneficial impact on conception rate in buffaloes.