REPRODUCTIVE MEASUREMENTS IN SINCLAIR AND NIH MINIATURE PIGS - A RETROSPECTIVE ANALYSIS

The data presented here represent a retrospective analysis of informat ion gathered while collecting data for other studies on miniature pigs . Two different breeds of miniature pigs, NIH and Sinclair, were used in this study. The NIH females were gilts, while Sinclair females incl uded both gilts and sows. The pigs were checked twice a day for estrus and were mated at 12 and 24 h after the onset of estrus. One- and 2-c ell stage embryos were collected on Day 2; while 4-cell, 8-cell, compa ct morula and blastocyst stage embryos were collected on Days 2.7, 3.5 , 4.3 and 6.0, respectively. The percentage of recovery of these embry os was dependent upon the surgeon (P=0.002) and the stage of developme nt (P=0.018). The number of ovulations was higher (P<0.04) in the Sinc lair sows (10.4+/-0.60) than in the Sinclair gilts (8.9+/-0.67) and in the NIH gilts (8.3+/-0.67). When the NIH gilts were divided into swin e leukocyte antigen (SLA) haplotypes, it was found that SLA(dd) gilts (8.5+/-0.43) had more ovulations (P=0.02) than SLA(ad) gilts (6.8+/-0. 57). Some animals were treated with Regumate(R) to synchronize estrus. The Sinclair gilts (7.8+/-0.28) and NIH gilts (7.7+/-0.27) took more days (P<0.07) to show estrus than the Sinclair sows (6.3+/-0.58) after the removal of Regumates(R). Four of the animals had reproductive tra ct abnormalities; more specifically, a blind uterine horn or oviduct t hat was not patent with the other horn. All 4 were NIH gilts with the SLA(dd) haplotype. (C) 1997 by Elsevier Science Inc.