02855naa a2200241 a 450000100080000000500110000800800410001902400380006010000220009824501310012026000090025150001300026052019710039065000100236165300180237165300190238965300180240870000170242670000150244370000170245870000240247577301140249910626522022-01-20       2022    bl uuuu     u00u1 u    #d7 a10.1016/j.livsci.2021.1048172DOI1 aMINTEGUIAGA, M.A.  aImpact of focus feeding on reproductive losses, prolificacy, or fecundity of estrous synchronized ewes.h[electronic resource]  c2022  aArticle history:Received 4 June 2021/ Revised 24 December 2021/ Accepted 27 December 2021/ Available online 30 December 2021.  aABSTRACT:The aim of this study was to evaluate the impact of a focus feeding (energy-protein supplementation) after a fixed  timed artificial insemination (TAI) and before the review service, on reproductive and metabolic variables. Multiparous Merino ewes (312) from a commercial flock (-30? 44´ S; -57?39´W) grazing native pastures were synchronized with progestogens devices for 12 days (Days -14 to -2) and eCG at removal and cervical TAI (Day=0). On Day 7 post-TAI the ovulation rate (OR) was estimated, and two groups were formed: Supplemented (S; n = 155) and Control (C; n = 157). The S group was supplemented with soybean meal (1.2% of body weight)  between Days 8 and 14. The review service was carried out between Days 14 and 21 using 2.5% fertile chest painted rams and the non-service return rate on Day 21 (NR-D21) calculated. Blood samples were obtained from 25 ewes of each group on Days 8, 12, 14, and 17 to evaluate no esterified fatty acid (NEFA) and urea plasma concentrations. On Day 26 OR was evaluated on the ewes with review service. Embryo losses, fertility, prolificacy, and fecundity of both services were estimated on Day 60 by transabdominal ultrasonography. No significant differences were observed in NR-D21 (65.8 vs. 63.7%), fertility (62.4 vs. 64.5%), prolificacy (1.32±0.75 vs. 1.33±0.76), fecundity (85.2 vs. 82.8%), or embryo losses from TAI service, or OR (1.16±0.37 vs. 1.15±0.36), fertility (87.7 vs. 92.4%), prolificacy (1.00±0.0 vs. 1.02±0.14) or fecundity (87.7 vs. 90.6%) of the review service for S and C groups respectively (P > 0.05). The urea concentrations increased significantly between Days 12 and 14 in S group (P < 0.05), and the NEFA concentration decreased faster with supplementation in the S group (P > 0.05). We concluded that a high energy-protein supplementation before the review service does not increases the reproductive losses from TAI, neither prolificacy nor fecundity of the review service.  aOVEJA  aEmbryo losses  aFecundity  Ewe  aFocus feeding1 aBANCHERO, G.1 aFIERRO, S.1 aADRIEN, M.L.1 aOLIVERA-MUZANTE, J.  tLivestock Science, 2022, Volume 256, Article number 104817. doi: https://doi.org/10.1016/j.livsci.2021.104817