Our objective was to evaluate the economics of dairy heifers managed for first AI service with programs that relied primarily on insemination at detected estrus (AIE) or timed AI (TAI). After a voluntary waiting period (VWP) of 12 mo, Holstein heifers from 2 farms received first AI after: 1) PG+AIE (n = 246): AIE after PGF2α (PGF) treatments 14 d apart (up to 3) starting at the end of the VWP. Heifers not AIE within 9 d of the third PGF were enrolled in a 5d-Cosynch protocol (5dCP = CIDR+GnRH-5d-CIDR-out+PGF-3d-GnRH⁺TAI), 2) TAI (n = 235): TAI after a 5dCP protocol, and 3) PG+TAI (n = 250): AIE after the second of 2 PGF treatments 14 d apart. Heifers not AIE within 9 d after the second PGF were enrolled in the 5dCP. Individual heifer costs and revenues were collected for 15 mo after their VWP [all rearing period (RP) and part of the first lactation (FL)]. Total cash flow (CF) for 15 mo was the aggregation of RP reproductive cost (RC), RP feed cost (FDC), RP replacement cost (RPLC), RP fixed cost (FXC), calf value (CFV), FL income over feed cost (IOFC), FL RPLC, and FL FXC. All results are in Table 1. Time to pregnancy was only reduced for TAI vs. PG+AIE. During the RP, the RC was greater for TAI but no differences (P > 0.10) were observed for FDC, RPLC, and FXC. During FL, all parameters evaluated were similar (P > 0.10). We conclude that despite some differences in reproductive performance and some factors that affect overall cash flow, economics were similar for heifers managed with reproductive programs that relied primarily on AIE or TAI. Supported by NYFVI Project AOR2015-020. Table 1. Reproductive performance and economics

	PG + AIE	TAI	PG + TAI	P-value
Time to pregnancy, HR (95%CI)1	Referent	1.20 (1.02–1.42)	1.07 (0.91–1.26)	0.08
Rearing, $/heifer
RC	56.0 ± 1.9a	73.1 ± 2.6b	59.8 ± 1.9a	<0.01
FDC	395 ± 4.0	390 ± 4.5	387 ± 3.8	0.41
RPLC	3.31 ± 3.1	1.33 ± 1.5	0.40 ± 0.8	0.59
FXC	266 ± 2.6	264 ± 3.1	261 ± 2.4	0.43
First lactation
CFV	126 ± 3.9	125 ± 4.0	132 ± 3.5	0.33
IOFC	1,034 ± 26	1,057 ± 31	1,083 ± 25	0.48
RPLC	99.1 ± 21.5	76.0 ± 18.9	67.2 ± 17.3	0.50
FXC	349 ± 7.7	354 ± 9.1	365 ± 7.0	0.43
CF 15 mo	−23.3 ± 36.4	3.1 ± 38.0	61.6 ± 32.6	0.25

¹HR TAI vs PG+TAI 1.13 (0.96–1.32).