179 Cost and Profit Per Pregnancy Associated with Estrous Synchronization Utilizing Estrus Detection And/Or Fixed-Time Artificial Insemination

Abstract

Abstract This experiment aimed to compare synchronization cost associated with two protocols: one utilizing estrus detection (6d; PG 6-d CIDR+TAI) and one utilizing strictly fixed-time artificial insemination (FTAI; 7d; 7-d CO-Synch+CIDR). Cows and heifers (n = 657) from 10 herds in three states were grouped by days postpartum and age, and randomly assigned to one of two protocols. Cows and heifers assigned to the 6 d protocol were administered prostaglandin F2α (PGF) on d-9, CIDR insertion and administration of gonadotropin-releasing hormone (GnRH1) on d -6, and CIDR removal and PGF administration on d 0. Cows and heifers that were assigned to the 6-d protocol were subsequently grouped into three treatments based on presence and/or timing of estrus and insemination (PG1: Insemination before CIDR insertion, n = 136; PG2: Insemination after CIDR removal, n = 26; T6: Insemination at TAI, n = 166). Cows and heifers assigned to the 7-d protocol (T7: Insemination at FTAI, n = 329) were administered GnRH1 and CIDR insertion on d -7, followed by CIDR removal and PGF administration on d 0. For all animals, FTAI and GnRH2 administration occurred at 54 h (heifers) or 66 h (cows) after CIDR removal. Pregnancy was determined from d 30 to d 40 after FTAI by transrectal ultrasonography. Total cost and profit per pregnancy was calculated for herds of 30, 100, 300, and 500 females with varying estrus response and pregnancy rates. Expenditures were calculated assuming synchronization costs (PG1 = $46.15, PG2 = $75.05, T6 = $77.91, T7 = $73.72), general labor cost considering herd size and handling days, as well as estrus detection labor cost assuming $10.00 per h, a 95% overall herd pregnancy rate, a 1:40 bull:cow ratio, and average bull purchase price of $3,000.00. Revenue was estimated assuming a maximum 205-d weaning age, 1.09 kg/d gain, $200.00/45.4 kg, and 85% weaning rate. Differences in estrus response and pregnancy rate were determined using the GLIMMIX procedure of SAS (v9.4), including herd as a random variable. Estrus response was greater (P < 0.0001) in females assigned to the 6d (73 ± 4%) compared with the 7d (53 ± 4%) protocol; however, pregnancy success was similar among treatment groups (P = 0.32; PG1 = 45 ± 4%, PG2 = 58 ± 10%, T6 = 46±4%, T7 = 52±3%). At the observed estrus response and pregnancy rate for each treatment group, the 6d protocol resulted in a decreased cost per pregnancy compared with the 7d protocol [Table 1; herds of: 30 = ($3.53), 100 = ($5.16), 300 = ($6.58), 500 = ($7.00) females]. Additionally, using the same variables, the 6d protocol resulted in an increased profit per pregnancy compared with the 7d protocol (herds of: 30 = $3.50, 100 = $6.41, 300 = $17.27, 500 = $12.06 females). These results suggest that labor associated with estrus detection may be offset by the proportion of calves subsequently born earlier within the calving season, allowing for improvements to profitability, especially in larger herds.