Two estrus-synchronization programs were compared and factors influencing their success over a year were evaluated. All cows received a setup injection of PGF2alpha at 39 +/- 3 d postpartum. Fourteen days later they received GnRH, followed in 7 d by a second injection of PGF2alpha. Cows (n = 523) assigned to treatment 1 (modified targeted breeding) were inseminated based on visual signs of estrus at 24, 48, or 72 h after the second PGF2alpha injection. Any cow not observed in estrus was inseminated at 72 h. Cows (n = 440) assigned to treatment 2 received a second GnRH injection 48 h after the second PGF2alpha, and all were inseminated 24 h later. Treatment, season of calving, multiple birth, estrual status at insemination, number of occurrences of estrus before second PGF2alpha, prophylactic use of PGF2alpha, retained fetal membranes, and occurrence of estrus following the setup PGF2alpha influenced success. Conception rate was 31.2% (treatment 1) and 29.1% (treatment 2). A significant interaction occurred between protocol and estrual status at insemination. Cows in estrus at insemination had a 45.8% (treatment 1) or 35.4% (treatment 2) conception rate. The conception rate for cows not expressing estrus at insemination was 19.2% (treatment 1) and 27.7% (treatment 2). Provided good estrous detection exists, modified targeted breeding can be as successful as other timed artificial insemination programs. Nutritional, environmental, and management strategies to reduce postpartum disorders and to minimize the duration of postpartum anestrus are critical if synchronization schemes are used to program first insemination after the voluntary waiting period.

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Record-keeping systems have provided an essential link that significantly increases milk production. As new technologies are introduced, they are integrated into total management programs that provide for proactive management. Maintenance of data flow, not only for the producer but also for other users, requires increased cooperation among the various sectors. Larger production units demand products that integrate production and economic parameters to plan strategically for maximum profitability.

The dissemination of information by extension agents on dairy management prac tices used to control mastitis and the recep tion and use of that information by producers are investigated. Producers are surveyed to determine current practices used. The rela tionship between milk yield, somatic cell count, management practices, and producer and production characteristics is estimated. Subjective probabilities are elicited from "ex perts," extension agents, and producers con cerning the impact and cost of various management practices. Subjective marginal value products and marginal input costs are computed and compared for the respondent groups. Stochastic dominance is used to rank the relative importance of the practices as perceived by the respondents.

Yearly production and reproduction data on dairy farms in The Netherlands were obtained to determine whether management information systems significantly improved herd performance variables (management information systems (MIS) effects). The analysis included 357 adopters of a management information system and 357 herds were used as controls. The data comprised years 1987 through 1996, and included for the adopters both the 'before' and 'after' period. Panel data analysis enabled to estimate MIS effects both within and between farms, allowing for a separation of farm-specific effects and common (trend) effects. Adoption and use of a management information system resulted in a significant annual increase in rolling herd average milk (carrier) and protein production of 62 and 2.36 kg per cow, respectively. Calving interval was shortened by 5 days. The pay-back period was approximately 5 years of the system (including the hardware), and therefore, MIS appears to be economically profitable.