Effect of a targeted reproductive management program based on automated detection of estrus during the voluntary waiting period on reproductive performance of lactating dairy cows.

The objective of this experiment was to evaluate the effect on reproductive performance of a targeted reproductive management (TRM) program for first postpartum insemination (AI) that prioritized AI at detected estrus (AIE) by providing different intervals for estrus detection based on records of automated estrus alerts (AEA) during the voluntary waiting period (VWP). A secondary objective was to evaluate the association between occurrence of AEA during the VWP and reproductive performance. Lactating Holstein cows (n = 1,260) fitted with neck behavior monitoring sensors for detection of estrus were randomly assigned to a program that used all-timed AI (TAI) for first service (ALL-TAI; n = 632) or a TRM program that prioritized AIE and used TAI only for cows not detected in estrus (TP-AIE; n = 628).

Design of a handheld and portable fluorescence imaging system for quantitative detection of pregnancy-specific biomarkers in cattle.

Reproductive management significantly impacts dairy farm productivity, necessitating accurate timely pregnancy detection in cattle. This paper presents a novel handheld and portable fluorescence imaging system designed for quantitative assessment of pregnancy-specific biomarkers, addressing the limitations of current detection methods. The objective was to develop a cost-effective, at-farm solution for detecting pregnancy-specific protein B (PSPB) in bovine plasma samples.

Reproduction in the era of genomics and automation.

Much progress has been made in the reproductive efficiency of lactating dairy cows across the USA in the past 20years. The standardisation of evaluation of reproductive efficiency, particularly with greater focus on metrics with lesser momentum and less lag-time such as 21-day pregnancy rates (21-day PR), and the recognition that subpar reproductive efficiency negatively impacted profitability were major drivers for the changes that resulted in such progress. Once it became evident that the genetic selection of cattle for milk yield regardless of fertility traits was associated with reduced fertility, geneticists raced to identify fertility traits that could be incorporated in genetic selection programs with the hopes of improving fertility of lactating cows.

Effects of feeding rumen-protected methionine pre- and postpartum on reproductive outcomes of multiparous Holstein cows.

Our primary objective was to evaluate the effect of feeding rumen-protected Met (RPM) in the pre- and postpartum total mixed ration (TMR) on pregnancy per artificial insemination (AI) and pregnancy loss in multiparous Holstein cows. We also evaluated multiple secondary reproductive physiological outcomes before and after AI, including uterine health, ovarian cyclicity, response to synchronization of ovulation, and markers of embryo development and size. A total of 470 multiparous Holstein cows [235 at the University of Wisconsin (UW) and 235 at Cornell University (CU)] were used for this experiment.

Effects of feeding rumen-protected methionine pre- and postpartum in multiparous Holstein cows: Lactation performance and plasma amino acid concentrations.

Objectives were to evaluate the effect of feeding rumen-protected methionine (RPM) in pre- and postpartum total mix ration (TMR) on lactation performance and plasma AA concentrations in dairy cows. A total of 470 multiparous Holstein cows [235 cows at University of Wisconsin (UW) and 235 cows at Cornell University (CU)] were enrolled approximately 4 wk before parturition, housed in close-up dry cow and replicated lactation pens. Pens were randomly assigned to treatment diets (pre- and postpartum, respectively): UW control (CON) diet = 2.

Embryo Mortality Around the Period of Maintenance of the Corpus Luteum Causes Alterations to the Ovarian Function of Lactating Dairy Cows.

Objectives were to identify cows with embryo mortality (EM) around the period of corpus luteum maintenance by interferon tau (IFNT) and to characterize ovarian function in cows that underwent EM. Lactating Holstein cows received artificial insemination (AI) (Day = 0) with semen or extender only. From Day 14 to 42 transrectal ultrasonography was performed daily to monitor ovarian dynamics and uterine contents whereas blood was collected every 48 h to determine ISG15 and MX2 mRNA abundance in blood mononuclear cells (Day 14 to 22 only) and determination of hormone concentrations.

Methods for and Implementation of Pregnancy Diagnosis in Dairy Cows.

The first part of this article defines the attributes of the ideal pregnancy test and describes the direct and indirect methods for pregnancy diagnosis in dairy cows that are currently available that have the potential to replace transrectal palpation. Second, this new technology must be practically integrated into a systematic on-farm reproductive management strategy and empirically demonstrated to exceed the status quo of the industry in reproductive performance. Finally a future direction for research and technology in the area of early pregnancy diagnosis in dairy cows is presented, and the overall conclusions of the ideas presented herein are drawn.

Effect of increasing GnRH and PGF2α dose during Double-Ovsynch on ovulatory response, luteal regression, and fertility of lactating dairy cows.

Ovsynch-type synchronization of ovulation protocols have suboptimal synchronization rates due to reduced ovulation to the first GnRH treatment and inadequate luteolysis to the prostaglandin F2α (PGF2α) treatment before timed artificial insemination (TAI). Our objective was to determine whether increasing the dose of the first GnRH or the PGF2α treatment during the Breeding-Ovsynch portion of Double-Ovsynch could improve the rates of ovulation and luteolysis and therefore increase pregnancies per artificial insemination (P/AI). In experiment 1, cows were randomly assigned to a two-by-two factorial design to receive either a low (L) or high (H) doses of GnRH (Gonadorelin; 100 vs.