Delaying induction of ovulation and timed artificial insemination in a Double-Ovsynch protocol increased expression of estrus and altered first-service reproductive outcomes of lactating dairy cows.

The objective of this randomized controlled experiment was to evaluate the effect of delaying induction of ovulation and timed artificial insemination (TAI) on expression of estrus before AI and first-service reproductive outcomes. A secondary objective was to evaluate the effects of delaying induction of ovulation in a Double-Ovsynch protocol on ovarian function. Lactating Holstein cows (n = 4,672) from 2 commercial dairy farms fitted with sensors for automated detection of estrus were synchronized with a Double-Ovsynch protocol up to the first PGF (PGF-L) of the Breeding-Ovsynch portion of the protocol (Pre-Ovsynch: GnRH, 7 d later PGF, 3 d later GnRH, 7 d later Breeding-Ovsynch: GnRH, 7 d later PGF, 1 d later PGF).

Effect of automated health monitoring based on rumination, activity, and milk yield alerts versus visual observation on herd health monitoring and performance outcomes.

A primary objective of this randomized trial was to compare the percentage of cows that underwent clinical examination and were diagnosed with clinical health disorders (CHD) using a health monitoring program that relied only on automated monitoring system alerts versus a program that relied only on visual observation of clinical signs of disease to select cows for clinical examination. Another objective was to compare the effects of these health monitoring programs on milk yield, the herd exit dynamics (i.e.

Effect of feeding a Saccharomyces cerevisiae fermentation product to Holstein cows exposed to high temperature and humidity conditions on milk production performance and efficiency-A pen-level trial.

The objective of this study was to evaluate the effect of feeding a Saccharomyces cerevisiae fermentation product (SCFP) on milk production efficiency of Holstein cows naturally exposed to high temperature and humidity conditions. The study was conducted in 2 commercial farms in Mexico from July to October 2020 and included 1 wk covariate period, 3 wk adaptation, and 12 wk data collection. Cows [n = 1,843; ≥21 d in milk (DIM) and <100 d carried calf] were enrolled and assigned to the study pens (n = 10) balanced for parity, milk yield, and DIM.

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.