Presynchronization with a progesterone device and prostaglandin F2α enhances ovulatory response to first GnRH, estrus expression and tended to increase fertility in beef heifers submitted to a 5-day CO-Synch protocol.

The main objectives of the present study were to determine the effects of presynchronizing with a 1.0 g intravaginal progesterone device (IVPD) and prostaglandin F2α and to assess the effects of re-utilization of IVPD in a 2x2 factorial design, on the ovulatory response to first GnRH, ovarian status at different protocol stages, estrus expression and fertility in beef heifers submitted to a 5d-CO-Synch + Progesterone (P4) protocol. Beef heifers (n = 564) were assigned to 1 of 2 treatments at D-15: Pres5 (n = 283), where heifers received a (IVPD) for 5 days and administration of prostaglandin F2α (25 mg of dinoprost) at D-10; and Control (n = 281), where heifers received no treatment.

The association of circulating prepartum metabolites, minerals, cytokines and hormones with postpartum health status in dairy cattle.

The objectives were to evaluate differences in circulating prepartum metabolites, minerals, cytokines and hormones based on postpartum disease category and determine critical circulating concentrations of prepartum analytes associated with postpartum disease in 229 cattle from 11 commercial dairies in Alberta, Canada. Blood was collected at 8.8 ± 2.

Maternal nutrient restriction in early pregnancy increases the risk of late embryo loss despite no effects on peri-implantation interferon-stimulated genes in suckler beef cattle.

Reducing feeding costs in suckler beef herds to improve economic returns could have detrimental impacts on fertility. This study sought to determine whether maternal nutrient restriction during early pregnancy affects interferon-stimulated gene (ISG) expression in peripheral blood mononuclear cells during the peri-implantation period in two beef cattle breeds. Relationships were also examined between subnutrition and pregnancy failure defined according to ISG fold changes on Days 18 and 21 and to plasma pregnancy specific protein B (PSPB) concentrations on Day 28 post-artificial insemination (AI).

Effects of maternal subnutrition during early pregnancy on cow hematological profiles and offspring physiology and vitality in two beef breeds.

This experiment evaluated the effects of subnutrition during early gestation on hematology in cows (Bos Taurus) and on hematological, metabolic, endocrine, and vitality parameters in their calves. Parda de Montaña and Pirenaica dams were inseminated and assigned to either a control (CONTROL, 100% requirements) or a nutrient-restricted group (SUBNUT, 65%) during the first third of gestation. Dam blood samples were collected on days 20 and 253 of gestation, and calf samples were obtained during the first days of life.

Resynchronization with the G6G protocol: A retrospective, observational study of second and later timed artificial inseminations on commercial dairy farms.

We recorded conception rates and estimated pregnancy rates following second and later timed artificial inseminations (TAIs) after hormonal resynchronization on commercial dairy farms, using the so-called G6G protocol (PGF day-0; GnRH 2, 8 days; PGF 15, 16 days, GnRH 17 days; TAI 18 days), and the 5-day Ovsynch protocol or 5DO (GnRH day 0; PGF 5, 6 days; GnRH 7 days; TAI 8 days). In four farms, both protocols were implemented in parallel, and these 1,368 s and later TAIs were used for the protocols' comparison based on logistic regression (544 TAIs in primiparous; 824 in multiparous cows; 1,024 TAIs after G6G [600 TAIs in multiparous and 424 in primiparous]; 344 TAIs after 5DO [224 TAIs in multiparous and 120 in primiparous]; 280 TAIs during the hot season; 1,088 during the cool season). Conception rate (CR) was 31.