Dairy heifers have an earlier increase in serum pregnancy-specific protein B compared with lactating dairy cows. Is this an indicator of earlier conceptus attachment?

This study was designed to use within-individual daily increases in circulating pregnancy-specific protein B (PSPB) to determine time to increase in serum PSPB in nulliparous heifers and multiparous dairy cows following artificial insemination (AI). Weekly cohorts of lactating Holstein cows (n = 56) averaging 122 ± 7 d in milk at AI and nulliparous Holstein heifers (n = 23) averaging 16 ± 0.24 mo old at AI were used in this study. Lactating cows received AI to either Ovsynch (n = 38) or at ~12 h following observed standing estrus (n = 18). All heifers were inseminated ~12 h after observed standing estrus. Blood samples for measurement of PSPB were collected daily from d 15 through d 35 postovulation. Nulliparous heifers had increases in serum PSPB earlier compared with both primiparous and multiparous cows. Day of increase in serum PSPB was defined as the day serum PSPB optical density levels initially increased ≥10% from baseline and continued to increase from baseline of ≥10% the following 2 d. Average PSPB were greater in pregnant heifers compared pregnant cows from d 23 through 29. Early lactation nonpregnant cows maintained greater average optical density of serum PSPB from 15 to 35 d postovulation compared with nonpregnant heifers (n = 38). In summary, fertility differences in heifers versus lactating cows may be due to the differences in timing of increases in serum PSPB. This appears to be one of the first publications that used daily PSPB sampling to investigate possible differences in fertility in heifers versus lactating cows.

The effect of a double dose of cloprostenol sodium on luteal blood flow and pregnancy rates per artificial insemination in lactating dairy cows.

Inadequate luteolysis in fertility programs is a problem for lactating dairy cows treated with a single dose of PGF2α. The proportion of cows with complete luteolysis can be increased by administering 2 doses of PGF2α 24 h apart. This study hypothesized that a double dose of cloprostenol sodium (1.0 mg) could take the place of 2 doses 24 h apart due to its enhanced half-life. Cows were allocated to receive 1 of 3 treatments: negative controls: 0.5 mg of cloprostenol sodium (single; n = 337); positive controls: two 0.5-mg doses of cloprostenol sodium 24 h apart (two/24; n = 313); and treated: 1.0 mg of cloprostenol sodium (double; n = 298) at the final PGF2α of Double-Ovsynch. Cows received artificial insemination (AI) 16 h after final GnRH of Double-Ovsynch. Pregnancy diagnosis was determined at 24, 34, 62, and 184 d post-AI. Pregnancy loss was categorized in the following periods: between 24 to 34, 34 to 62, and 62 to 184 d post-AI. Ultrasonography (B-mode and color Doppler) was used to assess luteal function pre- and posttreatment with various doses of cloprostenol sodium. Luteal volume and luteal blood flow (LBF) from d 7 and 14 corpora lutea were determined before treatment (d -1), and 2 and 4 d after treatment. No evidence was observed of an effect of treatment on pregnancy rates per AI at 24, 34, or 62 d post-AI. No effect was observed of treatment on pregnancy losses occurring between d 24 and 34, 34, and 62, and between 62 and 184 d post-AI. However, third-plus parity cows treated with the single treatment had greater pregnancy loss compared with two/24 and double between d 24 and 34 post-AI. Third-plus parity cows that received the double treatment had lower LBF 2 and 4 d after treatment compared with cows treated with single. Amount of LBF present 4 d after treatment was not a predictor of pregnancy or pregnancy loss. A double dose (1.0 mg) of cloprostenol sodium may be a feasible alternative for fertility programs based on nondifferent outcomes to the two/24 treatment, lower pregnancy losses, and reduced LBF disappearance following treatment in third-plus parity cows in comparison with the single treatment.

Short communication: Blood samples before and after embryonic attachment accurately determine non-pregnant lactating dairy cows at 24 d post-artificial insemination using a commercially available assay for pregnancy-specific protein B.

Early pregnancy diagnosis is critical to reproductive success on dairy farms. Reproductive success depends on cows becoming pregnant before 130 d in milk and then maintaining that pregnancy. The earlier non-pregnant cows are identified, the sooner they can be reinseminated, thus reducing days to pregnancy. Assays for pregnancy-specific protein B (PSPB) and pregnancy-associated glycoproteins can be used to diagnose pregnancy >28 d post-artificial insemination (AI) in lactating cows. The objective of this study was to determine whether percentage change in serum levels of PSPB within cow from d 17 to 24 can be used to identify non-pregnant cows using a commercially available assay. This study was performed on a large commercial dairy. Blood samples were taken at d 17 and 24 post-AI. The d 17 sample served as a baseline based on previous data. Cows with a 10% increase in serum PSPB levels from d 17 to 24 were considered pregnant. Lactating dairy cows (n = 206; 39% primiparous and 61% multiparous) were synchronized using G6G-Ovsynch. The PSPB diagnosis was compared with the herd veterinarian's diagnosis via ultrasound on d 34. The sensitivity for a 10% cutoff as a non-pregnant diagnosis was 100%, and the specificity was 93.58%. The positive predictive value was 93.27%, and the negative predictive value was 100%. Low PSPB levels at d 24 were predictive of early pregnancy loss by 60 d post-AI. To our knowledge no other method can diagnose non-pregnancy with 100% accuracy and predict pregnancy loss earlier than 24 d post-AI. Using comparative PSPB samples at d 17 and 24 post-AI provides an accurate non-pregnancy diagnosis earlier than any other pregnancy diagnosing method.

The high-fertility cycle: How timely pregnancies in one lactation may lead to less body condition loss, fewer health issues, greater fertility, and reduced early pregnancy losses in the next lactation.

Body condition loss during early lactation varies among cows in the herd and is associated with future health and reproductive outcomes. The objective of this study was to gain a greater understanding of the relationship between previous calving interval and body condition change during the first 30 d in milk (DIM) and their relationship to subsequent fertility and health variables and sex ratio at birth. Dry cows and heifers (n = 851) from a single farm entered the study approximately 25 d before the due date. They were evaluated and given a body condition score on a 1-to-5 scale with 0.1-point increments weekly until parturition. Body condition score was assessed within 1 wk of parturition and then again 27 to 33 DIM. Previous calving interval, gestation length, periparturient health events (giving birth to twins, dystocia, retained placentas, ketosis, metritis, and displaced abomasum), sire net merit ($), and milk data were used for each cow as recorded in PCDART (Dairy Records Management Systems, Raleigh, NC) by the herd managers. Longer previous calving intervals were related to greater body condition at parturition and body condition loss during the first 30 DIM. A 75% greater proportion of cows with a calving-to-pregnancy interval shorter than 130 d maintained or gained body condition during the first 30 DIM compared with cows with calving-to-pregnancy intervals longer than 130 d. Multiparous cows that maintained or gained body condition (n = 144) had greater pregnancies per AI following first service compared with cows that lost body condition (n = 577) during the first 30 DIM when health events were considered or removed. When cows with health events were considered, multiparous cows that maintained or gained body condition had a greater percentage pregnant by 130 DIM compared with cows that lost body condition (67 vs. 55%; n = 522). Cows that lost body condition during the first 30 DIM regardless of health events experienced greater pregnancy loss (n = 224) between 35 and 60 d after first AI (0.0 vs. 6.7%) compared with cows that maintained or gained body condition (n = 69) during that period. Based on data in this study from a single herd, maintaining a cycle of pregnancy before 130 DIM may reduce the amount of body condition lost after the next parturition, enhance subsequent pregnancies per AI, and reduce the possibility of early pregnancy loss. We refer to this phenomenon as the high-fertility cycle.

Primary care in the emergency room: a collaborative model.

Emergency rooms have become primary care centers for a large portion of the population. Unfortunately, most are neither designed nor appropriately staffed to deliver first-line, continuous, comprehensive, family-oriented, and self-actualizing care. This paper describes a nurse-managed collaborative primary care practice model that has been functioning for 8 years in an inner city emergency department.