Effects of prepartum diets supplemented with rolled oilseeds on calf birth weight, postpartum health, feed intake, milk yield, and reproductive performance of dairy cows

AbstractThe objectives were to determine the effects of supplemental fat (no oilseed vs. oilseed) during late gestation and the source of fat (canola vs. sunflower seed), on dry matter intake (DMI), plasma metabolite concentrations, milk production and composition, calf birth weight, postpartum health disorders, ovarian function and reproductive performance in dairy cows. Pregnant Holstein cows, blocked by body condition and parity, were assigned to 1 of 3 diets containing rolled canola seed (high in oleic acid; n=43) or sunflower (high in linoleic acid; n=45) at 8% of dry matter, or no oilseed (control; n=43), for the last 35±2 d of pregnancy. After calving, all cows received a common lactation diet. Blood samples were collected at wk −3 (i.e., 2 wk after initiation of prepartum diets) and at wk +1, +2, +3, +4 and +5 postpartum to determine the concentration of fatty acids (mEq/dL), β-hydroxybutyrate (mg/dL), and glucose (mg/dL). Ovarian ultrasonography was performed twice weekly to determine the first appearance of dominant (10mm) and preovulatory-size (≥16mm) follicles, and ovulation. Uterine inflammatory status based on the proportion of polymorphonuclear leukocytes (PMN; subclinical endometritis: >8% PMN) was assessed at d 25±1 postpartum. Significant parity by treatment interactions were observed for DMI and milk yield. Prepartum oilseed supplementation, more specifically sunflower seed supplementation, increased postpartum DMI in primiparous cows without affecting prepartum DMI or milk yield. Contrarily, in multiparous cows, prepartum oilseed supplementation decreased both prepartum and postpartum DMI and milk yield during the first 2 wk. Regardless of parity, prepartum feeding of canola reduced postpartum DMI compared with those fed sunflower. Mean fatty acids concentrations at wk −3 were greater in cows given supplemental oilseed than those fed no oilseeds. Gestation length and calf birth weight were increased in cows given supplemental oilseed prepartum compared with cows fed no oilseeds, and a disproportionate increase in the birth weight of female calves was evident in cows fed oilseed. Total reproductive disorders tended to be greater in cows fed supplemental oilseed than those fed no oilseed (42 vs. 23%). Furthermore, cows fed sunflower seed had greater incidences of dystocia (35 vs. 18%) and total health disorders (52 vs. 32%) than those fed canola seed. Added oilseed and type of oilseed did not affect uterine inflammation at 25±1 d postpartum. Oilseed supplementation did not alter the intervals from calving to establishment of the first dominant follicle, preovulatory-size follicle, and ovulation, nor did it affect fertility (conception rate to first artificial insemination and proportion of pregnant cows by 150 d after calving). In summary, prepartum oilseed supplementation (6.2 to 7.4% ether extract, % of dietary dry matter) decreased DMI during the entire experimental period (pre- and postpartum), decreased milk yield during early lactation in multiparous cows, and increased calf birth weight with no significant improvement in ovarian function and reproductive performance

Well-posedness of Hydrodynamics on the Moving Elastic Surface

The dynamics of a membrane is a coupled system comprising a moving elastic surface and an incompressible membrane fluid. We will consider a reduced elastic surface model, which involves the evolution equations of the moving surface, the dynamic equations of the two-dimensional fluid, and the incompressible equation, all of which operate within a curved geometry. In this paper, we prove the local existence and uniqueness of the solution to the reduced elastic surface model by reformulating the model into a new system in the isothermal coordinates. One major difficulty is that of constructing an appropriate iterative scheme such that the limit system is consistent with the original system.Comment: The introduction is rewritte

Characterization of the variability and repeatability of gonadotropin-releasing hormone–induced luteinizing hormone responses in dairy cows within a synchronized ovulation protocol

peer-reviewedThe primary objective was to determine the variability and repeatability of GnRH-induced LH responses. The secondary objective was to evaluate the associations among plasma LH, FSH, estradiol (E2), and progesterone (P4) concentrations. One hundred lactating Holstein cows (35 primiparous, 65 multiparous) were initially subjected to a presynchronization protocol (d 0, PGF2α; d 3, GnRH) followed 7 d later by Ovsynch (d 10, GnRH; d 17, PGF2α; 56 h later, GnRH) and timed artificial insemination 16 h after the last GnRH. Blood samples were collected immediately before the GnRH injection of presynchronization and the second GnRH of Ovsynch to determine plasma concentrations of LH, FSH, and P4. A second blood sample was collected 2 h after each of the above GnRH injections to determine GnRH-induced LH and FSH concentrations. Plasma concentrations of E2 were also determined in samples collected immediately before the second GnRH of Ovsynch. Cows that (1) had higher LH concentrations at 0 h than at 2 h after GnRH, (2) showed an ongoing spontaneous LH surge, (3) did not respond to GnRH, and (4) had P4 ≥ 0.5 ng/mL at GnRH of presynchronization and the second GnRH of Ovsynch were excluded from the analysis. The variability (coefficient of variation) and repeatability [between animal variance/(within animal variance + between animal variance)] of GnRH-induced LH response were determined from samples collected 2 h after the GnRH of presynchronization and the second GnRH of Ovsynch. The associations among plasma LH, FSH, E2, and P4 were determined at the second GnRH of Ovsynch. Mean (±SEM) LH concentrations before GnRH were 0.5 ± 0.04 and 0.6 ± 0.03 ng/mL, whereas mean LH concentrations 2 h after GnRH were 9.8 ± 1.0 and 12.1 ± 0.8 ng/mL at GnRH of presynchronization and the second GnRH of Ovsynch, respectively. The variability of GnRH-induced LH was 76.1 and 52.1% at GnRH of presynchronization and the second GnRH of Ovsynch, respectively. The repeatability estimate for GnRH-induced LH concentration between GnRH of presynchronization and Ovsynch assessments was 0.10. Plasma concentrations of LH were positively associated with FSH and E2 (r = 0.61 and 0.30, respectively) and negatively associated with P4 (r = −0.46) at the second GnRH of Ovsynch. In summary, GnRH-induced LH responses were highly variable and unrepeatable, and LH concentrations were positively associated with FSH and E2 and negatively associated with P4

Measurement of the ttbar Production Cross Section in ppbar collisions at sqrt s = 1.96 TeV in the All Hadronic Decay Mode

We report a measurement of the ttbar production cross section using the CDF-II detector at the Fermilab Tevatron. The analysis is performed using 311 pb-1 of ppbar collisions at sqrt(s)=1.96 TeV. The data consist of events selected with six or more hadronic jets with additional kinematic requirements. At least one of these jets must be identified as a b-quark jet by the reconstruction of a secondary vertex. The cross section is measured to be sigma(tbart)=7.5+-2.1(stat.)+3.3-2.2(syst.)+0.5-0.4(lumi.) pb, which is consistent with the standard model prediction.Comment: By CDF collaboratio

Measurement of the W+W- Production Cross Section in ppbar Collisions at sqrt(s)=1.96 TeV using Dilepton Events

We present a measurement of the W+W- production cross section using 184/pb of ppbar collisions at a center-of-mass energy of 1.96 TeV collected with the Collider Detector at Fermilab. Using the dilepton decay channel W+W- -> l+l-vvbar, where the charged leptons can be either electrons or muons, we find 17 candidate events compared to an expected background of 5.0+2.2-0.8 events. The resulting W+W- production cross section measurement of sigma(ppbar -> W+W-) = 14.6 +5.8 -5.1 (stat) +1.8 -3.0 (syst) +-0.9 (lum) pb agrees well with the Standard Model expectation.Comment: 8 pages, 2 figures, 2 tables. To be submitted to Physical Review Letter