Publications by authors named "M A Portaluppi"

An ethanol extract prepared from the gametophyte Chilean native moss Sphagnum magellanicum was dried out, weighed and dissolved in distilled water. This extract was then assayed for its antibacterial activity against the G(-) bacteria Azotobacter vinelandii, Erwinia carotovora subsp. carotovora, Enterobacter aerogenes, Escherichia coli, Pseudomonas aeruginosa, Salmonella typhi, Vibrio cholerae, and the G(+) bacteria Staphylococcus aureus subsp.

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Our objectives were to determine relationships among factors influencing responses to the first GnRH injection in a timed artificial insemination (TAI) protocol and subsequent fertility after altering timing of the second GnRH injection and AI relative to PGF(2alpha) injection. Replacement heifers (n = 86) and 613 lactating cows previously inseminated were diagnosed not pregnant to form 77 breeding clusters spanning 36 mo. At not-pregnant diagnosis (d 0), females received 100 mug of GnRH, and then 7 d later, they received 25 mg of PGF(2alpha).

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Our objective was to determine whether delaying the PGF2alpha injection by 24 or 48 h after the first GnRH injection in an Ovsynch protocol (from a standard 7 d) altered ovarian characteristics in lactating dairy cows. Beginning 9 d after removal of a progesterone-releasing controlled internal drug release (CIDR) insert and injection of PGF2alpha (d 6.4 of the estrous cycle), 36 Holsteins (average body weight = 707 +/- 12 kg and body condition score = 2.

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We hypothesized that increasing concentrations of progesterone (P4) after artificial insemination would increase fertility. Our objective was to assess changes in ovarian structures, incidence of ovulation, and change in serum P4 in response to GnRH, human chorionic gonadotropin (hCG), or exogenous P4 (controlled internal drug release; CIDR insert) treatment beginning 4 to 9 d after artificial insemination (d 0) and again 7 d later (experiment 1). Blood was collected from 753 cows in 3 herds on d 0 and 7.

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Our objectives were to determine pregnancy rates after altering times of the second GnRH injection, insemination, or both in a combined Presynch + Ovsynch protocol, to accommodate once-daily lockup of dairy cows. Lactating dairy cows (n = 665) from 2 dairy herds in northeastern Kansas were studied. Cows ranged from 24 to 44 d in milk (DIM) at the start of the Pre-synch protocol, which consisted of 2 injections of PGF(2alpha) 14 d apart, with the second injection given 12 d before initiating the Ovsynch protocol.

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