Effect of increasing proportion of supplemental N from urea in prepartum supplements on range beef cow performance and on forage intake and digestibility by steers fed low-quality forage

Four experiments were conducted to evaluate the influence of changing the proportion of supplemental degradable intake protein (DIP) from urea on forage intake, digestion, and performance by beef cattle consuming either low-quality, tallgrass prairie forage (Exp. 1, 2, and 4) or forage sorghum hay (Exp. 3). Experiments 1, 2, and 3 were intended to have four levels of supplemental DIP from urea: 0, 20, 40, and 60%. However, refusal to consume the 60% supplement by cows grazing tallgrass prairie resulted in elimination of this treatment from Exp. 1 and 2. Levels of supplemental DIP from urea in Exp. 4 were 0, 15, 30, and 45%. Supplements contained approximately 30% CP, provided sufficient DIP to maximize digestible OM intake (DOMI) of low-quality forage diets, and were fed to cows during the prepartum period. In Exp. 1, 12 Angus x Hereford steers (average initial BW = 379) were assigned to the 0, 20, and 40% treatments. Forage OM intake, DOMI, OM, and NDF digestion were not affected by urea level. In Exp. 2, 90 pregnant, Angus x Hereford cows (average initial BW = 504 kg and body condition [BC] = 5.0) were assigned to the 0, 20, and 40% treatments. Treatment had little effect on cow BW and BC changes and calf birth weight, ADG, or weaning weight. However, pregnancy rate tended to be lowest (P = 0.13) for the greatest level of urea. In Exp. 3, 120 pregnant, crossbred beef cows (average initial BW = 498 kg and BC = 4.6) were assigned to the 0, 20, 40, and 60% treatments. Prepartum BC change tended (P = 0.08) to be quadratic (least increase for 60% treatment), although BW change was not statistically significant. Treatment effect on calf birth weight was inconsistent (cubic; P = 0.03), but calf ADG and weaning weight were not affected by treatment. Pregnancy rate was not affected by prepartum treatment. In Exp. 4, 132 pregnant, Angus x Hereford cows (average initial BW = 533 and BC = 5.3) were assigned to the 0, 15, 30, and 45% treatments. Prepartum BC loss was greatest (quadratic; P = 0.04) for the high-urea (45%) treatment, although BW loss during this period declined linearly (P < 0.01). Prepartum treatment did not affect pregnancy rate, calf birth weight, or ADG. In conclusion, when sufficient DIP was offered to prepartum cows to maximize low-quality forage DOMI, urea could replace between 20 and 40% of the DIP in a high-protein (30%) supplement without significantly altering supplement palatability or cow and calf performance.     

Apparent ELISA detection times for albuterol after administration with the torpex equine inhaler device

Single doses of one, three, and six actuations (120 micro g albuterol/actuation) and multiple daily doses (six actuations per dose four times daily) for 5 days of aerosol albuterol sulfate were sequentially administered to each of six horses using an equine inhaler device (Torpex, 3M Animal Care Products, St. Paul, MN [corrected] and Boehringer Ingleheim Vetmedica, Inc., St. Joseph, MO [corrected]). A 2-week washout period was allowed between each dose. ELISA testing revealed no evidence of albuterol in urine at 24 hours after any single-dose administration. Results indicated that 48 hours or longer should be allowed for albuterol to be cleared from urine after single doses. When given at the maximum recommended rate of six actuations per dose four times a day for 5 days, urine samples tested by ELISA showed no evidence of albuterol at 48 hours after the final dose. Testing of nasal swabs by ELISA demonstrated the presence of albuterol for 8 hours after each single dose, and some horses might have detectable levels of albuterol in nasal swabs for several days following administration of multiple doses. As a guideline for withdrawal time, 72 hours or longer should be allowed after administration of aerosol albuterol sulfate to horses before participation in equestrian competitions that are regulated for detection of certain performance-enhancing substances. However, these recommendations were based on a small sample of horses and the specific ELISA test used and interpreted as described. Factors specific to individual horses may influence these detection times.     

Sum rules and interlayer conductivity of high-Tc cuprates

Analysis of the interlayer infrared conductivity of cuprate high-transition temperature superconductors reveals an anomalously large energy scale extending up to midinfrared frequencies that can be attributed to formation of the superconducting condensate. This unusual effect is observed in a va- riety of materials, including Tl2Ba2CuO6+x, La2-xSrxCuO4, and YBa2Cu3O6.6, which show an incoherent interlayer response in the normal state. Midinfrared range condensation was examined in the context of sum rules that can be formulated for the complex conductivity. One possible interpretation of these experiments is in terms of a kinetic energy change associated with the superconducting transition.     

Extreme diversity, conservation, and convergence of spider silk fibroin sequences

Spiders (Araneae) spin high-performance silks from liquid fibroin proteins. Fibroin sequences from basal spider lineages reveal mosaics of amino acid motifs that differ radically from previously described spider silk sequences. The silk fibers of Araneae are constructed from many protein designs. Yet, the repetitive sequences of fibroins from orb-weaving spiders have been maintained, presumably by stabilizing selection, over 125 million years of evolutionary history. The retention of these conserved motifs since the Mesozoic and their convergent evolution in other structural superproteins imply that these sequences are central to understanding the exceptional mechanical properties of orb weaver silks.     

Liveweight estimation of cattle by scale and by tape,a method comparison study

Summary The repeatability of weight estimation of cattle by scale and by tape and the agreement of weight estimates obtained by the 2 methods were evaluated. The within-subject standard deviation of replicates was used as a measure of repeatability while the agreement of the 2 methods was evaluated by analysis of the differences in weight estimates. In young cattle, the measurement error of the tape was about twice that of the scale while in adult cattle it was more than 4 times as great. Although weight estimates by the 2 methods were highly correlated, considerable differences occurred in individual cattle. The same was true for estimates of weight gain. It does not appear advisable to use the tape in trials where weight is an independent variable whereas the use of the tape can be justified in experiments where weight is the dependent variable.

---

Resumen Se evaluó la repetibilidad y concordancia de la estimación del peso vivo de bovinos, mediante balanza y cinta. La desviación estándar, entre sujetos de las réplicas, se utilizó como una medida de repetibilidad, mientras que la concordancia de los dos métodos se evaluó mediante el análisis de la diferencia en las estimaciones de peso. En ganado joven, la media de error de la cinta fue cerca del doble que aquella de la balanza, mientras que en ganado adulto ésta fue más de cuatro veces mayor. Aunque los estimaciones de peso mediante ambos métodos tuvieron una correlación positiva, se encontraron diferencias individuales considerables. Lo mismo ocurrió para los estimaciones de ganancia de peso. No parece entonces recomendable utilizar la cinta, para pesar en ensayos donde el peso es una variable independiente, mientras que ésta se puede usar cuando el peso es la variable dependiente.

---

Résumé L'étude porte sur une comparaison des poids des bovins obtenus soit par pesée directe soit par barymétrie. La répétabilité des diverses mesures est évaluée. La variabilité residuelle de ces différentes mesures prises sur le même sujet et á des moments proches est une bonne estimation de cette répétabilité. La concordance des deux méthodes est évaluée par l'analyse des poids estimés. Chez les jeunes bovins, par barymétrie, l'erreur de mesure est environ deux fois supérieure à celle faite par pesée. Elle passe à 4 fois chez les adultes. Les estimations du poids par ces deux méthodes sont fortement corrélées, avec des variations individuelles très importantes. Les mêmes remarques peuvent être faites sur l'estimation des gains de poids. Il appara?t qu'il n'est pas envisageable de se servir, dans des expérimentations, des mesures barymétriques lorsque le poids est pris comme une variable indépendante alors que cela peut l'être lorsque le poids est pris en tant que variable dépendante.

     

The relationship between vaginal electrical impedence and hormone profiles during pregnancy and parturition of a white rhinoceros (Ceratotherium simum simum).

In this study, an attempt was made to use vaginal electrical impedance to predict calving in a female white rhinoceros (Ceratotherium simum simum) and to determine the relationship between vaginal electrical impedance and hormonal profiles during pregnancy. The principle behind vaginal electrical impedance is that a change in the ionic balance of vaginal and cervical mucus occurs in response to changes in reproductive hormones. Three times weekly vaginal electrical impedance readings and fecal samples were collected from midgestation to calving (a 6-mo period). The extracted fecal samples were analyzed for immunoreactive estrogens, progestagens, and corticoids by RIA. Vaginal electrical impedance readings did not decrease before calving but remained consistent throughout the last 140 days of pregnancy. Fecal progestagens in the white rhinoceros decreased between day 17 and day 1 before calving, whereas estrogens increased between 4 and 2 mo before calving, with an additional increase occurring 1 mo before calving. Fecal corticoids increased 5 mo before calving, slowly declined, and increased again within 3 wk before calving. A decline in vaginal electrical impedance was noted 168 days before calving and remained at low levels for 4 wk. At the time of this decrease, the female became aggressive toward the male and began lactating. Fecal progestagens and estrogens did not change during this time; however, fecal corticoids increased as vaginal electrical impedance readings returned to normal along with her behavior and cessation of lactation. In summary, the use of vaginal electrical impedance could not predict parturition in the white rhinoceros. However, an anomaly occurred during pregnancy that was supported by vaginal electrical impedance readings, a change in female behavior, premature lactation, and a subsequent increase in fecal corticoids. The etiology of this physiological anomaly is unknown, yet it did not compromise pregnancy.     

Inflammatory arthritis in canids: spondyloarthropathy.

Spondyloarthropathy was observed in 25 (2.8%) of 895 preserved canid museum specimens and was catalogued by species. The associated skeletal alterations in canids are indistinguishable grossly and physiologically from those in humans with spondyloarthropathy of the reactive type. Rate of affliction was independent of captive or wild-caught status or gender. In canids, spondyloarthropathy was much more common than osteoarthritis (0.3%), which predominantly is limited to captive animals. Animal well-being may be enhanced by recognition of the condition and initiation of specific treatment.     

Use of a Compounded Long-Acting Progesterone Formulation for Equine Pregnancy Maintenance

The objective of this study was to test the efficacy of a compounded long-acting progesterone formulation (BioRelease P4 LA 150; BETPHARM, Lexington, KY) containing 150 mg progesterone/ml for pregnancy maintenance in mares after prostaglandin (PG) F_2α-induced luteolysis. On day 18 of gestation, mares were randomly assigned to one of four groups (n = 7/group): (1) saline-treated control (Saline); (2) PGF_2α-treated control (PGF); (3) PGF_2α- and Regu-Mate-treated (Regu-Mate); and (4) PGF_2α- and BioRelease P4 LA 150-treated (BioRelease). On day 18, Saline mares received 1 ml sterile saline IM, whereas PGF, Regu-Mate, and BioRelease mares received 250 μg cloprostenol IM. Beginning on day 18, Regu-Mate mares received 10 ml Regu-Mate orally once daily and BioRelease mares received 10 ml BioRelease P4 LA 150 containing 150 mg/ml progesterone IM once every 7 days; treatments were continued until day 45 or until pregnancy loss occurred. Pregnancy diagnosis was performed every 3 days between days 18 and 45 (or until pregnancy loss). Pregnancy loss was defined as complete absence of a discernible embryonic vesicle as determined with transrectal ultrasonography. Pregnancy loss rates between days 18 and 45 were: Saline, 1/7; PGF, 7/7; Regu-Mate, 1/7; and BioRelease, 0/7. The pregnancy loss rate was higher (P < .01) in PGF_2α-treated control mares compared with the other groups. There were no differences (P > .1) in pregnancy loss rates among the saline-treated control, Regu-Mate-treated, and BioRelease P4 LA 150-treated mares. These results indicate that intramuscular administration of BioRelease P4 LA 150 containing a total of 1.5 g progesterone every 7 days provided a sufficient level of progesterone to maintain pregnancy between days 18 and 45 of gestation in mares that lacked an endogenous source of progesterone; therefore, this long-acting formulation of progesterone appears to be an efficacious and suitable alternative to currently available progesterone formulations that require daily administration.     

Studies of enteric coronaviruses in a feline cell line

Development is reported of a feline cell line which can support the growth of coronaviruses from canine (CCV), feline (FIPV) and porcine (TGEV) species. The cell culture has been serially transferred over 100 times and has retained its initial growth requirements, proliferative capacity and morphologic features. Each virus had specific growth characteristics in this cell culture although all produced a similar CPE and plaques under agar. Cross neutralization studies demonstrated a two-way relationship between TGEV and CCV and between TGEV and FIPV, whereas a one-way relationship was demonstrated between CCV and FIPV.     

Active and Passive Immunity to Bovine Viral Respiratory Diseases in Beef Calves After Shipment

Fifteen steers were vaccinated after shipment with a modified live virus vaccine containing infectious bovine rhinotracheitis (IBR), bovine virus diarrhea (BVD), and bovine myxovirus parainfluenza-3 (PI3), and 16 unvaccinated steers were kept as controls. Geometric mean titers one month after vaccination were highest to BVD, followed by PI3 and IBR. Weight gains were higher during 30 days after vaccination in the controls. One case of acute respiratory disease developed in one vaccinated calf. Revaccination 79 days after the first dose increased antibody to PI3 and BVD virus but not IBR. In a second trial, no clinical respiratory disease developed after shipment of 13 heifers that received an antibacterial-antiviral antiserum or in the 12 controls. Weight gains 30 days after shipment were identical in both groups.