Error Sources Affecting Variable Rate Application of Nitrogen Fertilizer

The accuracy and interaction among global positioning system (GPS) horizontal accuracy, differential GPS (DGPS) sampling frequencies and machine delay times of a hypothetical variable rate applicator for nitrogen (N) fertilizer application based on an application map in Florida citrus were studied. Parameters studied included: five GPS horizontal accuracy levels, two levels of DGPS horizontal accuracy, two DGPS sampling frequencies and two machine delay times. Two integrated models were developed which documented the effects of the parameters. Machine delay time was the most important factor and GPS horizontal accuracy was the second most important.     

Error Sources on Yield-Based Fertilizer Variable Rate Application Maps

Spatially-variable application of inputs to agricultural fields is dependent upon accuracy of the input variables. The effects of boundary determination, interpolation method, and GPS location errors were studied for determining a variable rate nitrogen application map based upon yield maps of a 3.6 ha Florida citrus block. A general linear model for the mean absolute error approximated the error effects.     

Effect of long-term tetracycline exposure (drinking water additive) on antibiotic-resistance of aerobic gram-negative intestinal flora of rats.

A study was undertaken to determine the effect of 2 years of intermittent administration of tetracycline in drinking water on antibiotic resistance in the aerobic gram-negative enterobacteria of rats in a closed colony. The bacterial isolates examined were resistant to tetracycline and streptomycin. Minimal inhibitory concentrations of tetracycline and streptomycin for intestinal organisms were similar in all of the animals, regardless of whether the animals were sampled while they were given drinking water with added tetracycline or at intervals of 3, 8, and 9 months after the antibiotic was no longer added to the drinking water. Biochemical examination of the isolates from each principal showed that Escherichia coli was the predominant enteric organism. In conjugation experiments, all E coli and Klebsiella pneumoniae isolated transferred tetracycline and streptomycin resistance to an E coli K-12 recipient. Four different strains of rats that had not been treated with tetracycline (controls) were examined for tetracycline resistance. Tetracycline-resistant Proteus mirabilis was isolated from the intestines of these animals. Plasmid-mediated resistance could not be demonstrated. The E coli and P vulgaris isolates from these control animals were susceptible to tetracycline.     

Polydipsia in the dog--symposium. 2. Polydipsia and its relationship to pyometra

Abstract— —A generalised hormonal imbalance in adult bitches produces a hyperplasia of the endo-metrium and would seem to lower its resistance to secondary bacterial invaders. A variety of organisms, including E. coli, invade the endometrium and set up an inflammatory reaction with the formation of pus, i.e. pyometra. The clinical signs of pyometra include a polydipsia which is secondary to excessive fluid loss through the kidney. The histological examination of the kidneys from these cases of pyometra show extensive lesions. The capillary tuft and basement membrane of the glomerulus are thickened by a PAS-positive material. Similar, though less severe changes are seen in the renal tubules. All these lesions are said to be reversible following ovaro-hysterectomy. Some doubts are raised as to the specificity of these kidney changes. Résumé— —Un déséquilibre hormonal généralisé provoque chez la chienne adulte une hyperplasie de l'endomètre et semble réduire la résistance de celui-ci aux agressions bactériennes secondaires. Divers microbes, dont le colibacille, envahissent l'endomètre, pour y provoquer une réaction inflam-rnatoire pyogène, c'est-à-dire la pyométrie. Les manifestations cliniques de la pyométrie comprennent notamment la polydipsie, effet d'une déperdition hydrique excessive par la voie rénale. L'examen histologique du rein permet de constater, dans ces cas de pyométrie, d'importantes lésions rénales. Le floculus capillaire et las basale du glomérule sont épaissis par une substance positive à la coloration hématoxyline-acide périodique-Schiff. Les tubes urinaires présentent des altérations comparables, quoique moins marquées. L'ensemble de ces lésions serait réversibie à la suite de l'hystéro-ovariectomie. La spécificité de ces altérations rénales est douteuse à certains égards. Suivant une certaine hypothèse, la polyurie serait imputable à l'absorption de toxines d'origine utérine. Zusammenfassung— —Eine generalisierte hormonale Unausgeglichenheit bei erwachsenen Hün-dinnen erzeugt eine Hyperplasie des Endometriums und scheint dessen Widerstandsfähigkeit gegen sekundären Bakterienbefall herabzusetzen. Verschiedene Organismen einschliesslich E. coli können das Endometrium befallen und eine Entzündung mit Eiterbildung, d.h. Pyometra, hervorrufen. Zu den klinischen Zeichen von Pyometra gehört eine sekundäre Polydipsie nach übermässigem Flüssigkeitsverlust durch die Nieren. Die histologische Untersuchung der Nieren in diesen Fällen von Pyometra zeigt ausgedehnte Läsionen. Die Kapillarschicht und die Basalmembrane des Glomerulus sind durch ein PAS-positives Material verdickt. Ähnliche, doch weniger schwere Veränderungen sind an den Nierenkanälchen zu beobachten. Nach Ovariohysterectomie sollen alle diese Läsionen reversibel sein. Hinsichtlich der Spezifischkeit dieser Nierenveränderungen sind einiga Zweifel angemeldet worden. Es wurde auf die Möglichkeit hingewiesen, dass die Polyurie auf die Absorption von Toxinen aus dem Uterus zurückzuführen sein kann. It has been suggested that the polyuria is due to the absorption of toxins from the uterus.     

Four cats with fungal rhinitis

Fungal rhinitis is uncommon in the cat and cases of nasal aspergillosis-penicilliosis have been rarely reported. Signs of fungal rhinitis include epistaxis, sneezing, mucopurulent nasal discharge and exophthalmos. Brachycephalic feline breeds seem to be at increased risk for development of nasal aspergillosis-penicilliosis. Computed tomography (CT) imaging and rhinoscopy are useful in assessing the extent of the disease and in obtaining diagnostic samples. Fungal culture may lead to false negative or positive results and must be used in conjunction with other diagnostic tests. Serological testing was not useful in two cats tested. The cats in this study were treated with oral itraconazole therapy. When itraconazole therapy was discontinued prematurely, clinical signs recurred. Hepatotoxicosis is a possible sequel to itraconazole therapy.     

The Response of the Bitch to Treatment with Medroxyprogesterone Acetate

Abstract— —Medroxyprogesterone acetate (M.A.P.) was administered to three groups of bitches as follows:

• 1 Eighty-six bitches received a total of 166 injections of M.A.P. to prevent or suppress oestrus. This procedure was entirely successful in 83 bitches (96.5 per cent) and partially successful or unsuccessful in the remaining 3 bitches. Nine others showed unfortunate sequelae of which three bitches subsequently required an ovaro-hysterectomy, 1 showing a chronic endometritis and 2 showing a gross cystic hyperplasia of the endometrium upon histopathological examination. Methods of reducing the rate of failure are suggested.
• 2 Forty bitches received 5 cm³ M.A.P. (250 mg) to suppress false pregnancy and the results were satisfactory in 31 (86 per cent) of the 36 bitches where a follow-up history was obtained. However, the use of M.A.P. to control this condition is considered to be beyond the financial means of the average client.
• 3 Three “poor risk” cases of pyometra were given 5 cm³ M.A.P. and the initial response was good, but all 3 died subsequently. Two suffered a relapse of pyometra, 1 died of nephritis. This form of therapy demands further investigation.

Two bitches developed signs of diabetes mellitus following the administration of M.A.P. Résumé— —L'Acétate de Medroxyprogesterone (M.A.P.) a ?té administréà 3 groupes de chiennes comme il suit:

• 1 Quatre-vingt six chiennes ont reçu un total de 166 injections de M.A.P., pour prévenir ou supprimer l'oestrus. Ce procédé a eu un réultat parfait dans quatre-vingt trois cas (96.5 pour cent) et un succès partiel or un résultat nul dans les 3 autres cas. Neuf autres chiennes ont montré des séquelles malheureuses et conséquemment 3 chiennes durent subir une ovaro-hystérectomie, une montrant une endomedArite chronique et deux autres, une hyperplasie cystique de l'endomètre, visible à l'oeil nu et vérifiée par examen histologique. Des méthodes pour réduire le nombre d'échecs ont été suggérées.
• 2 Quarante chiennes ont reçu 5 cm³ M.A.P. (250 mgm), pour supprimer une fausse grossesse et les résultats furent satisfaisants dans 31 cas (86 pour cent) de 36 chiennes mises en observation. Cependant, l'utilisation du M.A.P. pour dominer cette situation, est considérée au-delà de possibilités financières d'un client moyen.
• 3 Trois chiennes avec pyométrie, dans un mauvais état général, reçurent 5 cm⁵ de M.A.P., et mêrne que la réaction initiale fut bonne, toutes les 3 décédérent subséquemment. Deux chiennes eurent une rechute de la pyométrie et une décéda à cause d'une néphrite. Cette forme de traitement nécéssite d'autres investigations. Deux cas deéeloppèrent des signes de diabète sucré, suivant l'administration de M.A.P.

Zusammenfassung— —Medroxyprogesteron Acetat (M.A.P.) wurde 3 Gruppen von Huendinnen wie folgt verabreicht:

• 1 86 Huendinnen erhielten im ganzen 166 Injektionen von M.A.P., urn Brunst zu verhindern oder zu unterdruecken. Dieses Verfahren war bie 83 Huendinnen (96.5%) voellig erfolgreich und bie den ucbrigen 3 Huendinnen entweder teilweise erfolgreich oder erfolglos. Neun andere zeigten unerwuenschte Folgen; in 3 Faellen war Ovaro-Hysterektomie erforderlich; davon wurde in einem Fall chronische Endometritis gefunden, und in 2 Faellen stark ausgepraegte zytiscshe Hyperplasie des Endometriums bie histologischer Untersuchung. Methoden zur prozentualen Reduktion der Versager werden vorgeschlagen.
• 1 40 Huendinnen erhielten 5 ml M.A.P. (250 mg), um Pseudo-Schwangerschaft zu unterdruecken. Die Resultate waren bie 31 (86%) von den 36 Huendinnen erfolgreich, wo der weitere Verlauf verfolgt werden konnte. Die Anwendung von M.A.P., um diesen Zustand unter Kontrolle zu halten, is jedoch zu teuer fuer den Durchschnitte-Klienten.
• 1 In 3 Faellen von Pyometrium mit zweifelhafter Prognose wurde 5 ml M.A.P. gegeben. Der Anfangserfolg war gut, aber alle drei starben spaeter. Zwei hatten einen Rueckfall von Pyometrium, ein Tier starb an Nephritis. Diese Behandlungsform bedarf weiterer Untersuchung.

Zwei Faelle entwickelten Symptome von Diabetes mellitus nach der Anwendung von M.A.P.     

Growth performance of nursery pigs fed diets containing increasing levels of corn distiller's dried grains with solubles originating from a modern Midwestern ethanol plant

Two experiments were conducted to determine the effects of including distiller's dried grains with solubles in nursery diets on growth performance, and to establish maximum inclusion rates for corn distiller's dried grains with solubles originating from modern, "new-generation" ethanol plants (built since 1990). Ninety-six crossbred pigs (BW = 6.18 +/- 0.14 kg) were blocked by gender and ancestry, and pigs within each block were randomly assigned to one of six dietary treatments (four pigs/pen, four pens/dietary treatment) in each of two growth performance experiments. Dietary treatments provided 0, 5, 10, 15, 20, or 25% distiller's dried grains with solubles during Phases 2 and 3 of a three-phase nursery feeding program for early-weaned pigs. Pigs in Exp. 1 were slightly older (19.0 vs. 16.9 d of age) and heavier (7.10 vs. 5.26 kg) at the beginning of the experiment compared to pigs in Exp. 2. All pigs in both experiments were provided a commercial pelleted Phase 1 diet for the first 4 d after weaning and were then switched to their respective experimental Phase 2 diets, which were fed for 14 d, followed by their respective Phase 3 experimental diets, which were fed for a subsequent 21-d feeding period. Experimental diets were formulated to contain equivalent apparent ileal digestible lysine (1.35 and 1.15%), apparent ileal digestible methionine + cystine (0.80 and 0.65%), ME (3,340 and 3,390 kcal/kg), calcium (0.95 and 0.80%), and total phosphorus (0.80 and 0.70%) within Phases 2 and 3, respectively. Overall growth rate, ending body weight, and feed conversion were similar among pigs regardless of dietary distiller's dried grains with solubles level for both experiments. In Exp. 1, feed intake was not affected by dietary treatment (P > 0.10). In Exp. 2, however, increasing the level of distiller's dried grains with solubles linearly decreased feed intake (P < 0.02) during Phase 2 and tended to decrease voluntary feed intake (P < 0.09) over the length of the experiment. These results suggest that the corn distiller's dried grains with solubles used in this study can be included in Phase 3 diets for nursery pigs at dietary levels of up to 25% without negatively affecting growth performance after a 2-wk acclimation period. Including high levels of corn distiller's dried grains with solubles in diets for pigs weighing less than 7 kg in BW, however, may negatively influence feed intake and growth.