Failure of an intramuscular injection of an analogue of gonadotrophin-releasing hormone 11 to 13 days after insemination to increase pregnancy rates in dairy cattle

At 11 to 13 d after insemination, 1028 dairy cows on 19 farms were given an intramuscular injection of 10 micrograms of the GnRH analogue buserelin. Their reproductive performance was compared to 1022 control cows receiving a placebo. The GnRH analogue-treated cows had fewer short interoestrous intervals compared to the control cows, but there were no significant differences in pregnancy rates to either the insemination preceding or following treatment, in calving to conception interval, or to percent pregnant by the end of mating. There were no differences between treatments in herds of high, average or low pregnancy rate, in 2-year-old cows or cows greater than 2-years-old and in cows calved 40 d or less, or greater than 40 d. The use of 10 micrograms of the GnRH analogue, buserelin, 11 to 13 d after insemination, cannot be recommended as a method of improving reproductive performance in dairy herds.     

Reproductive performance of Thoroughbred mares on six commercial stud farms

The records of 1630 mare years from 6 Thoroughbred stud farms in south eastern Australia were analysed for the years 1981 to 1986. Overall pregnancy and foaling rates were 83.9% and 69.3%, respectively. When calculated per served oestrous cycle, pregnancy and foaling rates were 54.7% and 43.1%, respectively. Pregnancy and foaling rates were higher (P < 0.001) for mares 3 to 10 years of age than for older mares. There was no difference in the pregnancy rates of maiden, barren and foaling mares. The foaling rate was significantly higher (P < 0.001) in mares that became pregnant during the first served oestrous cycle (77.8%) than in mares that needed two served oestrous cycles to become pregnant (65.4%). Of all diagnosed pregnancies, 19.5% were not completed. Pregnancy loss was lower (P < 0.05) in maiden (12.4%) than in barren (19.7%) or foaling (20.9%) mares. Twins were diagnosed in 7.8% of all pregnancies. If one conceptus was lost without external interference, 84.1% of pregnancies went to term. If one conceptus was manually crushed, 55.9% of pregnancies were maintained. If prostaglandin was used to terminate twin pregnancies, 60% of mares so treated produced foals the following year.     

Taenia crassiceps Infection in the Woodchuck: A Retrospective Study of 13 Cases

Abstract— Large, fluctuant, fluid-filled subcutaneous masses containing hundreds of Taenia crassiceps cysticerci were detected in 13 woodchucks trapped in central New York and Maryland. The axillary region (7 of 13 animals) and adjacent lateral thoracic wall (4 of 13 animals) were most frequently affected. One animal had a focal parasitic granuloma in the lung and another had numerous cysticerci present within the hepatic parenchyma. Histologically, parasite sections were surrounded by varying degrees of fibrosis and mild scattered to coalescing lymphocytic aggregates were present in the adjacent subcutaneous tissues. There was minimal infiltration of subcutaneous lesions into the underlying musculature. Scanning electron microscopy of the parasites indicated the presence of numerous developing buds in the area of the posterior bladder. Scanning and transmission electron microscopy indicated that cysticerci were covered with a dense coating of microtriches. Taenia crassiceps lesions were found in 13 (2.6 per cent) of 501 trapped woodchucks, and in none of 293 colony-born woodchucks. No relationship between Taenia crassiceps infection and woodchuck hepatitis virus infection could be established. Résumé— Des masses sous-cutanées volumineuses, fluctuantes, remplies de liquides, contenant des centaines de cysticerques de Taenia crassiceps furent découvertes chez 13 marmottes capturées au centre de l'Etat de New-York et dans le Maryland. La région axillaire (7 des 13 animaux) et la paroi thoracique latérale adjacente (4 des 13 animaux) étaient les plus fréquemment atteintes. Un animal avait un granulome parasitaire focal dans un poumon et un autre avaient de nombreux cysticerques dans le parenchyme hépatique. D'un point de vue histologique, les sections de parasite étaient entourées par une fibrose d'importance variable, et des aggrégats lymphocytaires modérés, dispersés ou coalescents, étaient présents dans les tissus sous-cutanés adjacents. Il y avait une infiltration minimale des lésions sous-cutanées dans les muscles sous-jacents. La microscopie électronique à balayage montra la présence de nombreux bourgeons en développement dans la zone postérieure de la vessie. La microscopie électronique à balayage et par transmission indiqua que les cysticerques étaient couverts par un enduit dense de microtriches. Des lésions dûes àTanenia crassiceps furent découvertes chez 2.6% (13 sur 501) des marmottes capturées, et 0% (0 sur 293) des marmottes nées en captivité. Aucune relation entre l'infestation par Taenia crassiceps et l'hépatite infectieuse virale de la marmotte ne put être établie. Zusammenfassung— Bei 13 im Zentrum von New York und Maryland gefangenen Waldmurmeltieren wurden große, fluktuierende, flüssigkeits-gefüllte subcutane Massen festgestellt, die Hunderte von Taenia crossiceps cysticerci enthielten. Am häufigsten waren der Axillarbereich (boi 7 von 13 Tieren) und die angrenzende seitliche Brustwand (bei 4 von 13 Tieren) betroffen. Ein Murmeltier hatte ein fokales parasitäres Granulom in der Lunge, ein anderes zahlreiche Cysticerci im Leberparenchym. Im histologischen Bild zeigten sich von verschieden starken Fibrosen umgebene Parasitenausschnitte und leicht verstreute bis konfluierende Lymphozytenaggregate im angrenzenden subcutanen Gewebe. Die darunterliegende Muskulatur wurde nur minimal von den subcutanen Läsionen infiltriert. Unter dem Rasterelektronenmikroskop zeigten die Parasiten zahlreiche sich entwickelnde Knospen im Bereich der hinteren Blase. Im Rasterelektronenmikroskop und im Transmissions-Elektronenmikroskop waren die Cysticeri mit einer dichten Schicht aus Mikrotrichen bedeckt. Taenia crassiceps-Läsionen wurden bei 2.6% (13 von 501) der gefangenen und bei 0% (0 von 293) der koloniegeborenen Waldmurmeltiere nachgewiesen. Ein Zusammenhang zwischen der Taenia crassiceps - Infektion und einer Waldmurmeltier-Hepatitis-Virusinfektion konnte nicht festgestellt werden. Resumen En 13 marmotas capturados en Nueva York y en Maryland se detectaron masas subcutáneas de gran tamaño, llenas de líquido y que contenían cientos de cisticercos de Taenia crassiceps. Las zonas más afectadas fueron la región axilar (7 de 13 animales) y la pared torácica adyacente (4 de 13 animales). Un animal presentaba un granuloma parasitario focal en un pulmón y otro presentaba numerosos cisticercos en el parénquima hepático. Histológicamente, los parásitos aparecían rodeados por una reacción fibrosa de diferente intensidad y en el tejido subcutáneo próximo se observaban agregados linfocitarios. La musculatura subyacente no aparecía afectada. Estudios de microscopía electrónica de transmisión y de barrido demostraron que los cisticercos estaben recubiertos por una densa capa de microtricos. Lesiones producidas par Taenia crassiceps se detectaron en el 2,6% (13 de 501) de los capturados y en el 0% (0 de 293) de los procedentes de un criadero. No se pudo demostrar relación alguna entre la infestación con Taenia crassiceps y la infección con el virus de la hepatitis de las marmotas.