Identification of IGF binding proteins in bovine milk and the demonstration of IGFBP-3 synthesis and release by bovine mammary epithelial cells.

Insulin-like growth factor system components are synthesized and secreted by mammary epithelial cells and multiple IGF binding proteins (IGFBP) are found in milk of various species. This study was conducted to identify the IGFBP in bovine milk, to compare them with those found in blood, and to identify the cell(s) responsible for mammary IGFBP synthesis. Bovine blood, milk, and cell culture-conditioned media were analyzed and characterized with Western ligand blot procedures for specific IGFBP. Electrophoresis and [125I]IGF-II ligand blot analyses of the samples indicated that, unlike serum and mammary primary cell culture-conditioned media, milk required removal of casein in order to accurately disclose all IGFBP. Immunoprecipitation studies identified IGFBP-2, -3, -4, and -5 in blood, milk, and primary cell culture conditioned media. The IGFBP were present at higher concentrations in serum than in milk, and milk concentrations were greater than that shown in conditioned media from primary cultures of bovine mammary cells. Northern analysis detected IGFBP-3 messenger RNA in extracts from fresh tissue and cells in culture, and in situ hybridization studies with fresh tissue utilizing probes for IGFBP-3 and alphaS1-casein showed that the mRNA for IGFBP-3 is predominant in the secretory epithelial cells, when compared to other tissue cell types.     

Value of direct smears of synovial fluid in the diagnosis of canine joint disease.

Assessments of direct smears of synovial fluid by four clinicians were compared with the results obtained with a Coulter counter. Estimates of total white cell counts by the clinicians were inaccurate and generally higher than the Coulter counter results. The method had a low sensitivity and specificity for the identification of degenerative joint disease and normal joints in comparison with the identification of inflammatory joint disease. There were marked variations in the results obtained by the four clinicians for all the analyses in the study.     

Transmission of potato virus Y by cereal aphids

Summary The cereal aphidRhopalosiphum padi transmitted PVY^O and PVY^N from and to both tobacco and potato. However, it transmitted much less frequently thanMyzus persicae, even when aphids making single probes were compared.R. padi andM. persicae retained PVY for a similar duration. Both alatae and apterae ofR. padi transmitted infrequently, as also did progenies of individual aphids that had transmitted PVY.Metopolophium dirhodum also transmitted PVY infequently butSitobion avenae did not transmit.

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Zusammenfassung In Laborversuchen übertrugen ca, 1% der Getreideblattl?useRhopalosiphum padi undMetopolophium dirhodum, nicht jedochSitobion avenae das Kartoffel-Y-Virus (PVY). 65% vonMyzus persicae übertrugen PVY.R. padi übertrugauch dann weniger h?ufig alsM. persicae, wenn die Aphiden bei Einzelentnahmen untersucht wurden.R. padi übertrug PVY^O und PVY^N von und auf die Tabaksorte White Burley und die Kartoffelsorte King Edward. Zwei oder zehn Minuten Einwirkung waren optimal fürM. persicae, um PVY zu erlangen, w?hrendR. padi PVY h?ufiger nach l?ngeren Entwirkungszeiten übertrug (Tabelle 1).R. padi undM. persicae beinhalteten PVY für eine ?hnliche Zeitdauer (Tabelle 2). Sowohl alatae als auch apterae vonR. padi übertrugen unregelm?ssig, ebenso Nachkommen von individuellen Aphiden, welche PVY übertragen hatten.

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Résumé En tests de laboratoire, environ 1% des pucerons des céréalesRhopalosiphum padi etMetopolophium dirhodum, aucun deSitobion avenae et environ 65% deMyzus persicae transmettent PVY.R. padi transmet également moins fréquemment queM. persicae lorsque les pucerons sont mis en comparaison par piq?re unique.R. padi acquiert PVY^O et PVY^N à partir des variétés de tabac White Burley et de pomme de terre King Edward et les transmet à ces deux mêmes variétés. Deux ou 10 minutes d'acquisition sont optimum pour queM. persicae acquiert PVY tandis queR. padi transmet PVY plus fréquemment après une plus longue période d'acquisition (tableau 1).R. padi etM. persicae conservent PVY dans les mêmes délais (tableau 2). Les ailés et les aptères deR. padi transmettent rarement PVY comme les descendants de pucerons ayant transmis PVY.

     

Control of saprolegniosis in the eel Anguilla australis Richardson, by Aeromonas media strain A199

The probiotic activity of Aeromonas media strain A199 for the control of saprolegniosis at low water temperatures was trialled in a laboratory-based challenge using the eel, Anguilla australis Richardson. Eels were challenged in the presence of a physiological and physical stress akin to that preceding the winter outbreaks of saprolegniosis in farms. The concentration of Saprolegnia parasitica cysts was 9±1.2 cysts/ml for the initial challenge. Morbidity due to saprolegniosis was low, at 27% in A199-treated tanks, in comparison to the 44% recorded for the non-treated control tanks. The subsequent addition of live A199 cultures to the treatment tanks resulted in the recovery of fish suffering from saprolegniosis (p=0.038), with temperature appearing to be a factor regulating the effect of A199. It was concluded that A199 is a potential agent for the management of winter outbreaks of saprolegniosis in eels.     

Further observations on the effect of different levels of larval intake on the output of eggs of Ostertagia circumcincta in lambs

Three groups of lambs were given 50, 250 or 2800 infective larvae of Ostertagia circumcincta per day for a period of six weeks. All groups then received 25,00 larvae per day for a similar period and observations were continued for a further six weeks. Egg output following the initial infection varied directly with the level of larval intake, but fell to a low during the second period of infection and decreased still further in the final six weeks of the observation. The investigation suggests that, provided high levels of residual larval infection on pasture are avoided, there appears to be considerable merit in exposing lambs to a low level of initial infection.     

Sickness, mortality and the buller steer syndrome in a western Canadian feedlot

Objective To determine if an association existed between sickness, mortality and bullers in a western Canadian feedlot.
Design A retrospective epidemiological study.
Animals 78,445 male cattle that entered a 24,000-head feedlot in western Canada from 1991 to 1993.
Procedure Animal health records for bullers were collected and analysed to see if they were at greater risk of sickness and mortality than other steers, and to see if pens with a high prevalence of bullers also had a high prevalence of sickness and mortality.
Results The prevalence of bullers increased with increasing age of cattle on arrival at the feedlot (R = 0.36; P < 0.001). Sickness and mortality decreased with increasing age of cattle on arrival. However, sickness and mortality in bullers relative to other steers actually increased with increasing age on arrival suggesting an interaction existed between sickness and bullers. Bullers were significantly (P < 0.05) more likely to get sick and to die than other steers. In all cases, there was a strong temporal association between sickness and bullers, with sickness and bullers mostly occurring within the first 30 days of the feeding period. On average, pens of cattle with a high prevalence of bullers did not have a correspondingly high prevalence of sickness or mortality.
Conclusion This study suggests that sickness is an effect modifier of dominance behaviour and therefore bullers in feedlot steers. Bullers should always be checked for signs of sickness and treated accordingly. Further research is needed to investigate the effects of sickness on dominance behaviour in pens of feedlot cattle.