Rapeseed meal and egg taint: Treatment of rapeseed meal to reduce tainting potential

1. Treatment of rapeseed meal with calcium hydroxide suspension decreased the sinapine content by up to 90%. Smaller decreases were obtained by autolysis, steaming and treatment with ammonia.

2. When this treated meal was fed to susceptible ("tainting") hens the concentration of trimethylamine in the eggs was decreased to much less than that required to cause taint.     

Rapeseed Meal and egg taint

1. Certain rapeseed meals in the diet of hens laying brown eggs result in the production, from some birds, of eggs which have a “ fishy ” or “ crabby ” odour because of the presence of trimethylamine.

2. Such susceptible birds have been used to demonstrate that the activity can be extracted from rapeseed meal with appropriate solvents.     

Changes in the glucosinolate content of oilseed rape plants following infection with turnip mosaic virus

Low and high glucosinolate cultivars of oilseed rape were analysed for variation in both individual and total glucosinolate content up to 27 days after inoculation with turnip mosaic virus. Both infected and control plants of the two cultivars differed in the concentration of aliphatic, aromatic and indole glucosinolates. The biggest differences in glucosinolate content between the cultivars were found in the aliphatic and aromatic glucosinolate groups. Infected plants of the high glucosinolate cultivar, Solida, possessed lower amounts of glucosinolates, than did healthy control plants. Similar results were obtained with a low glucosinolate cultivar, S1. No significant difference was found between the two cultivars in resistance to turnip mosaic virus, using qualitative and quantitative ELISA to determine virus content in their tissues.     

Salmonella Brandenburg--emergence of a variant strain on a sheep farm in the South Island of New Zealand

Salmonella Brandenburg was initially diagnosed in New Zealand in an aborted ewe from a Merino flock in mid-Canterbury in1996. The following year, the disease occurred on farms in mid-Canterbury and on one farm near Winton in Southland (Bailey1997). Since then, this bacterium has caused widespread abortion and deaths in pregnant ewes in Southland, coastal Otago and south- and mid-Canterbury. In cattle, the same organism has caused diarrhoea and dysentery in calves and adult cattle, and abortions and deaths in first-calving cows and, to a lesser extent, in second-calving and older cows. Salmonella Brandenburg has also caused diarrhoea and fetal deaths in dogs, and diarrhoea and deaths in foals. The outbreak strain has been extensively studied using pulsed-field gel electrophoresis (PFGE). All isolates tested to date have had an indistinguishable molecular pattern with the exception of a single isolate from a sheep-yard dust sample recovered in October 2000 that is the subject of this report. The molecular pattern of the variant strain differed from that of the epidemic strain by the absence of one high molecular weight band and the addition of three lower molecular weight bands.     

Circulating cortisol, tumor necrosis factor-alpha interleukin-1beta, and interferon-gamma in pigs infected with Actinobacillus pleuropneumoniae

This study evaluated the time course of systemic cytokine concentrations in an acute model of pneumonia in pigs challenged intranasally with Actinobacillus pleuropneumoniae. Feed intake and serum cortisol were measured as overt clinical and systemic markers of disease onset, respectively, and serum tumor necrosis factor-alpha, interleukin-1beta, and interferon-gamma as representative systemic inflammatory markers. Crossbred barrows (n = 15), approximately 5 wk of age, were used in the study. Pigs were housed in an environmentally controlled facility at 25 degrees C and under continuous illumination in pens measuring approximately 1.5 m2. Pigs had free access to water and an unmedicated diet. Approximately 1 wk prior to disease challenge, pigs were fitted nonsurgically with venous catheters. At challenge, pigs were given 5 x 10(8) CFU Actinobacillus pleuropneumoniae intranasally (n = 8) or a similar volume of sterile growth media intranasally (Control; n = 7). Feed intake was estimated by the change in feeder weight at 12-h intervals from -12 to 72 h relative to the time of disease challenge. Blood sampling began 12 h prior to challenge and continued until 72 h after challenge. Pigs were sampled at -12, -6, and 0 h, then at 90-min intervals until 12-h post-challenge, continuing at 3-h intervals until 24-h post-challenge, then again at 6-h intervals until 72 h after challenge. Serum was harvested and frozen until assayed for cortisol, tumor necrosis factor-alpha, interleukin-1beta, and interferon-gamma. Feed intake was reduced in Actinobacillus pleuropneumoniae pigs during the intervals 0 to 12 h (P < 0.001), 24 to 36 h (P < 0.001), 48 to 60 h (P <0.05), and 60 to 72 h (P < 0.05). TheActnobacillus pleuropneumoniae-challenged pigs had elevated serum cortisol from 180-min to 18-h post-challenge (P < 0.001) and also at 36 (P < 0.05), 42 (P < 0.001), and 60 (P < 0.05) h following infection. Circulating cytokines were not affected by disease challenge. Thus, in this experimental model of pneumonia, weaned pigs demonstrated expected behavioral and endocrine characteristics of disease in the absence of significant changes in circulating inflammatory cytokines.