Interaction of heat-moisture conditions and physical properties in oat processing: I. Mechanical properties of steamed oat groats

Research interest in oats has focussed on their nutritional value, but there have been few studies of their food processing. Heat treatment is characteristic of oat processing, as it is needed to inactivate lipase and to facilitate flaking. A Texture Analyser was used to characterise the mechanical properties of unkilned and kilned oat groats after steaming and tempering in an oven for 30, 60 and 90 min at 80, 95 and 110 °C. Maximum force, number of peaks before maximum and final force after 5 s hold were used to characterise the behaviour of the groats during compression. Kilned groats were larger and softer before steaming. After steaming and tempering, the moisture content of the kilned groats was higher than for unkilned groats. Hot, steamed oats were softer than cold, unsteamed groats, indicated by a decrease in maximum force from 59 to 55 N, and there was no significant difference between kilned and unkilned groats. However, higher temperatures during tempering increased maximum force. These results suggest that mild steam treatment yields softer oat groats, whereas cold or over-treated groats tend to be harder.     

Interaction of heat–moisture conditions and physical properties in oat processing: II. Flake quality

Product quality is an important determinant of consumer acceptance. Consistent oat flake properties are thus necessary in the mill as well as in the marketplace. The effects of kilning and tempering conditions (30, 60 or 90 min at 80, 95 or 110 °C) on flake peroxidase activity, size, thickness, strength and water absorption were therefore determined. After kilning, some peroxidase activity remained but steaming and tempering effectively destroyed the activity of these enzymes. Thus the supposed protective effect of kilning or groat durability was not confirmed. Kilning resulted in an increase in flake specific weight, but no other significant effect on flake quality was observed. Tempering time and temperature interacted significantly to produce complex effects on flake specific weight, thickness and water absorption. Flake thickness and specific weight were significantly correlated (r = 0.808, n = 54). Longer tempering times resulted in an increased fines' fraction, from 1.45% at 30 min to 1.75% at 90 min. It is concluded that whilst kilning has little effect on flake quality, the heat treatment immediately prior to flaking can be used to adjust flake quality independently of flake thickness.     

Activity of the ilicicolins against plant pathogenic fungi

Ilicicolins D, E, F, dechloroilicicolin D, ascofuranone and arthrichitin were isolated from the fermentation broth of Nectria sp (HIL Y 90 3333). The ilicicolins showed good fungicidal activity in planta.     

Ovine abortion associated with an anaerobic bacterium

An anaerobic, slightly curved, tapered, corrugated, rod-shaped bacterium with O to greater than 12 flagella at each pole was isolated from 2 aborted lambs with focal hepatic necrosis. The organism stained faintly Gram-negative, but stained better by the Giemsa method. It was pleomorphic in culture, ranging from filaments containing granules to faintly staining spheroids.     

The reversal of xylazine/ketamine immobilisation of fallow deer with yohimbine

Fallow deer were immobilised using a combination of xylazine and ketamine. Adult males (n = 10) and adult females (n = 10) received 4 mg/kg of each drug intramuscularly. Juveniles (n = 11) received 2 mg/kg of each drug, intravenously. Times to recumbency were as follows: adult males 4.9 +/- 2.9 min, adult females 4.1 +/- 1.9 min, juveniles 2.3 +/- 1.1 min. After 30 min each deer received 0.2 mg/kg of yohimbine, or an equal volume of sterile diluent intravenously. Yohimbine substantially reduced the recovery times of treated deer. Adults males were releasable 7.2 +/- 4.3 min after yohimbine administration, whereas control males were not releasable until 165 +/- 18 min. Treated adult females were releasable after 6.6 +/- 4.3 min, while control females were not releasable until 84 +/- 29 min. Juveniles were releasable 2.1 +/- 0.8 min after administration of yohimbine but control juveniles were not releasable until 62 +/- 16 min. Xylazine/ketamine administration produced statistically significant changes in packed cell volume, total plasma protein, albumin, sodium, glucose, creatine phosphokinase and inorganic phosphate values after 30 min. Yohimbine administration had no effect on these changes.     

Abortion in sheep caused by a nonclassified, anaerobic, flagellated bacterium

Twenty-eight pregnant ewes were inoculated IV with approximately 6 X 10(8) nonclassified, anaerobic, flagellated bacteria (NAFB) that had been isolated from an aborted lamb. Abortion occurred in 3 of the ewes and 1 ewe gave birth to a weak lamb. The remaining 24 ewes and 3 other ewes inoculated orally with NAFB did not develop clinical signs of illness. Suppuration and vasculitis were seen in the placentas of the 3 aborted lambs, 1 of which had necropurulent hepatitis indistinguishable from that usually attributed to Campylobacter fetus infection. The NAFB was isolated from fetal placenta, abomasal content, or internal organs of 2 aborted lambs and the weak lamb. A morphologically similar organism was seen in the abomasal content of the other aborted lamb, but the organism did not grow on bacteriologic culture medium. Therefore, in susceptible pregnant ewes, NAFB can cause fetal placentitis and hepatitis and subsequent birth of weak lambs or abortion.     

Practices and opinions of New Zealand beef cattle farmers towards bovine viral diarrhoea control in relation to real and perceived herd serological status

ABSTRACT

Aims: To investigate the seroprevalence of infection with bovine viral diarrhoea (BVD) virus among 75 beef herds and seroconversion in cattle during early pregnancy, and to determine the practices and opinions of farmers towards BVD control and their association with real and perceived herd serological status.

Methods: Blood samples were collected before mating in 75 beef herds across New Zealand from 15 unvaccinated heifers that had delivered their first calf that season. Serum samples were tested for BVD antibodies using ELISA individually, and after pooling samples for each farm. Animals that were antibody-negative were retested at either pregnancy diagnosis or weaning. Farmers were asked to complete a detailed survey about herd demographics, BVD testing and vaccination practices, and opinions towards national BVD control.

Results: Based on the pooled serum antibody ELISA results, there were 28/75 (37%) negative herds, 15/75 (20%) suspect herds, and 32/75 (43%) positive herds. Of 1,117 animals sampled 729 (65.3%) tested negative for BVD virus antibodies; when retested, 47/589 (8.0%) animals from 13/55 (24%) herds had seroconverted. Among 71 famers providing survey responses 11 (15%) believed their herd was infected with BVD, 24 (34%) were unsure and 36 (51%) did not think their herd was infected. Only 19/71 (18%) farmers had performed any BVD testing within the past 5 years and 50/70 (71%) had not vaccinated any cattle for BVD. Support for national BVD eradication programme was strong in 51/71 (56%) respondents, but the biggest challenge to BVD control was considered to be famer compliance. Compared to farmers who did not think their herd was infected, more farmers who thought BVD was present in their herds had previously tested for BVD, would consider testing all replacement calves, and would support establishing a national BVD database; fewer would consider purchasing BVD tested or vaccinated cattle only.

Conclusions and clinical relevance: Only 15% of the beef farmers in this study believed their herds were infected with BVD virus and few of them had undertaken BVD screening. Nevertheless many were supportive of implementing a national BVD control programme. It is likely that the lack of farmer awareness around BVD and the failure of farmers to recognise the potential impacts in their herds are hindering progress in controlling the disease in New Zealand. There are opportunities for New Zealand veterinarians to be more proactive in helping beef farmers explore BVD management options.