ATP content and sperm motility of extended bovine semen under different storage conditions.

The effects of incubation temperature (+20 degrees C vs +35 degrees C) and media type on the ATP content and motility of spermatozoa were determined in fresh bovine semen in order to develop a method for assaying post-thaw quality. Semen was obtained from 3 bulls at 2 occasions. The spermatozoa were washed using a Ficoll-containing medium before being resuspended in each of 4 different media (I. 0.9% NaCl; II. Tris-buffer solution; III. seminal plasma; IV. seminal plasma+Tris-buffer solution) and incubated for 6 h. The least-squares means for ATP content were higher (p less than or equal to 0.05) at +20 degrees C than +35 degrees C for all media except no. I. By contrast, the least-squares means for sperm motility were higher (p less than or equal to 0.05) at +35 degrees C than at +20 degrees C in media II and III. A decrease over time in ATP content and motility at both temperatures was also observed. The single most important factor responsible for changes in ATP content and sperm motility was the temperature and the medium, respectively.     

A survey of the hygienic quality of beef and pork carcasses in Norway

The bacteriological quality of beef and pig carcasses was assessed at 9 Norwegian abattoirs by sampling 10 carcasses at multiple sites on each of several visits. On beef carcasses the following sites consistently carried higher numbers of bacteria: the Brisket, the Fore-ribs, the Flank groin, and the Round medial. There was no evidence that beef slaughter and dressing in the hanging position was superior to methods where the carcass was lying until the hide puller. On pork carcasses the Cheek, and the Abdomen lateral surface (belly) were most heavily contaminated. The hygienic quality of pork carcasses in abattoirs where singeing was a separate step tended to be better than where a combined singeing and dehairing machine was used.This survey suggests that bacteriological monitoring of slaughter at this level of sampling and visiting is able to detect consistently poor hygienic practices.Where direct comparisons with data from other countries could be made, the present investigation indicates that the bacterial counts on Norwegian beef and pork carcasses are of the same order or better.Key words: abattoir, slaughter, beef, pork, hygiene     

Efficacy and fate of glyphosate on Swedish railway embankments

The herbicide glyphosate, N-(phosphonomethyl)glycine, as Spectra (240 g AI litre(-1) SL; Monsanto Europe AB), RoundUp (360 g AI litre(-1) SL; Monsanto) and RoundUp Bio (360 g AI litre(-1) SL; Monsanto), have been used for weed control on Swedish railway embankments since 1986. This article summarizes results from studies of the weed effect and behaviour of glyphosate for the period 1984-2003. Studies on a railway embankment with a range of application rates showed excellent weed control at 5 litre ha(-1) of RoundUp Bio. The appearance of glyphosate and its metabolite AMPA [(aminomethyl)phosphonic acid] in the embankment, eg mobility and persistence, was also studied. Mobility was low in most cases, the main proportion of both glyphosate and AMPA being found in the upper 30-cm layer although minor amounts penetrated to lower depths. The 50% disappearance time of glyphosate was generally <5 months in railway embankments but cases with longer persistence were found. Transport to the groundwater was observed for glyphosate and AMPA in groundwater pipes along tracks. Downward transport appears to be dependent on the application rate, which should not exceed 3 litre ha(-1) of RoundUp Bio to avoid groundwater contamination. A lower rate of glyphosate mixed with a low rate of another herbicide may achieve acceptable weed control and be environmentally safer.     

The neonatal Fc receptor (FcRn) is expressed in the bovine lung

In neonatal calves, maternal immunoglobulin (Ig) is transferred into respiratory secretion which contributes to protection against pathogens. The early predominance of IgG1 in respiratory tract secretions is progressively reduced in favor of IgA by age but in the lower, bronchoalveolar system secreted IgG remains the dominant secreted Ig even in adulthood. The trans-epithelial transport of secretory IgA into mucosal secretions is carried out by the polymeric Ig receptor. However, the mechanism by which IgG crosses epithelial cells to provide defense on mucosal surfaces is still unknown. In order to investigate the possibility that the neonatal Fc receptor, FcRn is involved in this transport we have first analyzed the localization of this receptor in the upper and lower respiratory tracts. Consistent with the in situ hybridization data, immunohistochemistry showed undetectable expression in the tracheal epithelial cells, relatively weak expression in epithelial cells of the bronchi, apparent staining those lining the bronchioli and randomly scattered signal over the alveolar tissue. The bovine FcRn may thus play a role in IgG transport across mucosal epithelial barriers as a trafficking receptor and ensure IgG predominance in the lower respiratory tract.     

Degradation of isoproturon by the white rot fungus Phanerochaete chrysosporium

The ability of the white rot fungus Phanerochaete chrysosporium to degrade isoproturon was tested in solid substrate fermentation (SSF) cultures using straw as substrate/carrier material. The role of the lignin degrading enzymes, lignin peroxidase (LiP) and manganese peroxidase (MnP), in the degradation of the herbicide was also studied. Isoproturon concentration and LiP and MnP activities were followed in sterile straw cultures of the fungus. In vitro degradation tests with pure LiP and MnP were performed. P. chrysosporium in straw cultures was able to degrade 91% of the herbicide isoproturon in 14 days of incubation. A sharp decrease of isoproturon coincided with the largest MnP activity. Although LiP activity was also present, its role in SSF is unclear. The in vitro tests showed a strong isoproturon oxidation by LiP and a slower oxidation by MnP in the presence of Tween 80 probably by a lipid peroxidation process. Two N-demethylated metabolites were identified in pure enzyme tests and in SSF cultures. Several unidentified isoproturon derivatives, most likely hydroxylated, were also formed in both systems. The different pattern of derivatives detected in pure LiP and MnP tests showed a completely different metabolism by these two enzymes.     

Degradation of isoproturon in biobeds

The fate of isoproturon {N,N-dimethyl-N'-[4-(1-methylethyl)phenyl]urea} in biobeds with and without inoculation with the white rot fungus Phanerochaete chrysosporium was studied. Total extractable isoproturon, its metabolites and formation of non-extractable residues were evaluated. Studies with ¹⁴C-isoproturon were also included. A strong decrease in isoproturon was observed in non-inoculated biobeds. Total extractable isoproturon decreased by 76% after 100 days. The decrease was even larger in biobeds inoculated with the white rot fungus P. chrysosporium. After 28 days, total extractable isoproturon decreased by 78%, and after 100 days >99% had disappeared in the inoculated biobeds. However, the studies with ¹⁴C-isoproturon showed that 30% of the initially recovered ¹⁴C-isoproturon remained in the non-inoculated biobeds as non-extractable residues. As no studies with ¹⁴C-isoproturon were performed in inoculated biobeds, it is unclear if the higher rate of disappearance was due to higher biodegradation or higher formation of bound residues.