Systemic antibacterial drug use in dogs in Australia

A survey of veterinarians' use of antibacterial drugs was conducted by distributing a questionnaire to Australian practitioners. Respondents were asked to indicate their general patterns of use of various systemic antibacterial drugs and drug combinations in dogs and their approach to certain specified clinical disorders. Overall, antibacterials of the p-lactam type (penicillins and cephalosporins) were most commonly used. Other antibacterials with substantial use were doxycycline, sulphonamide-trimethoprim, metronidazole, fluoroquinolones and clindamycin. Drug selection for different disorders was generally appropriate when compared with recommendations in recent texts, although inappropriate use was evident in some circumstances.     

Durum wheat breadmaking quality: Effects of gluten strength,protein composition,semolina particle size and fermentation time

The effects of particle size of granulars (semolina and flour combined), gluten strength, protein composition and fermentation time on the breadmaking performance were compared for eleven durum wheat genotypes of diverse strength from North America and Italy grown in the same environment. All genotypes were γ-gliadin 45 types (low-molecular weight glutenin subunit 2 patterns) associated with superior pasta-making quality. Three cultivars with high-molecular weight glutenin subunit 20 exhibited relatively weak gluten, confirming that this subunit is associated with weakness in durum wheat. Gluten strength as measured by a range of technological tests was directly and strongly related to the proportion of insoluble glutenin (IG) in granulars protein as determined by a spectrophotometric procedure. Reducing the particle size of granulars by gradual reduction shortened development time in both the farinograph and mixograph. Reducing granulars also increased starch damage and, accordingly, farinograph water absorption, but remix-to-peak baking absorption was unaffected due to increased fermentation loss for finer granulars. Neither loaf volume, nor remix-to-peak mixing time were affected by the particle size of the granulars indicating that regrinding is not an asset for baking provided there is adequate gassing power. Loaf volume was directly related to gluten strength and IG content, and inversely related to residue protein, a non-gluten containing fraction. When fermentation time was reduced from the standard 165 to 90 min and 15 min, all genotypes exhibited a progressive increase in loaf volume. Therefore, regardless of strength, short fermentation time is preferred when high volume durum wheat bread is desired. Some of the stronger durum genotypes exhibited remix-to-peak bread volume comparable to that expected of good quality bread wheat, indicating that there is potential to select for genotypes with improved baking quality in conventional breeding programs by screening for high content of insoluble glutenin.     

Effect of setting a maximum milking time,from peak lactation,on production,milking time and udder health

Abstract

AIM: To examine the effect of setting a maximum milking time, from peak lactation until drying-off, on production, duration of milking, and udder health of dairy cows.

METHODS: Forty cows were assigned in twin-pairs to be either milked until cups were removed at a milk flow-rate threshold of 0.35 kg/minute (Control), or until cups were removed at a milk flow-rate threshold of 0.35 kg/minute, or maximum time, whichever came first (MaxT). The maximum time was set by determining the milking time of the 70th percentile cow when ranked from fastest to slowest, irrespective of yield. The milking routine was typical of that practised on dairy farms in New Zealand, and involved no pre-milking preparation. The study began at peak lactation (68 (SD 7) days in milk; DIM) and continued for 26 weeks. Duration of milking and milk yield were measured for each milking. Composition of milk was determined from weekly herd tests, and milk quality from fortnightly somatic cell counts (SCC). Completeness of milking and teat condition were assessed during the study. The bacterial status of quarter milk samples was determined at the beginning and end of the study, and all treated cases of clinical mastitis recorded. ANOVA was used to examine the effect of treatment group on variables of interest.

RESULTS: Total milk, fat and protein yields during the study period did not differ between treatments. On average, 30.3% of the morning and 27.6% of the afternoon milkings of MaxT cows reached the maximum time at which cups were removed, and were therefore shortened. While the average milking time of the slowest-milking cow was longer for the Control compared with MaxT group in Weeks 1–18, the average milking time did not differ between treatments. There was no difference in overall SCC, and the incidence of clinical mastitis, or the percentage of infected quarters at drying-off, was similar for the MaxT and Control cows.

CONCLUSION: The results show that setting a maximum milking time can reduce the milking time of slower-milking cows in a herd without compromising overall herd production and udder health.

CLINICAL RELEVANCE: Although the numbers of cows in the study were small there was no evidence of a major increase in SCC, or subclinical or clinical mastitis when a maximum milking time was set for slower-milking cows.     

Toll‐like receptor and related cytokine mRNA expression in bovine corpora lutea during the oestrous cycle and pregnancy

Improving our understanding of the mechanisms controlling the corpus luteum (CL) and its role in regulating the reproductive cycle should lead to improvements in the sustainability of today's global animal industry. The corpus luteum (CL) is a transient endocrine organ composed of a heterogeneous mixture steroidogenic, endothelial and immune cells, and it is becoming clear that immune mechanisms play a key role in CL regulation especially in luteolysis. Toll‐like receptors (TLR) mediate innate immune mechanisms via the production of pro‐inflammatory cytokines, especially within various tissues, although the role of TLR within CL remains unknown. Thus, the objectives of this study were to characterize TLR mRNA expression in the CL during the oestrous cycle and in pregnancy (day 30–50), and to examine the role of TLR signalling in luteal cells. Corpora lutea were collected at various stages of the cycle and pregnancy and analysed for TLR and cytokine mRNA expression. In addition, luteal cells were cultured with the TLR4 ligand (lipopolysaccharide, LPS) for 24 h to evaluate the role of TLR4 in regulating luteal function. Toll‐like receptors 1, 2, 4, 6, tumour necrosis factor alpha (TNF), interferon gamma (IFN‐G), and interleukin (IL)‐12, mRNA expressions were greatest in regressing CL compared with earlier stages (p < .05), whereas no change was observed for IL‐6 mRNA expression. Cytokine mRNA expression in cultured luteal cells was not altered by LPS. Based on these data, one or more of the TLRs found within the CL may play a role in luteolysis, perhaps via pro‐inflammatory cytokine mRNA expression.     

Complexed organic matter controls soil physical properties

It is shown that, for mineral soils, it is not the total amount of organic carbon (or organic matter) that controls soil physical behaviour but the amount of complexed organic carbon (COC). We assume that this complex is formed by the association of unit mass (i.e. 1 g) of organic carbon with n grams of clay. Analysis of data from two French and two Polish databases shows that, for these soils, n = 10. A consequence of this is that in soils with small contents of organic carbon (OC), such as arable soils, COC is proportional to OC. However, in soils with large contents of organic carbon, such as pasture soils, COC is proportional to the clay content. This explains why we find that soil bulk density is significantly correlated with OC in French arable soils but with the clay content in French pasture soils. The use of COC instead of OC enables the arable and pasture soils to be considered on the same scale.

Water retention data were fitted to a double-exponential equation which allows both the matrix and structural porosities to be estimated. It is shown that in soils with low contents of organic carbon, the carbon content is positively correlated with the matrix porosity. In contrast, in soils with high contents of organic carbon, the matrix porosity is constant at its maximum value and the structural porosity is not significantly correlated with either the total organic carbon or the non-complexed organic carbon (NCOC). It is suggested that the complexed organic carbon can be considered as being sequestered. The soil clay content can similarly be partitioned between clay that is complexed with organic carbon and clay that is not complexed. It is shown that non-complexed clay is more easily dispersed in water than clay that is complexed with organic carbon. These findings indicate how improved pedo-transfer functions for the prediction of soil physical properties may be produced. Such functions need to use the values of complexed and non-complexed organic carbon and clay which must be determined by algorithms. The values produced by the algorithms may then be used in the improved pedo-transfer functions.     

Strong regularities in world wide web surfing

One of the most common modes of accessing information in the World Wide Web is surfing from one document to another along hyperlinks. Several large empirical studies have revealed common patterns of surfing behavior. A model that assumes that users make a sequence of decisions to proceed to another page, continuing as long as the value of the current page exceeds some threshold, yields the probability distribution for the number of pages that a user visits within a given Web site. This model was verified by comparing its predictions with detailed measurements of surfing patterns. The model also explains the observed Zipf-like distributions in page hits observed at Web sites.