Factors influencing dairy calf and replacement heifer mortality in France

Herd-level risk factors for dairy calf and heifer mortality in France were identified by calculating herd-level variables (including mortality risk or rate) using the National Bovine Identification Database (2005 and 2006). Eleven dairy production areas representing different livestock systems were also included. Statistical analyses were based on a probit model (mortality risk or rate = 0 or >0) and a linear model (mortality risk or rate >0) corrected by the sample bias Heckman method. The same associations were reported for 2005 and 2006. The mortality risks or rates for calves and heifers were positively associated with the proportion of purchased cows or being a Milk Control Program member and negatively associated with adhering to the Good Breeding Practices charter and having an autumn calving peak. The associations between mortality and the breeds or the production areas were positive or negative, depending on the classes of animal. Mortality and having a beef herd in addition to the dairy herd were negatively associated for noncrossed birth to 2-d-old calves, noncrossed 3-d- to 1-mo-old calves, and 3-d- to 1-mo-old heifers. Having a beef herd probably provides specific know-how related to newborn and young calf management that makes it easier to attain low mortality in pure-breed dairy calves. The proportion of males born was positively associated with mortality for the birth to 2-d-old calves (all classes) and for the 3-d- to 1-mo-old beef-crossed calves, but negatively for all classes of heifers. This indicates that heifer management was improved when the availability of newborn heifers decreased, resulting in low mortality. This lower mortality is apparent for all classes of heifers present on the farm during the year when the proportion of males was low, and demonstrates an anticipatory effect. In conclusion, this study shows that the presence of a beef herd in addition to the dairy herd within a farm is associated with decreased dairy calf mortality. It also shows that heifer mortality decreases when the proportion of heifers born decreased. These determinants of dairy calf and heifer mortality are of great importance for farmer advisors, the dairy industry, and the political decision makers.     

Composition and insecticidal activity of essential oil from Pistacia lentiscus L. against Ectomyelois ceratoniae Zeller and Ephestia kuehniella Zeller (Lepidoptera: Pyralidae)

This study reports investigations on the chemical constituents and fumigant toxicity of Pistacia lentiscus L. (Anacardiaceae) essential oil against two major stored-date insects, carob moth Ectomyelois ceratoniae Zeller and Mediterranean flour moth Ephestia kuehniella Zeller. Results showed that P. lentiscus essential oil contained terpinene-4-ol (23.32%), α-terpineol (7.12%) and β-caryophyllene (22.62%) as major compounds. Fumigant toxicity tests showed that P. lentiscus oil was more toxic to E. kuehniella (LC₅₀ = 1.84 μl/l, LC₉₅ = 5.14 μl/l) than E. ceratoniae (LC₅₀ = 3.29 μl/l, LC₉₅ = 14.24 μl/l). The fecundity and hatching rate of both insects decreased with increases in concentration or exposure time to the oil. At 136 μl/l air, fecundities and hatching rates were respectively 35 eggs/female and 42.86% for E. ceratoniae and 78 eggs/female and 29.49% for E. kuehniella.     

Determination of trimethylamine in milk using an MS based electronic Nose

A simple, rapid, reliable and highly automated analytical method has been developed to determine trimethylamine (TMA) in milk using an MS based electronic nose (SMart Nose). A set of Swedish milk samples with and without naturally occurring TMA was used to compare this new method with sensory analysis and dynamic headspace (DHS) gas chromatography with flame ionisation detection (GC-FID). The results show good agreement between these three analytical methods. A lower detection limit (0.5 mg kg^-1) and better repeatability were achieved with this new method compared to both sensory and DHS GC-FID analyses (1-2 mg kg^-1). The user-friendly multivariate analysis software provided with the SMart Nose system was used for TMA determination via a numerical PCA. Using Excel, peak intensity, correlated with TMA concentration via a second order equation, gave similar results. Thus, this is an up to date method of choice for the quantitative determination of TMA in milk. It is also able to give further qualitative information on the milk analysed using the PCA analysis supplied with this equipment.     

Physical mapping of chromosomes VII and XV of Saccharomyces cerevisiae at 3·5 kb average resolution to allow their complete sequencing

The high resolution complete physical maps of chromosomes VII and XV were constructed to form the basis for sequencing these chromosomes as part of the European systematic sequencing programme of the yeast genome, using a unique cosmid library from strain FY1679, and an original top-down mapping strategy involving I-Sce I chromosome fragmentation. A total of 138 and 196 cosmid clones were used to construct the maps for VII and XV, respectively, forming two unique contigs that cover the entirety of chromosomes (1091 kb each), except the telomeric repeats. Colinearity of the cosmid inserts with yeast DNA was verified, and the physical maps were eventually compared with the independently generated genetic maps. © 1998 John Wiley & Sons, Ltd.     

Development of low fat beef patty using <Emphasis Type="Italic">Cucurbita maxima</Emphasis> Duchesne defatted seeds flour paste

The present work aimed at evaluating the Cucurbita maxima Duchesne defatted seeds flour (CDSF) as fat replacer in beef patty. Pastes obtained from CDSF containing 60 and 72 % water were prepared and used to replace fat in beef patty at 25, 50, 75 and 100 % respectively. A control patty was processed using kidney fat from beef. The proximate composition, technological yield, textural and sensorial properties of different samples were evaluated. Results showed that CDSF contains 77.76/100 g proteins based on dried matter. Protein content of patty increased with fat substitution rates (FSR) from 18.82/100 g wet matter (WM) to 23.24/100 g WM respectively for the control (P0) and the sample in which fat was substituted at 100 % with the CDSF paste with a water content of 60 % (P460). The lipid content dropped with the increase in the fat substitution rate and water content of CDSF paste from 10.70/100 to 0.28/100 g WM respectively for the sample in which fat was substituted at 25 % with the CDSF paste with a water content of 60 % (P160) and the sample in which fat was substituted at 100 % with the CDSF paste containing 72 % water (P472). Similarly, hardness dropped from 54.78 N (P0) to 37.56 N (P472) respectively. The cooking yield increased significantly (p < 0.05) with the increase in the water content of the CDSF paste and the fat substitution rate. From the sensory analysis, patties with 75 and 100 % of FSR were the most accepted. Thus, the CDSF paste can be used in beef patty as a fat replacer to reduce the detrimental effect of animal fat consumption.     

Microstructural changes in m. rectus abdominis bovine muscle after heating

A histological and ultrastructural study was conducted to characterize changes in beef muscle structure after heating. Pieces of rectus abdominis muscle were heated at 100 °C over varying time frames from 15 min to 60 min and at 270 °C for 1 min; samples were then prepared for optical and transmission electron microscopy. After 15 min of heating, at 100 °C, a lateral shrinkage in fibre of 48% and an increase in gaps between the myofibrillar masses of 27% was noted. No more significant evolution was observed as heating duration escalated. The ultrastructure showed strong myofibril to sarcolemma detachments in which granular aggregates, coming in part from myofibrillar proteins, are stored. Neighbouring muscle fibres showed strong heterogeneity in morphological behaviour after thermal treatment, suggesting that differences in composition and structure of the cytoskeleton proteins in the different fibres can cause denaturation/shrinkage of the proteins at different times along the timescale of microstructural changes during heating. Short heating at high temperatures expanded the gaps between myofibrillar mass, but the overall changes in the ultrastructure were similar to those obtained when heating at 100 °C.     

Beef sausage structure affected by sodium chloride and potassium lactate

A histological and ultrastructural study was conducted to characterize changes in the muscle fibre structure of three fresh sausage preparations, depending on meat composition, sodium chloride (NaCl) and potassium lactate (K-lactate) contents. After addition of 0.8% and 1.6% NaCl, 65% and 51%, respectively, of the area observed showed well preserved fibres (histological data). The altered regions presented a large disorganization of the myofilaments and a solubilization of the sarcolemma and of the Z lines. K-lactate addition had no marked effects on meat structure. The preparation containing some sheep meat was more sensitive to salt than the others containing only bovine meat. The level of alteration was much lower than those obtained in pork meat in another study. Technological conditions used to modify the internal muscle fibre structure during sausage processing depend on the species used. Therefore, the classification of the sausage preparation to “meat preparation” or “meat product” under the EU regulation (EC) No. 853/2004 (which assign meat preparations to meat if the product has undergone a process insufficient to modify the internal muscle fibre structure of the meat) must be systematically controlled when changing the meat sausage composition.     

In vitro interactions between DMSA-coated maghemite nanoparticles and human fibroblasts: A physicochemical and cyto-genotoxical study

Although the current production of oxide nanoparticles may be modest, the wide range of proposed applications and forecasted growth in production has raised questions about the potential impact of these nanoparticles on the environment and human health. Iron oxide nanoparticles have been proposed for an increasing number of biomedical applications although in vitro toxicity depending on the particles coating has been evidenced. The aim of this study was to examine the potential in vitro cyto- and genotoxicity on human dermal fibroblasts of DMSA-coated maghemite nanoparticles (NmDMSA) as a function of well-defined physicochemical states. Well-stabilized NmDMSA produced weak cytotoxic and no genotoxic effects. This is attributed in part to the DMSA coating, which serves as a barrier for a direct contact between nano-oxide and fibroblasts, inhibiting a potential toxic effect.     

A two-step cloning-free PCR-based method for the deletion of genes in the opportunistic pathogenic yeast Candida lusitaniae

We describe a new cloning-free strategy to delete genes in the opportunistic pathogenic yeast Candida lusitaniae. We first constructed two ura3 Δ strains in C. lusitaniae for their use in transformation experiments. One was deleted for the entire URA3 coding sequence; the other possessed a partial deletion within the coding region, which was used to determine the minimum amount of homology required for efficient homologous recombination by double crossing-over of a linear DNA fragment restoring URA3 expression. This amount was estimated to 200 bp on each side of the DNA fragment. These data constituted the basis of the development of a strategy to construct DNA cassettes for gene deletion by a cloning-free overlapping PCR method. Two cassettes were necessary in two successive transformation steps for the complete removal of a gene of interest. As an example, we report here the deletion of the LEU2 gene. The first cassette was constituted by the URA3 gene flanked by two large fragments (500 bp) homologous to the 5' and 3' non-coding regions of LEU2. After transformation of an ura3 Δ recipient strain and integration of the cassette at the LEU2 locus, the URA3 gene was removed by a second transformation round with a DNA cassette made by the fusion between the 5' and 3' non-coding regions of the LEU2 gene. The overall procedure takes less than 2 weeks and allows the creation of a clean null mutant that retains no foreign DNA sequence integrated in its genome.