Use of the range area in organic egg production systems: effect of climatic factors, flock size, age and artificial cover.

(1) To evaluate the effect of climate, flock size, age and artificial cover on the use of range area, a study was conducted in 1994 to 1998, involving 5 farms with a total of 37 flocks of layers kept in commercial, free-range, organic systems. Flocks were visited regularly during the production period to record the number and distribution of hens on the range. (2) On average 9% of the flock used the range area, but with large variations both within and between flocks, and this was partly influenced by climatic factors.

Derivation of sustainable breeding goals for dairy cattle using selection index theory.

The objective was to present 2 methods for the derivation of nonmarket values for functional traits in dairy cattle using deterministic simulation and selection index theory. A nonmarket value can be a value representing animal welfare and societal influences for animal production, which can be added to market economic values in the breeding goal to define sustainable breeding goals. The first method was restricted indices.

Origin of the high-frequency resonances in 1H NMR spectra of muscle tissue: an in vitro slow magic-angle spinning study.

High-resolution slow magic-angle spinning (150 Hz) 1H PASS NMR spectroscopy is performed on intact excised rat m. tibialis anterior. Untreated muscles and muscles in vitro incubated in Krebs-Ringers buffer based on deuterium oxide are investigated.

Visual appearance and CMT score of foremilk of individual quarters in relation to cell count of cows milked automatically.

The objectives of the study were: to evaluate the interaction between visual appearance and California mastitis test (CMT) score of the foremilk in relation to the cell count of the milk; to evaluate the consequences of sorting milk according to these criteria; and to explore whether visual appearance and CMT score of foremilk depended on the time interval between milkings. Measuring somatic cell count (SCC) in composite milk only and discarding milk above certain thresholds will not ensure that milk from all cows with visually abnormal foremilk is withheld from delivery. Low thresholds of SCC will reduce the frequency of cows with abnormal milk but increase the discarding of milk from cows with visually normal foremilk.

Mammary cell turnover and enzyme activity in dairy cows: effects of milking frequency and diet energy density.

The aim of the study was to investigate the effects of diet energy density and milking frequency on mammary cell turnover and synthetic capacity in dairy cows. Experiment 1 used 20 dairy cows. From d 4 to wk 16 postpartum, the cows were fed either a low-energy density or a high-energy density diet.

Basic concepts of the bovine teat canal.

The bovine teat canal is highly specialized in its unique function of preventing both leakage of milk and entry of bacteria and thereby plays a major role in the defence of the udder against mastitis. The teat canal is a longitudinally folded cylinder-shaped body opening, covered with approximately the same type of epithelia as the normal skin and surrounded with a net-like integrated musculoelastic system facilitating its opening and closure. During milking, dead, flattened, enucleated squamae (cellular detritus) are sloughed from the teat canal surface and are continually replaced by inner cells differentiating outwards.

Effects of diet energy density and milking frequency in early lactation on tumor necrosis factor-alpha responsiveness in dairy cows.

A whole blood stimulation assay (WBA) with Escherichia coli lipopolysaccharide (LPS) and an enzyme-linked immunosorbent assay (ELISA) were established to measure the production of tumor necrosis factor-alpha (TNF-alpha) in bovine plasma. The assays were used to study the effect of time around parturition, and diet energy density, and milking frequency on TNF-alpha responsiveness of dairy cows in early lactation. Forty cows were included in a 2 x 2 factorial block design.

Variance components and selection response for feather-pecking behavior in laying hens.

Variance components and selection response for feather pecking behavior were studied by analyzing the data from a divergent selection experiment. An investigation indicated that a Box-Cox transformation with power lambda = -0.2 made the data approximately normally distributed and gave the best fit for the model.

New device and method for flux-proportional sampling of mobile solutes in soil and groundwater.

The importance of monitoring the transport of organic contaminants in soil and groundwater, and the pros and cons of existing sampling methods, are outlined. A new, alternative sampling method is proposed, using a passive sampler that functions as a water-permeable, semi-infinite sink for passing solutes of interest. Tracers integrated in the device store information on the volume of water passing through the sampler during the installation period.

Tillage erosion and its effect on soil properties and crop yield in Denmark.

Tillage erosion had been identified as a major process of soil redistribution on sloping arable land. The objectives of our study were to investigate the extent of tillage erosion and its effect on soil quality and productivity under Danish conditions. Soil samples were collected to a 0.

A time-resolved immunofluorometric assay for quantification of collectin-43.

CL-43 is a serum collectin involved in the innate immunity of cattle and variability of serum CL-43 may relate to disease in cows. A high capacity time-resolved immunofluorometric assay (TRIFMA) for the bovine collectin-43 (CL-43) was developed. The TRIFMA was constructed as a noncompetitive sandwich based on polyclonal antibodies and a novel monoclonal antibody (mab) raised against CL-43 and was set up to run on an automatic analyser designed for the TRIFMA detection system.

Visualization of drip channels in meat using NMR microimaging.

The progressive changes in the water distribution within rabbit muscles were studied by nuclear magnetic resonance microscopy during the first 24 h postmortem. T(2) images revealed development of interspersed lines with higher signal intensities in the muscle, reflecting formation of channels containing mobile water. The appearance of the interspersed lines progressed throughout the measuring period and became increasingly evident.

Effect of flavonoids on stress responses in myotube cultures.

Effects of flavonoids on stress response of myotube cultures was studied by monitoring the release of [14C] taurine, leukotriene production, and 2',7'-dichlorodihydroflourescein (DCFH2) oxidation. Stress was induced by hypotonic shock, which was accompanied by cell swelling leading to increased leukotriene production and a concomitant increase in reactive oxygen species and osmolyte release. In this model system, addition of the flavonoids catechin and quercetin decreased leukotriene production, DCFH2 oxidation, and taurine efflux, indicating a reduction of cellular stress.

Functionality of myofibrillar proteins as affected by pH, ionic strength and heat treatment - a low-field NMR study.

Myofibrills were extracted from porcine muscle, and their water properties were characterized using low-field nuclear magnetic resonance (NMR) T(2) relaxometry. A T(2) relaxation pattern very similar to the pattern observed in intact meat and water contents comparable to the water content in meat were observed, implying that the myofibrillar structures are responsible for retaining the majority of water in meat. The effect of pH and ionic strength in the samples was investigated as pH was adjusted to 5.

Elucidation of membrane destabilization in post-mortem muscles using an extracellular paramagnetic agent (Gd-DTPA): an NMR study.

The effect of Gd-DTPA on the development in NMR relaxation of skeletal rabbit muscles post-mortem was investigated by dynamic low-field (0.47 T) relaxation measurements from 4 min post-mortem and until 23 h post-mortem. Twelve rabbits were included in the study, and half of the animals were administered 0.

Basic principles of muscle development and growth in meat-producing mammals as affected by the insulin-like growth factor (IGF) system.

This presentation aims to describe how the basic events in prenatal muscle development and postnatal muscle growth are controlled by the insulin-like growth factor system (IGF). The prenatal events (myogenesis) cover the rate of proliferation, the rate and extent of fusion, and the differentiation of three myoblast populations, giving rise to primary fibers, secondary fibers, and a satellite cell population, respectively. The number of muscle fibers, a key determinant of the postnatal growth rate, is fixed late in gestation.

Additional dietary zinc for weaning piglets is associated with elevated concentrations of serum IGF-I.

Two experiments were performed in order to study how weaning and post-weaning dietary zinc level affect serum IGF-I. Further, whether the growth-enhancing effect of 2500 ppm of dietary zinc (Zn2500) and/or 175 ppm of dietary copper (Cu175) in post-weaning diets is associated with elevated serum IGF-I levels in piglets was studied. Experiment 1 included 54 piglets (six litters of nine piglets).

Computer-controlled milk feeding of dairy calves: the effects of number of calves per feeder and number of milk portions on use of feeder and social behavior.

One hundred ninety-two calves (Holstein-Friesian, Danish Red, and Jersey) were allocated to either groups of 24 calves or groups of 12 calves with one computer-controlled milk feeder per group. Within group, one-half of the calves were offered the daily milk allowance in either 4 or 8 milk portions. In groups with 24 calves, there was a higher level of competition for access to the feeder than in groups with 12 calves.

Breast blisters in groups of slow-growing broilers in relation to strain and the availability and use of perches.

1. The relationship between perching behaviour, availability of perches and the incidence and severity of breast blisters in broilers was investigated together with a comparison between two slow-growing broiler strains. 2.

Rapid growth and elongation of bovine blastocysts in vitro in a three-dimensional gel system.

The aim of this study was to establish an in vitro system that supports development and differentiation of bovine blastocysts. Agar gel tunnels were covered with modified synthetic oviduct fluid medium supplemented with 10% fetal calf serum and 3g/l D-glucose. Of the total 67 blastocysts loaded individually into the tunnels, 46 continued expansion to 1mm and reached the walls of the gel on Day 10.

Undesired phenotypic and genetic trend for stillbirth in Danish Holsteins.

The primary aim of this study was to evaluate the phenotypic and genetic trends for stillbirth in Danish Holsteins. Trends of calving difficulty and calf size were also evaluated. The second aim was to compare predicted transmitting abilities (PTA) of sires for stillbirth using a linear and a threshold model.

Digestibility of carbohydrates in growing pigs: a comparison between the T-cannula and the steered ileo-caecal valve cannula.

We compared the determination of ileal and total tract digestibility of carbohydrates in five experimental diets using a double 5 x 5 Latin square design involving a total of 10 cannulated pigs; half of the pigs were equipped with a simple T-cannula and the other half with steered ileo-caecal valve (SICV)-cannula. The diets consisted of nitrogen-free mixture and soya bean meal, sunflower meal, peas or rape seed cake diluted to about 180 g/kg DM protein with the nitrogen-free mixture. There was no significant difference in the digestibility values using the two types of cannulas with regard to organic matter, sugars (sum of glucose, fructose and sucrose), alpha-galactosides (sum of raffinose, stachyose and verbascose), starch, cellulose, total non-cellulosic polysaccharides (NCP) and insoluble NCP constituents.

Influence of whole wheat and xylanase on broiler performance and microbial composition and activity in the digestive tract.

An experiment was carried out to study the effect of different forms of wheat (airtight silo stored whole wheat, conventionally stored whole wheat, and ground wheat included in pellets) and dietary xylanase addition on production results and gastrointestinal characteristics of broiler chickens. Ileal viscosity, pancreatic digestive enzyme activities, and the composition and activity of the intestinal microflora were considered as response parameters. Differences between the 2 types of whole wheat with respect to the various measured parameters were marginal, whereas distinct differences were found between pellet-fed birds and birds receiving whole wheat.

Genetic parameters for stillbirth in Danish Holstein cows using a Bayesian threshold model.

The objective of this study was to make an inference about the direct and maternal genetic variation of stillbirth for first-calving Holstein cows and to estimate the effect of breed and heterosis for original Danish black and white and Holstein-Friesian. A Bayesian threshold model, which included correlated genetic effects of sires and maternal grandsires was used. Marginal posterior distributions of effects were obtained using Gibbs sampling.

Simulation of vegetation cover on sidewalks in Denmark.

Data from five 3-year experiments comparing different strategies of non-chemical weed control were analysed in order to set up a model that could be used for simulating further strategies. The treatments included different frequencies and effects of weed control using flaming, steaming and weed brushing. Each plot consisted of about 100 m of sidewalk.