bluuebunny/crossref_metadata_2025 huggingface dataset:
Low-temperature InP∕GaAs wafer bonding using sulfide-treated surface
Authors: Huang Hui , Ren Xiaomin , Wang Xinyan , Wang Qi , Huang Yongqing
Published: February 2006

An approach for InP∕GaAs wafer bonding based on thiourea treatment was presented. The bonding energy reaches the InP fracture energy by annealing at 360°C. An In0.53Ga0.47As∕InP multiple quantum well (MQW) structure grown on InP was transferred onto GaAs substrate via the bonding process. X-ray diffraction and photoluminescence reveal that crystal quality of the bonded MQW was preserved. A thin sulfide layer with thickness of about 29nm at the bonding interface was detected. X-ray photoelectron spectroscopy analyses indicate that the formation of In–S and Ga–S bond at thiourea treated surface is responsible for the strong fusion obtained at such low temperature.
Electrical charge trapping at defects on the Si(111)7×7 surface
Authors: Jiang C.-S. , Moutinho H. R. , Romero M. J. , Al-Jassim M. M. , Kazmerski L. L.
Published: February 2006

We report on a direct measurement of electron trapping at defects on the Si(111)7×7 surface, by combining Kelvin probe force microscopy (KPFM) and scanning tunneling microscopy (STM) measurements. One-dimensional defects of atomic steps and two-dimensional defects of disordered domains were found on the surface. STM reveals that the disordered domain is located in the intersection area between three 7×7 domains. KPFM measurement shows that electrons are trapped at both the atomic steps and the disordered domains, and this electron trapping gives rise to a larger local work function on the defect region than on the defect-free 7×7 regions.
Semiconductor-laser-pumped high-power upconversion laser
Authors: Heumann Ernst , Bär Sebastian , Rademaker Katja , Huber Günter , Butterworth Stuart , Diening Andreas , Seelert Wolf
Published: February 2006

A high-power optically pumped semiconductor laser operating around 970 nm has been used as a pumping source for an upconversion laser based on an Er3+ doped LiLuF4 crystal. Nearly 0.5 W of continuous wave (cw) output power and 0.8 W peak power at a 50% pump duty cycle could be achieved at a wavelength of 552 nm. This represents the highest output power from a room temperature upconversion laser ever reported. Laser threshold and slope efficiency were measured to be below 100 mW of absorbed pump power and 30%, respectively. This experiment could be an important step along the route to realizing a compact and efficient upconversion laser emitting in the Watt level power regime.
Simultaneous time and frequency gating of weak molecular fluorescence in a thick nonlinear crystal
Authors: Branderhorst M. P. A. , Wasylczyk P. , Walmsley I. A.
Published: February 2006

Time and frequency gating of molecular spontaneous emission at a less than one photon per mode level is achieved using phase matching properties of sum frequency generation in a 3 mm type I BBO crystal. The results of time and frequency resolved fluorescence measurements from a vibrational wavepacket in diatomic potassium molecules are presented. The experimental arrangement is simplified compared to the classical setup which uses a short crystal and monochromator. Both the signal and the signal to noise ratio increase.
Deformation twinning mechanisms in nanocrystalline Ni
Authors: Wu Xiao-Lei , Ma En (Evan)
Published: February 2006

Extensive transmission electron microscopy examinations confirm that twinning does occur upon large plastic deformation in nanocrystalline Ni, for which no sign of deformation twinning was found in previous tensile tests. Compelling evidence has been obtained for several twinning mechanisms that operate in nanocrystalline grains, with the grain boundary emission of partial dislocations determined as the most proficient.
Polariton quantum boxes in semiconductor microcavities
Authors: El Daïf O. , Baas A. , Guillet T. , Brantut J.-P. , Kaitouni R. Idrissi , Staehli J. L. , Morier-Genoud F. , Deveaud B.
Published: February 2006

We report on the realization of polariton quantum boxes in a semiconductor microcavity under strong coupling regime. The quantum boxes consist of mesas, etched on the top of the spacer of a microcavity, that confine the cavity photon. For mesas with sizes of the order of a few microns in width and nanometers in depth, we observe quantization of the polariton modes in several states, caused by the lateral confinement. We evidence the strong exciton-photon coupling regime through a typical anticrossing curve for each quantized level. Moreover, the growth technique permits one to obtain high-quality samples, and opens the way for the conception of new optoelectronic devices.
Fast-response no-bias-bend liquid crystal displays using nanostructured surfaces
Authors: Yeung Fion Sze-Yan , Kwok Hoi-Sing
Published: February 2006

We present results of a fast-response no-bias-bend (NBB) liquid crystal display, made possible by using a nanostructured alignment layer. Such alignment layers allow high pretilt angles of over 45° to be fabricated reliably. Thus, a stable bend configuration pi-cell can be achieved without applying any bias voltage to the cell. This NBB cell has a total on-off response time of less than 1.8ms and is faster than the corresponding optically compensated bend cell with a low pretilt angle.
The development of harmful social behaviour in pigs with intact tails and different enrichment backgrounds in two housing systems
Authors: Van de Weerd H. A. , Docking C. M. , Day J. E. L. , Edwards S. A.
Published: February 2006

The present study compared the performance and development of adverse behaviours of pigs with intact tails, when housed in a straw-bedded system or a part-slatted system enriched with a commercial device. The pigs had previously received different enrichment treatments (rooting box, liquid dispenser, straw bedding or none), either in the farrowing crate or with their lactating dam or post weaning. The pigs were mixed in groups at 10 weeks of age and from then on, every 2 weeks, behavioural observations were performed, focusing mainly on harmful social behaviour and enrichment use. The study showed that pigs with undocked tails can be at high risk of tail biting in part-slatted systems, whereas the straw bedding prevented the development of tail biting. The immediate effects of the environment seemed to exert a greater influence on the development of adverse behaviour than early life enrichment and adding a simple enrichment device could not compensate for the deficiencies in the barren environment of the part-slatted system. In order to prevent vice, functional design of environmental enrichment is required.
Effects of sow nutrition on maternal and foetal serum growth factors and on foetal myogenesis
Authors: Nissen P. M. , Sørensen I. L. , Vestergaard M. , Oksbjerg N.
Published: February 2006

The objective of this study was to examine the effect of increased maternal nutrition in early to mid gestation on changes in serum growth factors of the sow and foetuses. Furthermore, the effect of the foetal sera on in vitro proliferation and differentiation of porcine primary myoblasts was examined. Pregnant sows were either given food either in accordance to requirements (2 kg/day; C) until day 50 or 70 of gestation or given food in accordance to requirements until day 25 and then ad libitum (A) until day 50 or 70. Sows were slaughtered at the Institute's veterinary controlled slaughterhouse at day 50 or 70, respectively. Serum from sows and pools of cord-blood serum from each litter were analysed for glucose, lactate, insulin, insulin-like growth factor (IGF; IGF-1 and -2) and IGF binding proteins (IGFBPs). IGF-1 (P < 0·001) was higher in A compared with C sows, and a 28-kDa IGFBP (P < 0·05) and a 24-kDa IGFBP (P < 0·05) was higher in serum from day 70 compared with day 50 sows. There was no significant effect of food intake on growth factor concentrations in foetal serum or on serum-induced proliferation and differentiation of myoblasts. A 28 kDa IGFBP, IGFBP-2 and -3 were all higher (P < 0·06) and serum-induced proliferation (P < 0·001) and differentiation (P < 0·1) lower at day 70 than day 50. Maternal food intake did not influence the DNA and RNA concentrations and the CPK activity in the foetal longissimus dorsi muscle. The glucose concentration in the liver was higher in C than A foetuses at day 70 of gestation, but not at day 50.

In conclusion, no significant effects of maternal nutrition were found on serum growth factor concentrations in the foetuses or on serum-induced proliferation and differentiation of primary myoblasts.
Performance of weanling pigs offered low or high lactose diets supplemented with avilamycin or inulin
Authors: Pierce K. M. , Callan J. J. , McCarthy P. , O'Doherty J. V.
Published: February 2006

One hundred and eighty piglets (24 days old, 6·0 kg live weight) were used to investigate interactions between lactose, avilamycin and inulin on growth performance and nutrient digestibility in weaned piglets. The piglets were blocked on the basis of live weight and within each block assigned to one of six dietary treatments (six replicates (pens) per treatment). The piglets were offered diets containing either a low (175 g/kg) or high (295 g/kg) lactose levels with one of the following food additives (1) 0 supplementation (2) avilamycin (60 mg/kg) or (3) inulin (15 g/kg) in a 2 × 3 factorial arrangement. The starter diets were offered for 21 days and all diets contained chromium III oxide at 150 p. p. m. There was an interaction (P< 0·05) between lactose level and both avilamycin and inulin on average daily gain (ADG) during the starter period (days 0 to 21). The pigs receiving 295 g/kg lactose level had a higher overall ADG than pigs receiving 175 g/kg lactose level. However, there was no difference between 295 g/kg lactose and 175 g/kg lactose in ADG when the diets were supplemented with avilamycin or inulin. There was an interaction between lactose level and inulin in the apparent digestibility of gross energy (GE) and nitrogen (N) (P< 0·05). The inclusion of inulin with 175 g/kg lactose increased GE digestibility compared with the 175 g/kg lactose only diet. However, the inclusion of inulin with 295 g/kg lactose had no effect on GE digestibility. The inclusion of inulin with 295 g/kg lactose reduced N digestibility compared with the inclusion of inulin at 175 g/kg lactose. However, there was no difference in N digestibility between 175 and 295 g/kg lactose only diets. In conclusion, there was no benefit in terms of pig growth rate to supplementing diets high in lactose with either inulin or avilamycin. However, the inclusion of inulin improved the energy digestibility of diets low in lactose.
Costs of the major endemic diseases of sheep in Great Britain and the potential benefits of reduction in disease impact
Authors: Nieuwhof G. J. , Bishop S. C.
Published: February 2006

The costs of three major endemic sheep diseases in Great Britain, gastro-intestinal (GI) parasites, footrot and scab, were estimated and compared with costs for other diseases from another study. Disease costs include lost performance, preventive measures and treatment of affected animals. The most costly disease, of those studied, for the British sheep industry is infestation with GI parasites, with estimated annual costs of £84 million. Annual costs for the other two diseases are £24 million for footrot and £8 million for sheep scab. This compares with literature estimates of £20 million for Chlamydial abortions and £12 million for toxoplasmosis. For sheep scab most costs are for preventive measures, therefore, short of eradication, a reduction in incidence will have a limited effect on costs. For GI parasites, costs are linearly related to the severity of the infestation and a reduction of the disease will have a proportional effect on the costs to the industry. For footrot about half the costs are for preventive measures, the other half is for lost production and treatment. A reduction in the incidence of footrot has a proportional effect on the £10 million associated with loss of production and treatment of infected animals. It is concluded that gastro-intestinal parasites and footrot are two sheep diseases in Britain for which a reduction of severity or incidence will have a large impact on costs of production.
Effect of drinking saline water on food and water intake, food digestibility, and nitrogen and mineral balances of rusa deer stags (Cervus timorensis russa)
Authors: Kii W. Yape , Dryden G. McL.
Published: February 2006

The salinity tolerance of Javan rusa deer (Cervus timorensis russa) was investigated with seven stags, aged 4·5 years. Animals were offered a medium-quality chaffed lucerne hay and given five different levels of water salinity: (a) control (570 mg/kg of total dissolved salts (TDS)) and (b) ‘saline’ water with TDS contents of 1000, 3500, 6000 and 8500 mg/kg. Food intake, food digestibility and nitrogen balance were not affected by increasing salt concentration in drinking water, however the drinking water (DW) intake, the total (food plus drinking) water intake and the DW:dry-matter ratio increased with increasing salt concentration. Some deer given water containing 8500 mg TDS per kg showed signs of stress which included large between-day fluctuations in water intake, opening of the orbital gland, head shaking, and rapid breathing. Rusa deer can tolerate drinking water containing 6000 mg TDS per kg for at least 9 days without harmful effect but may be unable to tolerate water with 8500 mg TDS per kg.
Intake, growth and meat quality of steers given diets based on varying proportions of maize silage and grass silage
Authors: Juniper D. T. , Browne E. M. , Fisher A. V. , Bryant M. J. , Nute G. R. , Beever D. E.
Published: February 2006

Simmental × Holstein-Friesian steers were offered four forage diets. These comprised grass silage (G); proportionately 0·67 grass silage, proportionately 0·33 maize silage (GGM); 0·33 grass silage, 0·67 maize silage (MMG); maize silage (M) from 424 (s.d. = 11·5) kg to slaughter at a minimum weight of 560 kg. Forages were mixed and offered ad libitum. Steers were offered 2 kg of a concentrate daily, the concentrate being formulated such that all steers had similar crude protein intakes across dietary treatments. A sample of steers was slaughtered at the beginning of the experimental period to allow the calculation of the rate of gain of the carcass and its components. Carcass dissection of a sample of steers allowed the development of a prediction equation of carcass composition based on thoracic limb dissection of all carcasses. Forage dry matter intake and live-weight gain increased linearly as maize silage replaced grass silage in the forage mixture, resulting in improvements in food conversion ratio (allP= 0·001). Killing-out proportion increased with maize silage inclusion (P< 0·001) but fat and conformation scores did not differ significantly between diets. However, increasing maize inclusion in the diet resulted in a greater weight (P= 0·05) and proportion (P= 0·008) of fat in the carcass, and significant increases in internal fat deposition. The inclusion of maize led to a progressive increase in the daily gains of carcass (P< 0·001), and significant increases in the daily gains of both fat (P< 0·001) and lean tissue (P< 0·001). Fat colour was more yellow in cattle given diets G and GGM than diets MMG and M(P< 0·001) and colour intensity was lower on diet M than the other three diets (P< 0·001). There were no significant differences in any aspects of eating quality between diets. Therefore, maize silage has the potential to reduce the time taken for finishing beef animals to achieve slaughter weight with no apparent detrimental effects on subsequent meat quality.
Effects of restricted feeding and re-feeding of Barbarine lambs: intake, growth and non-carcass components
Authors: Mahouachi M. , Atti N.
Published: February 2006

Abstract Fifty intact male Barbarine lambs were used to assess the effects of restricted feeding and re-alimentation on intake, growth and non-carcass components. Five lambs were slaughtered at the start of the trial, the remainder were randomly allocated into three groups. One group was offered only stubble grazing (low: L), another, also on stubble, received, indoors, an average of 80 g dry matter (DM) of soya-bean meal per day (medium: M); the third group was kept indoors and had free access to hay and 450 g of concentrate per day (high: H). At the end of this restriction period (70 days), five lambs per group were slaughtered. The 10 remaining animals in each group were divided into two groups receiving concentrate and hayad libitum. The crude protein content (CP) of the concentrate was 160 and 210 g/kg DM for the two treatments, respectively. At the end of the trial all animals were slaughtered at 37·61 ± 2·05 kg live weight.

In the restriction period, sheep from the H group had a significantly higher growth rate (108 g/day) than L group (61 g/day) with M intermediate. The empty body weight (EBW) as well as carcass weight were significantly higher in H than in restricted sheep. Digestive tract components and liver weight were the same for all treatments. However, skin weight was significantly (P< 0·01) affected by dietary treatment. The heart and lungs were also heavier in H lambs than in the two other groups. Conversely, the relative weights of gut and liver as proportion of EBW increased in restricted lambs, while that of skin and red organs was not affected by diet.

In the re-alimentation period and with both CP levels, the compensating animals showed the same growth rate as the previous unrestricted ones. At the end of this period, organ weights, in both absolute and relative value, were comparable among lambs of the three nutritional histories and two CP level. The absolute and proportional daily gains were similar in all animals for visceral and external organs, but they were significantly higher in H lambs than in L and M ones for the omental and mesenteric fat and testis.
An improved model for the French genetic evaluation of dairy bulls on length of productive life of their daughters
Authors: Ducrocq V.
Published: February 2006

Functional longevity of dairy cows has been routinely evaluated in France since 1997 using a survival analysis model. Recently, we proposed a genetic trend validation test that could be used before including national data in an international evaluation of bulls on longevity of their daughters. Its application to the French Holstein data revealed a large overestimation of the genetic trend. It was found that the bias is the result of a change in the baseline hazard rate over time. A new proportional hazards model is proposed which accounts for this change. In the new model, the baseline is described as a stratified, piecewise Weibull hazard function within lactation, i.e. a function of the number of days since the most recent calving. Stratification is within year and parity. Different Weibull hazard functions are used over four periods: 0 to 270 days, 271 to 380 days, 381 days to day when dried, dry period until the next calving. The non-genetic effects included in the model were slightly different from the previous one. In particular the interaction effects between the within herd-year class of production and lactation number × stage of lactation on the one hand and year-season were accounted for. The estimated genetic variance was smaller than with the old model. The new genetic trend is almost flat. An illustration of the efficiency of selection on the estimated breeding values for longevity is presented.
Assessment of amino acid requirements for optimum fermentation of xylan by mixed micro-organisms from the sheep rumen
Authors: Guliye A. Y. , Atasoglu C. , Wallace R. J.
Published: February 2006

A deletion approach was undertaken to identify which amino acids (AA) most limited the growth of mixed ruminal microorganisms on xylan. Ruminal fluid was withdrawn from sheep receiving a mixed grass hay/concentrate diet and incubated for 24 h with oat spelts xylan in the presence or absence of a mixture of 20 AA or the same mixture with a single AA deleted. Gas and volatile fatty acid production were increased by the AA mixture in comparison with incubations in which ammonia was the only added nitrogen (N) source, and the deletion of each of the aromatic AA, tyrosine, phenylalanine and tryptophan, as well as leucine and methionine, led to decreases (P< 0·05) in fermentation rate. The addition of aromatic AA as a mixture to ammonia-only fermentations increased (P< 0·05) the fermentation rate but failed to replicate the benefits of the complete mixture of AA. Although the addition of all 20 AA increased (P< 0·05) the microbial yield by up to 0·56, no single AA deletion had a significant (P> 0·05) influence on microbial yield, and the aromatic AA mixture also did not increase the microbial yield on xylan over the yield with ammonia as sole N source. It was concluded that aromatic AA may be first-limiting for xylan fermentation, but they cannot replace the benefits of a complete mixture of 20 AA in stimulating xylan fermentation by ruminal micro-organisms.
The use of visible (VIS) and near infrared (NIR) reflectance spectroscopy to predict fibre diameter in both clean and greasy wool samples
Authors: Cozzolino D. , Montossi F. , San Julian R.
Published: February 2006

Abstract Visible (VIS) and near infrared (NIR) reflectance spectroscopy combined with multivariate data analysis were explored to predict fibre diameter in both clean and greasy Merino wool samples. Fifty clean and 400 greasy wool samples were analysed. Samples were scanned in a large cuvette using a NIRSystems 6500 monochromator instrument by reflectance in the VIS and NIR regions (400 to 2500 nm). Partial least square (PLS) regression was used to develop a number of calibration models between the spectral and reference data. Different mathematical treatments were used during model development. Cross validation was used to assess the performance and avoid overfitting of the models. The NIR calibration models gave a coefficient of determination in calibration (R2) > 0·90 for clean wool samples and a R2 < 0·50 for greasy wool samples. The values for the residual predictive value, RPD (ratio of standard deviation (s. d.) to the root mean square of the standard error of cross validation (RMSECV)) were 3 for clean and 0·6 for greasy wool samples, respectively. The results indicated that fibre diameter in greasy wool samples was poorly predicted with NIR, while clean wool showed good relationships.

More research is required to improve the calibration on greasy wool samples if the technology is to be used for rapid analysis to assist in the selection of animals in breeding programmes.
The weight and concentration of body components in high genetic merit Holstein-Friesian dairy cows managed on four different grassland-based feeding regimes
Authors: Woods V. B. , Ferris C. P. , Gordon F. J.
Published: February 2006

It is well established that the genetic merit of the Holstein-Friesian dairy cow for milk production has increased over the past 20 years. Previous studies have examined the effect of feeding system on indices of body tissue reserves of medium genetic merit Holstein-Friesian dairy cows. The aim of the current study was to examine the weight and concentration of body components in high genetic merit Holstein-Friesian dairy cows, managed on four different grassland-based feeding regimes, using direct measures of body composition. Results indicate that there was no significant effect of different grassland-based feeding regimes on the weight or composition of body components of high genetic merit cows. Therefore, high levels of cow performance can be sustained from very different grassland-based systems of milk production without having a detrimental effect on body tissue reserves.
The interaction between cereal type and lactose level on piglet performance and diet digestibility post weaning
Authors: O'Connell J. M. , Callan J. J. , O'Doherty J. V.
Published: February 2006

Both barley and wheat contain anti-nutritive factors such as glucans and xylans respectively. However, β-glucans have been shown to promote lactic acid bacteria in the large intestine and this would be very beneficial in the absence of in-diet antimicrobial growth promoter. A 2 × 2 factorial was used to investigate the interaction between cereal type (wheatv. barley) and lactose inclusion (170v. 275 g/kg) on piglet performance post weaning. Two hundred and sixteen weaned piglets (24 days of age, 6·0 kg weight) were blocked on the basis of weight and were assigned to one of four dietary treatments. The treatments were as follows (T1) 170 g/kg lactose and wheat, (T2) 275 g/kg lactose and wheat, (T3) 170 g/kg lactose, wheat and 200 g/kg barley and (T4) 275 g/kg lactose, wheat and 200 g/kg barley. The diets were formulated to have identical concentrations of digestible energy (16 MJ/kg) and total lysine (16 g/kg). The pigs were offered the diets ad libitum for 33 days post weaning. There was a significant interaction (P< 0·05) between cereal source and lactose level in average daily gain (ADG). In wheat-based diets the inclusion of 275 gkg lactose resulted in a significant improvement in ADG, compared with the 170 g/kg lactose inclusion. However, in barley-based diets the inclusion of 275 g/kg lactose significantly (P< 0·05) reduced ADG. There was no significant effect of cereal type or lactose level on food intake or food conversion ratio (FCR). The inclusion of 275 g/kg lactose significantly reduced nitrogen digestibility (P< 0·01). In barley-based diets, the high level of lactose inclusion depressed digestibilities of dry matter (P< 0·01), organic matter (P< 0·05) and gross energy (P< 0·05) compared with low lactose inclusion. However, in wheat-based diets, lactose level had no significant effect. In conclusion, improvements in performance were achieved up to 275 g/kg lactose in wheat-based diets. However, in barley-based diets a dietary lactose level of 170 g/kg was adequate.
Accumulation of potentially toxic metals in the liver tissue of sheep grazed on sewage sludge-treated pastures
Authors: Rhind S. M. , Kyle C. E. , Owen J.
Published: February 2006

Concentrations of potentially toxic metals (PTMs) in the livers of pregnant, mature ewes and their 110 day foetuses, and in 6-month old lambs born to other ewes, were determined. The animals had been reared on pastures fertilized for 5 years with either sewage sludge (treated; T) or conventional inorganic fertilizer (control; C). The effects of treatment on patterns of accumulation of PTMs differed with stage of development and with individual PTM. In the liver of lambs, concentrations of Pb were elevated in T compared with C liver (P< 0·01), while Cu and Zn were lower (P< 0·001) in T than C liver. By contrast, in ewe liver, Cu concentrations were lower in T than C liver (P< 0·05), as in lambs, but there were no other treatment differences in PTM concentration. Ewe and lamb tissue data were not directly comparable because they were exposed to different diets but mean concentrations of Cd, Ni and Pb were approximately two- to four-fold higher in ewe than lamb liver while mean Cu concentrations were approximately five-fold lower, suggesting that more prolonged exposure to PTMs may have enhanced treatment differences in tissue PTM concentrations. Mean foetal PTM concentrations were not significantly affected by treatment. It is concluded that the repeated application of sludge to pasture is associated with altered, but not necessarily increased, rates of accumulation of PTMs in liver tissue, that rates of accumulation depend on the individual PTM measured and that they are probably influenced by duration and route of exposure and source of nutrient. Limited observations suggested that there was little effect of year, and associated variation in climatic conditions and herbage growth, on PTM accumulation.
Effects of age of Holstein-Friesian calves on plasma cortisol, acute-phase proteins, immunological function, scrotal measurements and growth in response to Burdizzo castration
Authors: Ting S. T. L. , Earley B. , Veissier I. , Gupta S. , Crowe M. A.
Published: February 2006

To determine the effect of age at castration on physiological and immunological stress indices, 60 Holstein-Friesian bull calves were sourced so that they were in one of five age groups for Burdizzo castration on day 0 (16 July 2002; no. = 10 per treatment) : 1·5, 2·5, 3·5, 4·5, and 5·5 months of age (mean body weight ± s.e. = 63 ± 2·5, 89 ± 3·7, 104 ± 3·7, 142 ± 3·6, 169 ± 8·1 kg, respectively), or were sham castrated at 5·5 months of age (171 ± 2·9 kg body weight) to serve as intact controls specific to this age group. Blood samples were collected at 15- to 30-min intervals from 2 h before until 8 h after treatment, with further samples collected at 10 and 12 h on day 0, and on days 1, 2 and 3, and weekly from days 7 to 35 after treatment. Following castration, peak plasma cortisol responses were significantly greater in 5·5-month-old castrates than intact calves, and all calves castrated at a younger age had reduced peak responses, with the greatest reduction in 1·5-month-old castrates. Overall, the integrated cortisol responses for the first 3 h after castration were three-fold greater in 5·5-month-old castrates than intact calves. While the integrated cortisol responses were reduced by proportionately 0·46 and 0·35 in 1·5- and 4·5-month-old castrates, the lower responses observed in 2·5- and 3·5- month-old castrates were not significantly different from the 5·5-month-old castrates. The integrated cortisol responses for the next 9 h after castration were not different among treatment groups. On day 3 after castration, peak plasma haptoglobin and fibrinogen concentrations were significantly greater in 5·5-month-old castrates than intact calves, but the concentrations were markedly reduced in calves castrated at 1·5 and 2·5 months than when castrated at 5·5 months of age. On day 1, phytohaemagglutinin-inducedin vitrointerferon-γ production was suppressed in 5·5-month-old castrates compared with intact calves. Scrotal circumferences increased in all castrates on day 1 and 7 and were greater in 5·5- month-old castrates than intact calves, but the swelling was reduced in the 1·5- compared with 5·5-month-old castrates. The temperature differences between the core body and scrotal skin were greater on day 2 and 3 in the 1·5-month-old than all other castrates. There was no effect of castration on the overall 42-day growth rates of calves. In conclusion, the physiological stress and inflammation caused by Burdizzo castration, indicated by increased plasma cortisol, acute-phase proteins, scrotal swelling, and depressed temperature differences between the core body and scrotal skin were reduced by castrating calves at 1·5 months rather than at 5·5 months of age.
Comparative apparent total tract digestibility of major nutrients and amino acids in dogs (Canis familiaris), blue foxes (Alopex lagopus) and mink (Mustela vison)
Authors: Vhile S. G. , Skrede A. , AhlstrØm Ø. , Hove K.
Published: February 2006

Major nutrient and amino acid digestibilities were evaluated in experiments with dogs (Canis familiaris), blue foxes (Alopex lagopus) and mink (Mustela vison) using seven extruded diets containing different protein sources. Four dogs (German shepherd), four blue foxes and four mink were offered each of the experimental diets to determine apparent total tract digestibility. Average digestibility of crude protein (CP) in blue foxes and mink was similar, and lower than the corresponding value in dogs (0·834 and 0·831 v. 0·864) (P< 0·001). CP digestibility in blue foxes showed significant correlations with dogs and mink (P< 0·05), while no significant correlation was observed between dogs and mink. Average digestibility of most amino acids was significantly lower in blue foxes than in dogs (P< 0·001), whereas mink digested most essential amino acids at the same level as did dogs. Most non-essential amino acids were digested at a significantly lower rate in the mink than in the dog and the blue fox (P< 0·001). There were significant correlations in the digestibility of most amino acids between dogs and blue foxes, and between blue foxes and mink (P< 0·05). Correlations were significant between dogs and mink for the digestibility of most essential amino acids (P< 0·05) but not significant (P> 0·05) for several non-essential amino acids. Average digestibility of crude fat was high and similar among the species studied: 0·968, 0·967 and 0·959 in dogs, blue foxes and mink, respectively. Average digestibility of starch ranged from 0·971 in mink to 0·998 in dogs; significantly higher in dogs than in blue foxes and mink, and significantly higher in blue foxes than in mink (P< 0·001). It was concluded that digestibility determined with mink, blue foxes or dogs may be used to predict digestibilities in the other investigated species. However, both the characteristics of the protein sources as well as the individual amino acid studied will influence the difference in digestibility among the species.
Effect of nucleotide supplementation on lymphocyte DNA damage induced by dietary oxidative stress in pigs
Authors: Salobir J. , Rezar V. , Pajk T. , Levart A.
Published: February 2006

The aim of the present study was to evaluate the effect of nucleotide supplementation on the oxidative stress induced by a high proportion of dietary polyunsaturated fatty acids ( PUFAs) in pigs. Twenty-four male growing pigs were penned individually and after an adaptation period divided into three groups. All groups received isocaloric daily rations composed of a basal diet supplemented with either: starch (CONT), linseed oil (LIN) and LIN and nucleotides (LIN + NUC). The experimental period lasted 21 days. Oxidative stress was evaluated by measuring the degree of lymphocyte nuclear DNA damage, the urine malondialdehyde ( MDA) excretion rate, erythrocyte glutathione peroxidase concentration and the total anti-oxidant status of plasma. Malondialdehyde concentrations in the blood and MDA urinary excretion rates were higher (P< 0·01) in animals supplemented with LIN and LIN + NUC compared with CONT animals. The degree of DNA damage in the LIN-supplemented animals was also higher (P< 0·01). Compared with the LIN-supplemented animals, nucleotide supplementation reduced (P< 0·01) the degree of DNA damage in lymphocytes to the level of the CONT group. Erythrocyte glutathione peroxidase concentration and plasma total anti-oxidant status were similar across treatments. The results of this experiment indicate that nucleotide supplementation effectively eliminates the genotoxic effects of high PUFA intakes on blood lymphocytes and demonstrates new evidence for the immunonutritive effect of nucleotides.
A comparison between feeding a single diet or phase feeding a series of diets, with either the same or reduced crude protein content, to growing finishing pigs
Authors: O'Connell M. K. , Lynch P. B. , O'Doherty J. V.
Published: February 2006

Abstract A study was designed to determine if pig performance and lysine conversion ratio would be improved by phase feeding a series of diets with either the same, or with reduced overall mean crude protein (lysine) content, compared with providing a single diet throughout the growing-finishing period. Four hundred and forty-eight group-penned pigs (no. = 32 groups) were assigned at random to one of four treatments: single diet (SD: 11·1 g lysine per kg), high lysine (HL: 12·2, 11·6, 11·1, 10·5 and 10·0 g lysine per kg), medium lysine (ML: 11·1, 10·5, 10·0, 9·5 and 8·9 g lysine per kg) and low lysine series of diets (LL: 10·0, 9·5, 8·9, 8·4 and 7·8 g lysine per kg). The mean lysine contents of the treatments were 11·1, 11·1, 10·0 and 8·9 g/kg for SD, HL, ML and LL respectively. There were five 2-week phases from 38·3 kg to slaughter at 97·3 kg live weight. LL pigs had lower carcass average daily gain (709 v. 742 g/day;P< 0·05) and poorer carcass FCR (P< 0·05: 2·95 v. 2·84 kg/kg) than SD pigs. Daily lysine intake was lower for pigs on HL (P< 0·05: 22·5 g/day), ML (P< 0·001: 20·9 g/day) and LL (P< 0·001: 18·2 g/day) compared with SD (23·4 g/day). Live weight lysine conversion ratio was better for HL (P< 0·05: 26·9 g/kg), ML (P< 0·001: 24·5 g/kg) and LL (P< 0·001: 22·6 g/kg) pigs compared with SD pigs (27·6 g/kg), but carcass lysine conversion ratio was only better for pigs on the ML (P< 0·001: 27·9 g/kg) and LL (P< 0·001: 25·7 g/kg) treatments compared with SD (31·6 g/kg). Nitrogen intake was lower for LL pigs than SD pigs (P< 0·001: 3·45 v. 4·03 kg). Estimated nitrogen excretion was lower for ML (P< 0·01: 2·16 kg) and LL (P< 0·001: 1·85 kg) pigs than SD pigs (2·47 kg). Nitrogen deposition rate was lower for pigs on the LL compared with the SD treatment (P< 0·05: 22·3 v. 23·2 g/day). Although phase feeding diets with the same mean lysine content (11·1 g/kg) as a single diet over the growing-finishing period resulted in similar pig performance, reduced overall daily lysine intake and improved lysine conversion ratio, there was no effect on carcass characteristics or carcass lysine conversion ratio. Reducing the overall mean lysine content to either 10·0 or 8·9 g/kg improved lysine conversion ratio and reduced nitrogen excretion. However, reducing the overall mean lysine content of the diet to 8·9 g/kg had a negative effect on pig growth performance.
Determination of the optimum dietary lysine concentration for growing pigs housed in pairs and in groups
Authors: O'Connell M. K. , Lynch P. B. , O'Doherty J. V.
Published: February 2006

Three 28-day trials were carried out to determine the optimum dietary lysine concentration for growing pigs between 20 and 68 kg. There were 96 pairs of pigs in experiment 1 (20 to 41 kg), 72 pairs in experiment 2 (40 to 68 kg) and 42 groups (14 per group) in exp. 3 (40 to 62 kg). All experiments were arranged as randomized complete block designs, blocked on the basis of sex and start weight. Treatments consisted of isoenergetic (13·8 MJ digestible energy per kg) diets with increasing lysine concentrations. Dietary lysine concentrations were 9·7, 10·7, 11·6, 12·5, 13·5 and 14·4 g/kg (experiment 1) and 9·0, 9·9, 11·0, 12·1, 13·1 and 14·1 g/kg (experiments 2 and 3). Response curves were fitted to the data to determine the optimum dietary lysine concentration for maximum average daily gain (ADG) and minimum food conversion ratio (FCR). In experiment 1, ADG and FCR responded quadratically to dietary lysine content (P < 0·01 and P < 0·05). Male pigs had better FCR and lysine conversion ratio (LCR) than female pigs (P < 0·05). In experiment 2, there was a quadratic effect of increasing dietary lysine concentration on FCR (P < 0·05). Male pigs had lower daily food intake (DFI, P < 0·01) and daily lysine intake (DLYIN, P < 0·01) and had better FCR (P < 0·01) and LCR (P < 0·01) than female pigs. In experiment 3, there was a quadratic effect of increasing lysine concentration on FCR (P < 0·05). Male pigs had better FCR and LCR (P < 0·05) than female pigs. In all experiments, increasing dietary lysine concentration resulted in an increase in DLYIN and a deterioration in LCR (all linear, P < 0·001). Regression analysis predicted optimum dietary lysine concentrations for maximum ADG at 13·1 and 12·7 g lysine per kg in experiments 1 and 2, and minimum FCR at lysine concentrations of 14·6, 12·2 and 12·7 g/kg for experiments 1, 2 and 3 respectively. In conclusion, the optimum dietary lysine concentration for maximum ADG and minimum FCR could be predicted using quadratic models and although males had better FCR than females, optimum dietary lysine concentrations were similar for both sexes.
Validation of use of purine bases as a microbial marker by15N labelling in growing lambs given high-concentrate diets: effects of grain processing, animal age and digesta sampling site
Authors: Askar A. R. , Guada J. A. , Balcells J. , de Vega A. , Castrillo C.
Published: February 2006

The origin of post-ruminal purine bases (PB) was studied in 24 growing lambs that were given a pelleted concentrate plus barley straw (C) or whole barley grain plus protein supplement (WB). Six lambs from each treatment were slaughtered at 10 and 30 days post weaning after15N labelling of microbial nitrogen (N) and PB. Microbial contribution to digesta non-ammonia N (NAN) and PB was lower (P< 0·01) when estimated from duodenal rather than abomasal samples (0·36 v. 0·52 (s.e.d. 0·021) for NAN and 0·47 v. 0·77 (s.e.d. 0·029) for PB) as a result of endogenous contamination. In comparison with15N, total PB/N led to higher estimates (P< 0·01) of microbial contribution to abomasal NAN in WB treatment (0·62 v. 0·46 s.e.d. 0·049). The difference was removed after correcting for microbial PB, while this effect was not observed with < the C diet, resulting in a marker by diet interaction (P< 0·05). Abomasal PB flow increased (P< 0·1) from 10 to 30 days after weaning mainly due to the higher proportion of microbial PB (0·70 v. 0·81 (s.e.d. 0·047)). Rumen apparent PB degradation did not differ between diets in older lambs, but it was proportionally 0·39 lower for WB treatment (P< 0·05) in younger lambs. When the microbial PB flow was estimated indirectly from labelled microbial N and the PB/N ratio of bacterial extracts the estimates were in agreement with those derived from PB-15N in the WB treatment but resulted in unrealistic values in lambs on diet C. Results suggest that significant proportions of dietary PB can escape rumen degradation which may lead to overestimation of microbial contribution to abomasal NAN when the PB/N ratio is used as marker. The extent of the overestimation is affected by the lamb age and grain processing.
Livestock production post CAP reform: implications for the environment
Authors: Oglethorpe D. R.
Published: February 2006

On 1 January 2005, the direct support schemes directed at UK livestock farmers as part of the Common Agricultural Policy (CAP) were replaced with a Single Farm Payment, decoupled from production. In practical term, this means that farmers now have freedom of choice over the particular farm enterprises they engage in since their income support is no longer dependent on their type of production. Farmer policy-response will be dependent on their previous dependence on the direct subsidies being replaced, which, as the paper shows, is considerable for UK livestock farmers. The paper suggests a dichotomous shift of farmer objective in the livestock sector in the future, with ‘environmental managers’ and ‘market managers’ focusing on different outputs. The outcome will be a significant down-sizing of the UK livestock sector but with probable net gains to the environment.
Similarities and differences in interaction of K + and Na + with condensed ordered DNA. A molecular dynamics computer simulation study
Authors: Cheng Yuhua , Korolev Nikolay , Nordenskiöld Lars
Published: February 2006

Four 20 ns molecular dynamics simulations have been performed with two counterions, K + or Na + , at two water contents, 15 or 20 H 2 O per nucleotide. A hexagonal simulation cell comprised of three identical DNA decamers [d(5′-ATGCAGTCAG) × d(5′-TGACTGCATC)] with periodic boundary condition along the DNA helix was used. The simulation setup mimics the DNA state in oriented DNA fibers or in crystals of DNA oligomers. Variation of counterion nature and water content do not alter averaged DNA structure. K + and Na + binding to DNA are different. K + binds to the electronegative sites of DNA bases in the major and the minor grooves, while Na + interacts preferentially with the phosphate groups. Increase of water causes a shift of both K + and Na + from the first hydration shell of O1P/O2P and of the DNA bases in the minor groove with lesser influence for the cation binding to the bases in the major groove. Mobility of both water and cations in the K–DNA systems is faster than in the Na–DNA systems: Na + organizes and immobilizes water structure around itself and near DNA while for K + water is less organized and more dynamic.
Racial Differences in Parenting Dimensions and Adolescent Condom Use at Sexual Debut
Authors: Cox Mary F.
Published: February 2006

ABSTRACT 
Objectives:
Parenting style may be a determinant in reducing adolescent risk behavior. Previous studies have relied on a typological parenting approach, with classification into four groups: authoritative, authoritarian, permissive, and neglectful. In this study, two distinct parenting dimensions, demandingness and responsiveness, were examined as independent predictors of adolescent condom use. Design and Sample: This study used a subsample of the National Longitudinal Study of Adolescent Health (Add Health) that included 153 adolescent–mother pairs. Measurement: Maternal demandingness and responsiveness were measured using Wave I mother interviews. Logistic regression analyses were used to predict adolescent condom use at sexual debut at Wave II and to assess moderation by gender and race. Results: (1) Maternal demandingness predicted increased likelihood of condom use in African American adolescents but decreased likelihood of condom use in White adolescents; (2) maternal responsiveness did not predict condom use; and (3) gender moderation was not present. Conclusions: To provide appropriate family counseling, public health nurses need to consider racial differences in contraceptive practices. Education regarding parental supervision practices should be considered as part of nursing interventions intended to increase condom use in African American adolescents.
Personal Access to Health Care: A Concept Analysis
Authors: Norris Tommie L. , Aiken Margaret
Published: February 2006

ABSTRACT  The objective of this concept analysis was to formulate an operational definition, so that those seeking, providing, and legislating health care policy would share a common interpretation of the concept. A concept analysis following the strategy suggested by Walker and Avant was used to identify antecedents, attributes, and empirical referents of access to health care. Furthermore, model, borderline, contrary, and invented cases were described. A theoretical definition was derived, which will lead to a better understanding of the concept and bring the concept closer to measurability and readiness for an operational definition. Access to health care has been addressed in political campaigns, studied by numerous legislative committees, and purported to be in an emergency state of disrepair. However, a measurable definition of access to health care continues to elude providers and legislators of health care; in as much, the meaning of the concept varies with the user.
A Conceptual Model for Understanding Effective Coalitions Involved in Health Promotion Programing
Authors: Cramer Mary E. , Atwood Jan R. , Stoner Julie A.
Published: February 2006

ABSTRACT  Funding agencies are increasingly focused on community coalitions as effective entities for promoting public health programs. Yet, there has been no conceptual model for understanding how effective coalition infrastructure works to facilitate a learning environment, wherein coalition members and leaders receive ongoing training and technical assistance needed to accomplish their external programing goals. This article presents a conceptual model for measuring the internal effectiveness of coalitions [Internal Coalition Outcome Hierarchy (ICOH)]. The ICOH model served as the basis for development of the evaluation instrument, Internal Coalition Effectiveness, which measures internal coalition effectiveness based on achievement of organizational outcomes at each of the model's seven hierarchical levels. The ICOH conceptual model has broad application for public health nurses who are frequently called on to serve as evaluators for community coalitions engaged in health programing. The model has implications for evaluators to use in teaching coalition members and leaders about their internal strengths and areas for improvement, so that coalitions can develop more effective internal structures and thereby promote long‐term sustainability.