bluuebunny/crossref_metadata_2025_split huggingface dataset:
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

AbstractA 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 Ruminal fluid was withdrawn from sheep receiving a mixed grass hay/concentrate diet and incubated for 24 h with oat spelts xylan in the presence or absence of a mixture of 20 AA or the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

AbstractAbstract 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

AbstractIt 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

AbstractBoth 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

AbstractConcentrations 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

AbstractTo 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

AbstractMajor 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

AbstractThe 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.
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

AbstractThree 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

AbstractThe 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

AbstractOn 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

AbstractFour 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.