Publications by authors named "KRUK Z"

Serial sections of Angus striploins that varied in marbling were analysed in three dimensions to assess potential differences in intramuscular fat structure. The majority of the intramuscular fat appeared to be connected along the 100 mm of muscle in both the highly marbled and less marbled striploins. Thus, rather than having dispersed individual flecks of marbling, the intramuscular fat was a single entity within the striploin.

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Twenty Angus steers were fed a diet low in β-carotene and vitamin A for 10months. Ten steers were supplemented with vitamin A weekly, while the other ten steers did not receive any additional vitamin A. The results demonstrated that the restriction of vitamin A intake increased intramuscular fat (IMF) by 46%.

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Introduction: Placental function impacts growth and development with lifelong consequences for performance and health. We provide novel insights into placental development in bovine, an important agricultural species and biomedical model.

Methods: Concepti with defined genetics and sex were recovered from nulliparous dams managed under standardized conditions to study placental gross morphological and histomorphological parameters at the late embryo (Day48) and early accelerated fetal growth (Day153) stages.

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This study was conducted to evaluate the combined effect of high pressure (HP) with the addition of soy sauce and/or olive oil on the quality and safety of chicken breast meats. Samples were cut into 100 g pieces and 10% (w/w) of soy sauce (SS), 10% (w/w) of olive oil (OO), and a mixture of both 5% of soy sauce and 5% olive oil (w/w) (SO) were pressurized into meat with high pressure at 300 or 600 MPa. Cooking loss was lower in OO samples than SS samples.

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Parent-of-origin-dependent (epi)genetic factors are important determinants of prenatal development that program adult phenotype. However, data on magnitude and specificity of maternal and paternal genome effects on fetal bone are lacking. We used an outbred bovine model to dissect and quantify effects of parental genomes, fetal sex, and nongenetic maternal effects on the fetal skeleton and analyzed phenotypic and molecular relationships between fetal muscle and bone.

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Postnatal myofibre characteristics and muscle mass are largely determined during fetal development and may be significantly affected by epigenetic parent-of-origin effects. However, data on such effects in prenatal muscle development that could help understand unexplained variation in postnatal muscle traits are lacking. In a bovine model we studied effects of distinct maternal and paternal genomes, fetal sex, and non-genetic maternal effects on fetal myofibre characteristics and muscle mass.

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A whole-genome scan was carried out in New Zealand and Australia to detect quantitative trait loci (QTL) for live animal and carcass composition traits and meat quality attributes in cattle. Backcross calves (385 heifers and 398 steers) were generated, with Jersey and Limousin backgrounds. The New Zealand cattle were reared and finished on pasture, whilst Australian cattle were reared on grass and finished on grain for at least 180 days.

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The effect of dietary mixture of gallic acid and linoleic acid (MGL) on the antioxidative potential and quality of breast meat from broilers was investigated. Broilers during the 22-36days on trial received 3 dietary treatments: 1) control (commercial finisher diet), 2) 0.5% MGL (gallic acid:linoleic acid=1M:1M), and 3) 1.

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Texture parameters (peak force and compression), muscle myofibre diameter, and hydroxyproline were measured in semitendinosus samples from a cattle gene-mapping herd. The data were analysed to determine the relationships between these traits. The traits were also mapped by genetic linkage analysis to identify quantitative trait loci, and hence, candidate genes for these traits.

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Single nucleotide polymorphisms (SNPs) in the calpain 1 (CAPN1) and calpastatin (CAST) genes were studied to determine their effects on meat tenderness in Bos taurus cattle. Strip loins (M. longissimus dorsi) were removed from cattle in four resource populations after slaughter (n = 1042), aged under controlled conditions until fixed times after rigor mortis, cooked and measured using a tenderometer.

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A group of Angus beef cattle was removed from temperate pastures and fed a very low beta-carotene cereal-based ration in a feedlot for over 300 d. Half the group was supplemented weekly with retinyl palmitate (at the rate of 60,000 IU vitamin A/100 live weight (LW)/day), sufficient to offset clinical vitamin A deficiency; the other half received no supplement. Blood was sampled from all animals at biweekly intervals to assess beta-carotene and vitamin A status.

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Studies of the desaturation of saturated fatty acids in animals may help explain conflicting reports of the response of coronary heart disease (CHD) to beta-carotene in humans. A negative relationship exists between desaturation and adipose beta-carotene in cattle when they consume different quantities of beta-carotene. Opposing this finding, however, is a positive relationship between desaturation and adipose beta-carotene when cattle are fed the same quantity of beta-carotene.

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An experiment examined delta9 desaturase activity and FA composition in subcutaneous adipose tissue in two differing breeds of cattle. Jersey-sired cattle had significantly higher rates of desaturase activity than Limousin-sired cattle (1.55 vs.

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We examined the effects of pressure ejected 3, 4-methylenedioxymethamphetamine (MDMA) from a micropipette on direct chemically stimulated release, and on electrically stimulated serotonin (5-HT) or dopamine (DA) release in the caudate putamen (CPu), nucleus accumbens (NAc), substantia nigra pars reticulata (SNr), and the dorsal raphé nucleus (DRN) brain slices of rat, using fast cyclic voltammetry (FCV). MDMA is electroactive, oxidising at +1100 mV. When the anodic input waveform was reduced from +1.

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The effects of a noncompetitive N-methyl-D-aspartate (NMDA) receptor antagonist dizocilpine ((+)-MK-801) and a competitive NMDA antagonist, (+/-)-3-2-carboxypiperazin-4-yl-propyl-1-phosphonic acid (CPP) were compared in electrically evoked 5-HT release in the brain slices incorporating the substantia nigra pars reticulata (SNr) or the dorsal raphé nucleus (DRN) using fast cyclic voltammetry (FCV). Electrical stimulation of either the SNr or the DRN with 50 pulses at frequencies greater than 10 Hz generated signals that were indistinguishable from 5-HT. In the SNr, 0.

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The in vivo measurement of electrically-evoked dopamine overflow was measured for the first time in the striatum of control and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-treated common marmosets using fast cyclic voltammetry at untreated carbon-fibre microelectrodes, (7 microm, o.d.).

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Fast cyclic voltammetry was used to measure NO and dopamine (DA) simultaneously in rat caudate putamen (CPu) slices. Analysis of electrochemical signals obtained from mixtures of DA and NO showed that subtraction of either the DA or the NO component revealed the contribution of the other component. Application of such data manipulation to signals obtained in CPu slices indicated that DA and NO components contributed to electrochemical signals.

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Fast cyclic voltammetry (FCV) was used to measure real time release of electrically stimulated endogenous dopamine in the nucleus accumbens (NAc) of conscious freely moving rats for up to 17 days. The method of electrode construction, implantation, electrical stimulation and recording of changes of extracellular dopamine concentration in the conscious rat are described. Rats trained on a continuous reinforcement schedule to perform intracranial self stimulation (ICSS) were implanted with electrodes for FCV.

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Fast cyclic voltammetry at a carbon fibre microelectrode was used to measure 5-HT signals following electrical or chemical stimulation in rat substantia nigra pars reticulata slices. Chemical stimulation with (+)-amphetamine or veratrine gave signals which were indistinguishable from those of exogenous 5-HT. Electrical stimulation of sufficient duration gave voltammetric signals which were characteristic of 5-HT.

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Behavioural sensitization to the locomotor stimulating effects of (+)-amphetamine or quinpirole was induced in rats by intermittent drug administration. Following expression of sensitization, locomotor activity scores on day 9 were: vehicle 87 +/- 9, (+)-amphetamine 1441 +/- 227 and quinpirole 2078 +/- 214. Electrically stimulated dopamine release was measured on day 12 in ventral tegmental slices using fast cyclic voltammetry.

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The functional role of N-methyl-D-aspartic acid (NMDA) glutamate receptors in the real-time regulation of single electrical pulse (1 p)-stimulated endogenous dopamine release was investigated in slices of rat caudate putamen using fast cyclic voltammetry at a carbon fibre electrode. In the presence of Mg2+, 20 microM NMDA had a weak effect on background signals but did not affect 1 p-stimulated dopamine release. Removal of Mg2+ increased the background and doubled 1 p-stimulated dopamine release.

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Fast cyclic voltammetry at a carbon fibre microelectrode was used to measure dopamine release following electrical or chemical stimulation in rat brain slices incorporating either the ventral tegmental area or the core region of the nucleus accumbens. Electrical or chemical stimulation gave clear voltammetric signals which corresponded to dopamine; less dopamine was released in the ventral tegmental area than in the nucleus accumbens. In contrast to the nucleus accumbens, electrically stimulated dopamine release in the ventral tegmental area was not sensitive to tetrodotoxin, was not modified by the presence of dopamine uptake inhibitors, or agonist or blockers acting at dopamine D2 autoreceptors.

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Fast cyclic voltammetry in rat brain slices containing the nucleus accumbens, was used to examine the regulation of the extracellular concentration of electrically stimulated dopamine overflow in the core, shell and rostral pole. One microM (-)-sulpiride, significantly increased dopamine overflow in all 3 regions but only when the duration of stimulation was greater than 500 ms. One microM cocaine, significantly potentiated dopamine overflow in all 3 regions following all patterns of stimulation.

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1. Fast cyclic voltammetry was used to investigate the effect of 7-OH-DPAT (7-hydroxy-N,N-di-n-propyl-2-aminotetralin), a putative D3 receptor agonist, on electrically stimulated endogenous dopamine release in slices of rat nucleus accumbens. 2.

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