Animal performance and meat quality characteristics from feedlot-finished steers fed increasing levels of wet distillers grain.

One hundred forty-four steers were group-housed in 24 pens that were randomly assigned to one of four dietary treatments defined by the proportion of wet distiller grain plus solubles (WDGS; 0, 15, 30, or 45%) and fed for 84 d pre-slaughter. Animal performance was evaluated using the pen as the experimental unit. Whereas for carcass and meat quality characteristics, meat oxidative stability, and the consumer sensory quality of longissimus thoracis muscle one animal from each pen was randomly selected and used as the experimental unit. No differences (P > 0.05) were observed for subcutaneous fat thickness, rib eye area, marbling score or pH, color parameters, proximate composition, sarcomere length, Warner Bratzler shear force, and cooking loss. Feeding WDGS linearly increased total PUFA (P = 0.05), C18:2 n-6 (P = 0.004) proportions, and n-6/n-3 ratio (P < 0.01) but reduced C16:1 to C18:0 ratio (P < 0.01). Lipid oxidation was greater in beef from steers fed 30% and 45% WDGS (P = 0.05). Dietary WDGS linearly improved (P < 0.05) flavor and overall linking score in the consumer sensory panel.

Patient centered guidelines for the laboratory diagnosis of Gaucher disease type 1.

Gaucher disease (GD) is an autosomal recessive lysosomal storage disorder due to the deficient activity of the acid beta-glucosidase (GCase) enzyme, resulting in the progressive lysosomal accumulation of glucosylceramide (GlcCer) and its deacylated derivate, glucosylsphingosine (GlcSph). GCase is encoded by the GBA1 gene, located on chromosome 1q21 16 kb upstream from a highly homologous pseudogene. To date, more than 400 GBA1 pathogenic variants have been reported, many of them derived from recombination events between the gene and the pseudogene. In the last years, the increased access to new technologies has led to an exponential growth in the number of diagnostic laboratories offering GD testing. However, both biochemical and genetic diagnosis of GD are challenging and to date no specific evidence-based guidelines for the laboratory diagnosis of GD have been published. The objective of the guidelines presented here is to provide evidence-based recommendations for the technical implementation and interpretation of biochemical and genetic testing for the diagnosis of GD to ensure a timely and accurate diagnosis for patients with GD worldwide. The guidelines have been developed by members of the Diagnostic Working group of the International Working Group of Gaucher Disease (IWGGD), a non-profit network established to promote clinical and basic research into GD for the ultimate purpose of improving the lives of patients with this disease. One of the goals of the IWGGD is to support equitable access to diagnosis of GD and to standardize procedures to ensure an accurate diagnosis. Therefore, a guideline development group consisting of biochemists and geneticists working in the field of GD diagnosis was established and a list of topics to be discussed was selected. In these guidelines, twenty recommendations are provided based on information gathered through a systematic review of the literature and two different diagnostic algorithms are presented, considering the geographical differences in the access to diagnostic services. Besides, several gaps in the current diagnostic workflow were identified and actions to fulfill them were taken within the IWGGD. We believe that the implementation of recommendations provided in these guidelines will promote an equitable, timely and accurate diagnosis for patients with GD worldwide.

Relationships between intramuscular fat percentage and fatty acid composition in M. longissimus lumborum of pasture-finished lambs in New Zealand.

This paper reports relationships between fatty acids (FAs) and intramuscular fat (IMF)% in M. longissimus lumborum samples from 108 pasture-fed ewe lambs. Samples ranged in IMF from 1 to 6%. Relationships between %FA with total IMF% were mainly linear with percentages of saturated and monounsaturated FAs (MUFA), including trans-FAs, increasing and polyunsaturated FAs decreasing as IMF% increased. Normalized FA content data at 5.5% relative to 1.5% IMF, showed the highest relative increase for C14:0 as rates of endogenous synthesis increase with higher IMF deposition. This can be related to enhanced C12:0 elongation and lower rates of C14:0 desaturation, supported by a preferential desaturation of C18:1 trans-11 and C18:0 compared with C14:0 and C16:0 as IMF increased. The greatest normalized increase after C14:0 was anteisoC17:0 followed by other branched chain FAs and then trans-MUFA and C18:2 cis-9,trans-11. Finally, C22:6 and C22:5 showed higher relative increase than C20:5 indicating greater rates of elongation and desaturation past C20:5 at higher levels of fatness.

Consumer liking of M. longissimus lumborum from New Zealand pasture-finished lamb is influenced by intramuscular fat.

Palatability of meat is known to be affected by intramuscular fat (IMF), but the effect in relatively low-fat New Zealand lamb is unknown. This study evaluated the eating quality of 108 loins (M. longissimus lumborum) from a single flock of ewe-lambs. Loins ranged from 1.09-5.68% IMF and were stratified into 6 groups: 1.65, 2.12, 2.65, 3.20, 3.58 and 4.40%. Consumers' (n = 165) overall liking of lamb increased significantly at around 3% IMF, achieving maximum scores at 4% IMF. One consumer cluster (n = 111) showed a linear increase in overall liking with increasing IMF%, regarded as 'IMF lovers: the more the better', while a second cluster (n = 54) preferred 2.5-3.5% IMF, described as 'IMF optimizers: just the right amount'. IMF% was modestly correlated (~ + 0.25) with all sensory attributes except juiciness. Liking scores were modestly correlated with monounsaturated (~ + 0.25) and polyunsaturated (~ - 0.20) fatty acids. Results suggest aiming for IMF% levels in New Zealand lamb beyond 3% to maximize eating quality for premium markets in particular.

Late-gestation protein restriction negatively impacts muscle growth and glucose regulation in steer progeny.

The objective of this study was to determine whether the amount of protein provided to cows during late gestation would affect postnatal growth and lead to changes in glucose and insulin concentrations. At 129 d of gestation, 10 mature multiparous Angus cows were stratified by body weight (BW) and body condition score (BCS) and allotted to either low protein level (LP, 6% crude protein [CP]) or high protein level (HP, 12% CP) groups. After calving, cows were managed together on improved pastures, which provided forage in excess of requirements until weaning. Male calves were maintained as a group after weaning on native range until 23 mo of age when individual steers were placed in single pens and fed a finishing diet for 84 d. The 12th rib fat thickness and longissimus muscle area were measured during finishing phase by ultrasound. Twenty days before the end of the finishing phase, steers were subjected to an intravenous glucose tolerance test. Steers were harvested and carcass characteristics collected. Cows' BW and BCS were similar at the initiation of treatment. During treatment HP dams gained 21 kg, whereas LP dams lost 7 kg (P = 0.04). Protein nutrition during late gestation did not influence calf birth weight, BW at weaning, adjusted 205 d BW, or average daily gain during lactation (P > 0.10). Longissimus muscle area measure by ultrasound was greater (P = 0.02) in HP steers at the beginning and end of finishing phase. Fat thickness of the 12th rib was not different (P > 0.10) between treatments. Glucose concentration after intravenous administration decreased (P = 0.002) in LP compared with HP steers. Peak of serum insulin concentration was greater (P = 0.04) and serum insulin concentration tended to decrease (P = 0.08) more rapidly in LP compared with HP steers after glucose infusion. At harvest, hot carcass weight was similar between treatments, but dressing percentage was increased (P = 0.05) in HP compared with LP steers. These data demonstrate that a lower protein nutrition level of dams during late gestation affect carcass characteristics and alter glucose regulation enhancing insulin secretion in steer progeny.

Evaluation of respiratory- and postural-induced changes on the ballistocardiogram signal by time warping averaging.

OBJECTIVE: The aim of this work was to evaluate the potential changes in the ballistocardiogram (BCG) signal induced by different respiratory patterns and posture, by using the dynamic time warping (DTW) technique. APPROACH: BCG signals were recorded in a group of 20 healthy volunteers, simultaneously with an electrocardiogram (ECG). Two recordings, one in a supine (SUP) and one in a standing (ST) position, including spontaneous breathing, two 1 min apneas (at full and empty-lungs, respectively) and 30 s of Valsalva, were analyzed. A warped averaged waveform was computed for each phase, from which amplitude and temporal parameters were extracted to characterize each condition. MAIN RESULTS: Variations were found in both amplitude and duration of BCG-derived parameters among manoeuvres, especially when compared to spontaneous breathing, suggesting a complex interaction between intra-thoracic pressure changes acting on venous return, together with the autonomic nervous system modulation on heart rate. The effect of a hydrostatic pressure gradient elicited by postural conditions was also evident. SIGNIFICANCE: Posture and respiratory manoeuvres affect the BCG signal in different ways, probably as a result of changes induced in preload and afterload. This supports the need to define separate normality ranges for each posture and/or breathing conditions, as well as the importance of applying specific manoeuvres to highlight any pathological response in the computed BCG parameters.

Utilization of fluorescence spectroscopy as a novel approach to evaluate the oxidative stability in beef retail displayed.

Beef samples from grazing steers finished with different seed-supplemented diets were vacuum packaged for 3, 14 and 56days (VC) and subsequently exposed to aerobic conditions (AE) for 0 and 5days. Different fluorescent compounds of interest in the oxidation process were detected in meat, namely tryptophan residues, Schiff bases and porphyrins. Tryptophan intensity fluorescence increased with 14days of VC; while Schiff bases intensity increased (P<0.05) in beef samples stored under VC-56 and in all samples after AE-5days. Porphyrins increased (P<0.05) gradually with the extension of vacuum storage time, but were degraded in beef with long vacuum storage and 5days of AE. Higher levels of porphyrins in beef under VC were correlated (P<0.05) with lower redness and higher TBARS after AE-5. This study revealed the potential of fluorescence signals to detect oxidative changes in beef under different storage conditions using a fast and nondestructive method such as fluorescence spectroscopy.

Beat-to-beat heart rate detection by smartphone's accelerometers: validation with ECG.

Mobile phones offer the possibility to monitor and track health parameters. Our aim was to test the feasibility and accuracy of measuring beat-to-beat heart rate using smartphone accelerometers by recording the vibrations generated by the heart during its function and transmitted to the chest wall, i.e. the so-called seismocardiographic signal (SCG). METHODS: 9 healthy male volunteers were studied in supine (SUP) and in standing (ST) posture. A smartphone (iPhone6, Apple) was positioned on the thorax (POS1) to acquire SCG signal. While supine, a second smartphone was positioned on the navel (POS2). The SCG signal was recorded for 3 minutes during spontaneous respiration, synchronous with 3-leads ECG. Using a fully automated algorithm based on amplitude thresholding after rectification, the characteristic peak of the SCG signal (IVC) was detected and used to compute beat-to-beat heart duration, to be compared with the corresponding RR intervals extracted from the ECG. RESULTS: A 100% feasibility of the approach resulted for POS1 in SUP, while 89% in POS2, and 78% for POS1 in ST. In supine, for each smartphones' position, the automated algorithm correctly identified the cardiac beats with >98% accuracy. Linear correlation (r2) with RR was very high (>0.98) in each posture and position, with no bias and narrow limits of agreement. CONCLUSIONS: The obtained results proved the feasibility of the proposed approach and the robustness of the applied algorithm in measuring the beat-to-beat heart rate from smartphone-derived SCG, with high accuracy compared to conventional ECG-derived measure.

Antioxidant status, lipid and color stability of aged beef from grazing steers supplemented with corn grain and increasing levels of flaxseed.

Angus steers were grazed on unsupplemented pasture (CNTRL), pasture supplemented with 0.7% BW cracked corn (FLAX-0), FLAX-0 with 0.125% and 0.250% BW of whole flaxseed (FLAX-1 and FLAX-2). Six steers were grazed per treatment for 70 days, with start and finish weights of 458 and 508 kg. At 24 h post slaughter, longissimus thoracis were harvested, and steaks assigned to treatments of postmortem aging time under vacuum (PM; 3, 14 and 56 days) with or without five days of aerobic exposure (AE). Meat antioxidant status was higher (P<0.05) when feeding CNTRL and FLAX-1 than FLAX-0 and FLAX-2. Under AE, lipid oxidation was highest for FLAX-2 (P<0.05), and lowest for FLAX-1. Greatest TBARs and lowest antioxidant capacity and redness values were obtained with AE and the longer PM (P<0.05). Beef oxidative stability through AE improved by adding a low flaxseed level to supplemented corn grain, but deteriorated by adding a high flaxseed level or by extending PM.

Effect of forage type with or without corn supplementation on animal performance, beef fatty acid composition, and palatability.

Thirty-two steers were used to examine forage type (legumes [ and ] vs. grasses [ and ]) with or without individual corn grain supplementation (0 vs. 0.75% of live weight [LW]/d) on beef fatty acid composition and palatability. In each year, steers ( = 16/yr) were randomly assigned to forage type ( = 8/forage type per yr) and to supplementation treatments within forage type ( = 4/supplementation treatment/forage type per yr). Forage types (grasses vs. legumes) were replicated in 2 paddocks of perennial and annual forage type pastures. A mixed model was developed with forage type, corn grain supplementation, and the 2-way interaction as fixed effects and 2 different error terms, one for testing forage and another for testing grain supplement and grain supplement × forage interaction. Corn grain supplementation increased ( = 0.01) ADG by 0.29 kg/d and final LW by 13 kg. Hot carcass weight, dressing percentage (DP), and KPH were greater ( < 0.05) for steers supplemented with corn grain. Carcasses from steers grazing legumes had greater ( = 0.04) DP compared with carcasses from steers grazing grasses. Alpha-linolenic acid concentration was higher ( < 0.05) in LM of steers grazing legumes than in LM of steers grazing grasses, both without supplementation. Supplementation decreased ( < 0.05) linolenic acid levels for both forage types; however, the magnitude of this reduction was greater for legumes than for grasses. The ratio of -6 to -3 PUFA was greater ( = 0.03) in the LM of corn grain-supplemented steers than in the LM of nonsupplemented steers. Supplementation of corn grain decreased ( < 0.05) the percentage of odd-chain fatty acids and increased ( < 0.05) the percentage of MUFA in the LM. Warner-Bratzler shear force values were not altered ( > 0.05) by forage type, supplementation, or the 2-way interaction. Beef finished on legumes had greater concentrations of -3 PUFA, whereas beef supplemented with corn grain had a greater ratio of -6 to -3 fatty acids. On a gravimetric basis (mg/100 g LM), -3 PUFA and CLA contents were not altered with supplementation, indicating that corn grain can be supplemented at this level in a forage-finishing beef system without negative consequences on perceived beneficial fatty acids.

The dimensioning and development of hospital electric installations to guarantee the continuity of use of the therapeutic and diagnostic system.

The Technical Services and the Medical Administration of the Hospitals of Trieste have been working for years to ensure the optimal functioning of the Medicine, Surgery, Diagnostics and Research services offered to the Patients and to the University in an 800-bed hospital complex, transforming and innovating the buildings and support installations. We have dedicated special attention to the technologies necessary to guarantee the continuity of the power supply to the electromedical devices, increasingly numerous in highly specialized hospitals. We report our electricity consumption and the power of the generator sets and the UPS and our opinion that their power must be related to the overall consumption of the Hospital, with a reserve margin.

Genetic variants in a lipid regulatory pathway as potential tools for improving the nutritional quality of grass-fed beef.

The aim of this study was to evaluate the effect of genetic variants on candidate genes corresponding to the sterol recognition element-binding protein-1 (SREBP-1) signaling pathway and stearoyl-CoA desaturases (SCD1 and SCD5) on muscle fatty acid (FA) composition of Brangus steers fattened on grass. FA profiles were measured on Longissimus lumborum muscle samples using a gas chromatography-flame ionization detection technique. A total of 43 tag single-nucleotide polymorphisms on the SCD1, SCD5, SREBP-1, SCAP, INSIG1, INSIG2, MBTPS1, MBTPS2, and SRPR genes were genotyped on 246 steers to perform a marker-trait association study. To evaluate the influence of the Indicine breed in the composite breed, additional groups of 48 Angus, 18 Hereford, 75 Hereford x Angus, and 36 Limousin x Hereford-Angus steers were also genotyped. To perform the association analysis, FA data were grouped according to the number of carbon atoms and/or number of double bonds (i.e. SFA, MUFA, PUFA, etc.). In addition, different indexes that reflect the activity of FA desaturase and elongase enzymes were calculated. SCD1 markers significantly affected C14:1/(C14:0 + C14:1) and C18:1/(C18:0 + C18:1) indexes, whereas one SNP in SCD5 was correlated with the C16:1/(C16:0 + C16:1) index. Polymorphisms in the signal recognition particle receptor (SRPR) gene were associated with all the estimated desaturase indexes. Because the evaluated markers showed no effect on total lipid content of beef, this work supports the potential utilization of these markers for the improvement of grass-fed beef without undesirable side effects.

Genetic markers of body composition and carcass quality in grazing Brangus steers.

The somatotropic axis is a major regulatory pathway of energy metabolism during postnatal growth in mammals. Genes involved in this pathway influence many economically important traits. The association of selected SNPs in these genes with carcass traits was examined in grazing Brangus steers. These traits included final live weight, ultrasound backfat thickness (UBFT), rib-eye area, kidney fat weight, hot carcass weight, and intramuscular fat percentage (%IMF). Genomic DNA (N = 246) was genotyped for a panel of 15 tag SNPs located in the growth hormone receptor (GHR), insulin-like growth factor I, insulin-like growth factor-binding protein 6, pro-melanin-concentrating hormone, suppressor of cytokine signaling 2, and signal transducer and activator of transcription 6 (STAT6) genes. Allelic and haplotype frequencies were compared with those of a sample of European breeds (N = 177 steers). Two tag SNPs in the GHR affected %IMF; one of them (ss86273136) was also strongly associated with UBFT (P < 0.003). The frequency of the most favorable GHR haplotype for %IMF was lower in Brangus steers. Moreover, the haplotype carrying two unfavorable alleles was present at a frequency of 31% in this group. Four tag SNPs on STAT6 had a significant effect on UBFT. One of these, SNP ss115492467, was also associated with %IMF. The STAT6 haplotype, including all the alleles favoring UBFT, was the most abundant variant (34%) in the European cattle, while it had a frequency of 14% in the Brangus steers. The four less favorable variants (absent in the European cattle) were found at a frequency of 38% in the Brangus steers. These results support the association of GHR and STAT6 SNP with carcass traits in composite breeds, such as Brangus, under grazing conditions.

Early signs of gait deviation in Duchenne muscular dystrophy.

BACKGROUND: Most analytical studies found in literature only focus on specific aspects of Duchenne muscular dystrophy (DMD) gait and posture (joint range of motion, standing balance, variations of gait spatial-temporal parameters). Some of them analyze single cases and do not provide a comprehensive evaluation of locomotion. There are few studies about DMD gait patterns, most of them concerning small groups of patients, sometimes not homogeneous, in which the clinical manifestations of the next stages of DMD were present. AIM: The goal of our study was to analyze the characteristics of gait patterns in early stage patients, when clinical and functional evaluation do not allow to quantify initial walking worsening or to identify the changes adopted to compensate for muscle weakness. SETTING: Gait Analysis Laboratory by using a six-camera motion capture system (Vicon, Oxford Metrics, UK), set at a sampling rate of 60 Hz. Subjects were asked to walk barefoot at their usual cadence, along a 10-m walkway, where one force platform (Kistler, Switzerland), embedded in the middle portion of the pathway, measured the foot-ground reaction forces. Retroreflective markers were placed on the subjects according to the protocol described in Davis et al. POPULATION: A group of 15 patients aging from 5 to 6.8 years was compared with a similar age control group composed of 9 healthy children. RESULTS: Spatial and temporal parameters showed significant differences between the two groups: cadence was increased and step length was decreased significantly in the DMD group. We found a significant increase in the range of anterior-posterior pelvic tilt and in pelvic rotation. In the frontal plane there was a tendency for an increased pelvic obliquity. Dynamic range of motion in sagittal plane showed a significant difference at the ankle, with an increased plantarflexion in swing in the dystrophic patients. Maximum dorsiflexion was reduced in the DMD group. Kinetic analysis showed significant differences in power generation and absorption at the hip joint and at the ankle joint. At knee there was a reduced flexor moment in mid-stance. Ankle showed a reduced dorsiflexor moment in terminal stance and pre-swing with a consequent reduction in the peak-to-peak excursion. CONCLUSION AND CLINICAL REHABILITATION IMPACT: It was shown that instrumented gait analysis, being more sensitive than other clinical and functional assessment methods, allowed to quantify the very early modifications characterizing locomotion worsening in the first stage of the DMD.

A dynamic model of quadriceps and hamstrings function.

The mechanical effect of hamstrings and quadriceps contractions on hip and knee joint motion was investigated using a dynamic model of the musculoskeletal system. The model consisted of 13 anatomically linked segments. The geometry of bones, joints, and muscle attachments was derived from magnetic resonance imaging of a healthy adult. The knee joint was represented by a crossing bars linkage to simulate cruciate ligament function, and muscles were represented by spring actuators. The effects of hamstring and quadriceps contractions, in various combinations, were tested on different configurations of hip and knee joint position in the absence of gravity. In the standing posture, with the foot free to move and the pelvis fixed in space, the effect of semimembranosus (SM) contraction was hip and knee flexion. If the foot was fixed to the ground, SM contraction produced hip extension and knee flexion. The addition of quadriceps contraction reduced or abolished the knee flexion and enhanced hip extension. In all other simulations, SM alone produced knee flexion and hip extension and the combination of SM with vastus (VA) and rectus femoris (RF) contractions resulted in knee extension and enhanced hip extension. Our findings suggest that co-contraction of quadriceps and hamstrings may be a strategy to increase the hip extension function of the hamstrings.

Middle-term expansion of hematopoietic cord blood cells with new human stromal cell line feeder-layers and different cytokine cocktails.

Cord blood (CB) is a source of hematopoietic stem cells (HSCs) and is an alternative to bone marrow for allogenic transplantation in patients with hematological disorders. The improvement of HSC in vitro expansion is one of the main challenges in cell therapy. Stromal components and soluble factors, such as cytokines, can be useful to induce in vitro cell expansion. Hence, we investigated whether feeder-layers from new stromal cell lines and different exogenous cytokine cocktails induce HSC expansion in middle-term cultures. CB HSC middle-term expansion was carried out in co-cultures on different feeder-layers exposed to three different cytokine cocktails. CB HSC expansion was also carried out in stroma-free cultures in the presence of different cytokine cocktails. Clonogenic tests were performed, and cell growth levels were evaluated. Moreover, the presence of VCAM-1 mRNA was assessed, and the mesenchymal cell-like phenotype expression was detected. All feeder-layers were able to induce a significant clonogenic growth with respect to the control culture, and all of the cytokine cocktails induced a significant increase in CB cell expansion indexes, even though no potential variation dependent on their composition was noted. The modulative effects of the different cocktails, exerted on each cell line used, was dependent on their composition. Finally, all cell lines were positive for CD73, CD117 and CD309, similar to mesenchymal stem cells present in adult bone marrow and in other human tissues, and negative for the hematopoietic markers. These data indicate that our cell lines have, not only a stromal cell-like phenotype, but also a mesenchymal cell-like phenotype, and they have the potential to support in vitro expansion of CB HSCs. Moreover, exogenous cytokines can be used in synergism with feeder-layers to improve the expansion levels of CB HSCs in preparation for their clinical use in allogenic transplantation.

Corn oil or corn grain supplementation to steers grazing endophyte-free tall fescue. II. Effects on subcutaneous fatty acid content and lipogenic gene expression.

Twenty-eight Angus steers (289 kg) were finished on a high-concentrate diet (85% concentrate: 15% roughage; CONC), or endophyte-free tall fescue pastures with corn grain supplement (0.52% of BW; PC), corn oil plus soybean hull supplement (0.10% of BW corn oil plus 0.45% of BW soybean hulls; PO), or no supplement (pasture only; PA). Subcutaneous adipose tissues were processed for total cellular RNA extraction and fatty acid composition by GLC. Relative expression of genes involved in lipogenesis [fatty acid synthase (FASN), acetyl-CoA carboxylase, lipoprotein lipase, stearoyl-CoA desaturase (SCD)] and activators of transcription [(peroxisome proliferator-activated receptor-gamma), C/EBPalpha, sterol regulatory binding protein-1, signal transducer and activator of transcription-5, and Spot-14] was determined by real-time quantitative PCR. Housekeeping gene (glyceraldehyde 3-phosphate dehydrogenase and beta-actin) expression was used in analysis to normalize expression data. Total fatty acid content was greatest (P < 0.001) for CONC and least (P < 0.001) for PA. Supplementation of grazing cattle increased (P < 0.001) total fatty acid content compared with PA, but concentrations were less (P < 0.001) than for CONC. Myristic and palmitic acid contents were greater (P < 0.001) for CONC than for PO and PC, which were greater (P < 0.001) than for PA. Stearic acid content was greater (P < 0.01) for PO than for CONC, PC, and PA. Finishing on CONC increased (P < 0.001) total MUFA content by 68% compared with PA. Corn grain supplementation increased (P < 0.001) MUFA content compared with PA; in contrast, MUFA content did not differ (P > 0.05) between PO and PA. Corn oil supplementation increased (P < 0.001) trans-11 vaccenic acid content in subcutaneous fat by 1.2-, 1.7- and 5.6-fold relative to PA, PC, and CONC, respectively. Concentrations of the cis-9, trans-11 CLA isomer were 54, 58, and 208% greater (P < 0.01) for PO than for PA, PC, and CONC, respectively. Corn grain supplementation to grazing steers did not alter (P > 0.05) the cis-9, trans-11 CLA isomer compared with PA. Oil supplementation increased (P < 0.001) linoleic acid (C18:2) content by 56, 98 and 262% compared with CONC, PC, and PA, respectively. Relative mRNA expression of SCD was upregulated (P < 0.001) by 46-, 18- and 7-fold, respectively, for CONC, PC, and PO compared with PA. Relative FASN mRNA expression was also upregulated (P = 0.004) by 9- and 5-fold, respectively, for CONC and PC compared with PA. Grain feeding, either on CONC or supplemented on pasture, upregulated FASN and SCD mRNA to increase MUFA and de novo fatty acids in subcutaneous adipose tissue. Upregulation of SCD with grain feeding and reduced tissue CLA concentrations suggest that the decreased CLA concentrations were the result of limited substrate (trans-11 vaccenic acid) availability.

Corn oil or corn grain supplementation to steers grazing endophyte-free tall fescue. I. Effects on in vivo digestibility, performance, and carcass quality.

Twenty-eight Angus (289 +/- 3.8 kg) steers were used in a completely randomized design to evaluate the effect of isocaloric supplementation of 2 different energy sources to steers rotationally grazing tall fescue pastures for 197 d in comparison to positive and negative controls. Steers were supplemented with either corn grain (0.52% BW on a DM basis; PC) or soybean hulls plus corn oil (0.45% BW on a DM basis + 0.10% BW on an as-fed basis; PO) using Calan gates for individual intake measurement. Negative, pasture only (PA), and positive, high-concentrate control diets (85% concentrate:15% roughage on DM basis; C) were also included in the study. Steers on PC, PO, and PA treatments were managed together under a rotational grazing system, whereas C steers were fed a high-concentrate diet for the final 113 d using Calan gates. Forage DMI and apparent DM and NDF digestibility for the grazing treatments were evaluated using Cr(2)O(5) and indigestible NDF as digesta markers. Energy supplementation decreased (P = 0.02) forage DMI (% of BW) with respect to PA, but not (P = 0.58) total DMI. There were no differences (P = 0.53) among grazing treatments on apparent total DM digestibility. However, NDF digestibility was less (P < or = 0.05) in PC than in PO and PA; the latter 2 treatments did not differ (P > 0.05). Overall ADG was greater (P < 0.01) in supplemented, regardless of type, than in nonsupplemented grazing treatments. During the final 113 d, ADG was greater (P < 0.01) in C than in the grazing treatments. Overall supplement conversion did not differ (P = 0.73) between supplement types and was less (P = 0.006) than C. Carcass traits did not differ (P > 0.05) between energy sources. Dressing percentage and HCW were greater (P < 0.01) in supplemented cattle than in PA. Fat thickness and KPH percentage for PA were less (P < 0.05) than for PO but did not differ (P > 0.14) from PC. Marbling score, LM area, and quality grade did not differ (P > 0.05) between grazing treatments. Hot carcass weight for C was heavier (P < 0.001) than for pastured cattle. Quality and yield grades of C carcasses were also greater (P < 0.001) than carcasses from pastured steers. Energy supplementation, regardless of source, to grazing steers increased ADG, dressing percentage, and carcass weight compared with PA steers; however, supplemented steers had less ADG, efficiency, dressing percentage, and carcass weight compared with high-concentrate finished steers.