Meat quality traits of M. longissimus lumborum from White Mangalica and (Duroc x White Mangalica) x White Mangalica pigs reared under intensive conditions and slaughtered at about 180-kg live weight

The objective of the study was to evaluate the meat quality of the Serbian autochthonous White Mangalica pure bred pig and its crossbreed with Duroc. A total of 24 pigs [White Mangalica WM, n = 12, and (Duroc x White Mangalica) x White Mangalica) - (DWM)WM, n = 12)] were slaughtered on average 638 and 509 d of age, respectively. Colour and marbling score, and all physical (pH, instrumental colour and water holding capacity) and chemical (proximate and mineral composition and fatty acids profile) analyses were performed on M. Iongissimus lumborum. Pork from WM had higher marbling score and intramuscular fat content and was redder in colour than from (DWM)WM; while opposite was determined for moisture content. In intramuscular fat, WM had higher content of oleic acid as well as total monounsaturated fatty acids than (DWM)WM, while (DWM)WM had higher linoleic and arachidonic acids as well as total polyunsaturated fatty acids content. Inclusion of 25% Duroc gave pork with lower content of iron, copper and manganese. In summary, irrespective of differences in some particular traits White Mangalica crossbreds can represent a good alternative to pure White Mangalica without worsening the meat quality

Mapping carcass and meat quality QTL on Sus Scrofa chromosome 2 in commercial finishing pigs

Quantitative trait loci (QTL) affecting carcass and meat quality located on SSC2 were identified using variance component methods. A large number of traits involved in meat and carcass quality was detected in a commercial crossbred population: 1855 pigs sired by 17 boars from a synthetic line, which where homozygous (A/A) for IGF2. Using combined linkage and linkage disequilibrium mapping (LDLA), several QTL significantly affecting loin muscle mass, ham weight and ham muscles (outer ham and knuckle ham) and meat quality traits, such as Minolta-L* and -b*, ultimate pH and Japanese colour score were detected. These results agreed well with previous QTL-studies involving SSC2. Since our study is carried out on crossbreds, different QTL may be segregating in the parental lines. To address this question, we compared models with a single QTL-variance component with models allowing for separate sire and dam QTL-variance components. The same QTL were identified using a single QTL variance component model compared to a model allowing for separate variances with minor differences with respect to QTL location. However, the variance component method made it possible to detect QTL segregating in the paternal line (e.g. HAMB), the maternal lines (e.g. Ham) or in both (e.g. pHu). Combining association and linkage information among haplotypes improved slightly the significance of the QTL compared to an analysis using linkage information only

Greenhouse Gas Emissions Payback for Lightweighted Vehicles Using Aluminum and High-Strength Steel

In this article we consider interactions between life cycle emissions and materials flows associated with lightweighting (LW) automobiles. Both aluminum and high-strength steel (HSS) lightweighting are considered, with LW ranging from 6% to 23% on the basis of literature references and input from industry experts. We compare the increase in greenhouse gas (GHG) emissions associated with producing lightweight vehicles with the saved emissions during vehicle use. This yields a calculation of how many years of vehicle use are required to offset the added GHG emissions from the production stage. Payback periods for HSS are shorter than for aluminum. Nevertheless, achieving significant LW with HSS comparable to aluminum-intensive vehicles requires not only material substitution but also the achievement of secondary LW by downsizing of other vehicle components in addition to the vehicle structure. GHG savings for aluminum LW varies strongly with location where the aluminum is produced and whether secondary aluminum can be utilized instead of primary. HSS is less sensitive to these parameters. In principle, payback times for vehicles lightweighted with aluminum can be shortened by closed-loop recycling of wrought aluminum (i.e., use of secondary wrought aluminum). Over a 15-year time horizon, however, it is unlikely that this could significantly reduce emissions from the automotive industry, given the challenges involved with enabling a closed-loop aluminum infrastructure without downcycling automotive body structures.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/79236/1/j.1530-9290.2010.00283.x.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/79236/2/JIEC_283_sm_SuppMatS1.pd

Use of electromyography to detect muscle exhaustion in finishing barrows fed ractopamine HCl

Citation: Noel, J. A., Broxterman, R. M., McCoy, G. M., Craig, J. C., Phelps, K. J., Burnett, D. D., . . . Gonzalez, J. M. (2016). Use of electromyography to detect muscle exhaustion in finishing barrows fed ractopamine HCl. Journal of Animal Science, 94(6), 2344-2356. doi:10.2527/jas2016-0398The objectives of this study were to determine the effects of dietary ractopamine HCl (RAC) on muscle fiber characteristics and electromyography (EMG) measures of finishing barrow exhaustion when barrows were subjected to increased levels of activity. Barrows (n = 34; 92 +/- 2 kg initial BW) were assigned to 1 of 2 treatments: a conventional swine finishing diet containing 0 mg/kg ractopamine HCl (CON) or a diet formulated to meet the requirements of finishing barrows fed 10 mg/kg RAC (RAC+). After 32 d on feed, barrows were individually moved around a track at 0.79 m/s until subjectively exhausted. Wireless EMG sensors were affixed to the deltoideus (DT), triceps brachii lateral head (TLH), tensor fasciae latae (TFL), and semitendinosus (ST) muscles to measure median power frequency (MdPF) and root mean square (RMS) as indicators of action potential conduction velocity and muscle fiber recruitment, respectively. After harvest, samples of each muscle were collected for fiber type, succinate dehydrogenase (SDH), and capillary density analysis. Speed was not different (P = 0.82) between treatments, but RAC+ barrows reached subjective exhaustion earlier and covered less distance than CON barrows (P 0.29). There was a treatment x muscle interaction (P = 0.04) for end-point RMS values. The RAC diet did not change end-point RMS values in the DT or TLH (P > 0.37); however, the diet tended to decrease and increase end-point RMS in the ST and TFL, respectively (P 0.10). Muscles of RAC+ barrows tended to have less type I fibers and more capillaries per fiber (P < 0.07). Type I and IIA fibers of RAC+ barrows were larger (P < 0.07). Compared with all other muscles, the ST had more (P < 0.01) type IIB fibers and larger type I, IIA, and IIX fibers (P < 0.01). Type I, IIA, and IIX fibers of the ST also contained less SDH compared with the other muscles (P < 0.01). Barrows fed a RAC diet had increased time to subjective exhaustion due to loss of active muscle fibers in the ST, possibly due to fibers being larger and less oxidative in metabolism. Size increases in type I and IIA fibers with no change in oxidative capacity could also contribute to early exhaustion of RAC+ barrows. Overall, EMG technology can measure real-time muscle fiber loss to help explain subjective exhaustion in barrows