Growth development, carcass composition, and pork quality of Duroc boars, barrows, and gilts slaughtered at various weights

A study involving 36 experimental and 8 observation pigs was conducted to acquire basic knowledge concerning body composition and development patterns of the growing meat-type pig. Linear measurements of muscle, fat, and bone were obtained on two boars, two barrows, and two gilts from each of six litters at three-week intervals up to a weight of 175 pounds and at two-week intervals up to 225 pounds when half of the pigs were slaughtered. Measurements were continued at two-week intervals on the remaining pigs to their slaughter weight of 300 pounds. A boar, gilt, and barrow from each litter were slaughtered at 225 pounds, and the remaining littermates were slaughtered at 300 pounds. Specific gravity, routine carcass data, pork quality determinations, and chemical composition data were obtained on each carcass. In addition, chemical composition data were collected on three pigs comparable to the experimental pigs at each of the observation weights of 75 and 150 pounds. Boars had a higher accumulative average daily gain than barrows and gilts up to 225 pounds, and barrows gained faster than gilts. The advantage of boars over barrows and gilts became more evident at weights beyond 225 pounds. Boars converted feed more efficiently than barrows. The feed efficiency advantage for boars over barrows and gilts was much greater at 300 than at 225 pounds as boars were only slightly less efficient between 225 and 300 pounds than from 75 to 225 pounds. Both skeleton and muscle had attained a greater percentage of their final 225- or 300-pound measurement at 75 pounds than had fat. The rate of increase of skeletal size was slower than muscular growth, and both skeleton and muscle developed at a slower rate than fat from 75 to 300 pounds. The rate of increase in fat depth became more rapid at weights beyond 150 pounds, and, also, differences among individuals and sexes became more apparent. The rapid growth and increase in variation among individuals was largely due to the rapid rate of increase in depth of the second and third fat layers. About 75 to 80 percent of the third fat layer depth at 300 pounds was deposited between 225 and 300 pounds. Ultrasonic estimates and carcass measures of fatness at the tenthand last-rib areas were highly correlated with percent lean cuts, percent ether extract, and percent protein in the carcass. Measurements obtained over the 1. dorsi on both the live animal and carcass were more highly correlated with carcass composition than were midline measurements of live-animal and carcass fatness. At 225 pounds, correlations involving depth of the first two fat layers were higher than those that included all three fat layers. However, at 300 pounds correlations including layers 1, 2, and 3 were as high or higher than those with only layers 1 and 2 included. The percentages of total body length constituted by each body section (poll to scapula, scapula to last rib, last rib to illium, and illium to root of tail) were similar at all weights. Correlations between carcass length and measures of fatness and muscling were of much greater magnitude at 300 than at 225 pounds. This indicates that the pigs which continued to grow skeleton from 225 to 300 pounds remained lean and continued to grow muscle; whereas, pigs that had a slower increase in skeletal growth tended to become fat and also had a slower rate of muscular growth than the longer pigs. These data indicate that individual differences become more evident at heavier weights and that these differences are more observable by practical methods of live-animal evaluation at the heavier weights. Therefore, for most effective results, selection of prospective breeding animals, especially boars, should be conducted at weights beyond 200 pounds

Validity of Ultrasound Velocity to detect changes in the hydration status of Male and Female Athletes during Acute Dehydration and Rehydration

Recent work by Utter, Mcanulty, Sarvazyan, Query, & Landram, (2010) determined that UV could be used to measure changes in the hydration status of male collegiate wrestlers undergoing acute dehydration. However there was a large amount of individual variability amongst participants. Additionally, Utter et al. (2010), only examined male athletes and not female athletes leaving a significant population gap in the potential use of UV for hydration status in a collegiate athletic setting. This paper further explores the validity of ultrasound velocity (UV) as a less invasive form of hydration assessment using improved technology than that used by Utter et al. (2010) in both male and female athletes. Key Words: ultrasound velocity, dehydration, athletes, plasma osmolality, urine specific gravity, total body wate

Ultrasonic Characterization and online monitoring of pork meat dry salting process

[EN] Bearing in mind the highly variable salt content in dry-cured meat products with anatomical integrity, such as pork loin or ham, non-destructive salt content characterization and the online monitoring of dry salting are highly relevant for industrial purposes. This study explores the ability of low-intensity ultrasound to monitor the dry salting of pork Biceps femoris (BF) and Longissimus dorsi (LD) online, as well as to estimate the salt content, both in these muscles and in hams. For this purpose, meat samples were dry salted for up to 16 d at 2 C. During the salting of the muscles, the ultrasonic velocity was continuously measured at time intervals of 5 min, while in the hams it was measured before and after salting. The ultrasonic velocity increased progressively during the salting due to salt gain and water loss, reaching a velocity variation (DV) of 46.8 m/s after 16 d of dry salting for hams and 59.5 and 30.6 m/s after 48 h of dry salting for LD and BF, respectively. Accurate correlations between salt gain and DV were obtained (R2 ¿ 0.903 in LD-BF muscles and R2 ¿ 0.758 in hams), which allowed the assessment of the salt content with an average estimation error of 0.4% w.b. for both muscles and hams. Further research should investigate the use of the time of flight obtained through the pulse-echo mode, instead of the ultrasonic velocity, in order to improve the industrial applicabiliThis work was supported by the Spanish Ministerio de Economia y Competitividad (MINECO), Instituto Nacional de Investigacion y Tecnologia Agraria y Alimentaria (INIA) and European Regional Development Fund (ERDF 2014-2020) (contract n. RTA2013-00030-C03-02), by the PROMETEOII\2014\005 and by the Universitat Politecnica de Valencia (UPV) through the FPI grant awarded to Marta de Prados (SP-1.2011-S1-2757).De Prados, M.; García Pérez, JV.; Benedito Fort, JJ. (2016). Ultrasonic Characterization and online monitoring of pork meat dry salting process. Food Control. 60:646-655. https://doi.org/10.1016/j.foodcont.2015.09.009S6466556

Enhancing Nonlinear Ultrasonic Methods for Laboratory and Clinical Applications

This thesis addresses the underlying physics associated with nonlinear ultrasonic field propagation, measurements of the nonlinear properties of materials, and mechanisms contributing to the observed systematic variation of backscattered ultrasonic energy from the heart over the heart cycle. Studies were performed to address the reliability of the methods of measurement used for the quantitative characterization of nonlinear phenomena and to explore the utility of these methods. This thesis examines the measurement of nonlinear acoustic properties of materials using several methods, including the transmission of ultrasound through the material, as well as the backscattered signal from a region of interest within the material. A method of transmitting ultrasound into the diffractive far field with a negligible amount of distortion is described, along with the consequences of working with different frequencies: and subsequently different diffractive regimes). This thesis also describes studies designed to assess the nature of backscattered ultrasound from the heart obtained by using harmonic imaging, which utilizes nonlinear phenomena to improve the overall quality of clinical ultrasonic images. Several investigators have previously reported a systematic cyclic variation in the backscattered ultrasonic signal from the tissue of the heart. However, a discrepancy in the reported magnitude of this variation seems to be present in the literature. This discrepancy is examined in the context of the multiple methods used to characterize the variation. Furthermore, the characteristics of this systematic variation of backscatter are compared with the dynamics of the left ventricle described using a damped harmonic oscillator model as an approach for identifying the underlying causes of the observed variation

Ultrasound elastomicroscopy using water beam indentation : preliminary study

Author name used in this publication: M. H. LuAuthor name used in this publication: Y. P. ZhengAuthor name used in this publication: Q. H. Huang2004-2005 > Academic research: not refereed > Chapter in an edited book (author)Accepted ManuscriptPublishe

Aerospace medicine and biology: A continuing bibliography with indexes

This bibliography lists 148 reports, articles and other documents introduced into the NASA scientific and technical information system in December 1984

Aerospace medicine and biology: A continuing bibliography with indexes, supplement 218, April 1981

This bibliography lists 161 reports, articles, and other documents introduced into the NASA scientific and technical information system in March 1981

The effects of subcutaneous fat thickness on the production efficiency and organopeltic properties of beef

Eighty-four weanling Hereford steers were used in a two-year study of the effects of three pre-determined subcutaneous fat thickness levels on the production efficiency and organoleptic properties of beef. Three rations (low, medium and high energy levels) were fed to produce a fat thickness over the 12th - 13th rib of 5 mm., 8 to 10 mm. and 13 to 15 mm. for the three rations respectively, after a 150 to 185 day feeding period. Average daily gains were 1.18 lb., 1.55 lb. and 2.07 lb. The rate of fat deposition was monitored by ultrasonic means. Carcass conformation grade, marbling score and carcass grade were significantly (P\u3c.01l) increased as level of energy in the ration increased. Higher feeding levels tended to produce brighter colored, firmer, finer textured muscle. Ration had no significant effect on flavor and juiciness scores. A tendency for tenderness to decrease as feeding level increased was observed. Carcasses from steers on the highest energy level had significantly (P\u3c.01) lower tenderness scores and higher shear values. Significant (P \u3c.01) negative relationships were found between tenderness and marbling score (r = -.35) carcans grade (r = -.40) and fat thickness (r = -.41). Ultrasonic estimates of fat thickness and carcass fat thickness were highly related