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The United States’ swine industry is under constant threat of foreign animal diseases, which may emerge without warning due to the globalized transportation networks moving people, animals, and products. Therefore, having disease control and elimination protocols in place prior to pathogen introduction is paramount for business continuity and economic recovery. During extraordinary circumstances, it may become necessary to depopulate large populations of animals, including swine, as a disease containment measure. Currently approved depopulation methods for swine present significant logistical challenges when scaled to large populations or performed in field conditions. In the United States, water-based foam is currently approved for poultry depopulation, and recent field studies demonstrate water-based foam is an effective depopulation alternative for swine. While effective, the speed at which water-based foam induces loss of consciousness prior to death, a major welfare consideration, has not been adequately investigated. In this study, 12 nursery pigs were terminated using water-based medium-expansion foam to quantify the time to induce loss of consciousness and ultimately brain death. Each pig was implanted with subdermal electrodes to capture electroencephalographic data, placed in a body sling, and suspended in a plastic bulk container that was subsequently filled with water-based foam. Electroencephalographic data was recorded for 15 min, during which the pigs remained immersed in the water-based foam. Conservatively, average (± SD) time to unconsciousness and brain death was 1 min, 53 s ± 36 s and 3 min, 3 s ± 56 s, respectively. The relatively rapid loss of consciousness compared to other methods limits the amount of distress and is overall a positive finding for the welfare of the pigs that might be depopulated with water-based foam. The findings of this study add additional evidence supporting the use of water-based medium-expansion foam for an emergency depopulation of swine.

The objective of this study was to describe the pharmacokinetics (PK) of flunixin in 12 nonlactating sows following transdermal (TD) flunixin (3.33 mg/kg) and intravenous (IV; 2.20 mg/kg) flunixin meglumine (FM) administration using a crossover design with a 10-day washout period. Blood samples were collected postadministration from sows receiving IV FM (3, 6, 10, 20, 40 min and 1, 3, 6, 12, 16, 24, 36, and 48 hr) and from sows receiving TD flunixin (10, 20, 40 min and 1, 2, 3, 4, 6, 8, 12, 16, 24, 36, 48, 60, and 72 hr). Liquid chromatography and mass spectrometry were used to determine plasma flunixin concentrations, and noncompartmental methods were used for PK analysis. The geometric mean ± SD area under the plasma concentration-time curve (AUC) following IV injection was 26,820.59 ± 9,033.88 and 511.83 ± 213.98 hr ng/ml for TD route. Mean initial plasma concentration (C0 ) was 26,279.70 ± 3,610.00 ng/ml, and peak concentration (Cmax ) was 14.61 ± 7.85 ng/ml for IV and TD administration, respectively. The percent mean bioavailability of TD flunixin was 1.55 ± 1.00. Our results demonstrate that topical administration is not an efficient route for delivering flunixin in mature sows.

The objective of this study was to find a practical means of reducing pain associated with surgical castration by evaluating the effects of oral meloxicam and topical lidocaine, separately and in combination, on behavioral indicators of pain in piglets. Two hundred thirty-five piglets were surgically castrated between three and seven days of age. Immediately following castration, piglets received one of four treatments: (1) No pain mitigation (C; control; n = 58); (2) NSAID only (M; meloxicam; n = 59); (3) Topical anesthetic (L; lidocaine spray; n = 60); or (4) NSAID and topical anesthetic (X; meloxicam and lidocaine spray; n = 59). Behaviors were recorded by direct observation of individual piglets using five-minute scan samples over a five-hour period, for three days post-castration. Results of the experiment demonstrate the administration of oral meloxicam and topical lidocaine spray at the time of castration under the current methods did not mitigate pain associated with the procedure (

OBJECTIVE To identify the geographic distribution of exhibition swine in the Midwestern United States, characterize management practices used for exhibition swine, and identify associations between those practices and influenza A virus (IAV) detection in exhibition swine arriving at county or state agricultural fairs. DESIGN Cross-sectional survey. SAMPLE 480 swine exhibitors and 641 exhibition swine. PROCEDURES Inventories of swine exhibited at fairs in 6 selected Midwestern states during 2013 and of the total swine population (including commercial swine) in these regions in 2012 were obtained and mapped. In 2014, snout wipe samples were collected from swine on arrival at 9 selected fairs in Indiana (n = 5) and Ohio (4) and tested for the presence of IAV. Also at fair arrival, swine exhibitors completed a survey regarding swine management practices. RESULTS Contrary to the total swine population, the exhibition swine population was heavily concentrated in Indiana and Ohio. Many swine exhibitors reported attending multiple exhibitions within a season (median number, 2; range, 0 to 50), with exhibited swine often returned to their farm of origin. Rearing of commercial and exhibition swine on the same premises was reported by 13.3% (56/422) of exhibitors. Hosting an on-farm open house or sale was associated with an increased odds of IAV detection in snout wipe samples. CONCLUSIONS AND CLINICAL RELEVANCE The exhibition swine population was highly variable and differed from the commercial swine population in terms of pig density across geographic locations, population integrity, and on-farm management practices. Exhibition swine may be important in IAV transmission, and identified biosecurity deficiencies may have important public and animal health consequences.

The present study was aimed at evaluating the effect of herbal extracts supplementation, particularly quaternary-benzo(c)phenanthridine alkaloids (QBA), which have been previously demonstrated to have anti-inflammatory, antimicrobial, and immune-modulator effects. We investigated the role of QBA on stress response and Salmonella shedding in finishing pigs transported to the slaughterhouse. A total of 82 pigs were orally challenged with a Salmonella cocktail (day 0) containing Salmonella Meleagridis, Hartford, Bovismorbificans and Newport serovars and randomly assigned to three treatment groups after 2 wks (day [D] 14): T1, in-feed QBA; T2, in-feed and water-soluble QBA; CON, nonsupplemented). Pigs were transported to the slaughterhouse 2 weeks after intervention (D 28) and slaughtered after nearly 19 h (D 29). Saliva, fecal samples, and carcass swabs were collected from all pigs. Salivary cortisol, Salmonella shedding, and carcass contamination were measured. A high positive correlation (Spearman rank correlation coefficient range 0.82-0.93) between salivary cortisol and Salmonella shedding was found after transportation in all groups (p

Linear measurements on live lambs and carcasses can be used to characterize sheep breeds and may have value for prediction of carcass yield and value. This study used 512 crossbred lambs produced over 3 yr by mating Columbia, U.S. Meat Animal Research Center (USMARC) Composite, Suffolk, and Texel rams to adult Rambouillet ewes to assess sire-breed differences in live-animal and carcass shape and to evaluate the value of shape measurements as predictors of chilled carcass weight (CCW), weight of high-value cuts (rack, loin, leg, and sirloin; HVW), weight of trimmed high-value cuts (trimmed rack and loin and trimmed, boneless leg and sirloin; TrHVW), and estimated carcass value before (CVal) and after trimming of high-value cuts (TrCVal). Lambs were produced under extensive rangeland conditions, weaned at an average age of 132 d, fed a concentrate diet in a drylot, and harvested in each year in 3 groups at target mean BW of 54, 61, and 68 kg. Canonical discriminant analysis indicated that over 93% of variation among sire breeds was accounted for by the contrast between tall, long, less-thickly muscled breeds with greater BW and CCW (i.e., the Columbia and Suffolk) compared with shorter, more thickly muscled breeds with smaller BW and CCW. After correcting for effects of year, harvest group, sire breed, and shipping BW, linear measurements on live lambs contributed little to prediction of CCW. Similarly, after accounting for effects of CCW, linear measurements on live animals further reduced residual SD (RSD) of dependent variables by 0.2 to 5.7%, with generally positive effects of increasing live leg width and generally negative effects of increasing heart girth. Carcass measurements were somewhat more valuable as predictors of carcass merit. After fitting effects of CCW, additional consideration of carcass shape reduced RSD by 2.1, 3.6, 9.5, and 2.2% for HVW, TrHVW, CVal, and TrCVal, respectively. Effects of increasing carcass leg width were positive for HVW, TrHVW, and TrCVal. We also observed positive effects of increasing carcass length on TrCVal and negative effects of increasing cannon bone length on HVW and CVal. Increasing shoulder width had positive effects on CVal but negative effects on TrHVW. Differences in lamb and carcass shape were significantly associated with carcass yield and value, but the additional accuracy associated with use of these measurements was modest relative to that achieved from use of only shipping BW or CCW.

Numerous reports have described genetic markers or genomic regions (QTL) associated with pork quality and/or palatability but few validation studies have been reported. Therefore, 156 SNP markers from 45 candidate genes and eight QTL regions were analyzed for association with pork quality and palatability traits from 888 pork loins. Loins were collected at three slaughter facilities and selected to represent a wide range of pork color, pH and marbling. Phenotypic data recorded included objective and subjective measures of color and marbling, purge loss, shear force, and cooking loss. Data were analyzed with SAS PROC MIXED where loin was fit as a random effect. Results indicated some of the markers tested should be useful in industry, while others are not segregating in all populations or linkage disequilibrium between markers and causative genetic variation fluctuates among populations limiting their universal utility. Genes with the largest effects on pork quality were MC4R, IGF2, CAST and PRKAG3.

We examined effects of deprivation of feed, social contact and bedding on the choice behaviour in Y maze tests. Eighty pigs were used to study two main effects: feed (estimated voluntary feed intake (VFI) vs. 70% VFI) and bedding (presence vs. absence), experiment 1; social contact (full vs. restricted) and bedding (presence vs. absence), experiment 2; and feed (as in experiment 1) and social contact (as in experiment 2), experiment 3. Overall pigs consistently chose feed and social contact over bedding. While social contact was more preferred than feed in experiment 3, there was substantial variation between pigs in their choice behaviour. The overall choice behaviour in experiment 3 contradicts previous research, but differences such as the preference methodology as well as the level of deprivation, level of reward and cost involved in accessing reward, may be responsible. Average daily weight gain (ADG) was affected in experiment 3: both feed and social restriction reduced ADG. While the feed effect is expected, one interpretation of the social effect is that social deprivation, through stress, may have reduced ADG. These results provide limited support for the notion that deprivation of a highly preferred resource may disrupt biological function.

The intestinal microbiota of broiler chickens and the microbiota in the litter have been well studied, but the interactions between these two microbiotas remain to be determined. Therefore, we examined their reciprocal effects by analyzing the intestinal microbiotas of broilers reared on fresh pine shavings versus reused litter, as well as the litter microbiota over a 6-week cycle. Composite ileal mucosal and cecal luminal samples from birds ( n = 10) reared with both litter conditions (fresh versus reused) were collected at 7, 14, 21, and 42 days of age. Litter samples were also collected at days 7, 14, 21, and 42. The microbiotas were profiled and compared within sample types based on litter condition using PCR and denaturing gradient gel electrophoresis (PCR-DGGE). The microbiotas were further analyzed using 16S rRNA gene clone libraries constructed from microbiota DNA extracted from both chick intestinal and litter samples collected at day 7. Results showed significant reciprocal effects between the microbiotas present in the litter and those in the intestines of broilers. Fresh litter had more environmental bacteria, while reused litter contained more bacteria of intestinal origin. Lactobacillus spp. dominated the ileal mucosal microbiota of fresh-litter chicks, while a group of bacteria yet to be classified within Clostridiales dominated in the ileal mucosal microbiota in the reused-litter chicks. The Litter condition (fresh versus reused) seemed to have a more profound impact on the ileal microbiota than on the cecal microbiota. The data suggest that the influence of fresh litter on ileal microbiota decreased as broilers grew, compared with temporal changes observed under reused-litter rearing conditions.

Pork loins (N=53) were selected from a commercial packing plant to determine the influence of subjective marbling score on sensory attributes and eating quality properties. The pork loins were obtained from commercially raised hybrid barrows (average carcass weight=67.7 kg), originating from nine cooperating herds, and fed similar diets throughout the finishing period. Carcass quality measurements, trained sensory panel analyses, fatty acid composition, thiobarbituric acid-reactive substance (TBARS) index, and cholesterol content were assessed and analyzed on the individual pork loins. With an increase in marbling level, there was a corresponding decrease in drip loss (P=0.049) and observed increases in pH (P=0.001), sensory tenderness (P=0.001), and sensory juiciness scores (P=0.017). The most notable results demonstrated that protein concentrations were reduced as marbling levels amplified (P=0.012). The increase in marbling score was observed to be a significant source of variation in polyunsaturated fatty acid (PUFA) concentrations. Linoleic and arachidonic acids decreased in both raw and cooked samples as marbling score increased. The data demonstrated that visual marbling score does have an influence on sensory properties and pork quality.

The present study evaluated individual and interactive influences of pork loin (n=679) ultimate ph (pH), intramuscular fat (IMF), Minolta L* color (L*), Warner-Bratzler shear force (WBSF), and internal cooked temperatures (62.8 degrees C, 68.3 degrees C, 73.9 degrees C, and 79.4 degrees C) on trained sensory perception of palatability. Logistical regression analyses were used, fitting sensory responses as dependent variables and quality and cooked temperature as independent variables, testing quadratic and interactive effects. Incremental increases in cooked temperature reduced sensory juiciness and tenderness scores by 3.8% and 0.9%, respectively, but did not influence sensory flavor or saltiness scores. An increase of 4.9N in WBSF, from a base of 14.7N (lowest) to 58.8N (greatest) was associated with a 3.7% and 1.8% reduction in sensory tenderness and juiciness scores, respectively, with predicted sensory tenderness scores reduced by 3.55 units when comparing ends of the WBSF range. Modeled sensory responses for loins with pH of 5.40 and 5.60 had reduced tenderness, chewiness, and fat flavor ratings when compared with responses for loins with pH of 5.80 to 6.40, the range indicative of optimal sensory response. Loin IMF and L* were significant model effects; however, their influence on sensory attributes was small, with predicted mean sensory responses measurably improved only when comparing 6% and 1% IMF and L* values of 46.9 (dark) when compared with 65.0 (pale). Tenderness and juiciness scores, were related to a greater extent to loin WBSF and pH, and to a lesser extent to cooked temperature, IMF and L*.

The study evaluated the interactive and individual effects of fresh pork loin (n=679) ultimate pH (pH), intramuscular fat (IMF), Minolta L* color (L*), Warner-Bratzler shear force (WBS), and four cooked temperatures (62.8 degrees C, 68.3 degrees C, 73.9 degrees C, and 79.4 degrees C) on consumer (n=2280) perception of eating quality (n=13,265 observations). Data were analyzed using ordered logistical regression. Predicted mean responses were consistently near or under five on the 1-8-point end-anchored scale, indicating a neutral perception of pork eating quality regardless of fresh quality or cooked temperature. Responses improved as IMF and pH increased and WBS decreased, whereas L* did not contribute significantly to variation in responses. Increasing IMF resulted in a very small incremental improvement in responses, but was of practical size only when comparing the least (1%) to the greatest (6%) levels. Loin pH and WBS were primary contributors to consumer perceptions, whereby an incremental increase in pH (0.20 unit) and decrease in WBS (4.9 N) resulted in a 4-5% reduction in the proportion of consumers rating pork as >or= 6 (favorable) on the 8-point scale. No interactions between quality and temperature effects were observed. Increased cooked temperature was negatively (P

Background Porcine Epidemic Diarrhea virus (PEDV) is a highly transmissible coronavirus that causes a severe enteric disease that is particularly deadly for neonatal piglets. Since its introduction to the United States in 2013, PEDV has spread quickly across the country and has caused significant financial losses to pork producers. With no fully licensed vaccines currently available in the United States, prevention and control of PEDV disease is heavily reliant on biosecurity measures. Despite proven, effective biosecurity practices, multiple sites and production stages, within and across designated production flows in an Ohio swine operation broke with confirmed PEDV in January 2014, leading the producer and attending veterinarian to investigate the route of introduction. Case presentation On January 12, 2014, several sows within a production flow were noted with signs of enteric illness. Within a few days, illness had spread to most of the sows in the facility and was confirmed by RT-PCR to be PEDV. Within a short time period, confirmed disease was present on multiple sites within and across breeding and post weaning production flows of the operation and mortality approached 100% in neonatal piglets. After an epidemiologic investigation, an outsourced, pelleted piglet diet was identified for assessment, and a bioassay, where naïve piglets were fed the suspected feed pellets, was initiated to test the pellets for infectious PEDV. Conclusions The epidemiological investigation provided strong evidence for contaminated feed as the source of the outbreak. In addition, feed pellets collected from unopened bags at the affected sites tested positive for PEDV using RT-PCR. However, the bioassay study was not able to show infectivity when feeding the suspected feed pellets to a small number of naïve piglets. The results highlight the critical need for surveillance of feed and feed components to further define transmission avenues in an effort to limit the spread of PEDV throughout the U.S. swine industry.

Adipose triglyceride lipase (ATGL), catalyzing the initial step of hydrolysis of triacylglycerol (TAG) in adipocytes, has been known to be inhibited by G0/G1 switch gene 2 (G0S2). In this study, we report the porcine G0S2 cDNA and amino acid sequences as well as the expression level of porcine G0S2. The porcine G0S2 mRNA was abundantly expressed in adipose tissue and liver among various tissues. In adipose tissue, porcine G0S2 expression was 16-fold higher in the fat cell fraction than the stromal vascular fraction. The G0S2 level increased significantly during adipogenesis in vitro and in vivo. These data indicate that G0S2 expression is closely associated with lipid accumulation and adipogenesis. Considering G0S2 as an inhibitor of cell proliferation, the relatively low levels of G0S2 in preadipocytes and adipose tissues of fetal and neonatal pigs compared to adipocytes and adipose tissues of adult pigs may allow the fast cell proliferation rates. Further studies showed that a short-term 24-h fast down-regulated G0S2 expression and increased ATGL expression in adipose tissue; however, a long-term calorie restriction for 8 days had no influence on the level of G0S2 but increased ATGL expression. Therefore, porcine G0S2, which is both a negative regulator of ATGL-mediated lipolysis and cell proliferation in adipose tissue, can be down-regulated in vivo by a short-term 24-h fast followed by increased ATGL-mediated lipolysis.

Delta-like homolog 1 (DLK1), a paternally imprinted gene with several alternative splicing isoforms, is an important regulator of fetal and postnatal development. We report the sequence of porcine DLK1 (pDLK1) and examine the expression and alternative splicing isoforms in the pig (Sus scrofa) and human. DLK1-A was the sole isoform identified in human tissues and has been shown to be present in mouse and cattle. Surprisingly, DLK1-A was undetected in various tissues from fetal and postnatal pigs. Instead, DLK1-C2 was the most abundant isoform while DLK1-B was expressed to a lesser extent. In fractionated adipose tissue, pDLK1 was most highly expressed in the stromal-vascular cell fraction. In addition, total pDLK1 was highly expressed in fetal adipose tissue but dramatically decreased postnatally. Our data suggests that expression of DLK1-B and -C2 isoforms is sufficient for normal pig development. Furthermore, human and pig samples showed no alterations in species-specific splicing, but expression levels decreased with age, suggesting that regulation of expression, not splicing, is the most likely mechanism controlling the biological function of DLK1.

Sixty-three Angus x Simmental calves were allotted to a bull or a steer group based on sire, birth date, and birth weight to determine effects of castration status on performance, carcass characteristics, and circulating insulin-like growth factor I (IGF-I) concentrations in early-weaned cattle. At 75 d of age, calves in the steer group were castrated. Calves were not creep-fed prior to weaning. All calves were weaned and weighed at an average age of 115 d and transported by truck to the OARDC feedlot in Wooster, OH. Performance and carcass characteristics were measured in three phases. Phase 1 was from 115 to 200 d of age, phase 2 was from 201 to 277 d of age, and phase 3 was from 278 d of age to slaughter. Before implantation, four bulls and four steers were selected for serial slaughter and carcass evaluation. Steers were implanted with Synovex-C at 130 d of age and with Revalor-S at 200 and 277 d of age. Serum samples were collected from all calves on the day of implantation, 28 and 42 d after implantation, and at slaughter and analyzed for circulating IGF-I concentration. Bulls gained 9.7% faster (1.75 vs 1.60 kg/d; P < 0.01), consumed 25 kg more DM (521 vs 496 kg; P = 0.11), and were 3.3% more efficient (282 vs 273 g/kg, P < 0.10) than steers in phase 1. However, steers gained 10.5% faster (1.62 vs 1.46 kg/d; P < 0.02), consumed similar amounts of DM, and were 6.5% more efficient than bulls (214 vs 201 g/kg; P < 0.06) in phase 2. Overall gains and efficiency were similar between bulls and steers; however, bulls consumed 140 kg more DM (P < 0.05), were 27 kg heavier (P < 0.05), and had to stay in the feedlot 18 more days (P < 0.05) than steers to achieve a similar amount of fat thickness. Implanted steers had greater concentrations of circulating IGF-I than bulls (P < 0.01), and the pattern of IGF-I concentration over time was affected by castration status (castration status x time interaction; P < 0.01). Synovex-C had a lower impact on circulating IGF-I concentration (implant effect, P < 0.01) than either Revalor-S implant. Eighty-five percent of both bulls and steers had marbling scores sufficient to grade low Choice or better. Bulls achieved their target fat thickness later, increased muscle growth, and deposited fat more favorably than steers, possibly due to a gradual increase in IGF-I concentration as the testicles grew rather than the large fluctuations in IGF-I concentration observed in steers following implantation.

One hundred forty-three Angus x Simmental crossbred steers (initial BW = 155.1 +/- 4.5 kg) were used in a 2-yr study (yr 1, n = 67; yr 2, n = 76) to determine the effects of weaning age, implant regimen, and the weaning age x implant regimen interaction on steer growth and performance, organ mass, carcass characteristics, and cooked beef palatability. Steers were early-weaned at an average age of 108 d (EW) or normally weaned at an average age of 202 d (NW) and allotted by weight to an aggressive or nonaggressive implant regimen. On their respective weaning dates, EW and NW steers were penned individually and fed a grain-based diet until they were slaughtered at a final BW of 546 kg. A subsample of steers (n = 2 per treatment) were slaughtered at 254 kg. At 254 kg, EW steers implanted with the aggressive implant regimen had 64% greater backfat depth than those implanted with the nonaggressive implant regimen; conversely, NW steers implanted with the aggressive implant regimen had 52% lower backfat depth than those implanted with the nonaggressive implant regimen (weaning status x implant regimen interaction; P0.01). A similar interaction was observed for empty visceral organ weights. Early-weaned steers were younger (354.7 vs 372.4 d; P0.01) at final slaughter but were in the feedlot longer (246.5 vs 169.6 d; P0.01) than NW steers, whereas the aggressive implant regimen decreased days fed (203.3 vs 212.7; P0.07) compared to the nonaggressive implant regimen. Overall ADG was greater for EW than for NW steers (1.61 vs 1.50 kg/d; P0.01) and for the aggressive compared with the nonaggressive implant regimen (1.59 vs 1.52 kg/d; P0.02). Early-weaned steers consumed less DM per day (7.4 vs 8.5 kg/d; P0.01) and were more efficient (0.217 vs 0.208 kg/kg; P0.02) but consumed more total DM (1,817 vs 1,429 kg; P0.01) than NW steers while in the feedlot. Implant regimen did not affect DMI (P0.37) or feed efficiency (P0.15). Weaning status did not affect carcass characteristics (P0.14), final empty body composition (P0.25), or final longissimus muscle composition (P0.18); however, steaks from EW steers had higher (P0.05) taste panel tenderness and juiciness ratings than steaks from NW steers. The aggressive implant regimen decreased yield grade (P0.02), but did not affect quality grade (P0.86) compared to the nonaggressive implant regimen. Placing early-weaned steers on an aggressive implant regimen is a viable management option.

Two experiments were conducted to determine the effects of diet on growth of steers weaned at approximately 100 vs 205 d of age. In Exp. 1, a 2 x 2 x 2 factorial experiment was conducted using 78 Angus crossbred cow-calf pairs. The factors examined were age at weaning (early, at 103+/-3 d [EW] vs normal, at 203+/-3 d [NW]), feeding strategy (ad libitum vs postweaning programmed intake), and dietary CP concentration (100 vs 120% of NRC [1984] recommended levels). Early-weaned calves had a greater (P.001) ADG than NW calves from 103 to 203 d and reached market weight at 385 d vs 418 d for NW calves (P.001). Likewise, steers offered feed for ad libitum consumption reached market weight at 394 d, compared with 409 d for programmed-intake steers (P.05). In Exp. 2, 64 Angus crossbred steers were either weaned at 93+/-3 d and fed one of four diets, weaned at 210+/-3 d without access to creep feed, or weaned at 210+/-3 d with access to creep feed for 60 d prior to weaning. Early-weaned calves were heavier (P.01) than NW calves at 210 d if fed either 100 or 90% concentrate diets, and they had greater (P.001) backfat thickness at 210 d but no difference (P.10) in longissimus muscle area compared to EW calves fed a 60% concentrate diet. At slaughter, 80 to 100% of steers on all treatments graded low Choice or higher. Feeding high-concentrate diets to EW beef calves accelerated growth rate and fat deposition early in the feeding period and may be a way to provide young cattle for a high-quality beef market.

Paired, boneless pork loin muscles were obtained from 76 market hogs to evaluate tenderness, meat quality characteristics, sensory attributes, and microbial characterization of pork muscle exposed to the Hydrodyne Process (H) compared with untreated control ( C ) loin. A subset of 16 paired loins was randomly selected for use in sensory evaluation and microbial characterization. Loins were vacuum packaged and immersed in a heat shrink tank prior to the H treatment. The Hydrodyne treatment exposed the loin to the pressure equivalent of a 150-g explosive, generating a pressure distribution of approximately 703 kg/cm 2 at the surface of the samples. Meat quality assessments taken following treatment included subjective color, firmness/wetness, marbling scores (1 to 5 scale), Minolta reflectance and color readings, drip loss, and lipid content. The P-value for statistical significance for main effects and interactions was set at

The relationship between estrogen receptor (ESR) genotype and reproductive traits in a population of Yorkshire, Large White, and crossbred animals was studied. Reproductive tract and litter data were analyzed for associations with ESR genotype, parity, and breed. Forty-six Yorkshire, 31 Large White, and 70 crossbred females from the above population were mated to Hampshire boars and slaughtered at 75 d of gestation. Data collected included ovulation rate, uterine horn length, number of fetuses, fetal weight, uterine weight, number of mummies, fetal sex, fetal placement, fetal survival, and fetal space. Data were analyzed using a model that included the fixed effects of ESR genotype, breed, parity, and all significant two-way interactions. Litter data representing 212 litter records were analyzed in a model that included the fixed effects of ESR genotype of dam, parity, farrowing month, dam breed, sire breed, and all significant two-way interactions. The ESR genotype was significantly associated with the total litter weight of piglets born and total litter weight of piglets born alive. Dams with the AA genotype had significantly (P = 0.04) heavier litters at birth (14.44 +/- 0.36 kg) than dams with the BB genotype (13.43 +/- 0.47 kg). Ovulation rate was significantly (P0.05) different between animals of parity 1 (17.22 +/- 0.41) and parityor = 3 (19.92 +/- 0.85). Significant breed effects were observed for fetal weight, with purebred Large White animals having a greater fetal weight per horn (3,909 +/- 114 g) than purebred Yorkshire animals (3,553 +/- 92 g). Notable, but nonsignificant, trends with respect to ESR genotype were also observed for number of piglets alive at weaning and total litter weight at weaning. The ESR gene is positively associated with several previously uninvestigated reproductive traits.

Two experiments were conducted to investigate a feeding regimen in which a programmed amount of feed was offered daily to control growth rate of steers. In Exp. 1, steers (n = 107, 309 +/- 3 kg) were used to determine effects of offering ad libitum access to feed (AL) vs a programmed intake feeding regimen (PI) and the number of days steers were fed (168 vs 203) on performance and carcass characteristics. Steers in the programmed intake feeding regimen were fed to achieve a predicted gain of 1.13 kg/d for the first 78 kg of gain, 1.36 kg/d for the next 124 kg of gain, and were given ad libitum access to feed for the final 54 or 103 kg of gain before slaughter (for steers fed for 168 d or 203 d, respectively). Feed efficiency was greater (P0.02) for steers in the PI than for those in the AL feeding regimen (0.193 vs 0.183 kg gain/kg feed, respectively). From d 169 to 203, steers in the PI feeding regimen had greater (P0.06) ADG (1.60 vs 1.38 kg/d) and similar (P = 0.38) feed efficiency than steers in the AL regimen. In Exp. 2, steers (n = 96; 308 +/- 3 kg BW) were offered feed ad libitum throughout the experiment (AL) or were programmed to gain at a high (PI-H) or low (PI-L) growth rate. For the first 78 kg of gain, intake was restricted to achieve predicted gains of 1.13 kg/d (PI-L) or 1.25 kg/d (PI-H). For the next 124 kg of gain, intake was restricted to achieve predicted gains of 1.36 kg/d (PI-L) or 1.47 kg/d (PI-H). Feed was offered ad libitum for the final 58 kg of gain. Overall ADG was similar (P0.37) among feeding regimens despite lower DMI for the steers in the PI-L and PI-H feeding regimens than for those in the AL regimen. Feeding regimen did not affect (P0.22) carcass characteristics. Programmed intake feeding regimens sustained growth rate and feed efficiency for an extended period of time without detrimental effects on carcass characteristics.

Real-time ultrasonic measurements of 10th-rib backfat (BF10) and loin muscle area (LMA) were made by a single technician at four mean BW (67.4, 80.3, 93.4, and 104.9 kg) on live hogs to assess the accuracy of predicting carcass measurements before and at slaughter weight. Records were evaluated on 655 purebred barrows and 472 purebred gilts in two tests. Residual correlations-accounting for test, sex, and breed effects, among and between scans and carcass measurements--were moderate to high for BF10 (r=.69 to .82) and LMA (r=.57 to .68), with the largest correlations at 104.9 kg of live weight. Ultrasonic BF10 and LMA were within +/-4 mm and +/-6.45 cm2, respectively, of the corresponding carcass measurement 75.9 and 89.8% of the time. Sex differences for LMA bias were significant (P.001); ultrasonic LMA was overestimated in barrows by .75 cm2 and underestimated in gilts by .91 cm2. Breed differences were significant (P.001) for BF10 and LMA bias. Standard errors of prediction (SEP) for BF10 and LMA across the two tests were 3.46 mm and 4.04 cm2, respectively. The SEP for BF10 were 3.60 mm for barrows and 3.19 mm for gilts. The SEP for LMA were 3.77 cm2 for barrows and 4.22 cm2 for gilts. The SEP for BF10 within breeds ranged from 3.25 to 3.72 mm, and for LMA, ranged from 2.98 cm2 to 4.90 cm2. Ultrasound measurements overestimated the carcass measurement by .57 mm for carcasses measuring24.1 mm and underestimated by 2.81 mm carcasses with BF1030.3 mm. Ultrasonic LMA overestimated the carcass by 2.35 cm2 in carcasses measuring32.5 cm2 and underestimated by 2.29 cm2 in carcasses measuring greater than 37.9 cm2. Results indicate that the magnitude of the carcass measurement affects bias and accuracy of prediction for real-time ultrasonic measurements of BF10 and LMA. The SEP statistic is more consistent in evaluating accuracy of ultrasonic measurement than bias, absolute deviations, and percentage of absolute deviation.

We recorded serial real-time ultrasonic measurements of backfat and loin muscle area to assess the rate of change per unit of live weight and growth rate measured as the change in weight per day of age during the finishing stage of production. Barrows (648) and gilts (459) representing eight major U.S. pure breeds of swine were evaluated in the study. Real-time ultrasonic measurements of backfat and loin muscle area were collected at average live weights (LW) of 67.4, 80.3, 93.4, and 104.9 kg. Backfat was measured at the midline over the last rib (LR) and last lumbar vertebra (LL) and off the midline at the 3/4 point (BF10) over the 10th rib. Loin muscle area (LMA) images were collected from the right-hand side of each pig at the 10th rib. Deposition rates were calculated on an intrapig basis for the dependent scan variables BF10, LMA, LR, and LL in models that included the independent variables LW and LW2. For growth rate (WDA), LW was regressed on age and age. Intrapig linear regression coefficients and y-intercepts were further analyzed as dependent variables in a mixed model that included the fixed effects test group, sex, and breed and random effects of sire and dam nested within breed. Significant breed effects were present for deposition rates of BF10, LMA, LR, LL, and WDA. Across the eight breeds, BF10 was deposited at a mean of .271 +/- .008 mm/kg, a rate faster than the average for LR (.201 mm/kg) and LL (.206 mm/kg). The LMA deposition rate across breeds averaged .304 cm2/kg. Average WDA across the breeds was .774 kg. Barrows deposited fat faster at all locations, deposited muscle slower, and grew faster than gilts in this study (P < .001). The results of this study indicate a need for breed- and sex-specific adjustment factors for rates of backfat and loin muscle deposition and for weight per day of age in swine.

The objectives of this study were to determine whether two preslaughter management treatments, rest and mixing, influence the muscle quality of porcine stress syndrome (PSS) heterozygous (Nn) market hogs and to verify the expected quality characteristics of carcasses produced from PSS-normal (NN) and PSS-susceptible (nn animals. Twenty-nine Nn, 14 NN, and 9 nn market hogs were randomly assigned to preslaughter handling treatments. One-half of the animals in each genotype group received 16 h of rest before slaughter, and the remaining pigs were slaughtered immediately upon arrival at the Iowa State University Meat Laboratory. Within each group, half of the Nn animals were mixed with unfamiliar pigs during transport and lairage. Length, backfat, and loin muscle area (LMA) were not affected by mixing and rest treatment. The carcasses from nn pigs had less fat (P