Effects of available dietary carbohydrate and preslaughter treatment on glycolytic potential, protein degradation, and quality traits of pig muscles

The current study was conducted to determine the interactive effects of a glycogen-reducing diet fed to finishing pigs and length of preslaughter transportion on muscle metabolic traits, proteolysis of intermediate filament and costameric proteins, and meat quality traits. Large White gilts and barrows (n = 48) were selected at 88 kg of BW and individually fed for 21 d a diet (2.6 kg/d) either high (HC) or low (LC) in available carbohydrates. Six gilts and 6 barrows fed the HC and LC diets were subjected to 0 or 3 h of transportation on the day of slaughter. Muscle temperature and pH were measured at 0.5, 1.5, 2.5, 3.5, 4.5, 5.5, and 24 h postmortem in the LM and 24 h postmortem in the dark (STD) and light (STL) portion of the semitendinosus. At 24 h postmortem, glycolytic potential (GP) was determined in the LM, STD, and STL, as well as proteolysis of titin, nebulin, desmin, vinculin, and talin in the LM and STD. The GP was lower (P \u3c 0.05) in muscles from LC-pigs than in muscles from HC-pigs. The LC diet also resulted in lower (P \u3c 0.05) pH, and a darker (P = 0.03), less (P \u3c 0.01) yellow color in the STL. The LC diet decreased (P = 0.04) cooking losses in the STL and STD. The 3-h journey further decreased (P = 0.05) the GP in the STD, regardless of the diet, but transport had no effect (P ≥ 0.67) on the GP of the LM and STL. Ultimate pH of the LM was lower (P = 0.02), and both portions of the semitendinosus were darker (P = 0.01) and less yellow (P \u3c 0.01), in pigs transported 3 vs. 0 h. In pigs transported for 3 h, intact vinculin tended to be more (P = 0.08) degraded in the LM, which coincided with lower (P = 0.04) drip losses in the LM of pigs transported for 3 compared with 0 h. Increased (P \u3c 0.01) proteolysis of titin paralleled lower (P = 0.02) shear force values in the STD of pigs transported 3 vs. 0 h. Although the present results demonstrated the potential of a glycogen-reducing diet to alter the GP of different porcine muscles, the effect of these changes on meat quality traits was limited to higher ultimate pH and darker color in the STL. The positive effects of length of transportation on water-holding capacity (LM and STD) and meat color (STD and STL) were only partially related to the resting muscle glycogen concentration because the 3-h transport lowered the GP only in the muscle with the lowest basal glycogen concentration

Effects of selection for decreased residual feed intake on composition and quality of fresh pork

The objectives of this study were to determine the extent to which selection for decreased residual feed intake (RFI) affects pork composition and quality. Pigs from the fifth generation of selection for decreased RFI (select) and a randomly selected line (control) were utilized. Two experiments were conducted. In Exp. 1, barrows (22.6 ± 3.9 kg) from select and control lines were paired based on age and BW. The test was conducted in 8 replicates of pairs for the test period of 6 wk. Calpastatin activity and myosin isoforms profile were determined on samples from the LM. Control barrows were heavier (59.1 vs. 55.0 kg; P \u3c 0.01) at the end of the test period. Calpastatin activity was greater (P \u3c 0.01) in LM of select barrows than control barrows. In Exp. 2, composition and quality of gilts (114 kg) from control and select lines were determined. The model included fixed effects of line, slaughter date, melanocortin-4 receptor (MC4R) genotype, barn group, line × slaughter date, genotype × line interactions, a covariate of off-test BW, and sire, pen, and litter fitted as random effects. The select line (n = 80) had 0.043 kg less (P \u3c 0.05) RFI per day than the control line (n = 89). Loin quality and composition were determined at 2 d postmortem. Desmin degradation was measured at 2 and 7 d postmortem. Purge, cook loss, sensory traits, and star probe texture were measured at 7 to 10 d postmortem on cooked chops. Residual correlations between RFI and composition and quality traits were calculated. Compared with the control line, carcasses from the select line tended to have less (P = 0.09) backfat, greater (P \u3c 0.05) loin depth, and greater (P \u3c 0.05) fat free lean. Loin chops from the select line had less (P\u3c 0.01) intramuscular lipid content than loin chops from control line. Significant residual correlations between RFI and both tenderness (r = 0.24, P \u3c 0.01) and star probe (r = −0.26, P \u3c 0.01) were identified. Selection for decreased RFI has the potential to improve carcass composition with few effects on pH and water-holding capacity. However, decreased RFI could negatively affect tenderness and texture because of decreased lipid content and decreased postmortem protein degradation

Finishing Steers in a Deep-bedded Hoop Barn and a Conventional Feedlot: Effects on Performance and Carcass Characteristics during Winter in Iowa

As the Iowa beef industry invests in environmental management, there has been increasing interest in systems that minimize runoff. A possible housing option used previously for pigs and sheep to help mitigate some of these environmental concerns are hoops. The objective of this study was to compare steer performance and carcass characteristics between two housing treatments; hoop confinement barn (HP n=3; 4.65m 2 /steer) vs. conventional feedlot (FD n=3; 14.7m 2 /steer). A total of 240 crossbred Bos taurus steers were used. Steers were ear tagged, implanted, and weighed (400 ± 23.38 kg) on arrival and allotted to balance weight and breed. Performance measures; average daily gain (ADG), average daily feed intake (ADFI), and feed to gain ratio (F:G) were collected over the trial. Carcass characteristics; dressing percentage, hot carcass weight (HCW), fat depth over the 12 rd rib, kidney pelvic and heart fat (KPH), ribeye area (REA), marbling score, quality grade, and USDA yield grade were collected at processing by the packing plant. ADG, ADFI and F:G did not differ (P \u3e 0.05) between housing treatments. Dressing percentage (P = 0.02) and HCW (P = 0.01) were higher for HP steers vs. FD steers between housing treatments. All other carcass characteristics did not differ (P \u3e 0.05) between housing treatments. Therefore, housing steers in a hoop does not result in detrimental alterations in either performance or carcass characteristics when compared to steers in a conventional feedlot

Finishing Steers in a Deep-bedded Hoop Barn and a Conventional Feedlot: Effects on Performance and Carcass Characteristics during Summer in Iowa

As the Iowa beef industry invests in environmental management, there has been increasing interest in systems where runoff is minimized. A possible housing option used previously for pigs and sheep are hoop barns. The objective of this study was to compare steer performance and carcass characteristics between two housing treatments; hoop confinement barn (HP; n=3; 4.7m 2 /steer) vs. conventional feedlot (FD; n=3; 14.7m 2 /steer). A total of 240 crossbred Bos taurus steers were used. Steers were ear tagged, implanted, and weighed (445 ± 31.7 kg) on arrival and allotted to balance weight and breed. Performance measures; average daily gain (ADG), average daily feed intake (ADFI), and feed to gain ratio (F:G) were collected for the trial. Carcass characteristics; dressing percentage, hot carcass weight (HCW), fat depth over the 12 th rib, kidney pelvic and heart fat (KPH), ribeye area (REA), marbling score, quality grade, and USDA yield grade were collected at processing by the packing plant. No performance or carcass characteristics differed (P \u3e 0.05) between housing treatments. Therefore, housing steers in a hoop barn does not result in detrimental alterations in either performance or carcass characteristics when compared to steers in a conventional feedlot

Amino acids in the uterine luminal fluid reflects the temporal changes in transporter expression in the endometrium and conceptus during early pregnancy in cattle

In cattle, conceptus-maternal interactions are critical for the establishment and maintenance of pregnancy. A major component of this early interaction involves the transport of nutrients and secretion of key molecules by uterine epithelial cells to help support conceptus development during the peri-implantation period of pregnancy. Objectives were to: 1) analyze temporal changes in the amino acid (AA) content of uterine luminal fluid (ULF) during the bovine estrous cycle; 2) understand conceptus-induced alterations in AA content; 3) determine expression of AA transporters in the endometrium and conceptus; and 4) determine how these transporters are modulated by (Progesterone) P4. Concentrations of aspartic acid, arginine, glutamine, histidine, lysine, isoleucine, leucine, phenylalanine and tyrosine decreased on Day 16 of the estrous cycle but increased on Day 19 in pregnant heifers (P < 0.05). Glutamic acid only increased in pregnant heifers on Day 19 (P,0.001). Asparagine concentrations were greater in ULF of cyclic compared to pregnant heifers on Day 7 (P < 0.05) while valine concentrations were higher in pregnant heifers on Day 16 (P < 0.05). Temporal changes in expression of the cationic AA transporters SLC7A1 SLC7A4 and SLC7A6 occurred in the endometrium during the estrous cycle/early pregnancy coordinate with changes in conceptus expression of SLC7A4, SLC7A2 and SLC7A1 (P < 0.05). Only one acidic AA transporter (SLC1A5) increased in the endometrium while conceptus expression of SLC1A4 increased (P < 0.05). The neutral AA transporters SLC38A2 and SLC7A5 increased in the endometrium in a temporal manner while conceptus expression of SLC38A7, SLC43A2, SLC38A11 and SLC7A8 also increased (P < 0.05). P4 modified the expression of SLC1A1, -1A4, -1A5, -38A2 , -38A4, -38A7, -43A2, -6A14, -7A1, -7A5 and -7A7 in the endometrium. Results demonstrate that temporal changes in AA in the ULF reflect changes in transporter expression in the endometrium and conceptus during early pregnancy in cattle, some of which are modified by P4. © 2014 Forde et al

Comparison of steer behavior when housed in a deep-bedded hoop barn versus an open feedlot with shelter

The use of hoop barns as an alternative housing system for beef cattle has not been widely researched. The objectives of this study were to determine the main effects of behavior of steers 1) over winter and summer, 2) when housed in either a hoop barn or a conventional feedlot, and 3) interactions between season and housing system. A total of 960 crossbredBos taurus steers were used [August 2006 to April 2008 (2 winter and 2 summer trials)]. Steers were housed in either 1 deep-bedded hoop barn (n = 12 pens; 4.65 m2/steer) or 1 open feedlot with shelter (n = 12 pens; 14.7 m2/steer). Steers were ear tagged, implanted, and weighed (414 ± 36 kg) on arrival and allotted to treatments that were balanced for source, BW, and hide color. Behavioral data (3 postures and 2 behaviors) were collected using a 10-min live scan. The experimental unit for behavior was a pen of steers. Behavioral data were arcsine transformed to achieve a normal distribution. There were no (P \u3e 0.05) differences for time spent at bunk or waterer for steers between housing treatments. Steers housed in an open feedlot with shelter spent less time lying and more time standing and walking (P \u3c 0.05) compared with steers housed in a hoop barn. There were no (P = 0.32) differences between seasons for standing. Steers spent more time at the bunk (P \u3c 0.0001) and waterer (P \u3c 0.0001) in the summer compared with the winter. In the winter, steers engaged in more lying (P = 0.0002) and walking (P \u3c 0.0001). Overall, steers stood less (P = 0.006) and spent more time lying (P = 0.024) when housed in a hoop barn than in the open feedlot with shelter regardless of season. Steers housed in the open feedlot with shelter walked more (P \u3c 0.0001) than steers housed in the hoop barn and walked more (P \u3c 0.0001) in winter than in summer months (6 vs. 3%). There were no (P \u3e 0.05) differences in time spent at bunk and waterer between housing systems within season, but time spent at the waterer and bunk decreased (P \u3c 0.05) for both housing systems during the winter. In conclusion, housing 40 steers per pen in a cornstalk-bedded hoop barn at 4.65m2/steer does not result in adverse behavioral alterations and can be considered as a housing alternative for finishing steers in the Midwestern United States when compared with steers fed in an open feedlot with shelter provided

Performance and Carcass Characteristics of Finishing Beef Cattle Managed in a Bedded Hoop-Barn System

The use of bedded hoop barns in finishing systems for beef cattle has not been widely researched. In this management system, beef cattle are confined to hoop barns throughout finishing, and bedding is used to absorb animal waste, which results in minimal effluent. The objective of this study was to compare the performance and carcass characteristics of finishing beef steers (n = 1,428) managed in a bedded hoop-barn management system vs. an open-feedlot system with shelter. Six feeding trials were conducted over a 3-yr period. Three trials were conducted during summer-fall and 3 trials were conducted during winter-spring. Crossbred steers were allotted to 3 pens in the hoop-barn system and to 3 pens in the open-lot system (approximately 40 steers per pen in both facility systems). Stocking densities for the steers were 4.65 m2 per steer in the hoop-barn system and 14.7 m2 per steer in the open-lot system. The steers were begun on trial weighing 410 and 411 kg (SD = 21), were fed for 102.3 and 103.0 d (SD = 3.8), and were weighed off test at 595 and 602 kg (SD = 21) for the hoop-barn and open-lot systems, respectively. Steer performance measures consisted of ADG, DMI, and G:F. Carcass characteristics were HCW, fat thickness, LM area, KPH percentage, marbling score, USDA yield grade, and USDA quality grade. No year, season, or pen (management system) main effects, or season × management system and year × management system interactions were observed for any of the items measured related to cattle performance or carcass characteristics (P \u3e 0.05). Final mud scores (a subjective evaluation of the amount of soil and manure adhering to the hair coat of the animals) were greater for the steers from the open-lot system compared with those from the hoop-barn system (P \u3c 0.02), suggesting steers in the hoop-barn system carried less mud than steers from the open-lot system. Average daily cornstalk bedding use in the hoop-barn system was 2.3 kg/steer during summer-fall and 2.6 kg/steer during winter-spring. The performance of finishing cattle managed in a hoop-barn system was not different from the performance of cattle managed in an open-feedlot system with shelter during summer and winter. Managing beef cattle in hoop barns required more bedding but resulted in decreased mud scores compared with cattle managed in an open-lot system with shelter. Hoop barns are a viable alternative housing management system for finishing beef cattle

Analysing the operative experience of basic surgical trainees in Ireland using a web-based logbook

<p>Abstract</p> <p>Background</p> <p>There is concern about the adequacy of operative exposure in surgical training programmes, in the context of changing work practices. We aimed to quantify the operative exposure of all trainees on the National Basic Surgical Training (BST) programme in Ireland and compare the results with arbitrary training targets.</p> <p>Methods</p> <p>Retrospective analysis of data obtained from a web-based logbook (<url>http://www.elogbook.org</url>) for all general surgery and orthopaedic training posts between July 2007 and June 2009.</p> <p>Results</p> <p>104 trainees recorded 23,918 operations between two 6-month general surgery posts. The most common general surgery operation performed was simple skin excision with trainees performing an average of 19.7 (± 9.9) over the 2-year training programme. Trainees most frequently assisted with cholecystectomy with an average of 16.0 (± 11.0) per trainee. Comparison of trainee operative experience to arbitrary training targets found that 2-38% of trainees achieved the targets for 9 emergency index operations and 24-90% of trainees achieved the targets for 8 index elective operations. 72 trainees also completed a 6-month post in orthopaedics and recorded 7,551 operations. The most common orthopaedic operation that trainees performed was removal of metal, with an average of 2.90 (± 3.27) per trainee. The most common orthopaedic operation that trainees assisted with was total hip replacement, with an average of 10.46 (± 6.21) per trainee.</p> <p>Conclusions</p> <p>A centralised web-based logbook provides valuable data to analyse training programme performance. Analysis of logbooks raises concerns about operative experience at junior trainee level. The provision of adequate operative exposure for trainees should be a key performance indicator for training programmes.</p

Impact of Mycoplasma hyopneumoniae and Lawsonia intracellularis on the performance of pigs divergently selected for feed efficiency

Feed efficiency (FE) is a valuable trait, yet how genetic selection for enhanced FE affects other processes such as response to disease is unknown. Disease from endemic respiratory and enteric pathogens such as Mycoplasma hyopneumoniae (Mh) and Lawsonia intracellularis (LI) are common in swine production. Therefore, the aim of this study was to examine if pigs selected for high versus low FE based on residual feed intake (RFI) respond differently to a dual respiratory and enteric challenge. Pigs selected for low RFI (LRFI, high feed efficiency) pigs are considered more FE compared to their high RFI (HRFI, low feed efficiency) selected counterparts. Using a 2 x 2 factorial design, 25 littermate pairs from the HRFI and 25 littermate pairs from the LRFI line (barrows, 50 ± 7 kg BW) were selected, with one pig from each pair assigned to individual pens in either the challenge or the non-challenge (control) rooms (n = 25 barrows per line/challenge). On days post inoculation (dpi) 0, the challenged pigs were inoculated with LI and Mh (MhLI). Feed intake, body weight, fecal swabs, and serum samples were collected and recorded weekly for 42 days. On dpi -2 and 47, 14 littermate pairs (n=7 barrows per line/challenge) were utilized for initial and final body composition scans using dual X-ray absorptiometry to calculate longitudinal whole body tissue accretion rates for lean, protein, fat, and bone mineral content. Serum antibody levels and fecal shedding of LI were used to confirm infection. Control pigs remained negative by all measures during the 6 week trial and MhLI inoculated pigs were confirmed positive via serological antibody responses by dpi 14 for LI and Mh. There were no interactions between RFI line and challenge status for any overall performance parameter (P \u3e 0.05). The six week MhLI challenge resulted in a 17% reduction in ADG, a 12% reduction in ADFI, and a 7% reduction in G:F versus controls (P \u3c 0.05). In addition, compared to the control pigs, MhLI challenge reduced lean, protein, and lipid accretion rates by 16% (P \u3c 0.05). Genetic selection for high FE resulted in decreased ADFI and increased G:F (P \u3c 0.01), but did not impact ADG or tissue accretion versus low FE pigs. Collectively, these results demonstrate that a dual enteric and respiratory pathogen challenge reduced ADG, ADFI, G:F and tissue accretion in growing pigs. Further, there was no evidence that selection for enhanced FE based on RFI index affects response to disease

FAK promotes stromal PD-L2 expression associated with poor survival in pancreatic cancer

BACKGROUND: Pancreatic Cancer is one of the most lethal cancers, with less than 8% of patients surviving 5 years following diagnosis. The last 40 years have seen only small incremental improvements in treatment options, highlighting the continued need to better define the cellular and molecular pathways contributing to therapy response and patient prognosis. METHODS: We combined CRISPR, shRNA and flow cytometry with mechanistic experiments using a Kras(G12D)p53(R172H) mouse model of pancreatic cancer and analysis of publicly available human PDAC transcriptomic datasets. RESULTS: Here, we identify that expression of the immune checkpoint, Programmed Death Ligand 2 (PD-L2), is associated with poor prognosis, tumour grade, clinical stage and molecular subtype in patients with Pancreatic Ductal Adenocarcinoma (PDAC). We further show that PD-L2 is predominantly expressed in the stroma and, using an orthotopic murine model of PDAC, identify cancer cell-intrinsic Focal Adhesion Kinase (FAK) signalling as a regulator of PD-L2 stromal expression. Mechanistically, we find that FAK regulates interleukin-6, which can act in concert with interleukin-4 secreted by CD4 T-cells to drive elevated expression of PD-L2 on tumour-associated macrophages, dendritic cells and endothelial cells. CONCLUSIONS: These findings identify further complex heterocellular signalling networks contributing to FAK-mediated immune suppression in pancreatic cancer