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

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

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

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