Effects of the feeding system on performance and myopathy occurrence in two broiler chicken genotypes

To evaluate whether performance and myopathy occurrence differed according to genotype (Cobb 500 vs. Ross 308) and feeding system (AL: ad libitum vs. ER: early restricted from 13 to 23 d of age, vs. LR: late restricted from 27 to 37 d; restriction rate: 80% of ad libitum), 828 day- old male chicks were assigned to 6 groups (2 x 3 arrangement), housed in 36 pens, and controlled for: individual live weight (weekly) and pen feed intake (daily) until slaughter (48 d); white striping and wooden breast occurrence at slaughter. Individual data were analysed by PROC MIXED of SAS (fixed effects: feeding system, genotype, and interaction; random effect: pen); pen feed intake and myopathy occurrence were analysed by PROC GLM and CATMOD, respectively. The feeding system affected performance: at the end of the first period (1-22 d), ER chickens showed lower weight gain (40.5 g/d vs. 47.8 g/d and 48.0 g/d), feed intake (50.8 g/d vs 61.0 g/d and 60.2 g/d) and weight (903 g vs 1056 g and 1059 g) than AL and LR broilers (P<0.001); at the end of the second period (23-48 d), ER chickens showed higher weight gain (98.3 g/d vs 93.6 g/d and 90.2 g/d) and feed intake (182 g/d vs. 177 g/d and 171 g/d) compared to AL and LR chickens (P<0.001). Final live weight was the highest in AL group, intermediate in ER group, and the lowest in the LR one (3482 g, 3454 g, and 3399 g; P<0.01). Feed conversion in the whole period did not change with the feeding system. At gross examination, white striping occurrence changed from 77.8% to 67.1%, and 81.7% in AL, ER and LR broilers (p<0.10). Differences between genotypes were evident from the first day and, at the end of the trial, weight gain (74.3 g/d vs 70.1 g/d), feed intake (126 g/d vs 114 g/d), feed conversion (1.69 vs 1.64), and live weight (3548 g vs. 3342 g) were higher in the Ross than in the Cobb chickens (P<0.001). At slaughter, the rate of white-striped breasts was similar (on average 75.5%), but the occurrence of severely white-striped breasts was higher in the Ross than in the Cobb chickens (25.9% vs. 7.41%; P<0.001). Wooden breast occurrence (on average 5.1%) did not change with the feeding system or the genotype. In conclusion, under our conditions, a late feed restriction did not permit to recover performance at the end of the trial nor to control white striping occurrence. Moreover, the genotype affected growth rate and white striping degree: the highest the growth rate, the highest the severity of white striping

Inhibition of HTLV-1 infection by HIV-1 first- and second-generation integrase strand transfer inhibitors

More than 10 million people worldwide are infected with the retrovirus human T-cell lymphotropic virus type 1 (HTLV-1). Infection phenotypes can range from asymptomatic to severe adult T-cell leukemia/lymphoma (ATLL) and HTLV-1-associated myelopathy. HTLV-1, like human immunodeficiency virus type 1 (HIV-1), is a blood-borne pathogen and viral infection happens in a similar fashion, with the major mode of transmission through breastfeeding. There is a strong correlation between time of infection and disease development, with a higher incidence of ATLL in patients infected during childhood. There is no successful therapeutic or preventative regimen for HTLV-1. It is therefore essential to develop therapies to inhibit transmission or block the onset/development of HTLV-1 associated diseases. Recently, we have seen the overwhelming success of integrase strand transfer inhibitors (INSTIs) in the treatment of HIV-1. Previously, raltegravir was shown to inhibit HTLV-1 infection. Here, we tested FDA-approved and two Phase II HIV-1 INSTIs in vitro and in a cell-to-cell infection model and show that they are highly active in blocking HTLV-1 infection, with bictegravir (EC50 = 0.30 ± 0.17 nM) performing best overall. INSTIs, in particular bictegravir, are more potent in blocking HTLV-1 transmission than tenofovir disproxil fumarate, an RT inhibitor. Our data suggest that HIV-1 INSTIs could present a good clinical strategy in HTLV-1 management and justifies the inclusion of INSTIs in clinical trials

Recommendations and guidelines for applied nutrition experiments in rabbits

[EN] The aim of this paper was to draw up a set of recommendations for applied nutrition and feeding trials with rabbits, in relation to certain aspects such as determining the nutritive value of raw materials or diets in growing or reproducing animals, studying digestive physiology and obtaining growth and reproduction parameters. We deal first with animals, size of the sample, housing conditions, diets, handling, measurements, and the data analyses relevant to the design of the experiment are described. Secondly, we give a list of recommended items and include some comments.This study was partly supported by the EUROPEAN COMMISSION (ERAFE program and the COST 848 Action).Fernández-Carmona, J.; Blas, E.; Pascual Amorós, JJ.; Maertens, L.; Gidenne, T.; Xiccato, G.; García, J. (2005). Recommendations and guidelines for applied nutrition experiments in rabbits. World Rabbit Science. 13. doi:10.4995/wrs.2005.516SWORD1

Effect of feed restriction timing on live performance, breast myopathy occurrence, and muscle fiber degeneration in 2 broiler chicken genetic lines

During recent years, research on meat quality in poultry has aimed to evaluate the presence and consequences of breast myopathies as well as the factors which can affect their occurrence by modifying the growth rate. A total of 900 broiler chickens were reared until slaughter (48 D) to evaluate the effect of 2 genetic lines (A vs. B) and feeding plans (ad libitum [AL], early restricted [ER], from 13 to 23 D of age, and late restricted [LR], from 27 to 37 D of age; restriction rate: 80%) on performance, meat quality, and breast muscle myopathies. Calsequestrin and vascular endothelial growth factor (VEGF) expressions, and muscle fiber degeneration (MFD) were recorded at 22, 36, and 48 D. Chickens in the AL treatment had greater final live (P < 0.01) and carcass weights and proportion of pectoralis major muscle (P = 0.04) compared to chickens in the LR treatment, whereas chickens in the ER treatment had intermediate final live (3,454 g) and carcass weights, and proportion of pectoralis major muscle (25.6%). Chickens of line A were heavier than chickens of line B (P < 0.001), and had a greater feed conversion rate. Chickens of line A also had a greater dressing out percentage (P < 0.001), but a lower proportion of pectoralis major muscle (P = 0.04), as well as a greater meat pH (P < 0.001), meat cooking losses (P < 0.01), and shear force of the pectoralis major muscle (P = 0.03). Calsequestrin and VEGF mRNA were significantly lower in ER and LR chickens compared to AL chickens after feed restriction and during refeeding (P < 0.05). MFD scores increased with chicken age (P < 0.001) and differed between genetic lines (P < 0.001). Neither feeding plan nor genetic line affected the occurrence of white striping or wooden breast condition

In vitro analysis, an accurate tool to estimate dry matter digestibility in rabbits. Intra- and inter- laboratory variability

[EN] The aim of the present study was to determine the intra- and inter-laboratory variability of an enzymatic system of in vitro analysis for estimating dry matter (DM) digestibility in rabbits and validating the predicted nutritive value of 4 complete diets and 4 raw materials during three different periods of time. Chemical composition, DM digestibility and digestible energy (diets only) were known. In vitro DM digestibility (DMdinv) of all samples was determined by 4 laboratories (triplicate analysis) at different times with an interval of one month between analyses. DMdinv variability and chemical parameters were measured in terms of repeatability (SR: intra-series variability within each laboratory), reproducibility (SL: intra-series variability among laboratories) and reliability (SF: variability through time within each laboratory). Both the laboratory and sample affected DMdinv values (P<0.001). The period of time also had a significant effect (P=0.002) on mean DMdinv values (67.4, 66.8 and 67.0% for the 1st, 2nd and 3rd month, respectively). Significant laboratory x sample, time x laboratory and time x sample interaction effects were also observed. Repeatability, reproducibility and reliability values for the diets were better than those obtained for the raw materials (by 2.0, 1.9 and 2.4 times, respectively). Repeatability values were also better than the values obtained for reproducibility and reliability (by 2.2 and 3.6 times, respectively). Repeatability and reproducibility values were consistently worse for raw materials than for complete diets (by 1.5, 4, 2.9 and 1.3, 4.3, 2.8 times for SR and SL in period 1, period 2 and period 3, respectively), and were also worse in period 1 with respect to the other two periods (by 2.1 and 2.2 times for SR and SL, respectively). Finally, the in vitro method always showed better coefficients of variation of repeatability (CVR) and reproducibility (CVL) than those of the chemical parameters frequently used as predictors of dietary energy value (acid detergent fibre and crude fibre) (1.73 vs. 2.41 and 3.88 for CVR and 3.24 vs. 3.70 and 5.17 for CVL, respectively). In conclusion, the proposed in vitro methodology showed adequate repeatability and reproducibility, being suitable for predictive purposes.This research was supported by ERAFE project CE-FAIR (3-CT96-1651)Carabaño, R.; Nicodemus, N.; García, J.; Xiccato, G.; Trocino, A.; Pascual Amorós, JJ.; Falcão-E-Cunha, L.... (2008). In vitro analysis, an accurate tool to estimate dry matter digestibility in rabbits. Intra- and inter- laboratory variability. World Rabbit Science. 16(4). doi:10.4995/wrs.2008.614SWORD16

Rapid genotyping of hepatitis C virus RNA-isolates obtained from patients residing in Western Europe

Two rapid genotyping methods for hepatitis C virus (HCV), the line probe assay (Inno‐LiPA) and the subtype‐specific core amplification system [Okamoto et al., (1992b) Journal of General Virology 73:673‐679], were applied to 58 HCV isolates which were typed as type 1 (n=37) and type 2 (n=21) by sequence analysis of the 5′ untranslated region (5′UTR). The line probe assay targets the 5′UTR and recognized 12 subtype 1a, 25 subtype 1b, 18 subtype 2a, 2 subtype 2b and 1 subtype 2d in accordance with sequence analysis of this region. Subtype‐specific core amplification revealed 7 discrepancies among the 37 type 1 isolates when compared to LiPA. A different subtype was observed in 3 isolates (la versus 1b), 2 isolates remained untyped and 2 isolates showed a coinfection of subtype la and 1b. The first 5 discrepancies were confirmed by sequence analysis of the core region whereas the coinfection could not be confirmed. Of the 21 type 2 isolates only one could be typed by subtype‐specific core amplification. HCV RNA was detected in all 21 cases after the general first round of polymerase chain reaction (PCR). Direct sequencing of the core region indicated sequence variation as a source of failure. It is concluded that LiPA results are conclusive for typing of HCV. However, LiPA is hampered occasionally for subtyping by lack

An approximate analysis of a bernoulli alternating service model

We consider a discrete-time queueing system with one server and two types of customers, say type-1 and type-2 customers. The server serves customers of either type alternately according to a Bernoulli pro- cess. The service times of the customers are deterministically equal to 1 time slot. For this queueing system, we derive a functional equation for the joint probability generating function of the number of type-1 and type-2 customers. The functional equation contains two unknown partial generating functions which complicates the analysis. We investigate the dominant singularity of these two unknown functions and propose an approximation for the coefficients of the Maclaurin series expansion of these functions. This approximation provides a fast method to compute approximations of various performance measures of interest

Application of the 2008 Definitions for Invasive Fungal Diseases to the Trial Comparing Voriconazole Versus Amphotericin B for Therapy of Invasive Aspergillosis: A Collaborative Study of the Mycoses Study Group (MSG 05) and the European Organization for Research and Treatment of Cancer Infectious Diseases Group

Episodes of invasive aspergillosis (IA) recruited to the voriconazole trial were reclassified according to the revised EORTC/MSG definitions. The efficacy of voriconazole was confirmed for possible, probable, and proven IA and was still better than found for the comparator ar