Effects of added phytase on growth performance, carcass traits, and tibia ash of broiler chickens fed diets with reduced amino acid, crude protein, and phosphorus concentration

This experiment was conducted to investigate the effect of phytase supplementation in diets reduced in amino acids (AA), crude protein (CP), and phosphorus (P) on growth performance, carcass traits, and tibia ash of broiler chickens. A total of 2,240 unsexed Ross 308 broiler chickens were used in 56 floor pens with 40 birds each and fed one of eight dietary treatments in seven replicates until 35 d of age. A positive control (PC) diet and diets with dietary AA/CP level reduced by 2, 4, and 6% were used with and without supplementation with 1,500 FTU phytase/kg. Starter, grower, and finisher diets were fed from d 1 to 10, d 10 to 25, and d 25 to 35, respectively. For the total period, no significant interaction effects between AA/CP level and phytase supplementation were detected for any measured traits. The ADG, ADFI, carcass weight, breast weight, and tibia ash weight were lower and FCR was higher compared to the PC diets when the AA/CP level was reduced by more than 2%. Phytase supplementation increased ADG, ADFI, final BW, and tibia ash weight. Tibia ash measurements showed that birds were adequately supplied with digestible phosphorus in all treatments, although dietary phosphorus and calcium were reduced in the phytase-supplemented diets. This enabled the feeding of broiler chickens without mineral phosphate supplements in grower and finisher diets. The results showed that supplementation with 1,500 FTU phytase/kg diminished the growth-decreasing effect of lower dietary AA/CP at all reduction steps.info:eu-repo/semantics/publishedVersio

The role of different strain backgrounds in bacterial endotoxin-mediated sensitization to neonatal hypoxic-ischemic brain damage

Genetic background is known to influence the outcome in mouse models of human disease, and previous experimental studies have shown strain variability in the neonatal mouse model of hypoxia-ischemia. To further map out this variability, we compared five commonly used mouse strains: C57BL/6, 129SVJ, BALB/c, CD1 and FVB in a pure hypoxic-ischemic setup and following pre-sensitization with lipopolysaccharide (LPS). Postnatal day 7 pups were subjected to unilateral carotid artery occlusion followed by continuous 30 min 8% oxygen exposure at 36 °C. Twelve hours prior, a third of the pups received a single intraperitoneal LPS (0.6 μg/g) or a saline (vehicle) administration, respectively; a further third underwent hypoxia-ischemia alone without preceding injection. Both C57BL/6 and 129SVJ strains showed minimal response to 30min hypoxia-ischemia alone, BALB/c demonstrated a moderate response, and both CD1 and FVB revealed the highest brain damage. LPS pre-sensitization led to substantial increase in overall brain infarction, microglial and astrocyte response and cell death in four of the five strains, with exception of BALB/c that only showed a significant effect with terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL). Saline administration prior to hypoxia-ischemia resulted in an increase in inflammatory-associated markers, particularly in the astroglial activation of C57BL/6 mice, and in combined microglial activation and neuronal cell loss in FVB mice. Finally, two of the four strongly affected strains--C57BL/6 and CD1--revealed pronounced contralateral astrogliosis with a neuroanatomical localization similar to that observed on the occluded hemisphere. Overall, the current findings demonstrate strain differences in response to hypoxia-ischemia alone, to stress associated with vehicle injection, and to LPS-mediated pre-sensitization, which partially explains the high variability seen in the neonatal mouse models of hypoxia-ischemia. These results can be useful in future studies of fetal/neonatal response to inflammation and reduced oxygen-blood supply

A Novel Bacterial 6-Phytase Improves Growth Performance, Tibia Mineralization and Precaecal Digestibility of Phosphorus in Broilers: Data from Four Independent Performance Trials

A series of four broiler performance studies were conducted in different facilities to investigate the efficacy of a novel bacterial 6-phytase added at 500 FTU/kg diet on growth performance, bone mineralization and precaecal digestibility of phosphorus (pcdP) in broilers fed diets deficient in available P (avP) and calcium (Ca). The experimental design was the same for all studies, with each having three treatments: positive control (PC) diet formulated to meet or exceed the requirements of birds, negative control (NC) diet similarly reduced by 0.15% points in avP and Ca compared to the PC diet, and the NC diet supplemented with phytase (PHY) at 500 FTU/kg diet from 1 to 35 days of age. Body weight (BW) and feed intake were measured at 21 and 35 days of age, and average daily gain (ADG), average daily feed intake (ADFI), feed conversion ratio (FCR), BW gain-corrected-FCR (cFCR), mortality and European performance efficiency factor (EPEF) were calculated. Tibia dry matter, tibia ash content and pcd of P were measured at 21 days of age in all experiments. The analysis of the data from the four experiments showed that compared with birds fed the adequate-nutrient diet, birds fed the NC diet resulted in a decrease (p < 0.05) in BW, ADG, ADFI and EPEF by 6.4, 6.3, 5.9 and 7.1%, respectively, and an increase in (p = 0.02) cFCR by 2.0%. The tibia dry matter and tibia ash content of these birds were also reduced (p < 0.001) by 3.8 and 4.0% points, respectively. PHY diets improved (p < 0.05) BW, ADG, ADFI, EPEF and cFCR by 8.0, 8.3, 7.3, 10.6 and 2.8%, respectively. Phytase addition at 500 FTU/kg diet also increased (p < 0.001) the tibia dry matter and tibia ash content by 3.5 and 4.2% points, respectively. The pcd of P was improved (p < 0.001) by 11.1 and 11.3% points, in comparison with NC and PC diets, respectively, when phytase was added. These performance parameters and tibia mineralization obtained with a diet supplemented with phytase were comparable to or better than the PC diet. The results demonstrated that avP and Ca could be lowered similarly by 0.15% points in broilers diets by using the new bacterial 6-phytase at 500 FTU/kg diet.info:eu-repo/semantics/publishedVersio

Lamellarin D bioconjugates II: synthesis and cellular internalization of dendrimer and nuclear location signal derivatives

The design and synthesis of Lamellarin D conjugates with a nuclear localization signal peptide and a poly(ethylene glycol)-based dendrimer are described. Conjugates 1-4 were obtained in 8-84% overall yields from the corresponding protected Lamellarin D. Conjugates 1 and 4 are 1.4 to 3.3-fold more cytotoxic than the parent compound against three human tumor cell lines(MDA-MB-231 breast, A-549 lung, and HT-29 colon). Besides, conjugates 3, 4 showed a decrease in activity potency in BJ skin fibroblasts, a normal cell culture. Cellular internalization was analyzed and nuclear distribution pattern was observed for 4, which contains a nuclear localization signalling sequence

Results of an international phosphorus digestibility ring test with broiler chickens

The objective of this ring test was to investigate the prececal phosphorus (P) digestibility of soybean meal (SBM) in broiler chickens using the trial protocol proposed by the World's Poultry Science Association. It was hypothesized that prececal P digestibility of SBM determined in the collaborating stations is similar. Three diets with different inclusion levels of SBM were mixed in a feed mill specialized in experimental diets and transported to 17 collaborating stations. Broiler chicks were raised on commercial starter diets according to station-specific management routine. Then they were fed the experimental diets for a minimum of 5 d before content of the posterior half of the ileum was collected. A minimum of 6 experimental replicates per diet was used in each station. All diets and digesta samples were analyzed in the same laboratory. Diet, station, and their interaction significantly affected (P &lt; 0.05) the prececal digestibility values of P and calcium of the diets. The prececal P digestibility of SBM was determined by linear regression and varied among stations from 19 to 51%, with significant differences among stations. In a subset of 4 stations, the prececal disappearance of myo-inositol 1,2,3,4,5,6-hexakis (dihydrogen phosphate)-P; InsP6-P) also was studied. The prececal InsP6-P disappearance correlated well with the prececal P digestibility. We hypothesized that factors influencing InsP6 hydrolysis were main contributors to the variation in prececal P digestibility among stations. These factors were probably related to the feeding and housing conditions (floor pens or cages) of the birds in the pre-experimental phase. Therefore, we suggest that the World's Poultry Science Association protocol for the determination of digestible P be should extended to the standardization of the pre-experimental period. We also suggest that comparisons of P digestibility measurements among studies are made only with great caution until the protocol is more refined