Enriching table eggs with n-3 polyunsaturated fatty acids through dietary supplementation with the phototrophically grown green algae Nannochloropsis limnetica: effects of microalgae on nutrient retention, performance, egg characteristics and health parameters.

The fatty acid content of microalgae, especially the high content of omega-3 fatty acids such as eicosapentaenoic acid (EPA, C20:5) and docosahexaenoic acid (DHA, C22:6), could enrich eggs when fed to laying hens. Moreover, the properties and bioactive components of omega-3 fatty acids could positively influence the health and production performance of laying hens. In this study, the effects of dried Nannochloropsis limnetica inclusions in diets on yolk omega-3 fatty acid content, laying hen performance, nutrient retention, intestinal morphometry and systemic inflammatory markers were measured. A total of 240 twenty-five-wk-old laying hens were randomly assigned to 5 treatments distributed among 30 pens. Treatment A received the reference diet, while diets in treatments B, C, and D contained the control diet with 1, 2, and 3% microalgae added, respectively. In treatment E, a portion of ingredients of the control diet was replaced with rapeseed meal to induce a mild nutritional challenge, along with an inclusion of 3% microalgae. Compared to the control group the rate of lay increased by approximately 5% (P = 0.039) when birds were fed 2 or 3% microalgae. Furthermore, inclusion of 2 and 3% microalgae resulted in higher feed intake compared to the control group (126, 125, and 119 g/hen/d respectively; P = 0.001). Other performance parameters such as nutrient retention and egg characteristics were not affected by the dietary treatments. The EPA and DHA content of the yolk increased with increasing microalgae inclusion level (P < 0.001). A 2% algal inclusion resulted in 58.3 (EPA) and 603 (DHA) mg per 100 g dry yolk, respectively. Plasma haptoglobin levels of laying hens in both treatments receiving 3% microalgae were almost 3 times lower compared to the control group (1.25 and 1.62 vs. 5.60; P < 0.001), regardless of the inclusion of rapeseed in the diet. Based on these results, it can be concluded that the inclusion of N. limnetica enriches the egg yolk without negatively affecting the performance of laying hens and egg characteristics. Due to the positive effect on feed intake, microalgae in the diet provide nutritional benefits for laying hens. However, the positive effects of microalgae, especially on the health of laying hens, warrants further research.

Effects of twice a day feeding and split feeding during lay on broiler breeder production performance, eggshell quality, incubation traits, and behavior.

Eggshell quality of broiler breeders' eggs decreases at the end of the laying period. Feeding a limited daily allowance of feed in the morning does not supply the necessary nutrients, particularly calcium for eggshell formation, at the right time of the day. Therefore, an experiment was conducted to study the effects of providing a standard diet twice a day or split feeding (special morning and afternoon diet) in broiler breeders on production performance, eggshell quality, incubation traits, and behavior. At 50 wk of age (WOA) 576 females and 48 males were randomly allotted to 24 floor pens and assigned to one of three treatments: 1) Standard breeder diet fed once a day (100% at 0730 h) (CON1x), 2) Standard breeder diet fed twice a day (50% at 0730 h and 50% at 1400 h) (CON2x), and 3) Split feeding fed twice a day, with a special morning (0730 h) and afternoon (1400 h) diet composition (SP2x). The morning diet was energetically comparable with the control diet, but it contained more protein and phosphorus (P) and less calcium (Ca). The afternoon diet had a lower energy, protein and P and a higher Ca content than the control and morning diet. The SP2x birds tended to have a higher egg production between 51 and 55 WOA (27.0 vs. 25.9 eggs; P = 0.088) compared to the CON1x birds, while the CON2x birds (26.6 eggs) did not differ from the other treatments. No differences were found on egg production for the total period (51-60 WOA) and on other production parameters. The different feeding strategies did not affect eggshell quality and incubation traits. However, the feeding strategies affected the behavioral patterns considerably. Twice a day feeding (CON2x and SP2x) resulted in more time spent on eating and sitting, and in less time spent on foraging and object pecking (P ≤ 0.05) compared to feeding once a day (CON1x). In conclusion, twice a day feeding improves behavior and split feeding improves both egg production and behavior in broiler breeders, however, no effects were observed on eggshell quality and incubation traits.

Effects of diet density and feeding frequency during the rearing period on broiler breeder performance.

1. An experiment was conducted to study the effects of diet density and feeding frequency during the rearing period on broiler breeder performance between three and 40 weeks of age.2. A total of 960 female one-day-old chicks (Ross 308) were randomly allocated to 24 floor pens (12 pens in two rooms). On day 21 pullets were assigned to a 2 × 2 factorial arrangement including two diets (control (CON) or 16% diluted (DIL)) and two feeding strategies (fed once (FO) or twice (FT) a day). The FO pullets were fed at 0815 h (100%) and FT pullets at 0815 h (60%) and 1215 h (40%). Water was provided by nipple drinkers with drip cups during 7 and 8 h in the rearing and laying period, respectively.3. Body weight (BW) and water intake were measured weekly and BW uniformity at 10 and 20 weeks of age. Litter characteristics were measured at 10, 15, and 20 weeks of age. During the laying period, egg production and incubation characteristics were recorded.4. The DIL pullets received a higher feed allowance in combination with similar water intake which resulted in a lower water/feed ratio compared to the CON pullets resulting in a higher DM content of the litter and improved litter quality. The higher feed allowance resulted in a 20% higher total manure production at 20 weeks of age. The FT pullets showed a lower body weight (BW) CV at 10 weeks of age; however, no effect was found at 20 weeks of age. During the laying period, FT pullets tended to have earlier onset of lay, higher total egg production at 30 weeks of age and better fertility.5. It was concluded that alternative feeding strategies can positively influence production performance during both the rearing and laying period.

Operando UV-Vis spectroscopy of a catalytic solid in a pilot-scale reactor: deactivation of a CrO(x)/Al2O3 propane dehydrogenation catalyst.

A novel operando UV-Vis spectroscopic set-up has been constructed and tested for the investigation of catalyst bodies loaded in a pilot-scale reactor under relevant reaction conditions. Spatiotemporal insight into the formation and burning of coke deposits on an industrial CrO(x)/Al(2)O(3) catalyst during propane dehydrogenation has been obtained.

Photometric observations of a polychromatic laser guide star.

We report the photometric observation of a polychromatic laser guide star (PLGS) using the AVLIS laser at the Lawrence Livermore National Laboratory (LLNL). The process aims at providing a measurement of the tilt of the incoming wave front at a telescope induced by atmospheric turbulence. It relies on the two-photon coherent excitation of the 4D5/2 energy level of sodium atoms in the mesosphere. We used two laser beams at 589 and 569 nm, with a maximum total average output power of approximately 350 W. For the purpose of photometric calibration, a natural star was observed simultaneously through the same instrument as the PLGS at the focus of the LLNL 50-cm telescope. Photometric measurements of the 330-nm return flux confirm our previous theoretical studies that the PLGS process should allow us at a later stage to correct for the tilt at wavelengths as short as approximately 1 microm at good astronomical sites. They show also that, at saturation of two-photon coherent absorption in the mesosphere, the backscattered flux increases by a factor of approximately 2 when the pulse repetition rate decreases by a factor of 3 at constant average power. This unexpected behavior is briefly discussed.