High efficiency multifrequency feed

Antenna systems and particularly compact and simple antenna feeds which can transmit and receive simultaneously in at least three frequency bands, each with high efficiency and polarization diversity are described. The feed system is applicable for frequency bands having nominal frequency bands with the ratio 1:4:6. By way of example, satellite communications telemetry bands operate in frequency bands 0.8 - 1.0 GHz, 3.7 - 4.2 GHz and 5.9 - 6.4 GHz. In addition, the antenna system of the invention has monopulse capability for reception with circular or diverse polarization at frequency band 1

A new impedance matching method for an ultra-wide band and dual circularly polarised feed

In traditional antenna design, metal components are not placed in the central part of the antenna as they change the characteristics of near field radiation. However, we show that placing a metal ring in the centre of the strip lines, which connect the ends of folded high-frequency dipoles, does not damage the performance of the feed. Instead it significantly improves the voltage standing wave ratio of the feed whilst other performance indicators are not compromised. Thus, our findings show an excellent way of improving the wide band feed. Based on this foundation, a new circularly polarised feed for operation between 0.4 to 2 GHz is introduced for the Chinese Spectral Radioheliograph in this paper. The issue of a feed impedance matching network is investigated. By optimising the impedance matching, the performance of the feed is enhanced with respect to the previous realisations of the Eleven feed. The simulation and experimental results show that the gain of the feed is about 10 dBi, and the VSWR is less than 2:1. In addition, the feed has a low axial ratio, fixed phase centre location, and constant beam width in the range of 0.4 to 2 GHz

The effect of an 18-hour delay in solid feed provisioning on the feed intake and performance of piglets in the first weeks after weaning

It is generally accepted that early post-weaning feed intake affects post-weaning health and performance. Especially piglets that have not consumed creep feed before weaning have to learn to recognize solid feed. Weaning is a stressful event with an important impact on the animals. The associated stress level may affect their learning capabilities. Consequently, the question arises whether the first day after weaning is the best day to discover their new type of feed. An experiment was therefore designed to study the effect of delayed provisioning of solid feed on feed intake and performance of piglets. In total, 144 piglets (8.1 +/- 1.1 kg, mean +/- SD), weaned at 4 weeks of age, were tested. They were assigned to 24 pens, blocked per sex (i.e. castrated male or female) and weight group. Prior to weaning, piglets received a commercial creep feed. Per body weight class and per sex, each pen was randomly assigned to one of the 2 treatments: control (C) and delay in feed provisioning (DF). For the control treatment, the pelleted feed (6 mm) was already present in the feeders when the piglets arrived in their pens (13:00-14:00 h). In the DF pens, the feed was provided the next morning (08:00). Feed and water were provided ad libitum. In the first week after weaning, it was not possible to observe differences. However, the DF pigs showed a higher feed intake during the first three weeks of the experiment (455 +/- 25 vs 430 +/- 37 g/day, P = 0.003), which was apparent throughout the entire experiment (4-9 weeks: 594 +/- 30 vs 569 +/- 48 g/day, P = 0.046). This resulted in higher body weights 3 weeks after weaning (7 weeks of age) in the DF vs C pigs (16.1 +/- 1.5 vs 15.6 +/- 1.6 kg, P = 0.005). However, at the end of the experiment at 9 weeks, differences were no longer significant (23.9 +/- 2.1 vs 23.4 +/- 2.0 kg, P = 0.285). Feed efficiency did not differ between the groups (P = 0.456 for the entire experiment). Further research into the underlying mechanisms of the observed differences are mandatory for developing improved management practices of weaned piglets

EVALUASI PENAMBAHAN PROBIOTIK TERHADAP KONSUMSI, PERTAMBAHAN BOBOT BADAN DAN KONVERSI PAKAN SAPI BRAHMAN CROSS TIPE STEER PADA FASE GROWER

The research aims to determine the level of feed consumption, daily body weight gain and feed conversion of Brahman cross type steer cattle in the grower phase given the addition of probiotics. This research was conducted for 30 days on 11 October – 9 November 2023 at PT. Kariyana Gita Utama Sukabumi, West Java. The material for this research was 70 Brahman cross type steer cattle in the grower phase divided into two treatments, 35 heads for the treatment of adding probiotics to the feed ration and the other 35 heads as controls. The method used in this research is the Experimental Method. The data analysis used in this research is unpaired T test analysis. The variables observed were feed consumption, body weight gain and feed conversion. The dry matter consumption (BK) of Brahman cross P1 cattle feed of 11.47 kg was not significantly different (P>0.05). The body weight gain of Brahman cross cattle was not significantly different (P>0.05) at 1.59, 2.02 and 2.14 kg at P1. The feed conversion rate for Brahman cross cattle was 8.1 P1 and was significantly different (P<0.05)

OK-Net EcoFeed: Organic Knowledge Network for Monogastric Animal Feed

When feeding organic farm animals, the goal is to offer balanced diets that are fully organic and from home-grown or regionally-sourced feedstuffs. For monogastrics, pigs and poultry, updated European legislation will come into force in 2021 which will require that “at least 30% of the feed shall come from the farm itself or, if this is not feasible or such feed is not available, shall be produced in cooperation with other organic or in-conversion production units and feed operators using feed and feed material from the same region.” (Regulation EU, 2018). Achieving diets containing 100% organic feed for monogastrics is problematic, and current EU Regulations acknowledge this difficulty by allowing the use of 5% non-organic feed. However, this will cease when the updated legislation comes into force. Senior Livestock Researcher Lindsay Whistancereports on progress being made by the OK-Net EcoFeed project to address the issues

Computer programs for antenna feed system design and analysis

Fourteen computer programs have been developed for antenna feed system design and analysis. The programs cover a large spectrum of feed design problems, from primary feed pattern synthesis to the farfield pattern of the main reflector, including analyses of structural distortions

Performance and Meat Cholesterol Content of Broiler Chickens Fed Pluchea Indica L. Leaf Meal Reared Under Stress Condition

This experiment was conducted to study the effects of dietary addition Pluchea indica L. leaf meal on performances and meat cholesterol content of broiler. One hundred sixty two DOC CP707 strain were reared for four weeks in high stocking density of 15 birds/m2. The birds were fed experimental diets consisted of R1 (commercial feed + Vitastress), R2 (commercial feed + 2% P. indica leaf meal), R3 (commercial feed + 4% P. indica leaf meal), R4 (commercial feed + 6% P. indica leaf meal), and R5 (commercial feed + 8% P. indica leaf meal). The data obtained were analyzed using analysis of variance (ANOVA) and any significant differences were further tested using least significance difference (LSD) test. The treatment significantly increased (P &lt; 0.05) final body weight, body weight gain, feed and water intake, and decreased (P &lt; 0.05) feed conversion ratio. It is concluded that P. indica leaf meal could be added into a diet at the level of 2%. P. indica leaf meal addition at the level of 2% into a diet is also able to decrease the cholesterol content of broiler meat up to 8%