Naked oats: metabolisable energy yield from a range of varieties in broilers, cockerels and turkeys

2008 ◽  
Vol 49 (3) ◽  
pp. 368-377 ◽  
Author(s):  
M.G. Macleod ◽  
J. Valentine ◽  
A. Cowan ◽  
A. Wade ◽  
L. McNeill ◽  
...  
Author(s):  
Jeannie M Everington ◽  
D I Givens

Oats constitute a small and decreasing share of the cereals grown and utilized in the United Kingdom. Compared with the major cereals wheat and barley, oats are perceived to have a low nutritive value in terms of metabolisable energy (ME). Unlike other cereals, the husk remains attached to the oat kernel at harvesting, hence increasing the fibre or cell wall content of the grain.The proportion of kernel to husk which largely determines the nutritive value of the oat grain is dependent on variety, environment and season.Previous values for oats (MAFF 1986) were based on a study of 16 samples at the Rowett Research Institute (RRI 1976) in which most were spring sown varieties with low oil contents. The aim of this present work was to examine currently recommended winter varieties and also to study naked oats. These differ from traditional husked oats by having a thin, non-lignified husk from which the grain threshes free.


Author(s):  
M. Cropper ◽  
M. Lloyd ◽  
G.C. Emmans ◽  
C. Hinks

Growing lambs are frequently subject to varying planes of nutrition. Knowledge of the response of lambs to the restoration of non-limiting feeding conditions following a period of feed restriction is necessary in order to determine economic systems for finishing lambs.Thirty Blackface wether lambs (birth weight 3.8 kg s.d. 0.38 kg) were treated in two ways from birth to 25 kg live weight (LW). One half were reared by well-fed ewes at grass (treatment UR). The other lambs sucked poorly-fed ewes up to weaning at 18.2 kg LW (s.d. 1.9); thereafter R lambs were given 700 g/day of a high quality pelleted feed (F) to 25 kg LW. Feed F contained 158 g crude protein/kg dry matter (DM) and had an estimated metabolisable energy yield of 12.5 MJ/kg DM.From 25kg LW both UR and R lambs had ad libitum access to feed F to a final LW of 45 kg unless slaughtered earlier. The feed intakes and LW of individual sheep were measured weekly. Six lambs from each treatment were slaughtered at 25 kg LW in order to assess the effect of treatment on body composition. Three lambs from each treatment were subsequently slaughtered at 35 kg, 40 kg and 45 kg LW. Weights of gut-fill and organs were recorded and the cold carcass (CC) dissected into lean, bone and fat.


2020 ◽  
Vol 80 (2) ◽  
pp. 133-146
Author(s):  
L Zhang ◽  
Z Zhang ◽  
J Cao ◽  
Y Luo ◽  
Z Li

Grain maize production exceeds the demand for grain maize in China. Methods for harvesting good-quality silage maize urgently need a theoretical basis and reference data in order to ensure its benefits to farmers. However, research on silage maize is limited, and very few studies have focused on its energetic value and quality. Here, we calibrated the CERES-Maize model for 24 cultivars with 93 field experiments and then performed a long-term (1980-2017) simulation to optimize genotype-environment-management (G-E-M) interactions in the 4 main agroecological zones across China. We found that CERES-Maize could reproduce the growth and development of maize well under various management and weather conditions with a phenology bias of <5 d and biomass relative root mean square error values of <5%. The simulated results showed that sowing long-growth-cycle cultivars approximately 10 d in advance could yield good-quality silage. The optimal sowing dates (from late May to July) and harvest dates (from early October to mid-November) gradually became later from north to south. A high-energy yield was expected when sowing at an early date and/or with late-maturing cultivars. We found that Northeast China and the North China Plain were potential silage maize growing areas, although these areas experienced a medium or even high frost risk. Southwestern maize experienced a low risk level, but the low soil fertility limited the attainable yield. The results of this paper provide information for designing an optimal G×E×M strategy to ensure silage maize production in the Chinese Maize Belt.


Author(s):  
Alisson H. Marinho ◽  
Eduardo V. Mendes ◽  
Rubens A. Vilela ◽  
Victor J. Bastos-Silva ◽  
Gustavo G. Araujo ◽  
...  

Electronics ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1121
Author(s):  
Kamran Ali Khan Niazi ◽  
Yongheng Yang ◽  
Tamas Kerekes ◽  
Dezso Sera

A reconfiguration technique using a switched-capacitor (SC)-based voltage equalizer differential power processing (DPP) concept is proposed in this paper for photovoltaic (PV) systems at a cell/subpanel/panel-level. The proposed active diffusion charge redistribution (ADCR) architecture increases the energy yield during mismatch and adds a voltage boosting capability to the PV system under no mismatch by connected the available PV cells/panels in series. The technique performs a reconfiguration by measuring the PV cell/panel voltages and their irradiances. The power balancing is achieved by charge redistribution through SC under mismatch conditions, e.g., partial shading. Moreover, PV cells/panels remain in series under no mismatch. Overall, this paper analyzes, simulates, and evaluates the effectiveness of the proposed DPP architecture through a simulation-based model prepared in PSIM. Additionally, the effectiveness is also demonstrated by comparing it with existing conventional DPP and traditional bypass diode architecture.


Author(s):  
Rounak Kharait ◽  
Simran Raju ◽  
Abhishek Parikh ◽  
Mark A. Mikofski ◽  
Jeff Newmiller

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Santiago Lopez-Ridaura ◽  
Luis Barba-Escoto ◽  
Cristian A. Reyna-Ramirez ◽  
Carlos Sum ◽  
Natalia Palacios-Rojas ◽  
...  

AbstractWe present an assessment of the extent, diversity, and nutritional contribution of the milpa through a quantitative analysis of data from a survey conducted in 989 small scale farm households in the Western Highlands of Guatemala (WHG). The milpa is a traditional agricultural system in which maize is intercropped with other species, such as common beans, faba beans, squashes or potatoes. Our study shows that more than two-thirds of the 1,205 plots recorded were under the milpa system, with a great diversity of crop combinations. As shown with the 357 plots for which specific yields were available, milpa systems present higher total productivity than monocropped maize, expressed as total energy yield of the harvested crops in the respective system, and were also better at providing the recommended daily allowances of fourteen essential nutrients, based on a Potential Nutrient Adequacy (PNA) indicator. Maize-bean-potato, maize-potato, and maize-bean-faba intercrops had the highest PNAs, and monocropped maize, the lowest. These results support the implementation of milpa systems tailored to different agro-ecologies in order to improve nutrition in the WHG and a variety of similar regions.


Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2308
Author(s):  
Kamran Ali Khan Niazi ◽  
Yongheng Yang ◽  
Tamas Kerekes ◽  
Dezso Sera

Partial shading affects the energy harvested from photovoltaic (PV) modules, leading to a mismatch in PV systems and causing energy losses. For this purpose, differential power processing (DPP) converters are the emerging power electronic-based topologies used to address the mismatch issues. Normally, PV modules are connected in series and DPP converters are used to extract the power from these PV modules by only processing the fraction of power called mismatched power. In this work, a switched-capacitor-inductor (SCL)-based DPP converter is presented, which mitigates the non-ideal conditions in solar PV systems. A proposed SCL-based DPP technique utilizes a simple control strategy to extract the maximum power from the partially shaded PV modules by only processing a fraction of the power. Furthermore, an operational principle and loss analysis for the proposed converter is presented. The proposed topology is examined and compared with the traditional bypass diode technique through simulations and experimental tests. The efficiency of the proposed DPP is validated by the experiment and simulation. The results demonstrate the performance in terms of higher energy yield without bypassing the low-producing PV module by using a simple control. The results indicate that achieved efficiency is higher than 98% under severe mismatch (higher than 50%).


Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1261
Author(s):  
Christopher Gradwohl ◽  
Vesna Dimitrievska ◽  
Federico Pittino ◽  
Wolfgang Muehleisen ◽  
András Montvay ◽  
...  

Photovoltaic (PV) technology allows large-scale investments in a renewable power-generating system at a competitive levelized cost of electricity (LCOE) and with a low environmental impact. Large-scale PV installations operate in a highly competitive market environment where even small performance losses have a high impact on profit margins. Therefore, operation at maximum performance is the key for long-term profitability. This can be achieved by advanced performance monitoring and instant or gradual failure detection methodologies. We present in this paper a combined approach on model-based fault detection by means of physical and statistical models and failure diagnosis based on physics of failure. Both approaches contribute to optimized PV plant operation and maintenance based on typically available supervisory control and data acquisition (SCADA) data. The failure detection and diagnosis capabilities were demonstrated in a case study based on six years of SCADA data from a PV plant in Slovenia. In this case study, underperforming values of the inverters of the PV plant were reliably detected and possible root causes were identified. Our work has led us to conclude that the combined approach can contribute to an efficient and long-term operation of photovoltaic power plants with a maximum energy yield and can be applied to the monitoring of photovoltaic plants.


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