scholarly journals Performance of growing pigs subjected to lighting programs in climate-controlled environments

2020 ◽  
Vol 24 (9) ◽  
pp. 616-621
Author(s):  
Janice M. C. Barnabé ◽  
Héliton Pandorfi ◽  
Nicoly F. Gomes ◽  
Marco A. C. Holanda ◽  
Mônica C. R. Holanda ◽  
...  
Keyword(s):  
Cooling System ◽  
Physiological Responses ◽  
Evaporative Cooling ◽  
Growing Pigs ◽  
Semiarid Region ◽  
Natural Light ◽  
Artificial Light ◽  
Feed Conversion ◽  
Climate Control ◽  
And Performance

ABSTRACT The objective of this research was to evaluate the thermal comfort, physiological responses and performance of pigs in the growth phase, subjected to supplemental lighting programs in air-conditioned environments, in semiarid region of Pernambuco state, Brazil. Twenty-seven pigs (3/4 Duroc, ¼ Pietrain) were subjected to pens with no climate control, pens with forced ventilation and pens with adiabatic evaporative cooling, associated with 12 h of natural light, 12 h of natural light + 4 h of artificial light and 12 h of natural light + 6 h of artificial light. The experimental design was completely randomized, in a 3 x 3 factorial arrangement with three repetitions. Meteorological responses, physiological responses and performance variables of the animals were recorded. The evaporative cooling system attenuated the action of the stressors and ensured adequate thermal conditions for the animals. Respiratory rate and rectal temperature indicated that evaporative cooling ensured the maintenance of homeothermy. Weight gain and feed conversion were positively influenced for the animals exposed to evaporative cooling, but without significant effect of lighting programs.

The effects of liquid feed on the small intestine mucosa and performance of finishing pigs at different water to feed ratios

2001 ◽  
Vol 2001 ◽  
pp. 161-161 ◽  
Author(s):  
D. Hurst ◽  
I.J. Lean ◽  
A.D. Hall
Keyword(s):  
Small Intestine ◽  
Growing Pigs ◽  
Finishing Pigs ◽  
Feed Conversion ◽  
Liquid Form ◽  
Physiological Basis ◽  
Liquid Feeding ◽  
Intestine Mucosa ◽  
And Performance ◽  
Dry Diet

Liquid feeding of growing pigs is believed to increase feed intake and growth performance compared to a dry diet. There is little information on the comparative feed conversion efficiency of pigs on the two forms of diet or the underlying physiological basis for the differences and how liquid diets affect the absorptive mucosa of the small intestine. This study was designed to investigate differences in feed utilisation and mucosal structure in modern genotype pigs offered equal amounts of feed in dry and liquid form. Additionally, the effect of reducing the pH of the liquid diet was considered.

Study of the Thermodynamic Processes and Performance Evaluation of Self-Circulation Evaporative Cooling System in Hydro-Generator

2014 ◽  
Vol 488-489 ◽  
pp. 979-982
Author(s):  
Hai Hong Dong ◽  
Lin Ruan ◽  
Shu Qin Guo ◽  
Rui Cao ◽  
Jin Xiu Chen
Keyword(s):  
Performance Evaluation ◽  
Power Loss ◽  
Heat Load ◽  
Cooling System ◽  
Evaporative Cooling ◽  
Second Law Of Thermodynamics ◽  
Evaporative Cooling System ◽  
Cooling Technology ◽  
And Performance ◽  
Thermodynamic Processes

The self-circulation evaporative cooling system (SECS) of stator collector ring is a kind of new cooling technology, utilizing the evaporating of work fluid to cool the stator collector ring of hydro-generator. In this article, the thermodynamic processes of SECS of stator collector ring were analyzed by the second law of thermodynamics. The entropy production and power loss of isolated SECS were analyzed. Based on the distinctive characteristics of SECS, a performance evaluation function was proposed. The influence of heat load on was discussed by simulating. The conclusions provide the theory basis for the application of this new cooling technology.

scholarly journals Evaporative cooling system for gestating and lactating sows: a systematic review

2020 ◽  
Vol 50 (10) ◽  
Author(s):  
Melissa Fabíola dos Santos Alves Mendes ◽  
David Henrique de Oliveira ◽  
Fábio Loures Cruz ◽  
Múcio André dos Santos Alves Mendes ◽  
Bruna Pontara Vilas Boas Ribeiro ◽  
...  
Keyword(s):  
Systematic Review ◽  
Cooling System ◽  
Evaporative Cooling ◽  
Ambient Temperatures ◽  
Lactating Sows ◽  
Evaporative Cooling System ◽  
Bibliographic Search ◽  
And Performance ◽  
Lactating Sow ◽  
Climatic Characteristics

ABSTRACT: Climatic characteristics of the production sites of pigs influence the yield of the system, with breeding sows being a category extremely sensitive to high temperatures, especially when their upper critical temperature is reached. This review evaluated the effects of the evaporative cooling system on environmental, physiological and performance parameters in breeding sows. By means of this review, a bibliographic search was performed using the following keywords: sow; swine; gilt and pig combined individually with the expression ‘evaporative cooling’. A total of 11 papers met the prerequisites determined to compose the systematic review and the studies involved gestating and lactating sows maintained in environments that presented ambient temperatures between 21.5 and 34.8 °C and relative humidity between 32.2 and 84.2%. The evaporative cooling system was used in order to cool the macro or micro environment. It can be concluded that the use of evaporative cooling system promotes increase in feed intake per lactating sow, decrease in weight loss in lactation, increase of weight of piglets at weaning, temperature reduction of the barns and decrease of the respiratory rate of the sows. For gestating sows, no changes in reproductive performance were reported.

Comparison of natural and artificial sources of light

1971 ◽  
Vol 179 (1056) ◽  
pp. 189-192
Keyword(s):  
High Pressure ◽  
Cooling System ◽  
Control Plant ◽  
Crop Plants ◽  
Natural Light ◽  
Artificial Light ◽  
The Moon ◽  
Terrestrial Environment ◽  
Pressure Discharge ◽  
High Pressure Discharge

The area of crop plants required to sustain a man in an artificial extra-terrestrial environment is probably about 10 m 2 . If the site is on the Moon, the natural light will alternate with periods of darkness, but will be brighter than any practicable arrangement of artificial lights. The latter can, however, be run continuously. To control plant temperature, an artificial cooling system will be required with either kind of illumination. The energy to be dissipated will be about 700 W m -2 with natural light, or three times this amount with artificial light (high pressure discharge lamps).

Effect of microbial enzyme supplementation on energy, amino acid digestibility and performance of pigs fed hulless barley based diets

1998 ◽  
Vol 78 (4) ◽  
pp. 625-631 ◽  
Author(s):  
S. K. Baidoo ◽  
Y. G. Liu ◽  
D. Yungblut
Keyword(s):  
Nutrient Utilization ◽  
Growing Pigs ◽  
Canola Meal ◽  
Feed Conversion ◽  
Hulless Barley ◽  
Microbial Enzyme ◽  
Indispensable Amino Acids ◽  
Gross Energy ◽  
Enzyme Supplementation ◽  
And Performance

Two experiments were conducted to investigate the influence of a microbial enzyme preparation on the digestibility and performance of starter-growing pigs fed hulless barley based diets. In the digestibility trial, eight pigs with an average initial body weight of 14.3 ± 0.4 kg initial liveweight were surgically fitted with steered ileo-cecal valve cannulas at the terminal ileum. Two hulless barley varieties (Condor and CDC Buck) were separately used as the dietary energy source (77.6%) with canola meal as the protein supplement (20%). Enzyme supplementation improved (P < 0.05) the ileal dry matter (DM) digestibility by 15.2%, gross energy (GE) by 11.0% and protein by 7.6%. The average apparent ileal digestibility of the indispensable amino acids was improved by 6.9% (P < 0.05), and of nonstarch polysaccharides (NSP) was improved by 90%. The total-tract digestibility of DM was increased by 6.2%, GE by 6% and crude protein (CP) by 9.4% (P < 0.05). Enzyme supplementation tended to enhance digestion in the small intestine instead of the hind-gut as expected. In the growth performance trial, positive responses from enzyme supplementation were observed from both mash and pelleted diets fed to 48 pigs grown from 9 to 60 kg liveweight. The ADG was improved by 8.6% (P < 0.05) and feed conversion by 8.7% (P = 0.09). Pelleting had no adverse effect on enzyme activity. The results demonstrated that the enzyme supplementation improved (P < 0.5) nutrient utilization and performance of pigs fed diets containing hulless barley. Key words: Enzyme, hulless barley, digestibility, performance, swine

scholarly journals Gas Turbine Performance Improvement Direct Mixing Evaporative Cooling System American Atlas Cogeneration Facility Rifle, Colorado

1990 ◽  
Author(s):  
J. P. Nolan ◽  
V. J. Twombly
Keyword(s):  
Gas Turbine ◽  
Performance Improvement ◽  
Return On Investment ◽  
Cooling System ◽  
Evaporative Cooling ◽  
Turbine Performance ◽  
Potential Problems ◽  
Evaporative Cooling System ◽  
Media Systems ◽  
And Performance

This paper discusses the design, installation, operation and performance of a direct mixing evaporative cooling system as an alternate to conventional wetted rigid media systems used for gas turbine power augmentation. The economic return on investment, the ease of installation, and the potential problems as they apply to a typical gas turbine based cogeneration facility are discussed and analyzed. Especially of interest is the low capital cost of this system, approximately one fourth that of a conventional system.

Important Parameters and Performance Testing of Evaporative Inlet Air Cooling System for Gas Turbines: A User’s Experience

2006 ◽  
Author(s):  
Hemant Gajjar
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Cooling System ◽  
Low Cost ◽  
Evaporative Cooling ◽  
Performance Testing ◽  
Air Cooling ◽  
Air Cooling System ◽  
Evaporative Cooling System ◽  
And Performance

Inlet Air Cooling of gas turbine engines for power augmentation has seen increasing application over the past decade. Evaporative inlet air cooling has been particularly preferred by the Gas Turbine operators due to its low cost and ease of installation. Two of the important considerations for a GT operator are the proper selection of the EIAC and, after installation, its proper testing to assure required performance. This paper is based on the experience, as a user, of selecting a inlet air cooling system and then implementing a Fogging type Evaporative Cooling system. It highlights the important parameters related to evaporative cooling system and in particular fogging, and how the site testing can be handled to ensure proper performance. Concepts of ‘Conversion Effectiveness’ and ‘Evaporation Effectiveness’ have also been introduced in this paper.

The effect of subclinical nematode parasitism on digestion and performance in growing pigs

1980 ◽  
Vol 30 (2) ◽  
pp. 285-294 ◽  
Author(s):  
H. D. Pattison ◽  
R. J. Thomas ◽  
W. C. Smith
Keyword(s):  
Nitrogen Retention ◽  
Live Weight ◽  
Growing Pigs ◽  
Feed Conversion ◽  
Crude Fibre ◽  
Eye Muscle ◽  
Oesophagostomum Dentatum ◽  
Gross Energy ◽  
Tissue Changes ◽  
And Performance

ABSTRACTA preliminary trial established a subclinical level of infection with Oesophagostomum dentatum capable of affecting the performance of growing pigs. Thereafter a slightly higher level of infection (100 000 larvae) was administered to each of 24 individually- and scale-fed pigs to investigate the effect of O. dentatum on performance, digestibility and nitrogen retention over the live-weight range 32 to 64 kg. Worm-free but otherwise similar pigs served as controls. Infection reduced growth rate (12·9 %) and decreased efficiency of feed conversion to body weight (14·9%). There was no effect on killing-out percentage or area of eye muscle in cross-section, but infected pigs had relatively lower backfat depths (5·5 to 12·5 %). Infection did not influence nitrogen retention, but apparent digestibility of the dry matter, organic matter, nitrogen, gross energy and crude fibre was reduced. Possible explanations for these effects are discussed in relation to tissue changes associated with larval development in the large intestine.

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