Low-phytate corn may decrease phosphorus

Posted in: Environment by admin on January 1, 1997 | No Comments

Pioneer Hi-Bred International and USDA are working to develop low-phytate corn after following the work on genes realised by Victor Raboy from USDA Aberdeen, ID. More than 20 mutations on corn, and others in rice and barley have been made to reduce the amount of phosphorus stored in the plant as phytic acid. The most promising mutant reduce the phytic acid by 2/3 with no reduction in the phosphorus content and up to now no problems have been found with the seeds. A research project is also conducted at the University of Minnesota on the management and culture of the low-phytate corn. Corn with more available phosphorus would reduce the phosphorus in the manure. Researchers hope that the phosphorus content of the manure obtained from pigs fed those hybrids could lowered from 30lb./1000gal. to 16lb./1000 gal.
According to the Pioneer officials, the low-phytic acid corn hybrid could be ready for commercial production in 2 to 3 years.

These changes in the phosphorus availability in plants are very interesting because the nutrients control is higher in the feeding chain. The yield obtained and cost of the seed should however be consider compare to phytase.

Livestock Odor Measurement using a Venturi Olfactometer and Odor Sampling using Cloth Swatches

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C. McGinley designed a venturi olfactometer that consists in a single presentation port to the panelist supplied by a solenoid and orifice system that control the air flow from the clean air supply and from the odorous sample. Tests of this design were done at the University of Minnesota over a period of three months and the venturi olfactometer proved his reliability and repeatability for dilution of 10.5 to 5793. This design presents many advantages which are: the very short distance between the mixing of the odorous sample and the fresh air and the presentation port, the purging time is short between the change of samples, the required odorous air mix to realize the sample testing is small, less residual contamination, and less time between dilution steps. Odor sampling with cloth swatch was also tested as a mean to transport the odors to the olfactometer. Cloth swatches were suspended (at 1,5 m from the slatted floor) in a finishing building for 8 hours and a pulsed air pump set to collect the air at the same level for the same period and store it in a Tedlar bag was also installed. Olfactometry analysis was then done on the cloth swatches and the air samples to compare both techniques. The results showed that for odor levels that are very low some correlation may exists between both techniques however, for medium to high odor concentrations no correlation could not be done.

The venturi olfactometer seems to be interesting considering its advantages. It would also be interesting to verify if the results obtained with this equipment are repeatable from one venturi olfactometer to another because apparently, the tests were done on the same olfactometer. The cloth swatch technique should not be used for odor intensity testing.

Odor Removal Using Biomass Filters

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In this publication, results are presented for a biomass filters made of cornstalks and corncobs as substrate. See the publication in the “Other notes” for more complete comments. More investigation is needed to understand the periodic odor release that occurred.
The experiment was also supposed to test a compost biofilter which technology was abandoned after few weeks trial due to the very high energy cost associated with the fan requirements and the high static pressure across the filter, the chosen design proved to be inappropriate.
More work is needed to better understand the relationship between dust concentration and associated odor components and also to find better filter media that is effective in dust and odor removal but show little airflow resistance considering the important air volumes that have to be treated from ventilated livestock buildings.

Odor Emission from Traditional and Low-emitting Swine Housing Systems: Emission Levels and their Accuracy

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The content of this publication is relatively similar to the following:
Evaluation of a Standard Sampling Method for Determination of Odour Emission from Animal Housing Systems and Calibration of the Dutch Pig Odour Unit into Standardized Odour Units.1997. Ogink, N.W.M. and J.V. Klarenbeek.
See the comments given.

Reduction of Odorous Compounds in Pig Manure by Lowering Dietary Crude Protein

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An experiment has been done with a group of 27 pigs fed (at 95% of ad-libitum) a 2 phase feeding program (growing (G) from 35 to 65 kg and finishing (F) from 65 to 95 kg) and 3 diet treatments were applied: low protein (G: 138.2g crude protein(CP)/kg feed and F: 131.0g/kg), medium protein (G: 161.2g/kg and F: 139.9/kg) and high protein (G: 208.4g/kg and F: 189.2g/kg). Lysine was incorporated in the diet. A nitrogen (N) balance was done to determine the N retained as lean tissues and the N excreted and analysis was realized on 10 components of the odor emission from the slurry to verify the effect of the treatment on variation of their concentration. The conclusions of this experiment are that: 40% less N was found in the slurry produce by growing and finishing pigs on the reduce CP diets compare to the high CP diet treatment; the concentration of the odorant components of the odor emissions decreased with the reduction of the CP in the diet; maximum lean tissue deposition is obtained with lowering the CP with an ideal balance of the essential amino acids(EAA).

The lower N level in the slurry obtained when reducing the CP level in the diet is interesting considering that the diet is balanced to maintain the EAA and allows a maximum lean tissues retention. The effect on certain components of the odor emissions can also be measured but unless olfactometric analysis of those emissions are done the reduction of certain components may not result in a lower odor intensity of on a better hedonic tone of the odorant.

GIBSI – A Watershed-Based Software System for Water Resources Management.

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A software system is presented, GIBSI, and this system was developed as a tool to assist decision makers in their management of water resources considering water quality and also quantity at watershed level. Simulations can be done with this software that is composed of a Geographical Information System (GIS), a Relational DataBase Management System (RDBMS) and simulation models. The user-friendly interface of the GIBSI is design for easy use and simulations with different management practices for agriculture, industrial and municipal applications can be made. The Chaudiere River watershed is currently represented in the GIBSI, as all spatial and attribute data have been collected and integrated in the GIS and the RDBMS.

The GIS system used is Grassland and the database system is Access TM. The model is made of submodels that represent five major processes: hydrologic cycle, the soil erosion process, the river erosion process, the transport of agricultural chemicals and the evolution of water quality. The precision of such system depends greatly on the accuracy of the data used and also the ability of the model used to well represent the reality. No information is given on this accuracy and the sensitivity of the system to different manure management or practices and the impact on the water quality.

Effects of repeated swine building exposures on normal naA?ve subjects

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Sensitivity analysis of particle cut-size to deduster parameters.

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The particle cut-size for a uniflow deduster is affected by many factors such as chamber configuration, particle characteristics, and air flow patterns. Sensitivities of five parameters on particle cut-size were analyzed. These include the vortex chamber length, annular tunnel height between inside and outside cylinders, vane angle, tangential and axial air velocities. It is not effective to reduce particle cut-size by changing air velocity when air velocity is higher than 10.0 m/s, or by changing the length when the length of Section 1 of the chamber is longer than 1.0 m. The sensitivity changes much faster when the annular gap is smaller than 2.0 cm. The sensitivity increases dramatically as the average radius decreases from 0.5 m, or when the vane angle is smaller than 4o. Further research is needed to examine the sensitivity of particle cut-size to turbulence intensity.

Emissions of Ammonia and Greenhouse Gases during Storage and Composting of Animal Manures

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The experiment has been done with cattle and pig manure. No statistical analysis is presented which make the results more difficult to draw conclusions. The emissions from the storage covers were measured using cattle manure.

Preparation and Sampling Technique for a Passive Ammonia Diffusion Sampler

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The more important advantage of the use of passive sampling methods is the ease and measurements can be done in many locations simultaneously. Such sampling methods were available however the analysis needed after sampling are time consuming and the sampling conditions need to be well respected (wind speed). The new sampling method being developed would improve those parameters. More work is being done to identify the source of the differences obtained between the calculated and measured rates. Protocols of use will also be developed. These samplers would be used in intensive livestock facilities (poultry and swine).