Source: UNIVERSITY OF MAINE submitted to
IMPROVEMENT OF SILAGE QUALITY AND ITS UTILIZATION BY DAIRY COWS.
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
NEW
Funding Source
Reporting Frequency
Annual
Accession No.
0218813
Grant No.
(N/A)
Project No.
ME08306-10
Proposal No.
(N/A)
Multistate No.
(N/A)
Program Code
(N/A)
Project Start Date
Oct 1, 2009
Project End Date
Sep 30, 2014
Grant Year
(N/A)
Project Director
Stokes, M. R.
Recipient Organization
UNIVERSITY OF MAINE
(N/A)
ORONO,ME 04469
Performing Department
Animal and Veterinary Sciences
Non Technical Summary
Satisfactory preservation of high quality forage is fundamental to the successful operation of ruminant animal agricultural enterprises, particularly dairy farms. Inclusion of the maximum amount of forage in an animal's diet reduces the use of purchased feed ingredients (concentrates) and makes a large contribution to the overall profitability of the operation since feed costs usually constitute at least 50 percent of the cost of producing milk. These purchased feed ingredients are often imported from other states and represent a drain on the Maine economy; a drain that could be reduced by the increased use of home-grown forages. Improvement of forage quality is particularly important in Maine because the dairy industry is the largest component of animal agriculture and together with beef and veal operations is probably the largest agricultural component of the Maine economy. In the northeastern United States, and particularly in Maine, the climate, topography, soil type, and soil drainage in many areas are more suitable for growing forages rather than row crops. Consequently, although corn for corn silage is a profitable crop in some areas, many areas are more suitable for the growth of grasses and legumes as forage crops. Work under previous Hatch projects (MAES 8306) examined the effects on silage fermentation, chemical composition, rumen digestion, and nutritive value of a range of forage crops ensiled with various biological and chemical additives. Laboratory-scale experiments were conducted to investigate the interaction of these additives, primarily enzyme and enzyme-bacteria mixtures, with forage type since carbohydrate composition and silage fermentation is markedly affected by forage species, its maturity, and its dry matter content. Some of these additives, both biological and chemical, were then evaluated at the farm level. The purpose of the proposed project is to evaluate some of the additives currently available to the Maine producer in an attempt to slow the decline of the Maine dairy industry. Many of these products have little or no scientific research to support their claims of improved forage preservation, greater animal performance or "improved bunk life" and rely on testimonials from other users. The current economic problems of the Maine dairy industry require that Maine milk producers have better information on which to base their purchases and forage management practices. These products will be evaluated in both laboratory-scale mini-silos and in farm-scale bunker silos. Previous research with corn silage showed that fermentation in a laboratory produced a different fermentation profile than that in the farm bunker due to differences in fermentation temperature profile and to the presence of a different microbial population on the forage fermented in the lab. These experiments will attempt to refine this data with first, second, and third crop mixed grass-legume forage to more accurately predict silage quality from mini-silo fermentations that cost less to perform, thus providing information to Maine producers more economically and faster than is possible from farm-scale experiments.
Animal Health Component
25%
Research Effort Categories
Basic
50%
Applied
25%
Developmental
25%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
3021699101050%
3023450101015%
3023499101010%
3027299101025%
Goals / Objectives
Activities will involve experiments to determine the fermentation temperature profile of first, second and third cut mixed grass-legume silage in 60-80 ton bunker silos. Ambient temperature around the silo and in the research laboratory will also be measured. Our goal is to improve our capabilities to perform laboratory-scale investigations with mini-silos by investigating the effects of fermentation temperature profile and forage source on the fermentation parameters of first, second, and third crop forage, ensiled with and without currently available silage additives. We will continue to investigate the effects of enzyme additives and inoculants on silage fermentation, composition, and performance of lactating dairy cattle. Outputs will include attendance at, and presentation of posters at, national and international scientific meetings. Presentations will be made to Maine producers at meetings arranged by Cooperative Extension. A revised procedure for using laboratory-scale mini-silos to more accurately predict farm-scale silage fermentation will be developed.
Project Methods
In different years, first, second and third crop mixed grass-legume forage will be ensiled in duplicate 60-80 ton bunker silos to generate replicate data. During packing, nine electronic temperature data-loggers will be placed into each silo to determine the fermentation temperature profile for 72 d. Ambient temperature around the silo and on a laboratory bench will be determined for comparison with the bunker temperature profile. The mean packing density of the silage will be estimated from measurements of the silo and the weight of forage ensiled. When the data-loggers are recovered during feed-out of the silage the packing density at the levels of the data-loggers will be determined by boring into the silo face with a 5 cm diameter stainless steel silage sampling tube. In subsequent years, mini-silo experiments will be performed to compare the fermentation profiles in the mini-silos with those produced in the duplicate farm-scale bunkers. The mini-silos will be fermented in a laboratory incubator or temperature controlled room to simulate the temperature profile of the bunker silos as determined in the experiments described above. Temperature profiles in both the mini-silos and the bunker will be recorded for 72 days for direct comparison of fermentation temperatures. The mini-silos will be packed to the same density as was determined for this cut in the experiments described above. Representative sub-samples of the unfermented forage and of silage samples taken weekly when the silage is fed out will be chemically analyzed to compare the fermentation profiles of the two types of silo. Bunker and mini-silo silages will be analyzed for DM, pH, ammonia, fermentation acids, crude protein, NDF, ADF, ADL, and WSC to determine effects on silage composition and fermentation quality. Original unfermented forages will be analyzed for the same parameters except ammonia and fermentation acids. Samples of each farm-scale silo and of composited sub-samples of mini-silo replicates will be monitored for their aerobic stability using a 36 cell computer-monitored aerobic incubation system to determine the length of time before heating after exposure of the silage to air. Silage densities will be determined as described above. Dry matter recovery in the mini-silos will be determined from the weights of DM before and after fermentation and from changes in the concentration of ash caused by fermentation. The effects of silage additives available to Maine producers on silage fermentation and nutritive value for lactating dairy cows will also be evaluated in these experiments. These results will allow us to develop a refined method for researchers to use mini-silos to predict farm-scale silage fermentation and provide information for Maine producers to improve their forage quality. Researchers will be targeted by publication of results in a peer-evaluated journal and producers will be educated by presentation of results in extension publications and at producer meetings.

Progress 10/01/12 to 09/30/13

Outputs
Target Audience: This research is targeted at producers and industryby influencing the procedures used by scientists and graduate students to predict the effectivenes of silage additives. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? The above experiment was used as the Senior Topics Research Project for Ashlyn Detlefsen, a UMaine senior student in the Animal and Veterinary Sciences bachelor's degree program. How have the results been disseminated to communities of interest? Nothing Reported What do you plan to do during the next reporting period to accomplish the goals? An experiment is in progress with first crop grass-legume silage to compare three methods of ensiling the forage.As in previous experiments duplicate bunker silages are being compared to the same forage ensiled in mini-silos fermented in the lab both clean and dirty and the same forage ensiled in mini-silos fermented in an incubator.The temperature of the incubator was adjusted daily to follow the bunker temperature profile of a previous first crop silage experiment.By imitating the bunker fermentation temperature profile I hope to closely predict the fermentation profile of the bunker silages. If this procedure accurately reflects the composition of the bunker silage then it will constitute a change in action for silage research. This experimentis beingused as the Senior Topics Research Project for Abigail Harnik, a UMaine senior student in the Animal and Veterinary Sciences bachelor's degree program.

Impacts
What was accomplished under these goals? The temperature profiles and silage composition of duplicate 80 ton bunkers of second crop mixed grass-legume forage were compared to the temperature profiles and composition of the same forage ensiled in mini-silos (140 g each). Forage for ensiling in the mini-silos was collected either directly from the dump wagon (clean) or by raking the top surface of the silos after packing (dirty). It was assumed that this forage could have been unintentionally inoculated with bacteria from the tires of the packing tractor and that this would influence the silage fermentation. The fermentation temperature profiles of forage ensiled in both the bunker silos and the mini-silos were recorded for 72 days. Depending on the location of the temperature detector in the bunker, the fermentation temperatures peaked in 4 to 7 days at 39 to 43ο C and then fell in a curvilinear manner over the remainder of the 72 days to 26 to 29οC. The fermentation temperatures of the mini-silos closely followed the changes in ambient temperature, which was approximately 15οC cooler than the bunker temperatures, and did not follow the same heating and cooling profile. The mini-silos thus did not heat up as does a bunker silo, presumably due to the high surface area to silage mass ratio of the mini-silo. The two bunkers of second crop forage were ensiled on successive days to generate silages containing 42.61 and 38.23% DM (NS between bunkers).The clean and dirty mini-silos contained 38.23 and 36.47% DM, which were both lower than the mean bunker level (P<.01).The silage pH in the mini-silos was lower (P<.001) than in the bunkers (4.62) and the dirty treatment was lower (3.99, P<.01) than the clean treatment (4.25).Similar changes were observed in the ethanol soluble carbohydrate and the water soluble carbohydrate concentrations in each silage, which reflects the greater fermentation of carbohydrates to generate the lower pH values.The lactic acid concentration (% DM) in the mini-silos was higher (7.69% and 8.13%) than in the bunkers (4.40%, P<.01) but there was no difference between the mini-silo treatments.Similarly, total acid concentration was higher in the mini-silos (9.80 and 10.22%) than in the bunkers (6.00%, P<.01).These differences in acid concentrations were reflected in the pH values for each treatment.All the silage treatments had homolactic fermentations so there was no unintentional inoculation of the dirty forage with heterolactic bacteria, as was seen in a previous experiment with third crop forage.Neither mini-silo treatment accurately predicted the acid composition of the bunker silages.

Publications


    Progress 10/01/11 to 09/30/12

    Outputs
    OUTPUTS: OUTPUTS: Two bunkers of third crop mixed grass-legume forage were ensiled in early September 2011 to compare the fermentation temperature profile, silage composition, and fermentation acid profile of this silage with the same parameters measured in laboratory-scale mini-silos (MS) fermented in a laboratory. Temperature profiles were recorded hourly for 72 d using Tiny-Talk data loggers at six locations in each bunker. Three data loggers were placed on top of the forage half way into the silo at one quarter, one half and three quarters of the width of the silo at depths of .75m and 1.5m. Original forage samples were taken from each load of forage to represent the mean composition of the entire bunker. Forage was also sampled for analysis at each level and at the lower level forage was sampled for packing into laboratory-scale MS. Forage was sampled directly from the dumped forage, clean, or after it had been packed with the packing tractor, dirty. This allowed us to determine the effect of unintentional inoculation of the forage with microorganisms on the tires of the packing tractor. Forage for the MS from bunker 1, was filled with forage averaging about 33% DM whereas the second bunker, bunker 4, filled 2 days later, was considerably drier at almost 55% DM. Forage from bunker 1, 140g, was pre-weighed for packing into each MS, 4 clean and 4 dirty, using a pneumatic packer to minimize variation in packing density between MS. A Tiny Talk temperature detector was packed into the middle of each MS. At 33% DM, 140g per silo produced a packing density of about 35 lb/cu.ft of forage. For the second bunker, the quantity of forage packed into the MS had to be reduced to 110 g because of the higher DM. This reduced the packing density to about 27 lb/cu. ft. The MS were kept in a warm room for the first 7 d of fermentation to help promote the initial rise in silage temperature before being relocated to a normal temperature research laboratory for the remaining 65 days of fermentation. The MS were opened and subsampled for analysis after 90 and 126 days for the two bunkers. After opening, silage pH and titratable acidity were measured immediately, silage DM was measured at 55 degrees C, and samples were sent to Dairy One Forage Lab for compositional analysis and fermentation acid profile. The temperature detectors in bunker 1 were recovered after 54 d of fermentation as the silage was fed to the university dairy cows. The detectors in bunker 4 were not recovered until the silage was fed out in January 2012. Differences between clean and dirty MS composition and between bunker silo and MS composition were determined by analysis of variance using the Systat 12 online statistical analysis package. This experiment was used as the Senior Topics research project for Paige Davidowicz and the results were presented as a poster at the 2012 Center for Undergraduate Research Exposition at the University of Maine. The above experiment was repeated in July 2012 with second crop mixed grass/legume forage as the Senior Topics research project of another UMaine senior student. Analysis of this data continues and will be reported in 2013. PARTICIPANTS: This experiment was used as the Senior Topics research project for Paige Davidowicz and the results were presented as a poster at the 2012 Center for Undergraduate Research Exposition at the University of Maine. The above experiment was repeated in July 2012 with second crop mixed grass/legume forage as the Senior Topics research project of another UMaine senior student, Ashlyn Detlefsen. TARGET AUDIENCES: This project provided experiential learning opportunities for two senior students at the University of Maine. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

    Impacts
    OUTCOMES/IMPACTS: Bunker 1 forage DM content varied considerably over the two day period of ensilage. The mini-silos (MS) were ensiled at 32.5% DM but the average DM of the bunker was 50.1%. In contrast, the bunker four MS were ensiled at about 54% DM. Consequently, data for the two bunkers were analyzed separately. There was however no differences in forage composition from different bunker 1 samples. Temperatures at four detectors peaked in 5 to 12 days at 33.7 to 36.9 degrees C and then cooled in an almost linear fashion to reach 25.8 to 30.7 degrees C. Silo ambient temperature fell irregularly from 25.3 to 3 degrees C over the 54 days of ensilage. The temperatures in the mini-silages were very similar to each other and closely followed changes in the laboratory ambient temperature. The mini-silages fermented cooler than the bunker, varying from 15 to 23 degrees C while the ambient temperature varied from about 18 to 23 degrees. Bunker one had higher fermentation temperatures (up to 36.9 degrees) and did not follow changes in the outside ambient temperature. Peak and average temperatures in bunker 1 were about 15 degrees C warmer than in the MS. Bunker 1 silage DM was 3 or 5 % units damper and its pH was .27 units higher than in the MS. The mini-silages contained more titratable acidity than the bunker and this was reflected in higher but non-significant levels of lactic acid in both mini-silo treatments. There was no difference in the total concentrations of fermentation acids but the lactic acid to acetic acid ratios indicated a more heterolactic fermentation in both the bunker and the dirty MS. The clean mini-silages also contained more residual WSC than the other two treatments, indicative of more efficient homolactic fermentations. There were no differences in the bunker 4 original forage compositions but the bunker top level samples, the bunker overall samples and the mini-silo original forage samples were 62.1, 55.25 and 54.05 %DM, markedly higher than for bunker 1. The fermentation temperatures peaked in 7-10 days at 37.6 to 40.6 degrees C and fell in an almost linear manner as observed in bunker one. Similarly to bunker one, the fermentation temperature did not follow the ambient temperature and remained about 15 degrees warmer than the ambient. The bunker four clean and dirty MS fermentation temperatures followed very closely to the ambient temperature. The temperatures varied from around 23-16 degrees C and the ambient varied from around 23 to 17 degrees C. The pH of the bunker 4 mini-silo treatments were lower than the bunker pH but there were few significant differences in fermentation acids or silage composition except that the bunker had a numerically higher content of lactic acid than the mini-silages and it had the highest residual WSC content, indicative of a more efficient, more homolactic fermentation. At the lower DM, bunker 1, neither mini-silo treatment adequately predicted the bunker silage fermentation but the bunker and the dirty MS both had heterolactic fermentations. At the higher DM, both mini-silo treatments produced similar fermentation profiles to that of the bunker.

    Publications

    • No publications reported this period


    Progress 10/01/10 to 09/30/11

    Outputs
    OUTPUTS: OUTPUTS: Two bunkers each of first crop and second crop mixed grass-legume forage were ensiled in May and June 2010 to compare the fermentation temperature profile, silage composition, and fermentation profile of this silage with the same parameters measured in 140g laboratory-scale mini-silos fermented in a laboratory. Fermentation temperature profiles were recorded every hour for 72 days. Second crop mini-silos were not opened until early spring when the second crop bunkers were being fed. Unfortunately, many of the mini-silos had developed mold at either the top of the silo or around the tiny-Talk data logger in the middle of the silo. Comparison of these composition and fermentation data with the bunker silo data will not be possible because of the modification of the mini-silo data by the mold. This experiment will be repeated in summer 2012 and the mini-silos will be opened after 72 to 90 days to avoid mold problems. A similar experiment with third crop hay crop silage was initiated in early September 2011 to compare third crop bunker silages with the same forage ensiled in mini-silos. The same procedures were followed as described in previous CRIS reports for ensiling, temperature measurement and forage sampling in two farm scale bunker silos that hold about 85 tons forage each and in the 8 mini-silos per bunker, 4 clean and 4 dirty after possible inoculation by microbes on the tires of the packing tractor. Eight mini-silos were pneumatically packed with 140 g forage from the first bunker at about 35% DM and each mini-silo also contained a Tiny Talk data monitor. This created a packing density of about 35 lb/cu.ft. This bunker silage is currently being fed and samples have been taken of silage from the first bunker around the Tiny Talk temperature monitors for comparison with the composition of silage in the mini-silos to be opened after 72 days of fermentation. The second bunker was filled 2 days later with forage that was considerably drier at 40 -45% DM. The quantity of silage packed into the mini-silos had to be reduced to 120 g because of the increased DM. This reduced the packing density to about 27 lb/cu. ft. After repeating the ensilage of second crop forage in 2012 we will be able to compare the fermentation temperature profiles of forages cut and ensiled in five different months with different ambient temperatures: May, first crop hay crop silage; June, second crop hay crop silage; September, third crop hay crop silage; and of corn silage made in early October and early November. Comparison of the silage composition and fermentation profiles of the bunker silages with those same parameters measured in laboratory scale mini-silos will indicate whether mini-silos fermented in a laboratory do accurately predict farm-scale silage composition, or whether mini-silos must be fermented at temperatures closer to bunker temperatures to predict farm-scale silage composition. PARTICIPANTS: Only the PI/PD, Martin Stokes, has spent at least one person month working on this project including initiating the project, guiding its progress, filling the mini-silos, sampling all the original forages and the silages during feed out. University of Maine farm crew were essential to the harvesting and ensilage of this forage but worked on the project for less than one person month per year each. One undergraduate student gained experience and training by assisting with the farm-scale ensilage, packing the mini-silos, opening the mini-silos and analyzing them for pH, and titratable acidity. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: In previous years corn silage was harvested as described above for mixed grass legume forage and bunker silage composition was compared to the composition of silages from mini-silos fermented in various locations. This corn forage was harvested in early October and early November when the weather was very cold. In 2009 the weather was very dry and warm with more growing degree days earlier in the year that allowed corn to be ensiled in late August/early September when the ambient temperatures were considerably warmer than in the previous experimental years. If this same weather pattern occurs in 2012 we will repeat harvesting and ensilage of corn forage to compare with the previous experiments, which is a possible modification of the project.

    Impacts
    There have been no outcomes or impacts from this project as the data from these experiments is incomplete.

    Publications

    • No publications reported this period


    Progress 10/01/09 to 09/30/10

    Outputs
    OUTPUTS: Two bunkers each of first crop and second crop mixed grass-legume forage were ensiled in May and June 2010. Half way back into each bunker as they were being filled, six Tiny Talk temperature data loggers were placed on top of the forage at one quarter, one half, and three quarters of the width of each silo at depths of one third and two thirds of the anticipated full forage depth of each bunker. Samples of forage at these two sites within each silo were removed for chemical analysis of nutritional value. At the lower depth, forage was also removed both before (clean) and after packing (dirty) for ensilage in 140g laboratory-scale silos, each fitted with a data logger. Packing was achieved with a pneumatic silo packer to minimize variation in packing density, which was estimated to be about 35 lb per cubic foot. Samples of clean and dirty forage were also reserved for later analysis. A data logger was taped to the top of the silo wall separating the two silos and to the bench in the laboratory to monitor ambient temperature at each fermentation site. Within 24 hours, original forage samples were analyzed for pH, titratable acidity and buffering capacity and were dried at 55 degrees Celsius to determine DM content. Representative samples were sent to the Dairy One Laboratory, Ithaca, NY for chemical analysis of nutritional value by NIR. The data loggers were set to record silage temperature every hour for 72 days. Silage will be sampled from around each data logger as the silage is being fed out for comparison with mini-silo silage composition. Silage fermentation profile will also be determined on both the bunker silages and on the contents of each mini-silo. Aerobic stability of each bunker and mini-silage will also be determined. All data will be statistically analyzed to compare the nutritional value, fermentation profile, fermentation temperature profile, and aerobic stability of the mini-silo silages with those of the bunker silos. Since this data is incomplete there has been no dissemination of results PARTICIPANTS: Only the PI/PD, Martin Stokes, has spent at least one person month working on this project including initiating the project, guiding its progress, filling the mini-silos, sampling all the original forages and the silages during feed out, and performing the aerobic stability measurements. University of Maine farm crew were essential to the harvesting and ensilage of this forage but worked on the project for less than one person month per year each. One undergraduate student gained experience and training by assisting with opening the mini-silos and analyzing them for pH, and titratable acidity. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: In the previous project corn silage was harvested as described above for mixed grass legume silage and bunker silage composition was compared to the composition of silages from mini-silos fermented in various locations. This corn forage was harvested in early October and early November when the weather was very cold. This year the weather was very dry and warm with more growing degree days earlier in the year that allowed corn to be ensiled in late August/early September when the ambient temperatures were considerably warmer than in the previous experimental years. If this same weather pattern occurs in 2011 we will repeat harvesting and ensilage of corn forage to compare with the previous experiments, which is a possible modification of the project.

    Impacts
    There have been no outcomes or impacts from this project as the data from these experiments is incomplete.

    Publications

    • No publications reported this period