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Gruber H.,Institute for Crop Science and Plant Breeding | Gruber H.,TU Munich | Gruber H.,Bavarian Health and Food Safety Authority | Paul V.,TU Munich | And 7 more authors.
Journal of Agricultural and Food Chemistry | Year: 2011

The objective of the study was to track the fate of recombinant Cry1Ab protein in a liquid manure field trial when feeding GM maize MON810 to dairy cows. A validated ELISA was applied for quantification of Cry1Ab in the agricultural chain from GM maize plants, feed, liquid manure and soil to crops grown on manured fields. Starting with 23.7 μg of Cry1Ab g-1 dry weight GM maize material, a rapid decline of Cry1Ab levels was observed as 2.6% and 0.9% of Cry1Ab from the GM plant were detected in feed and liquid manure, respectively. Half of this residual Cry1Ab persisted during slurry storage for 25 weeks. After application to experimental fields, final degradation of Cry1Ab to below detectable levels in soil was reported. Cry1Ab exhibited a higher rate of degradation compared to total protein in the agricultural processes. Immunoblotting revealed a degradation of the 65 kDa Cry1Ab into immunoreactive fragments of lower size in all analyzed materials. © 2011 American Chemical Society.


Edmunds B.,University of Bonn | Sudekum K.-H.,University of Bonn | Bennett R.,Adisseo Europe Africa Middle East | Schroder A.,Kemin AgriFoods Europe | And 2 more authors.
Journal of Dairy Science | Year: 2013

The objective of this study was to improve knowledge regarding the amino acid profile of the insoluble portion of ingested forage escaping rumen degradation. Six forage categories were analyzed. Categories varied in botanical composition and each contained 2 samples. Samples within categories were derived from the same parent material but differed in harvest, maturity, or conservation type. The rumen-undegradable protein of all forages was measured by incubation for 16. h in the rumen of 3 nonlactating cows. All residues were corrected for microbial colonization. The AA profile of the residue was different to the original profile. Degradation trends of individual AA, in terms of increase or decrease relative to the original concentration, were similar between all forages. The AA profiles of forage residues, both within and between categories, were more similar to each other than to their respective original profile. This information may aid in improving the accuracy of estimating postruminal AA supply from forages while decreasing the number of samples required to be analyzed. © 2013 American Dairy Science Association.


Edmunds B.,University of Bonn | Edmunds B.,Institute for Animal Nutrition and Feed Management | Spiekers H.,Institute for Animal Nutrition and Feed Management | Sudekum K.-H.,University of Bonn | And 3 more authors.
Grass and Forage Science | Year: 2014

Wilting grass prior to ensiling generally increases the dry matter (DM) intake but the effect of wilting on animal performance is still poorly understood. There is a need to improve understanding of the effects of wilting on the nutritional components and chemical composition of grass silage. This study focused on the effects of the extent and rate of wilting on N components of grass silage. Meadow grass was wilted to four DM contents (200, 350, 500, 650 g kg-1) at two different rates (fast, slow), creating a total of eight silages. Crude protein (CP) fractions were measured using the Cornell Net Carbohydrate and Protein System. Utilizable CP at the duodenum (uCP), a measure of feed protein value, was estimated using the modified Hohenheim gas test. Ruminally insoluble, undegraded feed CP (RUP) was measured using an in situ technique. Amino acid (AA) composition prior to and after rumen incubation was also investigated. Utilizable CP at the duodenum, RUP and true protein fractions B2 and B3 were increased by rapid wilting and high DM content (DM > 500 g kg-1), although the increase with DM was only mild for uCP, probably due to lower ME content in the DM-650 silages. Non-protein-N decreased with increasing DM and rapid wilting. The higher RUP content from both DM-650 silages leads to a higher total AA content after rumen incubation. Treatment also influenced the AA composition of the ensiled material, but the AA composition after rumen incubation was similar across treatments. Rapid and extensive wilting (DM > 500 g kg-1) improved protein value and reduced CP degradability. Increased uCP may result in higher milk protein yield, while reduced degradability may reduce N lost from urinary excretion. The primary effect of wilting on post-ruminal AA supply from RUP appeared to be quantitative, rather than qualitative. © 2012 John Wiley & Sons Ltd.


Edmunds B.,University of Bonn | Edmunds B.,Institute for Animal Nutrition and Feed Management | Sudekum K.-H.,University of Bonn | Spiekers H.,Institute for Animal Nutrition and Feed Management | And 2 more authors.
Animal Feed Science and Technology | Year: 2012

As protein evaluation systems are evolving, they are increasing in their sophistication and complexity. In almost all systems an estimate of microbial crude protein (MCP) and ruminally undegraded feed CP (RUP) must be available. A problem lies in the accuracy of these measurements, especially RUP, which is often estimated by the controversial in situ technique. A new in vitro method has been developed which provides a direct estimate of combined MCP and RUP. The modified Hohenheim gas test (modHGT) involves incubation of a feedstuff in rumen fluid. The non-ammonia N content after incubation is used to determine utilisable CP at the duodenum (uCP) which is defined as the sum of MCP and RUP at the duodenum. In our study, 23 forages were examined using the modHGT and shown at three assumed rates of rumen passage (K p: 0.02, 0.04, 0.06/h). Results were regressed against uCP values calculated using the standard procedure in Germany. Calculated uCP correlated with determined uCP at all rates of passage (K p2: P<0.038, r 2=0.19; K p4: P<0.0001, r 2=0.56; K p6: P<0.0001, r 2=0.67). Due to the simplicity of the reference method it is possible that the modHGT provides more accurate results. Although the new method is also simple, it considers interactions between carbohydrate and protein degradation by rumen microbes and uCP is estimated from the fermentation end product, ammonia. Utilisable CP may then be used to calculate metabolisable protein. © 2012 Elsevier B.V.


Bauer U.,Institute for Agricultural Engineering and Animal Husbandry | Harms J.,Institute for Agricultural Engineering and Animal Husbandry | Steyer M.,Institute for Animal Nutrition and Feed Management | Salau J.,University of Kiel | And 6 more authors.
Landtechnik | Year: 2012

The commonly used methods to estimate fat reserves of cows are body condition score (BCS) and backfat thickness (BFT). But these methods are subjected to restrictions regarding objectivity of results and amount of work. Therefore, a visual three-dimensional sensor systemhas been developed for the automatic determination of body conditionof cows during lactation. The designed software evaluates recorded images for further processing. In the next step characteristics for bodycondition were extracted of suitable images. These characteristicsareintegrated in a linear model, which estimates the body condition score. The correlation between manual recorded BCS and estimated BCS is 0.8 (p < 0.0001).


Kohler B.,Institute for Animal Nutrition and Feed Management | Diepolder M.,Institute for Agricultural Ecology | Ostertag J.,Institute for Animal Nutrition and Feed Management | Thurner S.,Institute for Agricultural Engineering and Animal Husbandry | Spiekers H.,Institute for Animal Nutrition and Feed Management
Agricultural and Food Science | Year: 2013

An efficient feed management is important for a sustainable and economic agricultural production. One of the main points for improving the efficiency is the reduction of feed losses. In the present investigation the dry matter (DM) losses of grass, lucerne and maize silages in farm scaled bunker silos were analysed. The method of determining DM losses was the total-in versus total-out DM mass flow of the silos, including the determination of DM content and other silage parameters via manual sampling. The results taken from 48 silos showed on average for all investigated crops 9-12% of DM losses. Density and feed out rate showed a negative correlation to DM losses in maize silages. According to the applied method for determining DM losses on farm scale, a guideline of 8% can be suggested for maximum DM losses in bunker silos for grass and maize silages. The described method seems to be applicable for improving the feed management by using largely automated measurements on the harvest and feeding side.


Gottschalk C.,Federal Institute for Risk Assessment BfR | Gottschalk C.,Ludwig Maximilians University of Munich | Ronczka S.,Federal Institute for Risk Assessment BfR | Preiss-Weigert A.,Federal Institute for Risk Assessment BfR | And 4 more authors.
Animal Feed Science and Technology | Year: 2015

Hepatotoxic 1,2-dehydro-pyrrolizidine alkaloids (PA) and their N-oxides (PANO) in feed are a potential threat for animal and human health. However, their risk assessment in preserved animal forage is difficult due to data gaps regarding their occurrence in field samples and contradictory results regarding their behavior during the ensilage process. In this study, 115 samples of grass silage originating from different districts in Bavaria (Germany) were analyzed for their PA and PANO contents. A sensitive LC-ESI-MS/MS method for the detection of 10 PA and 4 PANO was developed including a clean-up of the aqueous acidic extract by cation-exchange cartridges. The mean recoveries were between 70% for seneciphylline-. N-oxide and 104% for senecionine-. N-oxide. The limits of detection ranged between 0.14. μg senkirkine/kg dry matter (DM) and 1.3. μg retrorsine-. N-oxide or monocrotaline-. N-oxide/kg DM. Eighteen percent of the samples contained one or more of the analyzed compounds. The highest observed value, calculated as the sum of seneciphylline and senecionine, was 30. μg/kg DM. Other samples contained senecionine-. N-oxide, seneciphylline-. N-oxide, lycopsamine, intermedine, echimidine, and heliotrine in lower amounts. An accompanying laboratory scale ensilage trial showed a compound-dependent transformation of PANO during the fermentation process while PA-amounts remained stable or even increased. Impacts on safety of ensiled animal feed are discussed with regard to animal health. © 2015 Elsevier B.V.


Edmunds B.,University of Bonn | Edmunds B.,Institute for Animal Nutrition and Feed Management | Sudekum K.-H.,University of Bonn | Spiekers H.,Institute for Animal Nutrition and Feed Management | Schwarz F.J.,TU Munich
Animal Feed Science and Technology | Year: 2012

Rumen insoluble feed crude protein (CP) escaping degradation (RUP) was estimated from a variety of forages using two in vitro procedures: the Cornell protein fractionation procedure and the enzymatic degradation procedure by Streptomyces griseus protease. Some recent improvements to both in vitro procedures were applied. The in situ technique served as a reference method and a novel combination of methods was used to correct for microbial colonisation of residues. Twenty-five forages, varying in conservation type (unconserved, ensiled, dried) were analysed. Assumed passage rates (K p) of 0.02, 0.04 and 0.06/h were applied to estimates of RUP using in situ and chemical fractionation. Results from both in vitro procedures correlated linearly with in situ values (P<0.05). In terms of variation around the regression line, distance of the slope from zero and root mean square error, enzymatic degradation was the more accurate method in estimating in situ RUP (r 2=0.71, P<0.0001; K p4). In both in vitro procedures, silage and dried forage were more accurately estimated than unconserved forage, which may be explained by the higher and more variable concentration of intermediately degraded CP fraction B2 in the latter. Estimation of in situ RUP from CP fractions needs further improvement. Results imply that in vitro procedures may be used to predict in situ estimates of RUP with a higher level of confidence. © 2012.

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