Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

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Meal pattern analysis for effects of compound feed formulation in mid to late lactating dairy cows fed hay and compound feed both ad libitum
Leen, F. ; Navarro-Villa, A. ; Fowers, R. ; Martin-Tereso, J. ; Pellikaan, W.F. - \ 2014
Animal Production Science 54 (2014)10. - ISSN 1836-0939 - p. 1752 - 1756.
diet selection - rumen function - behavior - cattle - choice - concentrate - performance - drinking - silage - system
The Kempen System is a dairy feeding system allowing ad libitum access to pelleted compound feed (CF) and hay. This system allows high DM intake (DMI) up to 30 kg DM (80% CF), but small and frequent CF meals are essential to reduce negative ruminal pH fluctuations. Little is known about feed intake patterns of cows on ad libitum and separated access to CF and hay. Meal pattern analysis was performed to evaluate feed intake behaviour of two different isoenergetic and isonitrogenous CF (starch vs fibre), contrasting in neutral detergent fibre, acid detergent fibre and starch content. Twenty primi- and multiparous Holstein-Friesian cows (203 ± 35.4 days in milk) received grass hay ad libitum with one of the two CF also offered ad libitum. Meal criteria, the shortest non-feeding interval between feeding events separating two consecutive meals, were used to cluster feeding events into separate meals. The meal criteria were determined per cow by fitting the log10-transformed feeding intervals to Gaussian–Gaussian probability density functions. The DMI of CF fibre (18.8 ± 0.54 kg) tended to be greater (P = 0.09) than starch (18.1 ± 0.54 kg/day), while that of grass hay (4.8 ± 0.29 kg) was unaffected (P = 0.23). The CF meal size did not differ (P = 0.26) between treatments (starch 2.9 vs fibre 3.0 ± 0.11 kg/meal), but number of meals per day (6.36 ± 0.229, P = 0.87) and meal durations (64 ± 3.5 min, P = 0.87) did not differ between treatments. The differences in CF formulation were insufficient to create detectable differences in feed intake nor intake behaviour patterns
Critical parameters in cost-effective alkaline extraction for high protein yield from leaves
Zhang, C. ; Sanders, J.P.M. ; Bruins, M.E. - \ 2014
Biomass and Bioenergy 67 (2014). - ISSN 0961-9534 - p. 466 - 472.
leaf protein - functional-properties - chemical-composition - amino-acids - tea-leaves - biomass - concentrate - refinery - feed
Leaves are potential resources for feed or food, but their applications are limited due to a high proportion of insoluble protein and inefficient processing. To overcome these problems, parameters of alkaline extraction were evaluated using green tea residue (GTR). Protein extraction could be maximized to 95% of total protein, and, after precipitation by pH adjustment to 3.5, 85% of extracted protein was recovered with a purity of 52%. Temperature, NaOH amount, and extraction time are the protein yield determining parameters, while pH and volume of extraction liquid are critical parameters for production cost. The cost of energy and chemicals for producing 1 t GTR proteins is minimized to 102€, and its nutritional value is comparable to soybean protein. Furthermore, this technology was successfully applied to other sources of biomass and has potential to be used as a part of an integrated bio-refinery process.
The influence of pH and ionic strength on the swelling of dense protein particles
Saglam, D. ; Venema, P. ; Vries, R.J. de; Linden, E. van der - \ 2013
Soft Matter 9 (2013). - ISSN 1744-683X - p. 4598 - 4606.
whey-protein - drug-delivery - beta-lactoglobulin - sensitive hydrogels - mesh size - gels - gelation - isolate - concentrate - microstructure
We have studied swelling properties and stability of protein particles prepared through emulsification and heat-induced gelation of whey proteins under different conditions. The protein particles themselves are stable over a wide pH range, but around pH 5 aggregation was observed, presumably because of a weakened electrostatic repulsion close to the protein iso-electric point. Protein leakage from the particles was found not to be higher than 8% (w/w) in most of the pH range, but increased significantly at alkaline pH. The pore size of the particles is in the range of 4 to 20 nm at neutral pH and the particles show a pH- and salt-responsive swelling, due to their polyampholytic character, as shown by confocal scanning electron microscopy analysis. These results indicate that these whey protein particles could be used as targeted delivery vehicles. The pH sensitive swelling of the particles may also result in significant changes in the volume of the particles, thereby influencing the rheological properties of dispersions made out of these particles, especially in concentrated systems.
d13C as a marker to study digesta passage kinetics in ruminants: a combined in vivo and in vitro study
Pellikaan, W.F. ; Verstegen, M.W.A. ; Tamminga, S. ; Dijkstra, J. ; Hendriks, W.H. - \ 2013
Animal 7 (2013)5. - ISSN 1751-7311 - p. 754 - 767.
neutral detergent fiber - dairy-cows - internal markers - grass silages - particle-size - rumen - cattle - diets - digestibility - concentrate
The aim of the current study was to explore the use of the tracer 13C as an internal marker to assess feed fraction-specific digesta passage kinetics through the digestive tract of dairy cows. Knowledge on feed-specific fractional passage rates is essential to improve estimations on the extent of rumen degradation and microbial protein efficiency; however, this information is largely lacking. An in vivo and in vitro experiment was conducted with grass silages (Lolium perenne L.) that were enriched with 13C by growing the grass under elevated 13CO2 conditions. In a crossover design, two dairy cows received pulse doses of two 13C-enriched grass silages and chromium-mordanted neutral detergent fibre (Cr-NDF) into the rumen. The two 13C-enriched grass silages used differed in digestibility and were grown under identical field conditions as the bulk silages fed to the animals. Faecal excretion patterns of 13C-enriched dry matter (13C-DM), neutral detergent fibre (13C-NDF) and Cr-NDF were established, and a nonlinear multicompartmental model was used to determine their rumen passage kinetics. In addition, the 13C-enriched silages were incubated in rumen liquid in an in vitro batch culture system at different time intervals to determine the effect of fermentation on 13C-enrichment in the residue. The in vitro study showed that the 13C : 12C ratios in DM and NDF residues remained stable from 24 h of incubation onwards. In addition, in vitro fractional degradation rates for 12C in the DM and NDF did not differ from those of 13C, indicating that fermentative degradation does not affect the 13C : 12C ratio in the DM nor in the NDF fraction of the residue. Model fits to the faecal excretion curves showed a significant difference in fractional rumen passage rates between Cr-NDF, 13C-DM and 13C-NDF (P = 0.025). Silage type had no clear effect on rumen passage kinetics (P = 0.081). Moreover, it showed that peak enrichments for 13C-DM and 13C-NDF in faeces were reached at 30.7 and 41.7 h post dosing, respectively. This is well after the time (24 h) when the 13C : 12C ratios of the in vitro unfermented residues have reached stable enrichment level. Fractional rate constants for particle passage from the rumen are estimated from the descending slope of faecal excretion curves. The present study shows that the decline in 13C : 12C ratio after peak enrichment is not affected by fermentative degradation and therefore can be used to assess feed component-specific fractional passage rates.
Bio-reduction of elemental sulfur to increase the gold recovery from enargite
Hol, A. ; Weijden, R.D. van der; Weert, G. van; Kondos, P. ; Buisman, C.J.N. - \ 2012
Hydrometallurgy 115-116 (2012). - ISSN 0304-386X - p. 93 - 97.
refractory ore - dissolution - oxidation - sulfide - ferrooxidans - concentrate - bacteria - kinetics - pyrite - zinc
The mineral enargite can be of interest to the mining industry as a copper and precious metal source. The mineral has a refractory character towards oxidation, which is attributed to the formation of elemental sulfur that seals off the mineral surface. In this study it was investigated whether elemental sulfur resulting from oxidation during industrial milling can be converted into hydrogen sulfide via bio-reduction. The removal of elemental sulfur in this process will clean the mineral surfaces for subsequent oxidation, prevent interference with the gold extraction process and reduce consumption of chemicals such as cyanide. HPLC analysis confirmed that indeed elemental sulfur was formed during industrial milling of an enargite-pyrite gold concentrate. Removal of elemental sulfur via bio-reduction was successful and improved the gold leachability from 48.9% to 69.6%. The combination of milling and bio-reduction was therefore concluded to be a possible route to liberate metals. Further research is necessary to investigate if the enargite to sulfur conversion can be improved to obtain economically satisfactory (> 90%) gold recoveries.
Effects of early rumen development and solid feed composition on growth performance and abomasal health in veal calves.
Berends, H. ; Reenen, C.G. van; Stockhofe, N. ; Gerrits, W.J.J. - \ 2012
Journal of Dairy Science 95 (2012)6. - ISSN 0022-0302 - p. 3190 - 3199.
carbohydrate-composition - animal performance - calf diets - concentrate - milk - provision - mucosa - fermentation - frequency - drinking
The experiment was designed to study the importance of early rumen development and of the composition of solid feed intake on growth performance and abomasal health in milk-fed veal calves. One hundred and six Holstein-Friesian male calves were included in the experiment, and studied during 2 successive 12-wk periods (period 1 and period 2). In a 2 × 2 factorial arrangement, effects of partially replacing milk replacer by solid feed during period 1 and partially replacing dry matter (DM) intake from maize silage and barley straw by concentrate during period 2 were tested. Solid feed during period 1 consisted of maize silage, barley straw, and concentrate (25:25:50 on a DM basis). Solid feed during period 2 consisted of maize silage and barley straw (50:50 ratio on DM basis) for the nonconcentrate groups, and maize silage, barley straw and concentrates (25:25:50 on a DM basis) for the concentrate groups. At the end of period 1 (n = 16) and at the end of period 2 (n = 90), parameters of animal performance, rumen development, rumen fermentation, ruminal drinking, and abomasal damage were examined. Partially replacing milk replacer by solid feed during period 1 resulted in early rumen development (ERD) at the end of period 1, characterized by increased rumen weight, and an increased epithelial and absorptive surface area. Both ERD and partially replacing roughage by concentrates in period 2 increased the rumen development score at the end of period 2. Although ERD calves consumed more solid feed and less milk replacer during period 1 and 2 than non-ERD calves, carcass weight gains at 25 wk were identical, and utilization of the solid feed provided appeared similar to that of milk replacer. Partially replacing roughage by concentrates in period 2 increased dressing percentage and warm carcass weight. Plaque formation at the rumen mucosa was unaffected by ERD or partially replacing roughage by concentrates and generally low in all calves. The prevalence of large scars in the abomasum in ERD calves was decreased compared with non-ERD calves. This may indicate that ERD provided protection against abomasal lesions. In conclusion, early compared with late rumen development improves feed utilization and may be beneficial for abomasal health
Characterization of milk fatty acids based on genetic and herd parameters
Heck, J.M.L. ; Valenberg, H.J.F. van; Bovenhuis, H. ; Dijkstra, J. ; Hooijdonk, A.C.M. van - \ 2012
Journal of Dairy Research 79 (2012)1. - ISSN 0022-0299 - p. 39 - 46.
bovine-milk - dairy-cows - mammary-gland - methane production - lactation stage - linseed oil - odd-chain - concentrate - diet - supplementation
The objective of this study was to characterize the fatty acids (FA) in milk based on genetic and herd parameters to investigate the origin of the different FA in milk. Milk samples of 1912 Dutch Holstein-Friesian cows were analysed for 39 different FA including odd and branched-chain fatty acids. The proportion of variation caused by genetic and herd effects was calculated. In addition, genetic and herd correlations among the fatty acids were estimated and a clustering technique was used to visualise these correlations. The results indicated that in Dutch milk C12:0 is not completely synthesised de novo but also partly blood derived. It was suggested that C20:0 in milk is formed from the action of elongase enzymes on C18:0 and that the odd-chain FA C5:0-C13:0 and a part of C15:0 and C17:0 are synthesised de novo while the other part of C15:0 and C17:0 is blood derived. Furthermore, this work gives an overview of the opportunities to change the concentration of individual FA both by breeding and feeding. It is clearly shown that the extent to which the individual FA can be changed varies greatly and is dependent on the origin of the different FA in milk.
Kinetics of ferrous iron oxidation by batch and continuous cultures of thermoacidophilic Archaea at extremely low pH of 1.1–1.3
Gonzalez-Contreras, P.A. ; Weijma, J. ; Buisman, C.J.N. - \ 2012
Applied Microbiology and Biotechnology 93 (2012)3. - ISSN 0175-7598 - p. 1295 - 1303.
sulfolobus-metallicus - acidianus-sulfidivorans - metallosphaera-sedula - microorganisms - concentrate - pyrite - chalcopyrite - biooxidation - acidophiles - enrichment
The extreme acid conditions required for scorodite (FeAsO4·2H2O) biomineralization (pH below 1.3) are suboptimal for growth of most thermoacidophilic Archaea. With the objective to develop a continuous process suitable for biomineral production, this research focuses on growth kinetics of thermoacidophilic Archaea at low pH conditions. Ferrous iron oxidation rates were determined in batch-cultures at pH 1.3 and a temperature of 75°C for Acidianus sulfidivorans, Metallosphaera prunea and a mixed Sulfolobus culture. Ferrous iron and CO2 in air were added as sole energy and carbon source. The highest growth rate (0.066 h-1) was found with the mixed Sulfolobus culture. Therefore, this culture was selected for further experiments. Growth was not stimulated by increase of the CO2 concentration or by addition of sulphur as an additional energy source. In a CSTR operated at the suboptimal pH of 1.1, the maximum specific growth rate of the mixed culture was 0.022 h-1, with ferrous iron oxidation rates of 1.5 g L-1 d-1. Compared to pH 1.3, growth rates were strongly reduced but the ferrous iron oxidation rate remained unaffected. Influent ferrous iron concentrations above 6 g L-1 caused instability of Fe2+ oxidation, probably due to product (Fe3+) inhibition. Ferric-containing, nano-sized precipitates of K-jarosite were found on the cell surface. Continuous cultivation stimulated the formation of an exopolysaccharide-like substance. This indicates that biofilm formation may provide a means of biomass retention. Our findings showed that stable continuous cultivation of a mixed iron-oxidizing culture is feasible at the extreme conditions required for continuous biomineral formation.
Jatropha seed protein functional properties for technical applications
Lestari, D. ; Mulder, W.J. ; Sanders, J.P.M. - \ 2011
Biochemical Engineering Journal 53 (2011)3. - ISSN 1369-703X - p. 297 - 304.
soy protein - antinutritional factors - curcas - films - concentrate - interfaces - extraction - oilseed - plant - foams
Jatropha press cake, by-product after oil expression from Jatropha seeds, contains 24–28% protein on dry basis. Objectives of this research were to investigate functional properties, such as solubility, emulsifying, foaming, film forming, and adhesive properties, of Jatropha press cake proteins and compared those with relevant industrial proteins. From our study, we found that protein extracted from press cake proteins had a solubility of about 90% above pH 9. Emulsifying properties of press cake protein were comparable to sodium caseinates and reached the highest value at pH 9–10. Jatropha proteins formed films with tensile strength of 0.4–1.8 MPa with 10–75% elongation, which were below soy protein or wheat-gluten. Further oil removal from press cake decreased emulsifying properties, while increased foaming and adhesive properties of the extracted proteins. Protein extracted from de-oiled press cake showed better foaming properties than sodium caseinate at pH 10, but lower than egg white protein at all pH. Furthermore, press cake protein showed better adhesive properties than casein adhesives at the same dry matter content. Based on these results, Jatropha press cake protein showed most promising results on adhesive and emulsifying properties, which indicate the potential of Jatropha press cake protein as emulsifier or paper adhesive.
Dietary Energy Source in Dairy Cows in Early Lactation: Energy Partitioning and Milk Composition
Knegsel, A.T.M. van; Brand, H. van den; Dijkstra, J. ; Straalen, W.M. van; Heetkamp, M.J.W. ; Tamminga, S. ; Kemp, B. - \ 2007
Journal of Dairy Science 90 (2007)3. - ISSN 0022-0302 - p. 1467 - 1476.
fatty-acid-composition - follicular development - metabolic-disorders - ovarian-function - cattle - balance - digestion - glucose - concentrate - hormones
Metabolic problems related to negative energy balance suggest a role for the balance in supply of lipogenic and glucogenic nutrients. To test the effect of lipogenic and glucogenic nutrients on energy partitioning, energy balance and nitrogen balance of 16 lactating dairy cows were determined by indirect calorimetry in climate respiration chambers from wk 2 to 9 postpartum. Cows were fed a diet high in lipogenic nutrients or a diet high in glucogenic nutrients from wk 3 prepartum until wk 9 postpartum. Diets were isocaloric (net energy basis) and equal in intestinal digestible protein. There was no effect of diet on metabolizable energy intake and heat production. Cows fed the lipogenic diet partitioned more energy to milk than cows fed the glucogenic diet [1,175 ± 18 vs. 1,073 ± 12 kJ/(kg0.75·d)] and had a higher milk fat yield (1.89 ± 0.02 vs. 1.67 ± 0.03 kg/d). The increase in milk fat production was caused by an increase in C16:0, C18:0, and C18:1 in milk fat. No difference was found in energy retained as body protein, but energy mobilized from body fat tended to be higher in cows fed the lipogenic diet than in cows fed the glucogenic diet [190 ± 23 vs. 113 ± 26 kJ/(kg0.75·d)]. Overall, results demonstrate that energy partitioning between milk and body tissue can be altered by feeding isocaloric diets differing in lipogenic and glucogenic nutrient content.
Milk Odd- and Branched-Chain Fatty Acids in Relation to the Rumen Fermentation Pattern
Vlaeminck, B. ; Fievez, V. ; Tamminga, S. ; Dewhurst, R.J. ; Vuuren, A.M. van; Brabander, D. de; Demeyer, D. - \ 2006
Journal of Dairy Science 89 (2006)10. - ISSN 0022-0302 - p. 3954 - 3964.
lactating dairy-cows - in-vitro - fish-oil - linseed oil - bacteria - concentrate - digestion - forage - diets - metabolism
The objectives of this study were 1) to determine whether a relationship exists between molar proportions of volatile fatty acids in the rumen and milk odd-and branched-chain fatty acid concentrations (i.e., iso C13:0, anteiso C13:0, iso C14:0, C15:0, iso C15:0, anteiso C15:0, iso C16:0, C17:0, iso C17:0, anteiso C17:0, and cis-9 C17:1); and 2) to evaluate the accuracy of prediction of the latter equations using an independent data set. For development of the regression equations, individual cow data from 10 feeding experiments with rumen-fistulated dairy cows were used, resulting in a data set of 148 observations. Milk odd- and branched-chain fatty acids were closely related to the molar proportions of acetate (SE = 15.3 mmol/mol), propionate (SE = 14.7 mmol/mol), and butyrate (SE = 9.2 mmol/mol). These regression equations were further validated using data from the literature (n = 14). Evaluation of these prediction equations using the independent data set resulted in a root mean square prediction error of 3.0, 9.0, and 8.9% of the observed mean for acetate, propionate, and butyrate, respectively. In addition, less then 5% of the mean square prediction error was due to line bias. This suggests that the currently developed prediction equations based on milk odd- and branched-chain fatty acids show potential to predict molar proportions of individual volatile fatty acids in the rumen
Risk factors for interdigital dermatitis and heel erosion in dairy cows kept in cubicle houses in The Netherlands
Somers, J.G.C.J. ; Frankena, K. ; Noordhuizen-Stassen, E.N. ; Metz, J.H.M. - \ 2005
Preventive Veterinary Medicine 71 (2005)1-2. - ISSN 0167-5877 - p. 23 - 34.
papillomatous digital dermatitis - sole hemorrhages - floor systems - horn erosion - cattle - lameness - prevalence - concentrate - disorders - lesions
Risk factors concerning both the pasture and housing seasons for interdigital dermatitis and heel-horn erosion (IDHE) were studied in dairy cows in a cross-sectional study in The Netherlands. The study population included 2326 cows (41 herds) and 2751 cows (46 herds) for the pasture and housing seasons, respectively. Of these animals, 545 (23%) showed serious lesions of IDHE (stages 2 and 3) at the end of the pasture season and 1269 (46%) during housing. Logistic regression of the pasture study indicated that increased parity, solid concrete floor, restricted grazing time, and herd trimming at long intervals were associated with an increased odds of IDHE, while dry cows and lactating cows within 30 days after calving as well as cows on a slatted floor with manure scraper, and grassland with mixed type of soil were associated with lower odds. In the housing study, odds of IDHE increased with parity, administering low- or medium-energy roughage, and introduction of dry cows into the lactating herd at >2 weeks before calving. The presence of long cubicles, knee-bumpers installed in cubicles as well as rearing calves and heifers within the dairy cows¿ accommodation decreased the odds of IDHE.
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