Web application for the analysis and planning of dairy cow rations (KOKRA) was developed within the information system “CATTLE” which also includes the archive of regular monthly milk recording data. Application KOKRA also includes database “FEEDS” which enables the importing and storage of the results of feedstuff analyses from labs, data on the nutritive value of commercial feed mixtures, data which are entered into the database by farmers and the composition and nutritive value of different feedstuff form literature. In the application updated equations for the estimation of net energy for lactation and metabolizable protein were integrated. Additionally, the latest standards and systems for the prediction of dry matter intake, physically effective fibre, carbohydrate fractions and macro-mineral requirements were inserted. The integration of potential standard lactation curves for Slovene cattle breeds enables better planning of lactation and daily requirements of nutrients according to lactation phase and cow production potential. Application is upgraded with warnings and recommendations regarding the physiological adequacy of the diet and enables connectivity of existing databases on a farm level as also storing of planned rations.
F.15 Development of a new information system/databases
COBISS.SI-ID: 4352360Data on concentrations of Ca (n=3168), P (n=3165), K (n=1614), Mg (n=759) and Na (n=917) in farm samples of forages, which were analysed in four Slovenian laboratories during the period from the year 2000 to 2010, were gathered. The samples of grass silages, maize silages and hays contained on average 6.7, 2.1 and 5.7 g of Ca, 3.5, 2.0 and 2.6 g of P, 29.1, 9.8 and 21.0 g of K, 2.8, 1.5 and 2.4 g of Mg and 0.78, 0.17 and 0.39 g of Na per kg of dry matter, respectively. The concentrations of mineral elements were highly variable. Generally, the concentrations of mineral elements in group comprising 25% of samples with the lowest concentrations were at least two times lower when compared to group comprising 25% of samples with the highest concentrations of mineral elements. It was confirmed that grassland forage is considerably better source of mineral elements s than maize silages. Concentrations of Ca, P, K, Mg and Na in maize silages were 2.7, 1.3, 3.1, 1.6 and 3.5 times lower than in grass silages. In grassland forages high concentrations of K could be problematic due to the fact that about two thirds of grass silages and one half of hays exceeded the maximal recommended values of K for gestating cows before calving. Based on present data and literature data for the period 1990-1996 it can be assumed that the concentrations of K in grassland forages tend to increase. The relationships between concentrations of mineral elements and other forage constituents like crude protein, crude fibre or ash were poor.
B.03 Paper at an international scientific conference
COBISS.SI-ID: 4351080The results of chemical analyses of grass silage (n=1813), maize silage (n=1636) and hay (n=611) samples, which were analysed during the period from the year 2000 to 2010 in four Slovenian laboratories were collected. Samples of grass silage, maize silage and hay contained on average 442, 378 and 870 g of dry matter per kg. On dry matter basis they contained 5.89, 6.50 and 5.05 MJ per kg of net energy for lactation (NEL). Recommended minimal concentrations of NEL for dairy cows (6.1, 6.5 and 5.5 MJ per kg of dry matter for grass silage, maize silage and hay) were reached by 28.5 % of grass silages, by 51.4 % of maize silages and by 16.1 % of hays. In grass silage and hay no increase in concentration of NEL was observed during the period from the year 2000 to 2010 while in maize silage it increased. Upper recommended dry matter concentrations (450 and 400 g per kg for grass and maize silages) were exceeded by 43.8 % of grass and 28.1 % of maize silages. On the basis of concentration of ash it was estimated that 16.8 % of grass silages were contaminated by soil () 130 g of ash per kg dry matter).
B.03 Paper at an international scientific conference
COBISS.SI-ID: 3709800The aim of the paper was to examine the reliability of NIRS for estimating the concentration of net energy for lactation (NEL) in forages and to compare the results to those obtained on the basis of chemical composition and digestibility coefficients from German DLG tables. Separate NIRS equations for hay, grass silage and fresh forage and common equation for all forages were developed on the basis of 137 samples of hay, 141 samples of grass silage, 139 samples of fresh forage or 472 pooled samples. NEL concentrations which were assessed on the basis of chemical composition and in vitro gas production were used as reference values. Gas production was measured by the means of Hohenheim gas test, incubating forage samples with rumen liquor for 24 hours in graduated syringes. Chemical composition of forages was determined by standard laboratory procedures. Separate validation sets comprised of 30 samples were used to assess reliability of the method. The determination coefficient of cross validation (R2CV) and standard error of cross validation (SECV) for NIRS calibrations ranged from 0.81 to 0.90 and from 0.16 to 0.24 MJ NEL kg-1 dry matter (DM). NIRS estimates for samples from validation sets were much closer to corresponding in vitro values than the estimates based on digestibility coefficients from tables. In case of NIRS the average absolute individual deviations from in vitro values for hay, grass silage and fresh forage were 0.13, 0.19 and 0.15 while in case of DLG tables they were 0.29, 0.42 and 0.27 MJ NEL kg-1 DM. In comparison to DLG tables the maximal deviations from in vitro values were halved by the use of NIRS calibrations. The reliability of NIRS calibration developed on pooled set of hay, grass silage and fresh forage samples was superior to those obtained on separate sets except for hay.
B.04 Guest lecture
COBISS.SI-ID: 3964264Five different procedures of estimation of energy value of forages were tested on the basis of independant validation test comprising samples of fresh forage (n=19), grass silages (n=6) and hay (n=1) with known in vivo assessed digestibilities. The following procedures were examined: A – regression equations which require components of Weende analyses and were developed on the basis of gas production obtained by the means of Hohenheim gas test (VP), B – direct NIRS calibrations for ME and NEL, which were developed on the basis of sample composition and VP, C – Weende analyses and NIRS calibrations for VP and acid detergent insoluble fibre (KDVOS), in second step calculation according to GfE (2008) equation, D - NIRS calibrations for Weende analysis, VP and KDVOS, in second step calculation according to GfE (2008) equation, E – Weende analyses and DLG tables. In vivo estimated NEL concentrations were in procedures A, B, C, D and E on average underestimated for 0.04 ± 0.36, 0.15 ± 0.34, 0.10 ± 0.32, 0.13 ± 0.29 and 0.13 ± 0.41 MJ NEL kg-1 dry matter. The lowest average absolute deviations from in vivo estimates were obtained by procedures A and D (0.27 MJ NEL kg-1 dry matter) followed by procedures C, B and E (0.28, 0.31 in 0.32 MJ NEL kg-1 dry matter). For laboratories where NIRS calibrations for gas production obtained by the means of Hohenheim gas test are not available regression equations for prediction of energy value on the basis of the results of Weende analyses were suggested. Equations are based on 303 samples for which the concentrations of ME and NEL were assessed on the basis of their composition and VP according to equation GfE (2008). It was found that these equations are more reliable than forage evaluation on the basis of chemical composition and DLG tables.
B.03 Paper at an international scientific conference
COBISS.SI-ID: 3953256