Odling av majs för att användas som foder till mjölkkor har blivit allt populärare, därav ökar de... more Odling av majs för att användas som foder till mjölkkor har blivit allt populärare, därav ökar den svenska majsarealen år från år. Men svensk majsodling befinner sig i majsens nordligaste odlingsområde, därför är det extra viktigt att välja rätt sort och skörda majsen vid rätt tidpunkt. Väljer man en allt för sen sort, riskerar man ett lågt fodervärde och stora förluster vid ensilering på grund av avgång av pressvatten. En tidig sort kan ge en hög stärkelsehalt men samtidigt finns det risk att man skördar allt för sent, vilket ger ett hygieniskt dåligt ensilage på grund av hög andel torrsubstans (TS), vilket leder till packningsproblem i silon. Följer man amerikanska och danska rekommendationer bör majsen skördas när TS är mellan 28 och 35 procent. Det innebär ofta att majsens stärkelsehalt överstiger 30 procent av TS, vilket innebär ett bra fodervärde. Vid val av majssort bör man där för välja en sort som man med stor sannolikhet går att skörda inom det önskade intervallet.
The objective of this study was to evaluate two near-infrared reflectance spectroscopy (NIRS) app... more The objective of this study was to evaluate two near-infrared reflectance spectroscopy (NIRS) applications and different laboratory methods for determining indigestible neutral detergent fibre (iNDF) and organic matter digestibility (OMD) of forage maize hybrids harvested at high latitudes. Different in situ and in vitro methods have been used in calibrations of NIRS for routine determinations of forage feed value in the Nordic countries. Swedish and Finnish NIRS calibrations of iNDF generated biased estimates of low precision of iNDF determined in situ. All methods used to predict OMD in forage maize systematically underestimated the observed OMD calculated from the in situ determined value of iNDF. Digestibility was determined with least precision based on the enzymatic in vitro procedure. Values of OMD based on the in vitro incubation in buffered rumen fluid displayed the smallest error among the laboratory methods. The NIRS calibration developed with the forage maize samples of ...
ABSTRACT An experiment was conducted to examine how including NaOH-treated wheat in the diet of d... more ABSTRACT An experiment was conducted to examine how including NaOH-treated wheat in the diet of dairy cows affects dry matter intake (DMI) and milk production, using diets based on rolled wheat and an oat/barley mixture for comparative purposes. The study was based on 24 Swedish Red dairy cows that were 147±51 d in milk (DIM), with an average milk yield of 31±5.6 kg/d and a live weight of 611±66 kg. The cows were blocked according to DIM and randomly assigned to six replicated 4×4 balanced Latin squares with 21-d experimental periods. The diets were fed as total mixed rations consisting of grass silage supplemented with concentrates in a ratio of 52:48. Four diets were examined: an oat/barley mixture (OBM), 100% rolled wheat (RW) of which 50 (SHW/RW) or 100% was replaced with NaOH treated wheat (SHW). Total tract digestibility was determined using acid-insoluble ash as an internal marker. Ruminal degradation parameters for the cereal feeds were estimated using an in vitro gas production technique and modelling approach. Increased inclusion of NaOH-treated wheat did not affect DMI or milk production. NaOH-treatment reduced (P<0.01) milk protein concentrations and milk N efficiency (P<0.05), and tended (P=0.10) to decrease milk protein yield. There were no differences between the OBM and RW diets in terms of DMI, milk production, or milk composition. Increased levels of NaOH-treated wheat in the diet caused linear increases (P<0.05) in faecal N output and estimated urinary volumes and decreasing milk urea concentrations. This indicates that NaOH-treatment increased the mineral load of the diet and shifted starch digestion from the rumen to the small and large intestines. These results were consistent with the lower observed in vitro ruminal digestion rates of NaOH-treated wheat. It is concluded that the oat/barley mixture and the rolled wheat had comparable feeding values despite the higher tabulated metabolisable energy and protein concentrations of the latter. It is concluded that NaOH-treatment of wheat has no beneficial effects that justify its use.
Journal of the Science of Food and Agriculture, 2008
Page 1. Journal of the Science of Food and Agriculture J Sci Food Agric 88:199206 (2008) Compari... more Page 1. Journal of the Science of Food and Agriculture J Sci Food Agric 88:199206 (2008) Comparison of in vitro degradation of temperate forages using the gas production and filter bag techniques M ˚arten Hetta,1∗ Hege ...
A 2 × 2 factorial feeding experiment was conducted to examine the effects of varying the maturity... more A 2 × 2 factorial feeding experiment was conducted to examine the effects of varying the maturity level of the grass used to prepare silage and the nature of concentrate starch source and their interactions on dry matter intake (DMI), diet digestibility, energy corrected milk (ECM) production and milk composition in dairy cows. Twenty-eight multiparous Swedish Red dairy cows, 133 ± 45 days in milk (DIM), with an average milk yield of 30 ± 4 kg/day and a live weight of 624 ± 69 kg were blocked by DIM and randomly assigned to seven replicated balanced 4 × 4 Latin squares with four 21-day experimental periods. The experimental diets consisted of four total mixed rations (TMR) consisting of early-cut grass silage (EGS) supplemented with either barley- or maize-based concentrate and late-cut grass silage (LGS) supplemented with either barley- or maize-based concentrate. All TMR contained identical proportions of forage (51%) and concentrate (49%). Total tract digestibility was estimated by determining indigestible NDF (iNDF) concentrations in feeds and faeces and using iNDF as an internal marker. The feeds' ruminal degradation parameters were determined using both in situ (nylon bag) and in vitro (gas production (GP)) techniques. Cows offered diets containing EGS had greater (P < 0.001) daily dry matter (DM) intakes, ECM yields and total tract digestibilities for DM and organic matter (OM), but these were not affected by the nature of the concentrate starch source. No interaction between the maturity of the silage and the nature of the concentrate starch source was observed for DMI, diet digestibility or ECM yield. Both grass silages and concentrates had similar rates of ruminal degradation of NDF when measured in situ. The in situ DM (P < 0.001) and starch (P = 0.001) degradation rates of barley-based concentrate were greater than those for maize-based concentrate. In vitro OM GP rates and extents were similar for both concentrate feeds. The results showed that diets containing EGS offered better animal performance and diet digestibility than diets containing LGS. The concentrate starch source did not affect animal performance, but total NDF digestibility was better with diet containing barley- than maize-based concentrate.
ABSTRACT An experiment was conducted to study the rumen digestion characteristics of whole feeds ... more ABSTRACT An experiment was conducted to study the rumen digestion characteristics of whole feeds (WF) and the neutral detergent fibre (aNDF) and neutral detergent soluble (NDS) fractions of a range of starch-rich feeds using an automated in vitro gas production (GP) technique. In addition, the ruminal digestibility values predicted from the GP data were compared to previously acquired in vivo data. Nine feeds with starch concentrations ranging from 389 to 712 g/kg dry matter and with known in vivo digestibilities were subjected to neutral detergent extraction. The GP for each WF and the corresponding aNDF fractions were measured in duplicate in buffered rumen fluid during 72 h on two occasions. The fermentation residues were collected and analyzed for aNDF concentration to estimate their true organic matter (OM) and NDF digestibility. The GP from the NDS fraction was calculated by subtracting the GP from the aNDF fraction from the GP of the WF. A three-pool Gompertz model was fitted to the GP profiles (R2 = 0.99) and a two compartment, mechanistic and dynamic rumen model was used to predict the digestibility of the potentially digestible feed fraction and the effective digestion rate (kd). The true OM and NDF digestibility determined for the WF ranged from 0.804 to 1.011 and from 0.362 to 1.107, respectively. The NDF digestibility determined for the aNDF fraction ranged from 0.410 to 0.985. The effective kd values estimated using GP data varied from 0.118 to 0.282/h for the WF and from 0.123 to 0.301/h for the NDS fraction, and were less (P<0.05) for maize compared to small grains (SG) but did not differ between barley and wheat (P>0.05). The effective kd values for the aNDF fraction ranged from 0.039 to 0.082/h and did not differ (P>0.05) either between maize and SG or between barley and wheat. The predicted ruminal NDS digestibility determined using GP data closely matched the in vivo data describing starch digestion (R2 = 0.81). The effective kd values for the WF were strongly related (R2 = 0.94) to those for the NDS fractions. The results indicate that when measured with the GP technique, the differences in the digestion characteristics of maize and small grains are less than those previously reported in studies using the in situ method. It is concluded that the predicted NDS digestibility determined using GP data corresponded well to the in vivo starch digestibility. Our results also suggest that the first order digestion rates of NDS (starch) in starch-rich feeds can be accurately determined by incubating WF samples in the GP system and using the GP kinetic data in a dynamic, mechanistic rumen model.
ABSTRACT A crop model and environmental data were used to simulate genotype-environment interacti... more ABSTRACT A crop model and environmental data were used to simulate genotype-environment interactions for commercial forage maize cultivars. Genotype parameters defined by the MAISPROQ model were calibrated to observed aboveground dry matter (DM) yield and quality (concentrations of DM and starch) data from Swedish field experiments 2009–2011 on four forage maize cultivars with different maturation rates (Avenir, Isberi, Jasmic and Burli). The model calibration predictability (coefficient of determination, R 2) ranged from 0.18 to 0.45 for yield and 0.40 to 0.86 for quality. The corresponding values for validation were in a similar range for the growth model but less for the quality model (0.36–0.38 and 0.25–0.54, respectively). Thereafter the model was used to assess the cultivar performance for different locations and future climate conditions. The simulated DM yield averaged for 2003–2009 varied between 5% and 25% among nine locations in Sweden due to differences in weather conditions, depending on cultivar. The proportion of years with successful harvest (34% DM concentration being achieved by 31 October) varied between 60% and 100% for the early cultivar (Avenir) and 0% and 70% for the late cultivar (Jasmic). Under future climate conditions, harvest of the early-maturing cultivar (Avenir) will occur earlier (by up to 19 days in Lund [55.6°N] and 24 days in Uppsala [59.8°N] by 2085), but with unchanged or even slightly decreased DM yields compared with current levels. The starch concentration will remain almost unchanged in Lund but increase in Uppsala, especially for the late-maturing cultivar. We regard the model predictions of quality to be reasonably satisfactory, whereas those of DM yields are less reliable due to observations for calibration being available only for the period after flowering. Therefore, more frequent sampling in the early growing season is required to improve the predictive power of the model, especially for DM yield.
The objectives of this investigation were to study the effects of marginal site conditions and hy... more The objectives of this investigation were to study the effects of marginal site conditions and hybrid on plant development, agronomic performance and nutritive characteristics of forage maize (Zea mays L.) at high latitudes. Field experiments were conducted in 2008 and 2009 at three experimental sites, Kristianstad, Skara and Västerås, at increasing latitudes from 55°–60° N. Experimental design used two replicated
Acta Agriculturae Scandinavica, Section A - Animal Science, 2010
The effects of including wheat in the total mixed rations of dairy cows were evaluated using a 4×... more The effects of including wheat in the total mixed rations of dairy cows were evaluated using a 4×4 Latin square dose response experiment with 28 dairy cows (Swedish red). The animals were averaging 150 days in milk at the start of the experiment. Diets consisted of mixtures of maize and grass silage with wheat grain at four levels (8, 16,
Odling av majs för att användas som foder till mjölkkor har blivit allt populärare, därav ökar de... more Odling av majs för att användas som foder till mjölkkor har blivit allt populärare, därav ökar den svenska majsarealen år från år. Men svensk majsodling befinner sig i majsens nordligaste odlingsområde, därför är det extra viktigt att välja rätt sort och skörda majsen vid rätt tidpunkt. Väljer man en allt för sen sort, riskerar man ett lågt fodervärde och stora förluster vid ensilering på grund av avgång av pressvatten. En tidig sort kan ge en hög stärkelsehalt men samtidigt finns det risk att man skördar allt för sent, vilket ger ett hygieniskt dåligt ensilage på grund av hög andel torrsubstans (TS), vilket leder till packningsproblem i silon. Följer man amerikanska och danska rekommendationer bör majsen skördas när TS är mellan 28 och 35 procent. Det innebär ofta att majsens stärkelsehalt överstiger 30 procent av TS, vilket innebär ett bra fodervärde. Vid val av majssort bör man där för välja en sort som man med stor sannolikhet går att skörda inom det önskade intervallet.
The objective of this study was to evaluate two near-infrared reflectance spectroscopy (NIRS) app... more The objective of this study was to evaluate two near-infrared reflectance spectroscopy (NIRS) applications and different laboratory methods for determining indigestible neutral detergent fibre (iNDF) and organic matter digestibility (OMD) of forage maize hybrids harvested at high latitudes. Different in situ and in vitro methods have been used in calibrations of NIRS for routine determinations of forage feed value in the Nordic countries. Swedish and Finnish NIRS calibrations of iNDF generated biased estimates of low precision of iNDF determined in situ. All methods used to predict OMD in forage maize systematically underestimated the observed OMD calculated from the in situ determined value of iNDF. Digestibility was determined with least precision based on the enzymatic in vitro procedure. Values of OMD based on the in vitro incubation in buffered rumen fluid displayed the smallest error among the laboratory methods. The NIRS calibration developed with the forage maize samples of ...
ABSTRACT An experiment was conducted to examine how including NaOH-treated wheat in the diet of d... more ABSTRACT An experiment was conducted to examine how including NaOH-treated wheat in the diet of dairy cows affects dry matter intake (DMI) and milk production, using diets based on rolled wheat and an oat/barley mixture for comparative purposes. The study was based on 24 Swedish Red dairy cows that were 147±51 d in milk (DIM), with an average milk yield of 31±5.6 kg/d and a live weight of 611±66 kg. The cows were blocked according to DIM and randomly assigned to six replicated 4×4 balanced Latin squares with 21-d experimental periods. The diets were fed as total mixed rations consisting of grass silage supplemented with concentrates in a ratio of 52:48. Four diets were examined: an oat/barley mixture (OBM), 100% rolled wheat (RW) of which 50 (SHW/RW) or 100% was replaced with NaOH treated wheat (SHW). Total tract digestibility was determined using acid-insoluble ash as an internal marker. Ruminal degradation parameters for the cereal feeds were estimated using an in vitro gas production technique and modelling approach. Increased inclusion of NaOH-treated wheat did not affect DMI or milk production. NaOH-treatment reduced (P<0.01) milk protein concentrations and milk N efficiency (P<0.05), and tended (P=0.10) to decrease milk protein yield. There were no differences between the OBM and RW diets in terms of DMI, milk production, or milk composition. Increased levels of NaOH-treated wheat in the diet caused linear increases (P<0.05) in faecal N output and estimated urinary volumes and decreasing milk urea concentrations. This indicates that NaOH-treatment increased the mineral load of the diet and shifted starch digestion from the rumen to the small and large intestines. These results were consistent with the lower observed in vitro ruminal digestion rates of NaOH-treated wheat. It is concluded that the oat/barley mixture and the rolled wheat had comparable feeding values despite the higher tabulated metabolisable energy and protein concentrations of the latter. It is concluded that NaOH-treatment of wheat has no beneficial effects that justify its use.
Journal of the Science of Food and Agriculture, 2008
Page 1. Journal of the Science of Food and Agriculture J Sci Food Agric 88:199206 (2008) Compari... more Page 1. Journal of the Science of Food and Agriculture J Sci Food Agric 88:199206 (2008) Comparison of in vitro degradation of temperate forages using the gas production and filter bag techniques M ˚arten Hetta,1∗ Hege ...
A 2 × 2 factorial feeding experiment was conducted to examine the effects of varying the maturity... more A 2 × 2 factorial feeding experiment was conducted to examine the effects of varying the maturity level of the grass used to prepare silage and the nature of concentrate starch source and their interactions on dry matter intake (DMI), diet digestibility, energy corrected milk (ECM) production and milk composition in dairy cows. Twenty-eight multiparous Swedish Red dairy cows, 133 ± 45 days in milk (DIM), with an average milk yield of 30 ± 4 kg/day and a live weight of 624 ± 69 kg were blocked by DIM and randomly assigned to seven replicated balanced 4 × 4 Latin squares with four 21-day experimental periods. The experimental diets consisted of four total mixed rations (TMR) consisting of early-cut grass silage (EGS) supplemented with either barley- or maize-based concentrate and late-cut grass silage (LGS) supplemented with either barley- or maize-based concentrate. All TMR contained identical proportions of forage (51%) and concentrate (49%). Total tract digestibility was estimated by determining indigestible NDF (iNDF) concentrations in feeds and faeces and using iNDF as an internal marker. The feeds' ruminal degradation parameters were determined using both in situ (nylon bag) and in vitro (gas production (GP)) techniques. Cows offered diets containing EGS had greater (P < 0.001) daily dry matter (DM) intakes, ECM yields and total tract digestibilities for DM and organic matter (OM), but these were not affected by the nature of the concentrate starch source. No interaction between the maturity of the silage and the nature of the concentrate starch source was observed for DMI, diet digestibility or ECM yield. Both grass silages and concentrates had similar rates of ruminal degradation of NDF when measured in situ. The in situ DM (P < 0.001) and starch (P = 0.001) degradation rates of barley-based concentrate were greater than those for maize-based concentrate. In vitro OM GP rates and extents were similar for both concentrate feeds. The results showed that diets containing EGS offered better animal performance and diet digestibility than diets containing LGS. The concentrate starch source did not affect animal performance, but total NDF digestibility was better with diet containing barley- than maize-based concentrate.
ABSTRACT An experiment was conducted to study the rumen digestion characteristics of whole feeds ... more ABSTRACT An experiment was conducted to study the rumen digestion characteristics of whole feeds (WF) and the neutral detergent fibre (aNDF) and neutral detergent soluble (NDS) fractions of a range of starch-rich feeds using an automated in vitro gas production (GP) technique. In addition, the ruminal digestibility values predicted from the GP data were compared to previously acquired in vivo data. Nine feeds with starch concentrations ranging from 389 to 712 g/kg dry matter and with known in vivo digestibilities were subjected to neutral detergent extraction. The GP for each WF and the corresponding aNDF fractions were measured in duplicate in buffered rumen fluid during 72 h on two occasions. The fermentation residues were collected and analyzed for aNDF concentration to estimate their true organic matter (OM) and NDF digestibility. The GP from the NDS fraction was calculated by subtracting the GP from the aNDF fraction from the GP of the WF. A three-pool Gompertz model was fitted to the GP profiles (R2 = 0.99) and a two compartment, mechanistic and dynamic rumen model was used to predict the digestibility of the potentially digestible feed fraction and the effective digestion rate (kd). The true OM and NDF digestibility determined for the WF ranged from 0.804 to 1.011 and from 0.362 to 1.107, respectively. The NDF digestibility determined for the aNDF fraction ranged from 0.410 to 0.985. The effective kd values estimated using GP data varied from 0.118 to 0.282/h for the WF and from 0.123 to 0.301/h for the NDS fraction, and were less (P<0.05) for maize compared to small grains (SG) but did not differ between barley and wheat (P>0.05). The effective kd values for the aNDF fraction ranged from 0.039 to 0.082/h and did not differ (P>0.05) either between maize and SG or between barley and wheat. The predicted ruminal NDS digestibility determined using GP data closely matched the in vivo data describing starch digestion (R2 = 0.81). The effective kd values for the WF were strongly related (R2 = 0.94) to those for the NDS fractions. The results indicate that when measured with the GP technique, the differences in the digestion characteristics of maize and small grains are less than those previously reported in studies using the in situ method. It is concluded that the predicted NDS digestibility determined using GP data corresponded well to the in vivo starch digestibility. Our results also suggest that the first order digestion rates of NDS (starch) in starch-rich feeds can be accurately determined by incubating WF samples in the GP system and using the GP kinetic data in a dynamic, mechanistic rumen model.
ABSTRACT A crop model and environmental data were used to simulate genotype-environment interacti... more ABSTRACT A crop model and environmental data were used to simulate genotype-environment interactions for commercial forage maize cultivars. Genotype parameters defined by the MAISPROQ model were calibrated to observed aboveground dry matter (DM) yield and quality (concentrations of DM and starch) data from Swedish field experiments 2009–2011 on four forage maize cultivars with different maturation rates (Avenir, Isberi, Jasmic and Burli). The model calibration predictability (coefficient of determination, R 2) ranged from 0.18 to 0.45 for yield and 0.40 to 0.86 for quality. The corresponding values for validation were in a similar range for the growth model but less for the quality model (0.36–0.38 and 0.25–0.54, respectively). Thereafter the model was used to assess the cultivar performance for different locations and future climate conditions. The simulated DM yield averaged for 2003–2009 varied between 5% and 25% among nine locations in Sweden due to differences in weather conditions, depending on cultivar. The proportion of years with successful harvest (34% DM concentration being achieved by 31 October) varied between 60% and 100% for the early cultivar (Avenir) and 0% and 70% for the late cultivar (Jasmic). Under future climate conditions, harvest of the early-maturing cultivar (Avenir) will occur earlier (by up to 19 days in Lund [55.6°N] and 24 days in Uppsala [59.8°N] by 2085), but with unchanged or even slightly decreased DM yields compared with current levels. The starch concentration will remain almost unchanged in Lund but increase in Uppsala, especially for the late-maturing cultivar. We regard the model predictions of quality to be reasonably satisfactory, whereas those of DM yields are less reliable due to observations for calibration being available only for the period after flowering. Therefore, more frequent sampling in the early growing season is required to improve the predictive power of the model, especially for DM yield.
The objectives of this investigation were to study the effects of marginal site conditions and hy... more The objectives of this investigation were to study the effects of marginal site conditions and hybrid on plant development, agronomic performance and nutritive characteristics of forage maize (Zea mays L.) at high latitudes. Field experiments were conducted in 2008 and 2009 at three experimental sites, Kristianstad, Skara and Västerås, at increasing latitudes from 55°–60° N. Experimental design used two replicated
Acta Agriculturae Scandinavica, Section A - Animal Science, 2010
The effects of including wheat in the total mixed rations of dairy cows were evaluated using a 4×... more The effects of including wheat in the total mixed rations of dairy cows were evaluated using a 4×4 Latin square dose response experiment with 28 dairy cows (Swedish red). The animals were averaging 150 days in milk at the start of the experiment. Diets consisted of mixtures of maize and grass silage with wheat grain at four levels (8, 16,
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