Bestimmung der Futteraufnahme, Futterselektion und Verdaulichkeit weidender Mastrinder auf ökologisch bewirtschaftetem Ansaat- und Dauergrünland

In zwei aufeinander folgenden Jahren wurden Untersuchungen zu Fragen der Nutzung von n-Alkanen als Marker zur Bestimmung der Höhe der Futteraufnahme durchgeführt. Dazu standen Flächen von extensiv geführtem Grünland zur Verfügung, die entweder keiner oder einer Düngung mit 70 kg N/ha aus Gülle unterlagen. Von diesen Flächen wurde sowohl Weidefutter als auch Grassilage gewonnen und in jeweils 2 Bilanzversuchen an weibliche Rinder verfüttert. Im Zuge dieser Versuche wurden die Verdaulichkeiten der Rohnährstoffe und die Energiekonzentrationen ermittelt. Die aus den Bilanzversuchen ermittelten Wiederfindungen für einzelne n-Alkane wurden zur Schätzung der Futteraufnahme weidender Rinder verwendet. Zudem wurde versucht, aus einer Gegenüberstellung der Alkanmuster in einzelnen Pflanzenarten und dem Kot der Tiere Aussagen zur Futterselektion und der Verdaulichkeit der organischen Substanz des Weideaufwuchses der Tiere zu treffen. Die Ergebnisse dieser Studie zeigen, dass die Bestimmung der Wiederfindung von Alkanen für den jeweiligen Weideaufwuchs erforderlich ist, um die Fehler bei der Schätzung der Futteraufnahme zu minimieren. Es bestehen erheblich Unterschiede in den Wiederfindungen der Alkane zwischen den Jahren und zwischen den beiden verwendeten Grasprodukten. Eine Beurteilung der Futterselektion auf der Grundlage der Alkanmuster scheint zum derzeitigen Wissensstand nicht möglich zu sein. Die Unterschiede in der Düngung führten nicht zu Veränderungen in der Qualität der Aufwüchse. Die Erzielung einer bestimmten Weideleistung ist damit im Wesentlichen davon abhängig, dass die Tierzahl der Aufwuchsmasse angepasst ist

Practical Application of a One-Parameter Approach to Assess the Accuracy of Two Different Estimates of Diet Composition in Sheep

The composition of ingested herbage mixtures can be estimated using the alkane technique (Dove & Moore, 1995). Until now, the accuracy of the estimates is assessed by linear regression of estimated and actual proportions of the dietary components. The authors presented an approach to compare actual and estimated diet compositions using only one parameter named Distance (D; Elwert & Rodehutscord, 2005), thus enabling a statement regarding the similarity of estimated and known diet composition. In a feeding trial with sheep, diet composition was estimated using two different levels of information. The accuracy of the two estimates was assessed and compared using Distance

Theoretical Considerations on a One-Parameter Approach to Compare Actual and Estimated Compositions of Multi-Component Diets

The composition of ingested herbage mixtures can be estimated using the alkane technique (Dove & Moore, 1995), with the accuracy of the estimate assessed by linear regression of estimated and actual proportions of the dietary components (Dove, 1992). However, although the linear regression might not differ from the line of equality, large discrepancies may occur within individual components (Hoebee et al., 1998). This paper presents an approach to compare actual and estimated diet compositions using only one parameter

Performance of Dairy Cows, Feed Quality and N Balance on Pasture Systems with or without Mineral N Fertilizer

In a 2 year experiment, two levels of mineral N fertilization (nil and 225 kg N/ha) on pasture were checked for their effects on pasture yield and quality as well as for performance of dairy cows. Twenty six cows were used in each treatment and the stocking density was adapted to previous results on pasture growth rates. Cows were kept on pasture during summer and grass silages were harvested from the respective experimental areas for winter feeding periods. Digestibility of organic matter in these silages, determined in wether sheep, was always higher in those silages harvested from pasture without mineral N fertilization, probably due to higher proportions of white clover. Consequently, roughage intake in winter was higher in cows receiving silage from these plots. There was no effect of level of fertilizer on milk yield or fat and protein concentration of the milk. N balance calculated as a difference of N input from concentrates and fertilizer and N output from animal products was 235 and -19 kg N/(ha•y) for the treatments with and without mineral N fertilizer, respectively, when N fixing by legumes and N deposition was not included. Mean nitrate concentration in the soil (0 to 150 cm) was 130 kg N/ha when N fertilizer was applied but only 39 kg N/ha when N fertilizer was omitted

Effects of added phytase on growth performance, carcass traits, and tibia ash of broiler chickens fed diets with reduced amino acid, crude protein, and phosphorus concentration

This experiment was conducted to investigate the effect of phytase supplementation in diets reduced in amino acids (AA), crude protein (CP), and phosphorus (P) on growth performance, carcass traits, and tibia ash of broiler chickens. A total of 2,240 unsexed Ross 308 broiler chickens were used in 56 floor pens with 40 birds each and fed one of eight dietary treatments in seven replicates until 35 d of age. A positive control (PC) diet and diets with dietary AA/CP level reduced by 2, 4, and 6% were used with and without supplementation with 1,500 FTU phytase/kg. Starter, grower, and finisher diets were fed from d 1 to 10, d 10 to 25, and d 25 to 35, respectively. For the total period, no significant interaction effects between AA/CP level and phytase supplementation were detected for any measured traits. The ADG, ADFI, carcass weight, breast weight, and tibia ash weight were lower and FCR was higher compared to the PC diets when the AA/CP level was reduced by more than 2%. Phytase supplementation increased ADG, ADFI, final BW, and tibia ash weight. Tibia ash measurements showed that birds were adequately supplied with digestible phosphorus in all treatments, although dietary phosphorus and calcium were reduced in the phytase-supplemented diets. This enabled the feeding of broiler chickens without mineral phosphate supplements in grower and finisher diets. The results showed that supplementation with 1,500 FTU phytase/kg diminished the growth-decreasing effect of lower dietary AA/CP at all reduction steps.info:eu-repo/semantics/publishedVersio

Züchtung und Agronomie neuartiger, Vicin-armer Ackerbohnen und Einsatz als einheimisches Eiweißfutter

In Deutschland sind Ackerbohnen nach Erbsen und Lupinen gemessen an der Anbaufläche die drittbedeutendste Leguminose. Eine günstige Eigenschaft von Ackerbohnen als Futtermittel ist ein im Vergleich zu Erbsen und Lupinen höherer Rohproteingehalt. Dennoch ist die Akzeptanz von Ackerbohnen in Deutschland als Futtermittel im Vergleich zu Erbsen und Lupinen eher gering. Voraussetzung für eine höhere Akzeptanz von Ackerbohnen als Futtermittel ist, dass der genaue Futterwert von Ackerbohnen bekannt ist. Wichtige Kriterien sind Aminosäurenverdaulichkeit und Umsetzbare Energie (MEN). Zudem enthalten Ackerbohnen antinutritive Inhaltsstoffe wie Vicin/Convicin, Tannine und Phytat, welche die Verwendbarkeit als Futtermittel einschränken. Aus diesen Gründen wurde im Rahmen von Abo-Vici die Variation des Futterwertes von Ackerbohnen bei Legehennen und Einflüsse hierauf bewertet. Die Ergebnisse geben Aufschluss über Niveau und Variation von Aminosäurenverdaulichkeit und MEN. Unterschiede zwischen Sommer- und Winterackerbohnen hingen vom Anbaustandort ab. Phytat-Gehalte in Ackerbohnen wurden als Ursache für die Variation der Aminosäurenverdaulichkeit gefunden, während Tannine eher die Variation der MEN beeinflussten. Es gab keinen Hinweis auf einen Einfluss von Vicin/Convicin auf Aminosäurenverdaulichkeit und MEN. Eine Schätzung der Aminosäurenverdaulichkeit und MEN anhand chemischer Inhaltsstoffe war nicht mit ausreichender Genauigkeit möglich. Ein Entschälen der Bohnen erhöhte die MEN deutlich und steigerte die Verdaulichkeit einiger Aminosäuren. Die Erkenntnisse dieses Projekts tragen zu einem gezielteren Einsatz von Ackerbohnen in Legehennenfutter bei. Dies bietet die Möglichkeit, eine Überversorgung der Tiere mit Aminosäuren und MEN zu vermeiden und gleichzeitig die Gefahr einer unzureichenden Versorgung zu mindern. Dies ist günstig für die Ziele, einheimische Proteinfuttermittel zu fördern, das Tierwohl zu erhöhen und Emissionen aus der Tierhaltung zu verringern

Replacement of fish meal with a matrix of organic plant proteins in organic trout (Oncorhynchus mykiss) feed, and the effects on nutrient utilization and fish performance

This study examined the effects on nutrient utilization and fish performance when replacing 16, 31, and 47% of fish meal protein (corresponding to replacing 15, 29 and 44%, respectively, of total dietary protein) with a fixed matrix of organic pea, horsebean and rapeseed plant protein concentrates (PPC) in a ratio of 1.07:1.00:0.66. Four iso-energetic and iso-nitrogenous diets were produced to include 0, 136, 274 or 410 g kg-1 of the organic PPC matrix, respectively. The organic protein ingredients were chosen based on their high protein content, and the matrix was established to mirror the amino acid composition of fish meal. The plant ingredients were dried, dehulled, grinded and air classified in accordance with the European Union Commission Regulation on organic aquaculture production, increasing the protein concentrations up to 577 g kg-1 dry matter. Two experiments were carried out using juvenile rainbow trout (Oncorhynchus mykiss): 1) a digestibility study to examine the apparent digestibility of protein, lipid, nitrogen-free extract (NFE), total phosphorus and phytate-phosphorus, followed by a water sampling period to determine the output of nitrogen and phosphorus and enabling the setup of nitrogen and phosphorus mass-balances; and 2) a 57 days growth study including 3 growth periods each of 19 days and using pit-tagged fish. Substituting fish meal with organic PPC significantly increased the apparent digestibility coefficient (ADC) of protein and lipid (P<0.008) at the highest PPC inclusion level, while there was a significant (P<0.044) decrease in the ADC of NFE with increasing PPC inclusion level. The apparent digestibility coefficient of phytate-phosphorus was significantly lower (P<0.005) at the highest PPC inclusion level compared to the fish meal control diet. The mass-balances revealed a significant increase in the excretion of ammonium-nitrogen (NH4N, P< 0.017) at the two highest PPC inclusion levels and a decrease in phosphorus (P<0.009) excretion at the highest organic PPC inclusion level. There was no overall effect on the specific growth rates (SGRs) or feed conversion ratios (FCRs). The study thus demonstrated that it is possible to replace fish meal by 47% organic PPC without compromising rainbow trout performance. However, the results also indicated that it will be difficult to replace much more than this as long as supplementation with synthetic amino acids and exogenous phytase is not allowed in organic feed

The Effect of Using Low-Phytate Cereal Varieties on Phosphorus Digestibility and Selected Production Indices

The pollution of surface waters by excessive biogenic elements, especially phosphorus, is a highly topical subject. Fishery management on ponds may be one of the potential sources of phosphorus in waters. Cyprinid fish generally have a very poor digestion of the phosphorus contained in the plant-based components of feeds. In them, phosphorus is deposited in the form of phytic acid which is almost indigestible for cyprinids. The conducted testing was focused on affecting the digestibility of phosphorus contained in plant-based feeds. Two of the cereals most frequently grown in the Czech Republic were tested, namely, wheat and barley. Control feeds were varieties commonly grown in our country, i.e. Vánek and Bojos. Furthermore, we used special cereal mutant lines with a decreased content of the phytic acid, JS-12/IDO 563 and M955. The test results showed that when using the low-phytate wheat line, the digestibility of phosphorus was increased by up to 11.21 % (P &lt; 0.01); and by 5.89 % (P &lt; 0.05) in the case of barley. Both low-phytate lines of the cereals used significantly affect phosphorus digestibility and decrease the loading of the environment with phosphorus. When using the low-phytate wheat line, a significant effect (P &lt; 0.05) was found on the fat content in the fish body compared to the control variety but also compared to the low-phytate barley line. No significant effect was found comparing both control varieties and comparing the barley varieties mutually.O