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

Effect of substituting concentrate mix with Cajanus cajan leaf on growth performance traits and carcass components of yearling rams and its potential in mitigating methane production

The main challenges in ruminant production are to reduce feeding costs and to improve product quality while minimising environmental impact. The use of unconventional feedstuffs may contribute to decrease feeding costs and environmental impact. A study was conducted to investigate the supplementation effect of Cajanus cajan leaves (CCL) on the growth performance and carcass characteristics of yearling rams and its association with methane (CH4) reduction in vitro. Thirty yearling rams with an initial body weight of 15.1±0.68 kg were randomly allocated to five treatment diets with six rams each. A basal diet was prepared to contain 300 g/head/d concentrate mix (CM) for the control group (T1) and treatment (T) diets were formulated by replacing the CM with CCL at 5% (T2), 10% (T3), 15% (T4) and 20% (T5). Data were collected on feed intake, body weight, carcass components, and CH4 production from 24h in vitro gas production (GP). The digestible organic matter (dOM) and metabolizable energy (ME) were estimated from 24h GP. The CCL content of ash was 126 g kg-1 DM of ether extract 43 g kg-1 DM, and crude protein 240 g kg-1 DM. The feed intake, body weight gain, feed efficiency and carcass components were not affected by treatment diets. The 24 h GP (ml g-1 DM) was significantly higher for T1 and T2 diets than that of T4 and T5. The lowest CH4 was obtained from T5 and differed significantly with that of T1 and T2. The ME and dOM values in T1 and T2 diets were higher than those of T4 and T5. The supplementation of CCL considerably reduced the CH4 production across treatment diets without affecting the voluntary feed intake, weight gain and carcass components suggesting its potential as alternative supplement to poor quality forages while keeping CH4 production at a minimum level

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

A simple laboratory method for estimating the standardised precaecal digestible crude protein in pig feeds

Adequate protein supply for pigs to sustain performance and animal health can be determined in vivo from standardised precaecal digestible (pcd) crude protein (pcdCP). Until now, only time-consuming methods are available to estimate pcdCP from laboratory measurements without in vivo experiments. Therefore, the objective was to develop and establish a rapid laboratory method for estimating pcdCP based on the determination of neutral-detergent-insoluble or acid-detergent-insoluble crude protein (NDICP, ADICP). The CP was determined for cereal grains on the neutral detergent residue and for all protein feeds on the acid detergent residue, because N compounds such as Maillard products or N bound to tannin or in phytate complexes are retained in the acid detergent-insoluble fraction. A unique, large sample pool of 82 feed ingredients (cereal grains, differently heat-treated legume grains) was available on which in vivo pcdCP were determined in cannulated pigs. Crude protein (N ∙ 6.25) was determined in feed ingredients and in their ND or AD residues. The concentrations of ND- and AD-soluble CP (NDSCP, ADSCP) were calculated by difference. For the estimation of the concentrations of in vivo pcdCP for the entire dataset, a linear relationship was established between the concentrations of NDSCP or ADSCP and the in vivo pcdCP: y = 0.8640 (standard error [SE] 0.019) x - 13.37 (SE 7.479), where y represents the in vivo pcdCP (g/kg dry matter) and x represents the NDSCP (cereal grains) or ADSCP (protein feeds) value (g/kg dry matter). The coefficient of determination (R2) of this equation was 0.962. A validation with literature values showed a good fit of the equation to an independent data set (n = 20; R2 = 0.955). This study shows that based on chemical analysis alone, namely determination of NDICP and ADICP, from which NDSCP and ADSCP are calculated, in vivo pcdCP values can be estimated with a standardised and rapid laboratory method