17 results on '"Schwarz, F. J."'
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2. Hygienic quality of different forages and concentrates for horses
- Author
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Sliwinski, H, primary, Krabisch, P, additional, Rosenberger, E, additional, and Schwarz, F J, additional
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- 2005
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3. Variation in the energy and nutrient supply of horses under practical conditions
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Sliwinski, H, primary, Rosenberger, E, additional, and Schwarz, F J, additional
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- 2005
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4. Evaluation of the cobalt requirement of beef cattle based on vitamin B12, folate, homocysteine and methylmalonic acid
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Stangl, G. I., primary, Schwarz, F. J., additional, Müller, H., additional, and Kirchgessner, M., additional
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- 2000
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5. Cobalt–deficiency–induced hyperhomocysteinaemia and oxidative status of cattle
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Stangl, G. I., primary, Schwarz, F. J., additional, Jahn, B., additional, and Kirchgessner, M., additional
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- 2000
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6. Liver fat content and lipid metabolism in dairy cows during early lactation and during a mid-lactation feed restriction.
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Gross, J. J., Schwarz, F. J., Eder, K., van Dorland, H. A., and Bruckmaier, R. M.
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FATTY liver , *LIPID metabolism , *LACTATION in cattle , *LIVESTOCK diseases , *DAIRY cattle , *TRIGLYCERIDES - Abstract
During the transition period, the lipid metabolism of dairy cows is markedly affected by energy status. Fatty liver is one of the main health disorders after parturition. The aim of this study was to evaluate the effects of a negative energy balance (NEB) at 2 stages in lactation [NEB at the onset of lactation postpartum (p.p.) and a deliberately induced NEB by feed restriction near 100 d in milk] on liver triglyceride content and parameters of lipid metabolism in plasma and liver based on mRNA abundance of associated genes. Fifty multiparous dairy cows were studied from wk 3 antepartum to approximately wk 17 p.p. in 2 periods. According to their energy balance in period 1 (parturition to wk 12 p.p.), cows were allocated to a control (CON; n = 25) or a restriction group (RES; 70% of energy requirements; n = 25) for 3 wk in mid lactation starting at around 100 d in milk (period 2). Liver triglyceride (TG) content, plasma nonesterified fatty acids (NEFA), and β-hydroxybutyrate were highest in wk 1 p.p. and decreased thereafter. During period 2, feed restriction did not affect liver TG and β-hydroxybutyrate concentration, whereas NEFA concentration was increased in RES cows as compared with CON cows. Hepatic mRNA abundances of tumor necrosis factor α, ATP citrate lyase, mitochondrial glycerol-3-phosphate acyltransferase, and glycerol-3-phosphate dehydrogenase 2 were not altered by lactational and energy status during both experimental periods. The expression of fatty acid synthase was higher in period 2 compared with period 1, but did not differ between RES and CON groups. The mRNA abundance of acetyl-coenzyme Acarboxylase showed a tendency toward higher expression during period 2 compared with period 1. The solute carrier family 27 (fatty acid transporter), member 1 (SLC27A1) was upregulated in wk 1 p.p. and also during feed restriction in RES cows. In conclusion, the present study shows that a NEB has different effects on hepatic lipid metabolism and TG concentration in the liver of dairy cows at early and later lactation. Therefore, the homeorhetic adaptations during the periparturient period trigger excessive responses in metabolism, whereas during the homeostatic control of endocrine and metabolic systems after established lactation, as during the period of feed restriction in the present study, organs are well adapted to metabolic and environmental changes. [ABSTRACT FROM AUTHOR]
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- 2013
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7. Supplementation of zero-grazed dairy cows with molassed sugar beet pulp, maize or a cereal-rich concentrate
- Author
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Schwarz, F. J., Haffner, J., and Kirchgessner, M.
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- 1995
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8. Endocrine changes and liver mRNA abundance of somatotropic axis and insulin system constituents during negative energy balance at different stages of lactation in dairy cows.
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Gross, J., van Dorland, H. A., Schwarz, F. J., and Bruckmaier, R. M.
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ENDOCRINE system , *MESSENGER RNA , *INSULIN , *METABOLIC regulation , *BIOENERGETICS , *LACTATION , *COW physiology - Abstract
The liver has an important role in metabolic regulation and control of the somatotropic axis to adapt successfully to physiological and environmental changes in dairy cows. The aim of this study was to investigate the adaptation to negative energy balance (NEB) at parturition and to a deliberately induced NEB by feed restriction at 100 days in milk. The hepatic gene expression and the endocrine system of the somatotropic axis and related parameters were compared between the early and late NEB period. Fifty multiparous cows were subjected to 3 periods (1 = early lactation up to 12 wk postpartum, 2 = feed restriction for 3 wk beginning at around 100 days in milk with a feed-restricted and a control group, and 3 = subsequent realimentation period for the feed-restricted group for 8 wk). In period 1, plasma growth hormone reached a maximum in early lactation, whereas insulin-like growth factor-I (IGF-I), leptin, the thyroid hormones, insulin, and the revised quantitative insulin sensitivity check index increased gradually after a nadir in early lactation. Three days after parturition, hepatic mRNA abundance of growth hormone receptor 1A, IGF-I, IGF-I receptor and IGF-binding protein-3 (IGFBP-3) were decreased, whereas mRNA of IGFBP-1 and -2 and insulin receptor were upregulated as compared with wk 3 antepartum. During period 2, feed-restricted cows showed decreased plasma concentrations of IGF-I and leptin compared with those of control cows. The revised quantitative insulin sensitivity check index was lower for feed-restricted cows (period 2) than for control cows. Compared with the NEB in period 1, the changes due to the deliberately induced NEB (period 2) in hormones were less pronounced. At the end of the 3-wk feed restriction, the mRNA abundance of IGF-I, IGFBP-1, -2, -3, and insulin receptor was increased as compared with the control group. The different effects of energy deficiency at the 2 stages in lactation show that the endocrine regulation changes qualitatively and quantitatively during the course of lactation. [ABSTRACT FROM AUTHOR]
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- 2011
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9. Short communication: Circulating and milk adiponectin change differently during energy deficiency at different stages of lactation in dairy cows.
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Singh, S. P., Häussler, S., Gross, J. J., Schwarz, F. J., Bruckmaier, R. M., and Sauerwein, H.
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COMPOSITION of milk , *ADIPOKINES , *ADIPONECTIN , *HOLSTEIN-Friesian cattle , *DAIRY cattle - Abstract
Adiponectin, one of the most abundant adipokines in circulation, is known for its role in regulation of body metabolism. The aim of this study was to evaluate the effects of a negative energy balance (NEB) at 2 stages of lactation (lactational NEB at the onset of lactation and an induced NEB by feed restriction near 100 d of lactation) on circulating adiponectin concentrations. We also investigated the effect of feed restriction on adiponectin concentrations in milk and the relationships of blood and milk adiponectin with selected plasma or milk variables and with measures of body condition. Plasma adiponectin was measured in 50 multiparous Holstein dairy cows throughout 3 experimental periods [i.e., period 1 = 3 wk antepartum up to 12 wk postpartum, period 2 = 3 wk of feed restriction starting at around 100 d in milk with a control (n = 25) and feed-restricted group (50% of energy requirements; n = 25), and period 3 = subsequent realimentation period for 8 wk]. Milk adiponectin was investigated among 21 multiparous cows at wk 2 and wk 12 of period 1 and wk 2 of period 2. Adiponectin concentrations in plasma and skim milk were measured using an in-house ELISA specific for bovine adiponectin. Major changes in circulating adiponectin concentrations were observed during the periparturient period, whereas energy deficiency during established lactation at around 100 d in milk and subsequent refeeding did not affect plasma adiponectin. Together with lower adiponectin concentrations in milk (µg/mL), the reduction in milk yield led to decreased adiponectin secretion via milk (mg/d) at the second week of feed restriction. Irrespective of time and treatment, milk adiponectin represented about 0.002% of total milk protein. Mean adiponectin concentrations in milk (0.61 ± 0.03 µg/mL) were about 92% lower than the mean plasma adiponectin concentrations (32.1 ± 1.0 µg/mL). The proportion of the steady-state plasma adiponectin pool secreted daily via milk was 2.7%. In view of the similar extent of NEB in both periods of energy deficiency, decreasing adiponectin concentrations seems important for accomplishing the adaptation to the rapidly increasing metabolic rates in early lactation, whereas the lipolytic reaction toward feed restriction-induced NEB during established lactation seems to occur largely independent of changes in circulating adiponectin. [ABSTRACT FROM AUTHOR]
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- 2014
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10. The amino acid composition of rumen-undegradable protein: A comparison between forages.
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Edmunds, B., Südekum, K.-H., Bennett, R., Schröder, A., Spiekers, H., and Schwarz, F. J.
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AMINO acids , *COMPOSITION of forage plants , *RUMEN (Ruminants) , *PROTEINS , *BACTERIAL colonies , *CHEMICAL decomposition - Abstract
The objective of this study was to improve knowledge regarding the amino acid profile of the insoluble portion of ingested forage escaping rumen degradation. Six forage categories were analyzed. Categories varied in botanical composition and each contained 2 samples. Samples within categories were derived from the same parent material but differed in harvest, maturity, or conservation type. The rumen-undegradable protein of all forages was measured by incubation for 16 h in the rumen of 3 nonlactating cows. All residues were corrected for microbial colonization. The AA profile of the residue was different to the original profile. Degradation trends of individual AA, in terms of increase or decrease relative to the original concentration, were similar between all forages. The AA profiles of forage residues, both within and between categories, were more similar to each other than to their respective original profile. This information may aid in improving the accuracy of estimating postruminal AA supply from forages while decreasing the number of samples required to be analyzed. [ABSTRACT FROM AUTHOR]
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- 2013
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11. Expression of target genes of nuclear factor E2-related factor 2 in the liver of dairy cows in the transition period and at different stages of lactation.
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Gessner, D. K., Schlegel, G., Keller, J., Schwarz, F. J., Ringseis, R., and Eder, K.
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DAIRY farming research , *GENE expression , *HEPATITIS , *CATTLE diseases , *LACTATION - Abstract
In the liver of dairy cows, the production of cytokines is enhanced during the periparturient phase, which in turn leads to inflammation and an impairment of hepatic function. Nuclear factor E2-related factor 2 (Nrf2) is a redox-sensitive transcription factor that controls the transcription of genes encoding various antioxidative and cytoprotective proteins. In the present study, we investigated the hypothesis that Nrf2 is activated in the liver of dairy cows during the periparturient phase to protect the liver against the deleterious effects of cytokines and reactive oxygen species. Therefore, we determined relative mRNA abundances of TNF (encoding tumor necrosis factor-α), various acute phase proteins and several Nrf2 target genes in liver biopsy samples of 20 dairy cows at each time point from 3 wk antepartum to 1, 5, and 14 wk postpartum. We observed an increase in mRNA abundances of TNF and acute-phase proteins [serum amyloid A 3 (SAA3), haptoglobin (HP), and Creactive protein (CRP)] from 3 wk antepartum to 1 wk postpartum, indicative of a proinflammatory condition. Messenger RNA abundances of various Nrf2 target genes with antioxidative or cytoprotective functions [glutathione peroxidase 3 (GPX3); microsomal glutathione S-transferase 3 (MGST3); superoxide dismutase (SOD1); catalase (CAT); metallothioneins 1A, 1E, and 2A (MT1A, MT1E, and MT2A, respectively); NAD(P) H dehydrogenase, quinone 1 (NQO1); heme oxygenase 2 (HMOX2); and UDP glucuronosyltransferase 1 family, polypeptide A1 (UGT1A1)] were also greatly increased from 3 wk antepartum to 1 wk postpartum. From 1 wk postpartum to later lactation, mRNA abundances of all the Nrf2-target genes considered declined but remained at levels that were higher than those in 3 wk antepartum. No correlations were found, however, between plasma concentrations of nonesterified fatty acids or β-hydroxybutyrate and mRNA abundances of Nrf2 target genes, indicating that a negative energy balance might not have been the main factor responsible for upregulation of those genes in the liver during early lactation. In conclusion, this study provides additional evidence that the periparturient phase in dairy cows is associated with a proinflammatory condition in the liver. Moreover, it is shown for the first time that the transition from pregnancy to lactation leads to a strong upregulation of Nrf2 target genes with antioxidative or cytoprotective properties, which might be another physiologic means to prevent the liver against damage by the inflammation process and an increased generation of reactive oxygen species. [ABSTRACT FROM AUTHOR]
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- 2013
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12. Effects of a rumen-protected mixture of conjugated linoleic acids on hepatic expression of genes involved in lipid metabolism in dairy cows.
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Schlegel, G., Ringseis, R., Windisch, W., Schwarz, F. J., and Eder, K.
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DIETARY supplements , *LINOLEIC acid , *DAIRY cattle , *LIPID metabolism , *MILK yield - Abstract
Supplementation of conjugated linoleic acids (CLA) reduces milk fat content in dairy cows and, thus, may be a useful dietary strategy to improve energy balance during early lactation. The present study was performed to investigate whether supplementation of CLA could have adverse effects on hepatic lipid metabolism such as observed in rodents. For this aim, 40 Holstein cows were allotted to 2 groups, which were fed daily 172 g of either a CLA-free, rumen-protected control fat (control group) or a rumen-protected CLA fat supplying 4.3 g of cis-9,trans-11 CLA and 3.8 g of trans-10,cis-12 CLA per day (CLA group). To identify potential changes of lipid metabolism, expression of several genes involved in lipid metabolism was determined in liver biopsy samples taken at wk 5 of lactation, using a whole-genome gene chip. In the CLA group, milk fat content and daily milk fat yield were lower than in the control group. Milk yield was higher, whereas fat-corrected milk and energy-corrected milk were lower in the CLA group than in the control group. The CLA group, moreover, had an improved energy balance. To study potential effects of CLA on hepatic lipid metabolism, we considered 6 genes encoding fatty acid transporters, 7 genes involved in intracellular fatty acid transport, 21 and 7 genes, respectively, involved in mitochondrial and peroxisomal β-oxidation, 6 genes of carnitine metabolism, 3 genes of ketogenesis, 21 genes involved in fatty acid and triacylglycerol synthesis, 17 genes involved in cholesterol metabolism, and 20 genes involved in lipoprotein metabolism. None of these genes was differentially regulated between the CLA group and the control group. Gene chip data were confirmed by quantitative PCR analysis, which revealed no difference in the expression of key enzymes of various pathways such as lipogenesis, β-oxidation, and ketogenesis between the 2 groups of cows. In line with those findings, concentrations of triacylglycerols and cholesterol in liver and plasma were not different between the 2 groups of cows. In conclusion, the present study shows that CLA supplementation at a dose effective for milk fat depression does not induce adverse effects on hepatic lipid metabolism in dairy cows. [ABSTRACT FROM AUTHOR]
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- 2012
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13. Changes in the expression of hepatic genes involved in cholesterol homeostasis in dairy cows in the transition period and at different stages of lactation.
- Author
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Schlegel, G., Ringseis, R., Keller, J., Schwarz, F. J., and Eder, K.
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CHOLESTEROL , *DAIRY cattle , *HOMEOSTASIS , *LOW density lipoproteins , *LACTATION - Abstract
This study was performed to investigate changes in expression level of genes involved in hepatic cholesterol metabolism in the transition from pregnancy to lactation and during different stages of lactation in dairy cows. Therefore, relative mRNA abundances of several genes involved in various pathways of cholesterol homeostasis in liver biopsy samples of 20 dairy cows, taken in late pregnancy (3 wk prepartum) and early lactation (1, 5, and 14 wk postpartum), were determined. At 1 wk postpartum, hepatic mRNA abundances of genes involved in cholesterol synthesis (3-hydroxy-3-methylglutaryl-coenzyme A reductase, mevalonate kinase, and farnesyl diphosphate synthase), cholesterol uptake from blood (low-density lipoprotein receptor), bile acid synthesis (cholesterol-7α-hydroxylase), cholesterol efflux [ATP-binding cassette (ABC) transporter A1 and ABCG1], esterification of cholesterol (acyl-coenzyme A:cholesterol acyltransferase), and proteins involved in assembly and secretion of very low-density lipoproteins (microsomal triglyceride transfer protein, ApoB100) were increased compared with 3 wk prepartum. The mRNA abundances of most of these genes decreased after 1 wk of lactation and reached levels in 5 and 14 wk of lactation similar to those at 3 wk prepartum. Only mRNA abundances of cholesterol-7α-hydroxylase, ABC transporters, and ApoB100 remained at 5 and 14 wk postpartum at levels higher than those at 3 wk prepartum. Hepatic cholesterol abundance was highest at 1 wk postpartum and was, thereafter, decreasing to values similar to that at 3 wk prepartum. Overall, this study shows that the onset of lactation is associated with an increased expression of various genes involved in cholesterol metabolism in the liver of dairy cows, suggesting that pronounced changes in hepatic cholesterol metabolism take place in the periparturient phase. [ABSTRACT FROM AUTHOR]
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- 2012
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14. Performance and metabolic profile of dairy cows during a lactational and deliberately induced negative energy balance with subsequent realimentation.
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Gross, J., van Dorland, H. A., Bruckmaier, R. M., and Schwarz, F. J.
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COWS , *DAIRY cattle feeding & feeds , *BIOENERGETICS , *LACTATION , *PARTURITION , *MILK yield , *MILK proteins - Published
- 2011
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15. Comparative studies on protein and starch evaluation in dairy cow rations
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Ettle, Thomas, Schwarz, F. J. (apl. Prof. Dr.), Schwarz, Frieder Jörg (Prof. Dr.), and Bauer, Johann (Prof. Dr. Dr. h.c.)
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Dairy cows ,protein evaluation ,starch ,ruminal degradability ,ddc:630 ,Landwirtschaft, Veterinärmedizin ,Milchvieh ,Proteinbewertung ,Stärke ,ruminale Abbaubarkeit - Abstract
In einem ersten Teil der vorliegenden Arbeit sollte ein Beitrag zur Verbesserung der Einschätzung einer bedarfsgerechten Proteinversorgung der Milchkuh geleistet sowie ein Vergleich des deutschen und des niederländischen Proteinbewertungssystems in theoretischer Hinsicht und auf Datenmaterial aus praktischen Versuchsreihen bezogen vorgenommen werden. Zu diesem Zweck wurden vier Milchviehfütterungsversuche (Versuche 1 bis 4) durchgeführt. Eine Streuung der Datenbasis zur Evaluierung der Proteinbewertungssysteme wurde durch Vorlage unterschiedlicher Grundfuttermittel (Versuch 1: Rotklee und Wiesengras, Versuch 2: Wiesengras, Versuch 3: Grassilage, Versuch 4: Maissilage) erreicht. Durch isoenergetischen Austausch von Sojaextraktionsschrot gegen Winterweizen wurde in den Versuchen 1 und 3 die Zufuhr an nutzbarem Protein (nXP) in zwei Stufen gestaffelt, in den Versuchen 2 und 4 durch Substitution von Sojaextraktionsschrot mit Leistungskraftfutter in 3 Stufen. Während sich in den Versuchen mit frischem Grünfutter keine Effekte einer steigenden Proteinzufuhr auf Leistungskriterien zeigten, wurden nach Vorlage von Grassilage die Futteraufnahme, die Milchleistung sowie die Eiweiß- und die Laktoseausscheidung signifikant erhöht. Auch bei Vorlage von Maissilage wurden durch steigende Proteinversorgung die Futteraufnahme, Milchleistung, tägliche Eiweiß- und Laktoseausscheidung sowie der Laktosegehalt signifikant erhöht. Um eine Aussage über die Gültigkeit der beiden Proteinbewertungssysteme zu erhalten, wurden die nach jedem System theoretisch aus dem Proteinangebot erzielbaren Milcheiweißleistungen den tatsächlich erbrachten Leistungen gegenübergestellt. Die tatsächlich erbrachte Eiweißleistung wurde nach dem DVE- System um 223 g/Tier und Tag, nach dem nXP- System nur um 144 g/Tier und Tag überschätzt, wobei sich deutliche Einflüsse von Grundfutterart und Proteinversorgungsniveau zeigten. Bei vorliegendem hohen Proteinversorgungsniveau konnte keines der Proteinbewertungssysteme voll befriedigen. Der zweite Teil der Arbeit befasst sich mit der Stärkebewertung in der Rationsgestaltung für die Milchkuh. Die ruminale Abbaubarkeit der Stärke von Maissilagen 4 verschiedener Sorten wurde mit Hilfe von in sacco- Untersuchungen an silierten Körnern der 4 Hybriden charakterisiert. Um das Reifestadium als zusätzlichen Einflussfaktor aufnehmen zu können, wurden Körner aller Sorten an 4 Ernteterminen (01.09., 22.09., 06.10. und 19.10.1998) geerntet und auf die ruminale Abbaubarkeit hin untersucht. Des weiteren wurde die ruminale Abbaubarkeit der vier Maissilagen anhand weiterer in sacco- Untersuchungen sowie deren Verdaulichkeit im Hammelversuch überprüft. In zwei weiteren Milchviehfütterungsversuchen (Versuche 5 und 6) wurden die Auswirkungen der Verfütterung der Maissilagen der vier Sorten auf Leistungskriterien untersucht. Die mittlere effektive Abbaubarkeit (k=0,08) der organischen Substanz der silierten Körner betrug 93,0 %, 88,0 %, 85,4 % und 78,8 % zu den Erntezeitpunkten 1 bis 4, wobei in Abhängigkeit des Erntetermins Sortenunterschiede von bis zu 13 % festgestellt wurden. Um einen Effekt unterschiedlichen Abreifeverhaltens auszuschließen, wurden die Daten der Abbaubarkeit auf einen einheitlichen T- Gehalt hin extrapoliert. Dabei ergab sich eine mittlere Abbaubarkeit von etwa 89 %, die zwischen den Sorten kaum noch differierte. Die an den Maissilagen gemessenen effektiven Abbaubarkeiten der organischen Substanz lagen bei Annahme einer Passagerate von k=0,08 im Mittel aller Sorten bei 63 % wobei sich maximale Sortenunterschiede von 1,4 Prozentpunkten zeigten. Die Verdaulichkeiten der Maissilagen wurden im Hammelversuch gemessen. Die Verdaulichkeit der T, der OS und der XF lagen im Mittel bei 76,3 %, 78,6 % und 65,3 % wobei Sortenunterschiede von 5,3 %, 5,1 % und 8,7 % ermittelt wurden. Trotz der zunächst unterschiedlichen Abbaubarkeiten im Vergleich der vier Sorten zeigte sich, dass der Effekt in erster Linie auf das unterschiedliche Abreifeverhalten der Hybriden zurückzuführen ist. Dementsprechend ergab sich bei einheitlichem Reifestatus eine vergleichbare Stärkeanflutung in den Fütterungsversuchen zwischen den verschiedenen Gruppen, so dass nennenswerte Unterschiede in Milchleistungskriterien nicht auftraten. The first part of this study aims at contributing to the assessment of a correct protein supply to dairy cows. Additionally, the German (nXP) and the Dutch (DVE) protein evaluation systems are compared both in a theoretical way and based on data from a series of feeding trials. For this purpose, four feeding trials (experiments 1 to 4) were carried out. A wide range of database was collected by feeding different forages in each experiment (exp 1: meadow grass, exp. 2: meadow grass/red clover, exp. 3: grass silage, exp. 4: maize silage). Soya bean meal and winter wheat were interchanged iso-energetically in experiments 1 and 3 to give two levels of protein (nXP), while in experiments 2 and 4 three protein levels were achieved by substituting soya bean meal with concentrates. Whereas in the trials with fresh forages a higher protein supply had no effect on the performance of dairy cows, in the trial with grass silage an increasing protein level resulted in an increase in feed intake, milk yield, daily milk protein yield and daily milk lactose yield. Similarly, in the trial with maize silage the feed intake, milk yield, milk protein yield and milk lactose yield as well as lactose percentage were affected positively by a higher protein level. The expected milk protein yields were calculated, using protein supply data both in nXP and DVE systems, and compared with actual yields. The daily milk protein yields were overestimated by 223 g (DVE) and 144 g (nXP), whereas a clear influence of the type of basic forage as well as of the protein level could be noticed. As a result of the high level of protein intake, as performed in the present study, none of the protein evaluation systems was satisfying. The second part of the present study works on evaluating starch when formulating rations for dairy cows. The ruminal degradability of starch in maize silages of four different varieties was described by in-sacco-measurement with ensiled grains of the four hybrids. In order to include the stage of maturity as an additional influencing factor, kernels of all varieties were harvested at four harvest dates (Sept. 1st, Sept. 22nd, Oct. 6th, Oct. 19th) and tested for their ruminal degradability. Furthermore, the ruminal degradability as well as the apparent digestibility of whole plant silages were examined. To find out the effects of feeding maize silages of the four varieties, two more feeding trials (experiments 5 and 6) were carried out. Assuming a passage rate of k=0.08, the mean effective degradabilities of the organic matter of ensiled kernels averaged 93.0 %, 88.0 %, 85.4 % and 78.8 % on harvest dates 1 to 4. Depending on the harvest date, the silage varieties differed in up to 13 %. To exclude the effects of different growing characteristics, the data were extrapolated towards a uniform dry matter content, resulting in a mean degradability of about 89 % for all varieties. Whole plant maize silages showed a mean ruminal degradability of 63 %, with divergencies of up to 1.4 % depending on the varieties. The mean apparent digestibility of DM, OM and CF averaged 76.3%, 78.6 % and 65.3 %. The observed divergencies between the varieties were 5.3 %, 5.1 % and 8.7 %. Regardless to the apparent differences in ruminal degradability, the variations in ruminal degradation can be explained by the differing growing characteristics of the hybrids. Correspondingly, the feeding trials resulted in a comparable duodenal starch flow in the various feeding groups. So, all in all no differences in dairy cow performance were observed.
- Published
- 2005
16. On the impact of a different sulphur supply on performance, digestibility and trace element contents in different tissues in growing cattle
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Wessels, Anke, Schwarz, F. J. (apl Prof. Dr.), Schwarz, Frieder Jörg (Prof. Dr.), Bauer, Johann (Prof. Dr. Dr. h.c.), and Schenkel, H. (apl. Prof. Dr.)
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Schwefel ,Rinder ,Futteraufnahme ,Zunahme ,Verdaulichkeit ,Spurenelemente ,ddc:630 ,Landwirtschaft, Veterinärmedizin ,sulphur ,cattle ,feed intake ,growth performance ,digestibility ,trace elements - Abstract
Ziel der vorliegenden Arbeit war die Untersuchung des Einflusses einer unterschiedlichen Schwefelversorgung auf die tierischen Leistungsparameter (Futteraufnahme, Gewichtsentwicklung), die Verdaulichkeit der Ration und die Spurenelementgehalte in verschiedenen Geweben bei wachsenden Rindern. Zu diesen Fragestellungen wurden drei Versuchsreihen mit Fleckviehbullen durchgeführt, bei denen Ammoniumsulfat und Calciumsulfat eingesetzt wurden. Die Schwefelgehalte in den verschiedenen Rationen von 0,11 % bis zu 0,74 % in der Trockenmasse sollten geringe, mittlere und hohe Versorgungssituationen repräsentieren. Die Ammoniumsulfatzulagen hatten keinen Einfluss auf die Leistungsparameter der Tiere. Durch die Zulage von Calciumsulfat bis zu einem Schwefelgehalt in der Ration von 0,29 % in Versuchsreihe zwei, beziehungsweise 0,22 % in Versuchsreihe drei, wurden die Futteraufnahmen und die täglichen Zunahmen tendenziell verbessert. Darüber hinausgehende Schwefelgehalte, bedingt durch höhere Calciumsulfatzulagen, führten zu einer tendenziellen Verschlechterung der Leistungsparameter. Die Verdaulichkeit der Ration wurde durch die Sulfatzulage tendenziell positiv beeinflusst. Die Kupfer- und Selengehalte in der Leber wurden durch die Zulage von Sulfat deutlich reduziert. The aim of the present study was to determine the impact of different sulphur supplies on performance parameters, digestibility of the ration and trace element contents in different tissues in growing cattle. For this purpose, three feeding trials were conducted with Simmental bulls. The sulphur contents ranged from 0,11% to 0,74 % in the dry matter of the different rations. Sulphur was supplemented as calcium sulphate and ammonium sulphate. Growth performance and feed intake were not altered by dietary ammonium sulphate supplementation. Sulphur contents in the calcium sulphate diets up to 0.29 % in trial two and up to 0.22 % in trial three showed a trend to a higher feed intake and daily gain in both experiments. A further calcium sulphate supplementation caused a decrease of these parameters. The digestibility of the rations was positively affected by supplemented sulphate and copper and selenium content of the liver were clearly reduced.
- Published
- 2005
17. Effects of dietary conjugated linoleic acid supplementation on performance, carcass composition and sensory quality of carp and trout
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Maaß, Daniel, Schwarz, F. J. (apl. Prof. Dr.), Schwarz, Frieder Jörg (Prof. Dr.), and Meyer, H. H. D. (Prof. Dr.)
- Subjects
Technische Chemie ,CLA ,carp ,trout ,fatty acid pattern ,growth ,ddc:540 ,Karpfen ,Forellen ,Fettsäuremuster ,Wachstum ,ddc:660 ,Chemie ,ddc:630 ,Landwirtschaft, Veterinärmedizin - Abstract
In vorliegender Arbeit sollte ein Beitrag zur Einschätzung der Wirkung von konjugierten Linolsäureisomeren (CLA) auf die Leistungsparameter wie Gewichtsentwicklung und Futteraufwand, die Nährstoffverdaulichkeit und die Körperzusammensetzung von Karpfen und Forellen anhand des Datenmaterials aus drei Fütterungsversuchen vorgenommen werden. Des weiteren wurde untersucht, inwieweit nutritive CLA-Zulagen das Fettsäuremuster und die sensorische Qualität des Filets als verzehrsrelevantes Teilstück beeinflussen. Bezüglich der Leistungsparameter und der Körperzusammensetzung konnten infolge der CLA-Zufuhr über das Futter bei beiden Fischarten nahezu keine Veränderungen festgestellt werden. Allerdings konnte gezeigt werden, dass nutritive CLA-Zulagen - in Abhängigkeit von der Dosierungshöhe - zu einer massiven Anreicherung der konjugierten Linolsäureisomere und gleichzeitig zur Erhöhung des Anteils an SFA im Muskelfett führen.Die sensorische Qualität des Fischfilets blieb von der CLA-Zulage unbeeinflusst. To determine the effects of conjugated linoleic acid isomers (CLA) on performance parameters (growth, feed conversion ratio), digestibility and carcass composition in common carp and trout, 3 feeding experiments were conducted. Furthermore the influence of dietary CLA-supplementation on fatty acid pattern and sensory characteristics of fish fillet were evaluated in the present investigations. Performance parameters and body composition were in both, carp and trout nearly not altered by dietary CLA-supplementation. But it was shown, that depending on the CLA-dosage, common carp and trout were capable to accumulate dietary CLA in muscle while equally the content of saturated fatty acid was increased in this tissue. Sensory quality of fish fillets was not altered by dietary CLA-supplementation.
- Published
- 2005
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